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00:02 Hello folks. Um Welcome. Let's here. Okay. You hear me

00:11 back there ladder testing. Hello. Cat. Um Let's see here.

00:27 today we're gonna finish up uh chapter . Got a couple more topics to

00:35 about and um and there we That was really loud. Okay.

00:49 Here. Mhm. Okay so a of things. So we got a

00:57 for five, remember last time I it was last week? Uh checker

01:02 was one of those class things but not so don't worry about that.

01:08 we're gonna sacrifice ultimately short we'll finish up Tuesday. Right? So any

01:13 these things that are called a catch day, right? That's where um

01:21 um if I haven't finished everything up that point that I use that to

01:26 of Pretty sure. Right? So so it should not so it shouldn't

01:31 a full day on Tuesday, maybe minutes or something like that. But

01:35 , so that's kind of what those are about to finish up whatever materials

01:40 in that unit, there's always come before the next unit. So so

01:46 start unit to next thursday. So week from the day. Okay,

01:52 um that will be flipped, And that material unit two is

01:59 Everything in there is available. What have you? Um The flip

02:05 has the chapter six part one? . Okay. Which is mostly just

02:12 in terms of the viruses. Here's we define it. Here's the structure

02:16 it, we do life cycles in two. Okay um exam week from

02:25 uh see if you haven't already signed for it and uh you don't wanna

02:31 . So that starts tomorrow. That's little more comprehensive. I think there's

02:35 25 26 questions. Uh 45 minutes complete it. Um basically covering trucker

02:46 and as much as five as we about today. Okay then that's that

02:54 I think that's it. Um Any or anything? Okay so let's look

03:04 this as a recap from last So we went through um right that's

03:11 we started with you call it So we looked at um quantitative um

03:19 cells grow a couple of different practice there involving coming from generation time and

03:27 using that in a couple of different to find out how long it takes

03:32 X. Numbers to get to this or whether it was to calculate generation

03:37 . Okay if you are kind of comfortable with those equations just go through

03:43 practice problems around blackboard. They are worked out. Right? So hopefully

03:50 a logical way so that if but you have some questions about it,

03:55 me know you will be able to a calculator, handheld calculator during the

04:01 uh costs of people will be made that you're allowed to have those in

04:06 so you shouldn't be hassled about Okay um So uh after the after

04:14 the quantitative quantitative stuff we looked at batch growth curve. Right so all

04:22 , all the living things, we're have some kind of a growth

04:24 Even humans. Okay. Um It's that we can track the growth curve

04:30 bacteria rather quickly right within the span a day or less. Um In

04:35 case we're going to see all these phases. Right. The only difference

04:40 be is how it will vary. So we may have we may have

04:50 a pencil working. Okay we may , hold on. Okay one more

04:57 if this works or not let's try . Okay so you may we're gonna

05:02 all four of these. Okay but what will vary is will the lag

05:07 maybe it's extended. Maybe it's Maybe the inflection of exponential growth is

05:17 as steep or more like that. the duration of stationary phase this far

05:23 is it shorter? So all these of variables can occur depending on micro

05:28 , depending on what you're growing it depending on the physical and chemical growth

05:33 that are conditions that are going. all these things will vary um can

05:39 these different parties but the bottom line you're still gonna get four of these

05:44 . Okay. And so we can batch growth so remember match growth is

05:51 , take samples to monitor growth. it let it go its whole

05:56 Okay if you want to do more that. Right? We can if

06:00 interest is to get lots of higher yield than what that gives us.

06:05 add food. Right? So fed allows us to do that. We

06:11 um nutrients right to Our culture. ? Carbon pretty much the biggest

06:18 And that allow us to increase cell . Okay, remember that. We

06:24 add everything if we know that. grand will give us so you'll be

06:29 we typically can't add it up We have to add it at intervals

06:35 the growth cycle because adding an up is too much right? Osmolarity issues

06:41 highest values. So you have hypertension outside the cell. The cells fighting

06:48 instead of growing. Right. So can't really do those kind of

06:51 You have to add it as it's . Okay. Um if you really

06:56 to control everything, we talked about uh bioreactor where you control all the

07:03 . Okay. For the role of parameters uh all that stuff and of

07:15 they can grow crazy. Okay. they do. And then we think

07:20 finished kind of with if you don't are the resources you have to do

07:26 types of studies? Well do you a computer controlled reactor that does everything

07:32 you program or are you reduced to this? Okay, shake flask.

