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This Week in Microbiology

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is brought to you

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by the American Society

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for Microbiology at asm.org/TWIM.

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This is TWIM, This

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Week in

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Microbiology, Episode 310,

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recorded on May

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2nd, 2024. I'm

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Vincent Racaniello and you're listening to

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the podcast that explores unseen life

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on Earth. Joining

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me today from Ann Arbor, Michigan,

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Michelle Swanson. Hello, and it's

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a beautiful spring season here with

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colors popping and grass greening. It's

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lovely. Here, it's nice in New

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York. It's 26 C, which

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is like low 80s and sunny. Very

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nice day outside. Also joining

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us from Charleston, South Carolina,

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Michael Schmidt. Well, hello everyone.

1:00

And we have, as they say, Chamber

1:03

of Commerce weather. It's 82

1:05

degrees Fahrenheit. The sun is out and

1:07

there's no humidity. However,

1:09

the pollen is out. And

1:12

all I can say is thank

1:15

goodness for Big Pharma and

1:17

their antihistamines.

1:20

And from St. Louis, Missouri,

1:22

Petra Levin. It's

1:24

great to be here. We have our

1:26

humidity is back. Our pollen is back.

1:30

We have had some rain though after a long time,

1:32

so that's great. All right. It's

1:34

time for forget the pollen. It's time

1:37

for some science to distract you from

1:39

it. And we will start with a

1:42

snippet from Petra. So

1:44

today I'm going to just kind of

1:47

raise something that actually we haven't really

1:49

discussed. We talk a

1:51

lot about the microbiome. And when we

1:53

say the microbiome, we almost never really

1:55

define what we're talking about. But usually

1:57

it's from the colon. And

2:00

so from the, and

2:02

the reason most of the microbiome, I mean, their

2:04

skin microbiome and others, but mostly we focus on

2:06

when we talk about the microbiome, we're talking about

2:09

the one in the colon. And

2:11

the reason that the colon was sort of the

2:13

first kind of human microbiome to be

2:15

examined is we know that bacteria are

2:17

very important as our other, ours are

2:19

our Chia in the

2:22

colon to kind of have the final step

2:24

of digestion, but also because to

2:26

sample the colon, all you really need is

2:28

poop, which is easy to get.

2:32

And what's kind of becoming sort

2:34

of more important now is other microbiomes

2:36

in the human body. And particularly, I

2:38

think we're at a sort of new

2:41

beginning, really starting to look at the

2:43

small intestinal microbiome. So,

2:46

right, you have your colon, kind of does a

2:48

nice U shape, but then you have your small

2:50

intestine. And when you think about what's inside your

2:53

gut, you think about your small intestine and

2:55

it's, you know, curly and all sneaky inside.

2:58

And it fills quite a bit of space

3:00

when they tell you how long your intestines

3:02

are in elementary school, they're really mostly talking

3:04

about your small intestine. And the small intestine

3:07

is the part that goes from the end

3:09

of your stomach to the

3:11

beginning of your colon is the small

3:13

intestine. And it has, it turns out

3:15

its own microbiome. And it's

3:17

been really understudied, in

3:20

part because it's very difficult to sample,

3:22

right? You can't easily get

3:24

to it without some kind of invasive

3:27

procedure. And people

3:30

have either had it sampled from the

3:32

top, you know,

3:34

if you have some small intestinal problem, like

3:36

an overgrowth or something like that, people

3:39

will do sampling. But again,

3:41

that's not something you easily give up for science.

3:44

And then the other way that that

3:46

has been sampled is for people who've had

3:49

their colon removed or

3:51

at least disconnected from their

3:53

small intestine for chronic

3:56

bowel disease or for

3:59

cancer. are sort of

4:01

the typical ones. And,

4:03

you know, sometimes people have their colon

4:05

completely removed, and then you have this

4:08

pouch and ileostomy pouch, or you can actually

4:10

have one attached to different parts of your

4:12

colon, essentially to gather the

4:14

stuff that would normally go through

4:16

your entire gastrointestinal tract. And

4:19

so these pouches are connected to

4:21

ristoma, a little opening, and you

4:23

can sample from them. And

4:26

so the questions have been about

4:28

understanding the small intestine is how

4:30

do we do it in a way

4:32

that isn't as invasive and

4:34

is in healthy people? So once

4:36

you have one of these pouches

4:38

put in, you are in fact

4:40

usually healthy. If you've had ulcerative

4:42

colitis or something, it actually completely

4:44

cures you because you no longer

4:46

have a colon for

4:49

your immune system to attack. So

4:51

there's been some discussion about it.

4:53

And so we're two papers that

4:55

we have posted to the website.

4:59

One is actually a review

5:01

entitled, Small

5:03

Intestinal Microbiota from

5:06

Taxonomic Physician to

5:08

Metabolism. And then

5:10

the other paper is

5:13

entitled, it's actually a paper that came

5:15

out recently in Cellhost and Microbe, and

5:18

it's a research paper or resource, and

5:20

it talks about the

5:23

plasticity of the adult human

5:25

small intestinal stoma microbiota. And

5:28

really, it's a resource meaning it should

5:30

be of use. It sort of presents

5:32

things that are useful for investigators going

5:34

forward, how to study the small intestine,

5:37

because it does some nice diversity

5:39

studies, sort of what's the taxonomy

5:41

in the small intestine, what's

5:43

the diversity in the small intestine in

5:46

people who are having these ileostomy

5:49

pouches and pouches at different points

5:51

in the colon and

5:54

put in the surgery because they sample before and

5:56

after surgery and then sort

5:59

of longitudinally. as long as from these

6:01

pouches that are on the outside of the

6:03

body. And so I thought

6:05

it was just worth discussing, not too

6:08

long, but just briefly, kind of the

6:10

small intestine of microbiota, because actually

6:12

most of your food absorption happened in

6:14

your small intestine. And

6:16

I actually learned a lot reading these because I

6:18

hadn't thought that much about it, because

6:21

the review really talks about how

6:23

the small intestine has been difficult

6:25

to study, which I mentioned, but

6:28

also it's a very specialized place because

6:30

it has a huge range. For example,

6:32

the pH at the top is very

6:34

low because your stomach pH is very

6:36

low. And then at the bottom,

6:39

it basically comes closer to neutral or maybe

6:41

even slightly basic as it gets towards the

6:43

colon. So you have a big pH range

6:45

within the small intestine. You also

6:47

have, you go

6:49

from a primarily aerobic environment

6:52

to an anaerobic environment or a very

6:54

little oxygen as you get near the

6:56

colon. So you've got this big diversity.

6:59

You also have all these secretions, you

7:01

know, your body's creating all these pancreatic

7:03

enzymes to help you digest things. You

7:06

absorb sugar and amino acids, among other

7:08

things in the small intestine. And so

7:10

you have, you know, the bacteria, they

7:13

are really important because they're helping digest

7:15

your food a little more, break it

7:17

down. And so I thought

7:19

that was really interesting. They talk about the different

7:22

methods of sampling in detail. I

7:24

forgot, actually, there's this new method and we've talked

7:26

a little bit about this. I

7:28

always think of inner space with

7:30

Dennis Quaid, these movies, but they

7:32

have these capsules which people can

7:35

swallow and they sample, they are

7:37

open in your small intestine and

7:39

then somehow close the sample. Obviously,

7:41

then you have to retrieve them

7:43

from food. But they're not working

7:45

perfectly, but that's another way to

7:47

get samples. So I

7:50

think this review by

7:52

Simon Yersin and Pascal Venish

7:54

is really great, not only

7:57

because it describes sort of

7:59

the methodology. that people use,

8:01

but has these really wonderful figures. And

8:04

figure one is excellent. It

8:06

talks about the core microbiota.

8:09

And in the small intestine, and there

8:11

are really four groups in

8:15

there, there are sort

8:17

of gram-positive bacteria, axonomycetes,

8:21

some gram-negative bacteria as

8:24

well. So

8:26

they say the core microbes

8:28

are streptococcus, cesailonella, fusobacterium,

8:31

prevotella, and homophilus. But they

8:33

really sort of are striated

8:35

throughout different regions of the

8:38

small intestine. So they're almost

8:40

like in a continuum,

8:43

but sort of like different

8:45

segments have different bacteria. And this makes

8:47

sense because first of all, the pH

8:49

is changing, the oxygen amounts are changing

8:52

as you go through the small intestine.

8:54

And they also show kind of what

8:57

is in the small intestine that comes

8:59

from both the

9:01

host side, so like lipases

9:04

and peptidases and pancreatic enzymes,

9:07

as well as kind of

9:09

the ions that are in there and

9:12

vitamins, which also influence what the community

9:14

is in there. So again,

9:16

I think this review is really useful. So

9:19

again, I think it

9:21

discusses all these different ways to get

9:23

at the small intestine. But this review

9:25

is a little older and it says

9:28

that they're not sure that these ostomy

9:31

bags are really, you know, reflective

9:34

of what's normally in there. And so

9:37

that was kind of a big thing

9:39

hanging out there. Like what are we

9:41

getting an accurate view? Are these forphyla,

9:43

the vasculiota, which used to be the

9:45

firmicutes, I'm only now learning that they've

9:48

been renamed, the

9:50

bacteroidota, which are

9:52

formerly the bacteroidides, the

9:54

pseudomonads, and some

9:57

of the fusobacteria. And are these

9:59

any... are these guys

10:01

really what's in there? And that's why this

10:03

paper by Ilma

10:06

Spuhrer, Morgenthau, or Kruppkoe,

10:08

Wang, Spari, Candida,

10:12

Bisselwitz, Beldy, Sauer,

10:14

and McPherson I think is really great.

10:16

That's a paper from Self Health Micro

10:18

because the first thing that they do

10:21

is this controlled experiment to

10:24

show that what's in these

10:26

pouches is actually the

10:28

same as what was in the intestine

10:30

beforehand. So they have in their first

10:33

figure how they do

10:35

this experiment, sort of where these

10:37

pouches are, sort of the stoma,

10:39

the sort of openings are into

10:42

the intestine and how

10:44

they do the experiments. And so

10:46

that's excellent. But

10:49

then in figure two, they

10:53

really show that the composition

10:55

in the ilium before surgery

10:57

is not very different from

11:00

what's actually in the pouches after

11:02

surgery, even many, many days out.

11:05

And so it sets up that you

11:07

can use this less invasive

11:10

method to study what's in

11:12

the small intestine. And again, this is

11:15

critical for understanding what's there. And

11:18

could I just say, I just said, it

11:20

can't be understated what a bold

11:23

plan this was to

11:25

take advantage of this patient population, to

11:28

collaborate with the clinical side and

11:30

do really extensive

11:32

analysis over time before and after eating,

11:34

et cetera. It's an impressive data set

11:37

that they generate. It is really incredible.

11:39

And if people are interested in studying,

11:41

first of all, this resource and their

11:43

methodology, the methodology alone is super useful,

11:46

but as a resource of what's there

11:48

and not there is also really interesting

11:50

because they show there's very little in

11:52

the way of monosaccharides and disaccharides by

11:55

the time your food moves through your

11:57

small intestine, which says that it's

11:59

all absorbed. and they

12:01

show that the microbiota, that sort

12:03

of big picture composition at sort

12:06

of the group level is pretty

12:08

stable, but some of the subspecies fluctuate

12:10

when you eat, which makes perfect sense. You

12:12

might have a bloom when you eat because

12:14

now there's more for them to eat. And

12:17

I thought that was just really interesting and

12:20

exciting. And it'll be a theme that

12:22

we carry on in the next paper in the desert.

12:24

Oh, yeah. Exactly. I mean,

12:26

it's like when you feed your like snap

12:28

to it. Exactly. And things

12:30

move very quickly through your small intestine. So

12:32

if you haven't eaten for eight hours, it's

12:34

pretty much clear. Or it's

12:36

like cookies in the coffee room

12:39

or blueberry muffins in the coffee

12:41

room. All the graduate students flock.

12:44

And some of the faculty. Yeah, that too. But

12:47

again, this is just fascinating because there's, I

12:49

mean, there's, we haven't really

12:51

thought about it. We don't talk about it much.

12:53

And so between this review and the

12:55

paper, I thought it was really interesting. One of the kind

12:57

of maybe not surprising things that

12:59

I learned, but for some reason feels impactful

13:02

is that people sometimes

13:04

have bacterial overgrowth in their small intestine. It's

13:06

very difficult to get rid of. But

13:09

it comes from two places, which again,

13:11

is either your oral cavity, your mouth

13:13

and your pharynx, and in which

13:16

case it's mostly streptococci. Or

13:19

it comes from your colon, in

13:21

which case it's mostly enterobacteria. And

13:23

so it makes perfect sense that that's where the

13:25

overgrowth is coming from because they're not supposed to

13:28

be there, as many of them. And

13:31

that seems to be your

13:33

two choices. But to actually

13:35

know that's what happens is

13:37

very satisfying. And if

13:39

you look at what the small

13:41

intestine is processing, it's processing primary

13:44

food that we consume. And

13:46

so it's liberating and then

13:49

making waste products. The large intestine

13:51

effectively takes the waste products that

13:53

are produced by the microbes in

13:56

the small intestine and then uses

13:58

it to make more biomass

14:00

and the large intestine

14:02

to effectively dewater and

14:05

grab any remaining nutrients out

14:07

of the food that wasn't

14:09

grabbed by the small intestine

14:12

microbiota and the consequences were

14:14

very efficient, which is

14:16

principally why we're all getting so fat.