07:41 . Still do some things with that we talked about. You can control

07:44 you control um Aaron put to a right? By doing things like increase

07:53 shapers um have a flask that has kind of indentations in it. Right

08:00 more turbulence. More mixing of right? Um at a ph indicator

08:05 we can visualize when it's right so can do those things just very tedious

08:11 on your part rather had better to something like this that you don't have

08:17 keep the cost of. Anyway these issues these are issues for you biotech

08:26 because these kind of things that you be working. Okay so um and

08:31 course using this information from here to this kind of information. They're so

08:40 these and what um any questions about . Okay so let's so this next

08:50 is actually two for one. Right is gonna get us into the last

08:55 of this chapter four. Okay so question both questions will use the same

09:03 . So this is the first This is often a nutrient driven phenomenon

09:09 by lack or depletion of nutrients. not the only thing that will do

09:17 . E depletion nutrient, there's other that will cause this state. This

09:23 a common one, counting down five . Okay alright let's um I'm

10:09 The next question I'll come back to . So let's look at number 2

10:18 . This is often I'm gonna say that this is a nutrient driven phenomenon

10:28 a surface and the ability to attach and oh let me do that.

10:41 . You can yeah. Okay. down from 1312 54 21.

11:21 Yeah that is bio for information. ? The giveaways here are surface and

11:29 but it is nutrient driven biofilm. anything gonna boil it down to the

11:35 ? It's um have a surface cells able to attach that surface and then

11:43 because you're gonna you're going to a represents a lot of cell growth.

11:48 ? And if you're gonna sustain a or even initiated and then sustain

11:53 you're gonna need a constant flow of . Okay? So food surface

11:59 Okay. The basics of a Okay. The previous question that was

12:06 formation. Okay So that one was okay and that one was d Alright

12:14 the depletion of nutrients. So among things so endospore represents a dormant

12:21 Think of maybe now it's still plant . Plant seed doesn't produce a plant

12:27 you put it in the ground and water to it. Alright, Germany

12:31 in those four represents kind of a animation. Maybe um it's it's viable

12:39 that it was for but it's just growing right? But it's a very

12:45 form. Okay. And they form a result of nutrient deprivation radiation temperature

12:56 , Osmotic stress. Uh Any kind stress can potentially induce the deformed handles

13:04 . Okay so these are the last things we'll talk about Chapter four.

13:08 those four formation and biofilms. And we'll start with biofilm formation. Okay

13:15 biofilm formation um like I said represents lots of cell growth. Right?

13:22 you can see here From starting at and going clockwise right? So we

13:29 in its first two panels here. little bit of gross. Right?

13:33 of course it's all occurring on the . Right? So it begins with

13:36 surface so it's attaching to the surface then beginning to grow. Okay now

13:44 you really get beyond uh this stage right, approximate this stage here.

13:53 . And go forward. It depends um this is where the communication comes

14:01 . So if my film is not you might think to random assortment of

14:06 and just kind of comes together and as a single unit or something.

14:11 . It's completely orchestrated. It's gene um cells are communicating with each other

14:20 allow it to happen or not to . So it's far from a random

14:25 . It's a species specific thing. . It's yes as a bathroom forms

14:34 to the actual particular species certainly because in an environment it's out in the

14:41 . The microbes are there. Yeah of some other bacteria can stick on

14:46 maybe become a transient part of But it is a species specific

14:52 Typically a future you have to have bio for those that are lacking mutants

14:58 biofilm Formers that mutant lack of february follow by. Oh, okay.