14:19

But also like it's that your food doesn't spend

14:22

very much time in your small intestine. No. So

14:24

it has to go very quickly and your large

14:26

intestine is fermentative. It takes much longer eight hours.

14:29

So that was also really important. And the

14:31

other kind of cool thing that I learned

14:34

is that remember we eat our amino acids

14:36

getting complete protein is a really big deal.

14:38

But the bacteria that are in our small

14:40

intestine, right, some of them are excreting amino

14:43

acids and other things that we can absorb

14:45

from them some of these amino acids and

14:47

some fibers or some like more soluble

14:49

fiber and things are actually broken down by

14:52

the bacteria in your small intestine. And

14:54

then the other stuff has to go

14:57

through the more sort of complicated fermentation

14:59

process in your large intestine. Anyways, I

15:01

thought the review was really interesting. And

15:03

I thought this paper was just great.

15:06

And it's just like

15:08

a whole new world of microbiology, which is

15:10

of course awesome. The other impressive

15:13

thing about the paper is they could say

15:15

that in general, the community in the small

15:18

intestine was stable, like who is

15:20

there was fairly stable, even though

15:23

after fasting, you know, there weren't many

15:25

microbes there and then they bloomed. But

15:27

then they looked in more detail and they found that

15:29

within a particular strain, there

15:32

was actually quite a lot

15:34

of genetic variation as judged

15:36

by sequence variants. And so

15:38

some would bloom, others would

15:40

be lost. Overall, that

15:43

strain would be stable, but

15:45

there was constant selection probably

15:48

and for particular ones.

15:50

So just amazing evolution

15:53

happening on small scales.

15:55

Right. It's almost like a chemo study,

15:57

it moves so fast. Yeah. So it's... It's

16:00

constant culture. It's basically constant culture, except for

16:02

in a chemistat you want to keep your

16:04

nutrients. So a chemistat is how you keep

16:06

bacteria. You sort of add nutrients. And of

16:08

course, dilutates are not. Teary always stay at

16:10

the same concentration. So when you're eating, though,

16:12

obviously, it's more like you're giving your bacteria

16:14

and your small intestine a ton of nutrients

16:16

and then you starve them and then you

16:18

give them a ton of nutrients and then

16:20

you starve them. So it's a very different

16:22

feast famine situation. And again, in your large

16:24

intestine, that doesn't, it's much more stable. So

16:26

that was a really good question. It had

16:28

some evidence from sequencing that there are

16:31

bacteriophages in there that were also contributing

16:33

to who blooms and who doesn't. And

16:37

it might look in some of the graphs as

16:39

though things are fairly static, but there is a

16:41

lot going on at the sub-strain level and microbe

16:43

to microbe. Yeah, I also

16:46

found it comforting. I

16:48

was waiting for Vincent to comment about

16:50

where are the viruses? There

16:52

they are. Because I think, you

16:55

know, we're only beginning to understand the microbes

16:57

in the small intestine to our

17:00

first approximation. And I think we really

17:02

need to think about the

17:04

whole lysogeny lytic phase

17:06

of phage that are

17:08

going to control the population dynamic

17:10

that we're seeing. And

17:13

similarly, there are phage in the large

17:15

intestine as well that are contributory.

17:18

And I don't think anyone has

17:20

actually looked at the

17:22

contribution of the vyroem in

17:25

the context of the microbiome. And

17:28

when people say microbiome, they don't

17:30

often consider the vyroem, which

17:33

is completely distinct in

17:36

most people's minds from the microbiome,

17:38

which we only consider to be

17:41

bacteria. And occasionally, a few people

17:43

will throw in the fungi, namely

17:45

the yeast that

17:47

can live in our guts. Here,

17:49

they just looked at DNA viruses

17:52

because of the extraction method. But

17:55

they found that for those who didn't change much

17:57

with eating, so it's a pretty stable. viral

18:00

population. I think it should

18:02

also be comforting for people who have these

18:05

functions that

18:07

essentially they're not changing

18:10

their microbiome very much. And

18:13

my understanding about people who have had

18:15

these surgeries is, especially if you've had

18:17

ulcerative colitis or something

18:19

very painful, that

18:21

essentially you're cured by this. And

18:24

so you can

18:26

be very healthy and your

18:28

microbiome can stay healthy. A

18:30

couple of the resources that make

18:33

this kind of culture independent research

18:35

possible, they use

18:37

the Human Metabolome Database,

18:40

a public resource, and also the

18:42

Metabolomics Innovation Center

18:46

has a different one called Food

18:48

Database, F-O-O, it's kind of a

18:50

play on words, F-O-O-D-B. So

18:54

the whole community can now go into

18:57

these data sets and begin to deduce

18:59

what is happening, who's there, what's happening, based

19:03

on their DNA analysis,

19:05

culture independent. All right, thank

19:07

you Petra. All right, now it's Michael's

19:09

turn. Yeah, so we're gonna

19:12

go to a different part of

19:14

the planet, so to speak. We're actually

19:17

gonna go into the desert. And

19:20

the title of today's paper

19:22

is Survival in Rapid Resuscitation

19:24

Permit, Limited Productivity

19:27

in Desert Microbial Communities.

19:30

And it's a paper by

19:32

Emmeneger Meyer, Schindelmeiser, Legend,

19:35

Schnecker, Richter, Gilor,

19:37

Eichenhorst, Wobachan.

19:40

And it's an open access

19:43

paper that appeared in Nature

19:45

Communications in mid-April. And

19:47

these folks are at the

19:50

University of Vienna in

19:53

Vienna, Austria, and they're in various

19:55

departments throughout

19:57

that university. There are also...

20:01

affiliated with the Ben

20:03

Gurion University in Israel

20:05

as well. So

20:07

microbial activity in dry lands

20:11

tends to be confined to rare

20:13

and short periods of rain. The

20:16

microbes in this niche live

20:18

in the top of what

20:20

is termed the biocrust, the

20:22

top millimeters, and that's

20:24

the biocrust where they tend

20:27

to enrich the soil with

20:29

carbon and nitrogen while at the

20:32

same time they facilitate the prevention

20:34

of soil erosion and

20:36

the retention of what little

20:38

water the crust or if

20:40

you will soil in

20:43

the dry lands can possess.

20:46

Unfortunately for our

20:48

ever growing earth-based population

20:50

of humans, dry

20:52

lands now constitute 46 percent

20:56

of our terrestrial

20:58

surface and they play an

21:00

extremely important role in our global

21:03

carbon cycle. So it's

21:05

not surprising that dry lands

21:07

are currently expanding due

21:10

to global climatic changes.

21:13

Now the operational definition of what a

21:15

dry land is is what you

21:17

might expect that they are

21:19

fields subject to long periods of

21:22

drought with rare

21:24

and short periods of

21:26

rain that may only last a few days

21:28

in the whole year. So

21:30

you consider places like the southeastern

21:32

or excuse me southwestern United States

21:36

as an example or as in

21:38

the case here the Negev desert

21:40

where the word Negev is

21:43

derived from a Hebrew

21:45

root denoting dry. And

21:47

so the Negev desert I'll put a

21:49

map into the show notes is actually

21:51

in the nation of Israel and

21:54

one thing that I had not considered when

21:56

I first read this paper was the

21:59

activity. of desert microbes

22:02

is largely confined to

22:04

the short windows of

22:07

unpredictable episodes of rain

22:10

and thus are thus

22:12

so the main microbial mediated

22:14

ecosystem processes associated with dry

22:17

lands or desert soils

22:20

is subject to this stochastic process

22:22

of when is it going to

22:24

rain? A lot of

22:26

patience, a lot of patience. And

22:28

as the authors offer in

22:30

their introduction it remains unclear

22:34

how microbial functions are

22:36

executed if a

22:38

considerable proportion of desert soil

22:40

microbes remain dormant after

22:43

rehydration or whether they all

22:46

reanimate or

22:48

if they exhibit considerable delay

22:50

in their response to the

22:53

rehydration as was

22:55

often reported for other semi

22:57

arid soils or if

22:59

you will the outcomes that one

23:01

would measure namely the fraction and

23:04

identity of the responding desert soil

23:06

microbes their senses that is who's

23:08

there and how many and what

23:11

they're doing and

23:13

the associated resuscitation

23:15

speed of the population.

23:17

Now what we cannot

23:19

forget that growth

23:21

is a population thing

23:24

you're measuring the change

23:26

in population not

23:28

in the ability of the

23:30

individual to divide we're looking

23:32

at the population's ability

23:35

to divide. So classically, classically, yes

23:37

what we're looking at. Yeah classically.

23:39

This is very modern. This is

23:41

very modern. So

23:44

in other words we should consider that

23:47

rehydration offers us an opportunity

23:49

for rapid growth which in turn

23:52

should be the key to the

23:54

maintenance of ecosystem processes

23:56

in such a narrow and

23:59

un- unpredictable activity

24:01

window, which is then only

24:03

further complicated by the consequences

24:07

of desiccation and

24:09

then the effect size on

24:11

the community and or individual

24:14

that rehydration has. Simply

24:17

put, what does osmotic stress

24:20

do to the biocrust

24:22

population? Or it has

24:24

been suggested that dry down and or

24:28

rapid rehydration of soils via

24:30

rain can cause cell death.

24:32

And anyone who has ever

24:34

lyophilized a bacterial culture know

24:36

the great lengths we go to to preserving

24:40

the dehydration of microbes when

24:42

we lyophilize them. But

24:45

that's a story for another day. Well,

24:47

they certainly have teed up many

24:49

issues for us to think about

24:51

in their introduction. Especially

24:54

since we're seeing such a growth

24:57

in the area of dry lands across our planet.

25:00

So how did they approach the questions? Well

25:03

here they use simulated rain, but

25:05

they didn't use any

25:07

rain. They use deuterated

25:10

heavy water. So

25:12

they could employ a new technique

25:14

that I don't believe we've ever

25:17

covered on TWIM. And this

25:19

technique is termed single cell nanoscale

25:23

secondary ion

25:25

mass spectroscopy. Or nanosims,

25:28

which is nothing more than a

25:31

special mass spectrometer with

25:33

special optics that creates

25:35

incredible spatial resolution where

25:37

it enables the observer

25:40

to witness cellular processes

25:42

occurring within a 50

25:45

nanometer window. So

25:47

they could study the structures in the

25:50

processes carried out by a single cell

25:53

and literally watch an individual

25:55

work. And

25:57

that's because of the deuterated water.

26:00

They're looking for where

26:02

the hydrogen is going in the

26:05

materials that the cell is

26:07

making. But that's not

26:09

all, folks. Could I interrupt

26:11

this man of Sims as you point

26:14

out with really cutting edge

26:16

technology? And I just want it to the author's

26:18

credit. This is not just

26:20

sitting on the shelf. They didn't just

26:22

pull down and hit the on button.

26:24

They went through many iterations looking at

26:26

the literature. What methods can we apply?

26:29

Trial and error, trial and error, trying to look for

26:31

something that would be robust and would

26:33

be applicable for this population. And

26:36

so the two authors went

26:38

through very frustrating periods of optimization

26:41

and testing. And

26:44

Demetri, one of the first authors,

26:46

called it an odyssey to measure

26:48

this single cell biomass generation. But

26:51

in the end, because they tried

26:53

Raman spectroscopy and another method,

26:55

but they just wouldn't work in the soil

26:57

cost system. They finally

26:59

landed on NanoSims and you're going

27:01

to show us what beautiful results they got.

27:04

I mean, just jump to this

27:06

is open access, folks. So you can actually

27:08

go and see all their beautiful pictures. This

27:11

is what's in figure

27:13

two. If Michelle just tumbled

27:15

to is figure two. But

27:18

that's not all that they

27:20

use. In addition to using

27:22

the NanoSims technique, they also

27:24

employed metatranscriptomic analysis where they

27:26

were able to show that

27:29

the biocross microbial communities from the

27:31

Negev desert were

27:34

found to have limited productivity.

27:36

That is to say they

27:38

made only certain things

27:41

with median replication times. And

27:43

now here we're measuring the

27:45

population effect of between six

27:47

and 19 days with

27:49

a restricted number of days that allowed

27:51

for growth. And

27:53

as another one of the first authors

27:56

commented in one of the press releases,

27:58

and this was Stephanie imager

28:01

offered that they found that

28:03

almost all the biocrust cells

28:05

reactivate and this is

28:07

what really shocked me that they

28:10

reactivate but with

28:12

the limited rainfall only

28:14

a small proportion of the cells

28:17

would be able to double. So

28:20

they didn't put their energy into

28:23

dividing they put their energy into

28:26

effectively saving up for the

28:29

next drought. Repairing

28:31

damage. Repairing any DNA

28:33

damage. And

28:36

the way they figured this out is

28:38

they used genome resolved

28:41

metatranscriptomics and

28:43

they had already previously characterized this

28:46

desert population they did the metagenomics

28:48

so they knew who was there

28:50

and then they threw the transcripts

28:53

against this data set who

28:55

effectively allowed them who was

28:57

making what when and how

28:59

much. This allowed

29:01

them to demonstrate that nearly

29:03

all the microbial population was

29:06

able to resuscitate themselves within

29:10

minutes after seeing

29:12

this deuterated water using

29:14

and it was found that

29:16

this was and this is

29:18

what blew my mind was independent of

29:21

the taxonomy or the microbes

29:24

present in this desert community

29:26

and as you can well imagine there were

29:29

a lot of cyanobacteria which

29:31

are blue-green algae in

29:33

the in this desert population taking

29:35

advantage of the feast and famine

29:38

of the water and they're able

29:40

to photosynthesize and that's

29:43

a bit of the story of

29:46

how they can survive the hard times

29:48

because they can steal

29:50

light energy to effectively

29:52

make ATP but

29:55

what they're up to in this

29:57

paper is they're investing they they're

30:00

learning how the microbes

30:03

are investing this precious water

30:05

into, as Michelle already said,

30:08

the repair processes, making certain

30:10

that their genetic material was

30:12

up to snuff and

30:15

energy generation. They're effectively making

30:18

storage compounds that will get

30:20

them through the cold, dark

30:22

winter. If you will, they

30:24

plant a garden and

30:27

then they effectively put up what

30:30

they've grown and they put it on their

30:32

pantry so that in the cold,

30:34

dark winter, they can pull from the pantry

30:37

and survive until the next rainfall.