15:05 course. For attachment. So it's about getting enough cells on that

15:13 . Right threshold left. This is we call a cell density dependent

15:21 You have to have enough cells present the process to occur. That's what

15:26 called quorum sensing. Right? There been a part of a government entity

15:32 you have to have a quorum you , you have to have enough people

15:35 to vote. Right? So similarly have to have enough cells there to

15:41 to make a bio. Think about . Right? If you do then

15:46 can proceed on through Okay. To next steps. And so what's the

15:52 behind that kind of a process? , it's really about the viability of

15:58 whole of that species because presumably there's cells collected on the surface is because

16:05 are is a favorable environment, there's there for them to grow.

16:11 And so that's what you need if gonna initiate and maintain a steady supply

16:17 food. Okay. So presumably more more cells are gonna be attractive

16:23 You know, there's chemical signals going there being attracted to it but they're

16:28 there because of the favorable fire. . And they can then begin to

16:33 . And so in panels 12 and . Pretty much just growth on a

16:40 surface. Two dimensions. Right now can see this thing growing right out

16:46 off of the surface, right, over here. So it's growing in

16:50 dimensions. So obviously represents a tremendous of so gross going on as this

16:56 happening. Okay, so uh so these are taken on campus, there's

17:03 I left brick wall, that's if goes through SnR one heading toward

17:11 you walk out and look to the . Um that brick wall there,

17:17 this pipe coming out, I'm not it's coming from but uh they used

17:22 be a wooden board sitting here And it was just dripping on that

17:27 board, that wooden board was just green biofilm on it right now,

17:32 just kind of popping down to the below. Okay, but that massive

17:37 , that's the for me. uh this is like from last

17:41 I'm not sure if the freeze killed or what's going on with it right

17:45 , This is from STL building, can see the bow from rolling

17:50 So obviously similarity is we got, have a surface where this is occurring

17:57 these windows are very uh a lot water that drips down on them.

18:01 you're gonna have certainly supply of nutrients way. And of course a pipe

18:06 is dripping down material, it's gonna organic material in there that's gonna sustain

18:12 and formation of biofilms. So pipes notorious for having biofilm buildups in.

18:18 , so uh medically important types uh staph staphylococcus warriors which is a common

18:28 skin uh pathogen that can cause things oils and different types of rashes.

18:35 There are types that are bathroom forms so these you often see in the

18:43 what are called hospital or more turned as healthcare acquired infections, infections acquired

18:51 the setting of a health clinic or hospital or something. Um And that

18:56 often come from medical devices like a shown here um breathing ventilation tubes,

19:04 parts of people's bodies like knee hip replacements, heart about these are

19:10 certain to write surfaces can get contaminated these these these pieces of equipment becomes

19:18 right? But the person handling it maybe it's not wearing gloves or something

19:23 otherwise contaminates it. Staff is found your skin is found in your deepest

19:28 your nose and they can contaminate in person. Right? And now they

19:34 introduce that pathogen. Right? Um on that this case. Catheter bio

19:45 on that catheter, lots of cells produced very high cell density as you

19:50 here. And in a biofilm gets big um There's gonna be different

19:58 Right? So and not all the in a biofilm will behave the same

20:03 ? You have some more on the part of the biofilm that are more

20:08 in nutrients and and air if that . And investigated more maybe more interior

20:15 aren't growing as much getting as much and then you begin to see some

20:19 in terms of. Right? That's if you have a biofilm former that's

20:25 infection like this They can be very to get rid of. So it's

20:31 a 10 day to write about We're talking like weeks and months trying

20:36 get rid of this thing. Okay could be quite serious. Um and

20:40 this is not just on catheters but types of medical devices as well.

20:45 so it's something to to definitely be of if you are going to health

20:50 so because these are not a not thing. Okay. Um Yeah so

20:58 go look at basis of biofilm So we're gonna have, this is

21:03 examples biofilm So t the right Now typically a biofilm forming um This

21:12 down here this you see in um food restaurants, any kind of uh

21:21 gas station. Uh We get the of thing where you have the soda

21:26 where you fill up your drink because things have tubing that goes to it

21:30 a cylinder C. 02 with the to make the soda travels through the

21:37 that comes out and fills your cup . That tubing. Get environment that's

21:43 and sugars in there. Um You form these kinds of polymers that you

21:47 here clogging up the tubing and when gets clogged up overs occur and then

21:55 person running the restaurant is like So they get called in to try

21:59 fix the problem. But again, of you to buy from pipes are

22:03 for different pipes tubing can get uh can get biofilm formation in those.