30:39

Or the hot, dry winter. Yeah,

30:42

hot, dry winter. So if

30:45

you will, offering that these

30:48

biocrust microbes make optimal use

30:50

of these limited windows of

30:52

opportunity available to preserve the

30:54

individual rather than the

30:57

population until literally that rainy day.

30:59

Now the data that they offer

31:01

us... So Michael, I had a question.

31:03

Sure. I mean, on the one hand, yes, I

31:05

mean, it makes sense to me

31:08

that it's an individual because they

31:10

would have to have some way of

31:12

communicating if it was some population level

31:14

thing. But then also, what's the...

31:16

I think I can't remember, what

31:18

is the density of these guys in

31:20

the soil, in

31:22

the crust? They're not very dense.

31:25

Yeah. I mean, they can't really quorum

31:27

sense or anything. No, I don't know. This has

31:29

to be... Yeah. There's no

31:31

conductivity. There's no conductivity.

31:33

And in fact, many

31:35

of them are cyanobacteria.

31:37

And as you know,

31:39

cyanobacteria effectively form long

31:41

filamentous chains. The other

31:43

major players in this

31:45

population of microbes are

31:47

actinomycetes or

31:49

actinomycetes. And

31:52

so what

31:54

they're focusing on is, I

31:56

think they're beginning to try

31:58

to... let us

32:01

understand what's going on in

32:03

these very dynamic

32:05

and stochastic processes. And

32:07

they develop data that

32:10

are along four major

32:12

themes. First, the majority

32:14

of biocrust cells can

32:17

resuscitate in a simulated rain

32:19

event, albeit with slow growth

32:21

rates. And I'll get

32:23

to the data that support that. The second

32:25

thing that they focused on, and again, this

32:27

is what Michelle tumbled to, is the

32:30

microbial populations in

32:32

this feast and famine situation

32:35

from available water generate

32:37

energy and repair DNA

32:40

at the onset of

32:42

resuscitation. And that was what was

32:44

found to be so critical because

32:47

in these long extended

32:49

periods of drought, they're

32:52

generating free radicals from the normal

32:54

consumption of the stores of energy

32:57

that they may have maintained to

32:59

maintain their minimum energy charge. The

33:02

third area is that, and

33:04

this is really pretty

33:07

cool, is microbial populations

33:09

acquire carbon and energy

33:12

during the main hydration phase,

33:14

not the initial phase when

33:17

they effectively are reanimating. If

33:20

you will consider the rain being the

33:23

delivery of the monthly check. And

33:26

so what the microbe does before

33:28

it goes out to the bank to

33:31

cash the check, and microbes are all

33:33

cash society, there's no credit. They

33:36

first need to cash the check. And

33:38

before they do that, they'd

33:40

have to burn whatever energy stores

33:42

they have on the shelf. So

33:45

they are showing us through

33:48

the transcriptomics what the microbes

33:50

are consuming in that initial

33:52

rehydration phase. And

33:55

then they go shopping to restock the pantry, and

33:57

if you will, for the next time, we'll fix

34:00

the car, namely the DNA repair.

34:03

And finally, the last bit, and this

34:05

is perhaps I think the most important

34:08

bit that I found to be

34:10

most intriguing, is the

34:13

population was protected by

34:15

accumulated from the accumulated antioxidants

34:20

and that they

34:22

acquire energy from

34:25

inorganic sources, namely because a

34:27

lot of these are photosynthetic

34:29

microbes. So they're able to

34:31

effectively get their energy or

34:34

consume energy in the

34:36

dry phase. And it was all

34:39

done with a combination of this

34:41

nanosims process and

34:43

the transcriptomics that they did.

34:46

And for this last point, before I go back

34:49

to the beginning, the

34:51

transcriptomics found

34:53

with the reactive oxygen species

34:57

in energy generation from

34:59

inorganic sources showed

35:01

distinct patterns and they were particularly

35:03

abundant in the dry phase, which

35:05

was at 0, 39,

35:08

and 55 hours, and were

35:11

found with higher

35:13

proportions of manganese-based

35:15

catalase transcripts in the dry

35:17

phase. And manganese is,

35:20

of course, the transition metal that's

35:22

involved in catalase, which

35:24

can effectively diffuse

35:27

the molecular oxygen grenade

35:29

that goes off just

35:31

from normal interaction with

35:33

oxygen radicals in the environment.

35:36

And this wasn't in just one

35:39

microbe, but it was in 37

35:41

metagenomes that they evaluated.

35:45

So it was pretty cool. So

35:47

now, looping back to the first

35:49

data bullet, that the majority of

35:51

the biocrust cells resuscitate in

35:53

this simulated rain event. And this is

35:56

where they're using the nanosims using the

35:58

deuterated water. simply

36:00

ask the question, where does deuterium

36:02

go? Wearing that the

36:05

cellular isotope enrichment experiments, and this

36:07

is not for the faint of

36:09

heart, these are

36:11

challenging, revealed that in almost

36:14

all the biocross cells that were

36:16

retrieved with the applied cell separation

36:18

and concentration approach, the

36:21

anabolic pathways were

36:23

reactivated by the rain to

36:26

a level sufficient for biomass

36:28

production, which is shown

36:30

in their first figure where the

36:33

Negev desert biocross were

36:35

exposed to the simulated rain events.

36:38

And it looks like a reverse

36:40

growth curve. They get rehydrated and

36:42

then it slowly asymptops down to

36:45

where there's effectively no metabolism.

36:48

But when reactivated with the

36:50

heavy water, the

36:52

microbes can covalently bind the

36:55

deuterium, mainly in

36:57

the carbon hydrogen bonds during,

37:00

wait for it, the novella lipid synthesis

37:03

via NADPH. And

37:06

thereby they incorporate the isotope

37:08

tracer. And the

37:10

hydrogen isotope concentrations, they have

37:12

beautiful figure two. It

37:15

just goes on, show the

37:17

compositions of the biocross filaments

37:19

of the cyanobacteria and the

37:21

non cyanobacterial single cells, and

37:24

the resulting deuterium compound. They give

37:27

us a breakdown within

37:29

the first three hours of hydration, 68.4%

37:33

of the single cells

37:35

were significantly enriched with

37:37

deuterium and thus considered

37:39

active reaching 91% reactivation

37:44

after 12 hours. Amazing. This,

37:46

I mean, if we dehydrate for

37:48

less than eight hours,

37:51

we're in trouble for it. Nine to

37:53

10 are dead, not up and kicking.

37:55

We're falling all over ourselves. I mean,

37:57

it did, spent some time. time

38:00

on figure two for the sake of time, I'm

38:02

not going to go into all their, their beautiful

38:04

data. And it really

38:07

is so, so beautiful.

38:09

The take home is you need water

38:11

to divide. And I think even

38:13

a first year undergraduate would say,

38:15

well, that makes sense. But

38:17

their next experiments support the claim

38:20

that rapid reactivation of

38:23

diverse microbial populations occurs

38:26

almost universally upon rehydration. And

38:28

this again, is from

38:31

the beautiful metatranscriptomics data from

38:34

their rehydration experiments in which the

38:36

biocrust were exposed to

38:38

the simulated rain event that hydrated

38:40

the samples for 24 hours, followed

38:42

by a desiccation phase and

38:45

looking at the transcripts. So now they look

38:47

at transcripts from 15, 30 minutes, and then

38:51

three, six and 12 hour hydration

38:54

time points. And at time points 39 and

38:56

55 hours. So you get

38:59

a sense of what's going

39:01

on in this desert. And

39:03

what they learned is that

39:05

two phyla recruited the majority of the

39:08

transcript or produced most of the transcripts.

39:10

And those were the cyanobacteria

39:14

and the actinobacteria. And

39:17

among the analyzed hydration

39:19

time points, there was

39:22

no systematic or taxonomic

39:25

shifts. I mean, everybody

39:27

was rehydrated. They were all in the

39:29

pool together, and they all came up.

39:33

And it was You lose, you lose. Yeah.

39:36

Everyone plays this game, folks. It's

39:38

not, I'm gonna wait for Norman

39:40

to take over. I mean, they

39:43

did everything. And then

39:45

they did something really clever, in

39:47

that they normalized the number of

39:50

transcripts per metagenomic assembled genomes,

39:52

which then enabled them to

39:55

investigate differential expression of genes

39:57

between the different time points.

40:00

and phases of the experiment with

40:02

individual microbial populations. So this is

40:05

a lot of computational biology. This

40:08

is not for the faint of heart. The lights

40:10

are dimming as the computers are coming. I

40:13

mean, the most significant changes

40:15

in transcription occurred, as you

40:17

might guess, between zero and

40:19

15 minutes, 30

40:21

minutes and three hours, and between 12 and 39

40:24

hours. As the,

40:27

if you think about the growth

40:29

curve, it's effectively going through lag.

40:33

It's then going through log,

40:36

and then it's going into stationary phase.

40:39

It's really pretty cool. And

40:43

they go into most

40:46

summing up this data bullet

40:48

through their use of this

40:50

combination of genome-resolved metatranscriptomics and

40:52

single-cell activity analysis, which is

40:54

presented beautifully in Figure 2.5.

40:57

You can be a firsthand

41:00

witness to the wonder that

41:02

is microbial resuscitation dynamics, and

41:04

then begin to appreciate the

41:06

underlying molecular mechanisms following simulated

41:09

rain events in

41:11

a diverse-arid biocross microbial

41:13

community. And again, this is

41:16

all culture-independent. Yes. They went out and got

41:18

the sample, timed it just

41:20

right, sampled the same

41:22

depth. They had to get very uniform

41:24

depth and size of the samples. Yeah,

41:27

there are a lot of controls

41:30

we don't have time to go

41:32

into, but it's a beautifully illustrated

41:34

and documented paper. The

41:37

next aspect of this study, the one

41:39

that I metaphorically referred to as spending

41:42

your paycheck as soon as it is

41:44

cast during the early days of the

41:46

month, support – they

41:49

provide us data that supports that metaphor,

41:52

that the microbial populations

41:54

generate energy and repair

41:57

DNA at the onset of

41:59

resuscitation. So if

42:01

you will, they take the stock

42:03

out of the pantry and

42:06

fix the car. And here

42:08

they showed during the early hydration

42:10

event in that 15 to

42:12

30 minutes after the addition of the

42:15

deuterated rain, the transcripts

42:17

for DNA repair and energy

42:19

generation were significantly increased. The

42:22

transcripts involved the repair of

42:25

double-strand DNA breaks, which is

42:27

common to dehydration during desiccation.

42:31

And they were more abundant across

42:34

numerous taxonomic groups.

42:36

And they give us the

42:39

10 different, they give us

42:41

rubobacter, chloroflexor, cyanobacter, the

42:44

bacteroida, they go through all the lists.

42:46

One question I though had is

42:49

where does the energy for DNA

42:51

repair come? Well they offered that

42:53

the energy for DNA comes from

42:55

the pantry, namely

42:58

from the degradation of

43:00

storage compounds like polyhydroxyalkanates,

43:03

which if you remember your secondary

43:05

metabolism, that's where those suckers

43:07

are made before bacterial populations

43:10

go into stationary phase. Well

43:12

the microbes make that and

43:15

then they put it on the shelf and then when

43:17

they come out of starvation, they have to eat

43:19

something and they're effectively

43:21

eating that can of corned beef hash that

43:23

you bought and you never knew why you

43:25

bought it. But it's

43:27

really quite beautiful how

43:30

they show that this

43:32

PHA is gone and

43:35

the way they did that is

43:37

they looked at glycogen storage. Now

43:39

glycogen is much easier to eat. It's

43:41

sort of like the bag of candy

43:43

on the pantry. That gets gone first.

43:46

And the glycogen is consumed but

43:48

it's not made into the middle

43:50

of the hydration phase. So

43:53

there's no sense in making a transcript

43:55

that can degrade glycogen until you have

43:57

some glycogen. It's

44:00

really quite an impressive study.

44:03

And then the transcriptomics

44:05

then also shows us

44:07

that organic compound transporters

44:11

revealed that their highest transcript

44:13

abundance was in the main

44:15

hydration phase, where they're bringing

44:17

in the building blocks, suggesting

44:20

that organic energy sources simply

44:22

play no role in that

44:25

early resuscitation mechanism. And

44:27

they speculate that

44:30

it's because the majority of these

44:32

creatures are photosynthetic. They're making their

44:35

energy gradients or proton pumps via

44:38

using light. And

44:41

the third bullet that the microbial

44:43

populations acquire carbon energy during the

44:46

main hydration phase gets

44:48

us to the concept of growth or

44:52

population. And here, this is reflected

44:54

in the transcripts produced are

44:57

mainly for energy generation

44:59

and carbon acquisition. And

45:04

when you get to all of the things

45:06

that they did, you really

45:08

find they did a remarkable

45:10

job. But the one

45:12

thing that I found to be

45:14

most inspirational is

45:18

the microbes know that

45:20

dehydration is coming. And that of

45:22

course was designed by natural selection.

45:24

They don't know anything. Selection.

45:27

Experience has taught the littings.

45:29

You adapt or you die.

45:33

And that's the fourth

45:35

data bullet is the

45:37

microbial populations are protected

45:39

from accumulated antioxidants and acquire

45:42

energy from inorganic sources during

45:44

this dry phase. And again,

45:46

this was based on the

45:48

transcriptomics analysis. And they

45:52

put all of this together for us

45:54

in a summary finger. And

45:57

that's figure seven. Now Walking across their

45:59

figure from. Left to right we

46:01

started the Drought or the dorm

46:04

and say says they call it

46:06

the Reactive Oxygen Scavenging. They described

46:08

that the ah small protect and

46:11

serve presence and they're effectively oxidizing

46:13

hydrogen. Hydrogens the great energy source

46:15

and they're effectively able to oxidize

46:18

hydrogen. Then we get to the

46:20

early hydration caesar as I referred

46:23

to as eating the pantry stables

46:25

through the consumption of the P

46:27

Ha. Also the light driven Atp.

46:30

Production is here and they

46:32

go into talking about bacteria

46:34

were Dobson transcripts which is

46:36

involved in the Hills Cilic

46:38

Rg, a bacteria in of

46:40

course the Halo files are

46:42

all hallmark microbes in the

46:44

Negev desert and I think

46:47

that's where they were first

46:49

isolated and again, Bacteria or

46:51

Dobson is probably one of

46:53

the simple as proton palms

46:55

I'd known ah in ages.

46:57

You know it, it effectively. he

47:00

sees the light, it undergoes conformational

47:02

change and now effectively pumps the

47:04

protons. And then finally during the

47:07

main hydration phase we observe. Or

47:09

they observe the glycogen degradation and

47:11

carbonex acquisition. Hydrogen oxidation continues to

47:14

get poor Cel censuses so that

47:16

you can continue to make some

47:18

energy from the lights. You may

47:21

not have a lot of water

47:23

by a lease, you have it

47:25

and then they may be awesome.

47:28

Oh protect it's putting this on

47:30

some perspective. There's hope for drought,

47:32

sell the earth's I guess as

47:34

long as you're microbial, not much

47:36

hope for us. But.

47:39

The microbes have learned how

47:41

to adapt to the stressors

47:43

and a experiences and deserts.

47:45

Namely. High temperature and and

47:47

radiation and they have these

47:50

asthma protect and built into

47:52

their genetic code so that

47:54

they're able to survive these

47:56

extended drugs and and frequent

47:59

and stochastic. Sun. Ring

48:01

Events which was all supported

48:03

again beautifully by their Nano

48:05

Sim Saida in their Met

48:07

A Transcript O Max data

48:09

which in essence offers that

48:11

some microbes in these drylands

48:13

have adopted. In adapted. A

48:15

strategy where they are. Relying.

48:18

On this their ancestor of

48:20

their previous generation to have

48:22

protected them from the oxidative

48:25

damage and through the accumulation

48:27

of all those important trace

48:29

metal, Manganese compounds are coordinating

48:32

the catalyse. So.

48:34

You know they're They're ready for. Clarification.

48:37

So Michelle I know you've talked to the

48:39

the I. Have that at, but

48:41

actually up on it says contrast

48:43

the strategy of these desert microbes

48:45

in the crust to what we

48:47

learned classically in microbiology that I'm.

48:50

A hearty microbes that can live in the soil

48:52

for a long time were like guess for farmers

48:54

and spore from his and that's the strategy. Many

48:56

microbes years while these. Microbes. Do.

48:58

Not have the luxury of

49:00

undergoing that cellular differentiation so

49:02

instead that that a much.

49:05

More streamlined strategy of like

49:07

awesome. Oh, protects and I'm.

49:09

Turning. On turning off the cell, Falco. No.

49:12

No, I that are. I sounded super

49:14

interesting because we talk about more protected

49:16

and maybe actually it's really a drought

49:18

rehydration. The tracks insisted because for bacteria

49:20

right Nikolai go through life changes in

49:22

as malaria do you prefer a lot

49:25

of factory the out malaria he might

49:27

be relatively that they're going to dry

49:29

out even better in hospitals are you

49:31

bacteria that survive on surfaces completely dry

49:33

and that's a decontamination problem? So either

49:35

I did figure may be the we've

49:38

defined as malaria Iraq is this. I.

49:40

Think I think at this study

49:42

really gives us a lot to think

49:44

about. The. Up at Night also

49:46

makes me think about what we might

49:48

find as we explored deeper, deeper regions

49:51

of space. So

49:53

hi nice microbes can persist

49:55

so efficiently. That ninety

49:58

six percent or reactivating. right? Been there for. little

50:00

bit of moisture. Surely we're gonna find

50:02

something interesting on Mars or the moons

50:04

of Jupiter. Yeah? Give them a little

50:07

water. At the right temperature

50:09

that's the problem. So cold. What's

50:13

interesting here is that they're,

50:16

as you say, they're well adapted but you

50:18

know dry lands are expanding as

50:20

they point out and the microbes there are not going

50:22

to be able to adapt so quickly and it could

50:24

be a problem. It will

50:26

be, it will be a problem especially

50:29

from the agro economic perspective of being

50:31

able to grow food. So

50:35

that there are a pair of first authors, Stephanie

50:37

Imager is one of them. She's currently

50:39

a PhD student in the Vupkin lab

50:42

and she is a

50:44

avid listener of TwiM and was

50:46

very honored that we are following her

50:48

podcast and so she enjoys listening to

50:50

our discussions and always learns a lot

50:52

outside of her field. So

50:55

she became fascinated in environmental microbiology

50:57

in her early years at the

50:59

University of Constance in Germany. Her

51:01

lecturer Bernard Schink really got

51:03

her fascinated and especially she

51:05

got interested in the question

51:08

how do microorganisms survive harsh

51:10

environmental conditions? So

51:12

she did a master's at the

51:14

Swiss Federal Institute of Aquatic Science

51:17

and Technology in Zurich and was

51:19

actually studying microbial resistance to dissolved

51:22

copper ions. She then

51:24

stayed on and worked as a research

51:26

assistant looking at transmission of antibiotic resistance

51:28

genes in waste and drinking water and

51:31

during that time she went to a conference called,

51:33

it was the fourth annual How Dead

51:35

is Dead conference and

51:38

that's where she met Dagmar Fooken. I

51:40

had no idea that is an awesome

51:43

conference. Isn't it great? So

51:45

that's where she met the senior author of

51:47

this paper Dagmar Fooken who

51:49

is now her thesis advisor at

51:51

the University of Vienna. So

51:54

she did say that the sampling in

51:56

the Negev desert

51:59

Was. What's. Exciting, but

52:01

it was incredibly. Difficult.

52:04

They had to do a lot of

52:06

trial and error and troubleshooting before they

52:08

got to the step. Of

52:11

that's all this beautiful to the that

52:13

they eventually generated. I'm see. Grew

52:15

up in the alpine rates in the Southern

52:17

Germany and enjoy hiking and mountain biking. Or

52:19

just relaxing at the lake in

52:21

her free time. So she partnered

52:24

with Dmitri Meyer, who's now a

52:26

senior says scientists of the Department

52:28

of Ecological Microbiology at the University

52:30

Babe Ruth in Germany. And

52:33

he got his start

52:35

first studying classical michael

52:37

molecular biology, but then

52:39

realize that environmental. Microbiology is

52:41

like a whole nother unknown

52:43

and wanted to really focus

52:46

on that. And as a

52:48

master student he had the opportunity to. Go

52:50

on a research cruise arm and.

52:52

From that moment he was hooked.

52:54

He then went to the. Mp

52:57

I where he studied marine microbiology

52:59

in Bremen. And there

53:01

he studied deep sea hydrothermal

53:03

vents, which was exciting, but

53:06

it's not often. A student

53:08

gets to go on one of

53:10

those deep diving robot trips to

53:12

collect samples and do all that.

53:14

So he realized he wanted to

53:17

find a an experimental system of

53:19

environmental stress where he could. Have

53:21

a more hands on approach. Us.

53:24

So the field trips to Israel he

53:26

said where I'm a lot of a

53:28

lot of fun but hard work collecting

53:30

the soil and crusts and again none

53:32

of them had experience to in met.

53:34

A trip transcript helmets and soils.

53:37

And she was skeptical frankly, that they

53:39

were going to be able to figure

53:41

this out because the nucleic acids are

53:43

hard. To extract from soil, there's

53:45

a huge diversity of organisms and

53:47

the soil, sir. going. To have

53:50

very complex datasets and also the

53:52

soils themselves or. Heterogeneous, so you've

53:54

got to be really careful about

53:56

where you collector samples in a

53:58

time series. They were

54:01

thrilled when actually they were able

54:03

to extract Really to do is

54:05

very clear patterns if of the

54:07

life cycle of these microbes. He

54:10

also said that they generated so much

54:12

data they actually published a companion paper

54:14

that from prelude to this in Two

54:17

Thousand and Twenty One and M Systems.

54:19

So if you wanna look at more data on this

54:21

or you can find it there. And

54:23

they've generated, of course, a multitude. Of new

54:25

hypotheses from this data and he's

54:28

looking forward to now following that

54:30

fallen upon network in his you're

54:32

in the Years Ahead so he

54:34

says and in every new environmental.

54:38

Sperm it's You've got to optimize the

54:40

methods. You can't just. Jump.

54:42

Right and pull some off the shelf. Likewise,

54:45

publishing the paper was a

54:47

challenge. They were. Striving

54:49

to publish it at. A place that

54:51

will get of a wider readership.

54:53

Which means there was some back

54:55

and forth. With this with the

54:57

journal and that and etc. But

54:59

once they finally did get reviews,

55:01

he said they weren't really experts

55:04

in the topic, they really understood

55:06

the study, made some great suggestions,

55:08

and now that the. Papers published.

55:10

They're really proud. And delighted that

55:12

they're getting such. A great response to

55:14

meet you also points out that

55:16

he was working on another project

55:18

on hyper sailing microbial communities again

55:20

of water limited environment on the

55:23

Arabian peninsula and he one of

55:25

his colleagues was up a Palestinian

55:27

so traveling and for when across

55:29

the border was interesting. He frequently

55:31

got questioned who do you know

55:33

who are you going to work

55:35

with so he constantly see i'm

55:37

a microbiologist and this. And other scientists

55:39

were studying nature and Dimitri hopes that

55:41

one day we will live in a

55:44

world. Where this won't raise any suspicions.

55:46

He really enjoyed getting to know both

55:48

middle Eastern cultures and met very smart

55:50

and kind people in both places. and

55:52

it really hurts him to watch the

55:54

current conflict that we're all aware of.

55:57

Demetrius partners also scientist.

56:00

So they have a family, they're trying

56:02

to do the dual career thing without

56:04

having to live in separate towns. They're

56:07

optimistic that they've landed in a place that's

56:09

going to let that happen. He

56:12

also really enjoys field

56:14

work, as you can see, and

56:17

as a hobby, really relies on

56:20

music to keep him going through all the

56:22

ups and downs. Likes to go to live

56:24

shows, play music at home and in bands,

56:26

and just listening whenever possible. So, Vienna

56:29

is a great place for music. Yeah,

56:32

depends what kind of music you like. Well,

56:34

if you like Mozart, it's fantastic. If

56:36

you don't like Mozart, I don't know.

56:38

Maybe the Grateful Dead. There's probably a

56:40

good scene. He also points

56:43

out that through his career and moving

56:45

with his family among different

56:47

institutions in different countries, that he now

56:49

has friends around the world and that

56:51

something he really treasures about being a

56:53

scientist. What are we going to say,

56:55

Petra? Oh, I was just saying Vienna

56:57

has excellent pastry. They do. Oh,

56:59

yes. Coffee and

57:02

pastry, no better place. Yeah, Dimitri pointed

57:04

out that he and Stephanie first met

57:06

at a delicious bakery over pastries. Just

57:08

kind of started to brainstorm this project.

57:10

So, the Vienna pastries

57:13

contributed to the work. They are inspirational.

57:17

Thank you, Michelle. Yep. And

57:19

Michael, thank you. And Petra, thank you. And

57:22

Twiem310, show notes at

57:24

microbe.tv slash Twiem. If

57:27

you enjoyed this kind of discussion

57:29

of science, please consider

57:31

supporting us financially. You can

57:33

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57:36

We are a nonprofit entity, Microbe TV,

57:38

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57:41

your deductions are tax deductible

57:44

from your federal US taxes. And if

57:46

you have any questions or comments, twiem

57:49

at microbe.tv. Michelle

57:51

Swanson's at the University of Michigan.

57:53

Thank you, Michelle. Thank you.

57:56

My pleasure. Petra Levins at Washington University

57:58

in St. Louis. Thank you, Petra.

58:00

Thank you. Michael Schmidt is

58:03

at the Medical University of South

58:05

Carolina. Thank you, Michael. Thanks,

58:07

everyone. I'm Vincent Raconiello.