22:09 , so the process of this. , so look at it and kind

22:15 five step. So yeah, this a creative process is not random

22:21 There's a stepwise part of this step uh scheme to this. And so

22:30 gonna go through different a couple different types. Those that are kind of

22:35 and those that are sticking to the . Okay, so called plank tonic

22:41 are your swimming types? Okay. . And then you're what they call

22:48 types. Right. Are the ones expressed and allowing attachment to the

22:54 Right. So you're from swimming too . Um and then it's in this

23:01 phases right here where um you have course chemical signals going on.

23:10 Some cells have migrated down to the and are throwing out these chemical

23:17 It was a favorable environment certainly in beginning to grow multiple. And that

23:24 the level of the chemical signaling. , if it were an unfavorable environment

23:31 those shoes are there are likely not to be multiplying so very slowly.

23:36 you're not going to build up the signal. Okay. Uh So that's

23:42 you want to happen through that micro it's a favorable environment then. Yeah

23:47 more will come to be attractive and form the biofilm. If not well

23:52 you shouldn't have whether it's coming there it's not something that's going to sustain

23:57 . So find another more favorable So if it does kick in then

24:03 get into what's called policy saccharine or they secrete this. So um this

24:10 basically the glue that holds the biofilm . Okay. And um it's the

24:18 when that threshold level is reached, enough cells in the chemical signal that

24:23 induces the genetic program to produce the saccharin. So it becomes forms and

24:32 the biofilm begins to grow. And then of course it grows initially

24:36 the surface two dimensions and then eventually off the surface it's called biofilm

24:43 Okay. Now it would certainly be these biofilms are there's a finite lifetime

24:52 them although they can last quite long there's a steady supply of nutrients whether

24:56 tripping water nutrients tripping through a pipe can sustain it or but maybe

25:03 maybe it ends. And so you're have a large massive growth if you

25:08 have in the future it's applying they're not gonna be sustained so be

25:13 to break apart this solution it's called then you have so revert back to

25:20 plant tonic state so now they want detach right and go elsewhere to find

25:25 better environment. So they have to back into the swimming mode. Okay

25:30 we can kind of see this all . Okay so so again this phenomenon

25:37 harm sensing. Okay so that's the in this case you see this and

25:43 isn't exclusive to biofilms. You see sensing in various different phenomenon. We'll

25:51 it again in the context of uh transformation uh three transformation of the DNA

25:59 the environment and certain types only do , there's enough cells present. So

26:06 you see this in various different phenomenon bacteria. Um So as mentioned then

26:14 have these plant tonic swimming cells. will then come down to the surface

26:22 lose the uh and then uh attach you can have twitching motility, right

26:33 you can get that kind of motion then growth right then of course the

26:41 gets thrown off um And then themselves more and more attracted to that

26:47 Then you're gonna get more signal. you'll re threshold and you initiate biofilm

26:53 . So supply satellite production and growth from the surface and the biofilms.

27:00 , so as mentioned cells they're here the surface, right on the surface

27:08 . Okay well there'll be some differences those and those more on the

27:14 Okay just there separated away from nutrients oxygen so likely going a little slower

27:23 . Um And so you can see of these differences within your biofilm

27:27 And again you can relate to differences antibiotic resistance. So that's where issues

27:33 come in if it's a medically important . So but again this obviously represents

27:41 lot of cell growth. Okay to that you better have nutrients flowing

27:49 Sorry, depends on where you have rely on my finger to do

27:53 So let me try this again. . Um Okay so you're relying on

28:02 just will not work. Okay well know what I mean? Okay,

28:08 are flowing in. Okay that can the biofilm but if it goes down

28:13 drops out then no disillusion will And stickers will become swimmers. Look

28:21 more favorable environment. It's kind of cycle of the biofilm. But they

28:25 be maintained for quite some time if a steady supply. Um Many questions

28:32 that. Yeah. Yes, Yes. Yes. Any other

28:56 Okay so um Alright so in those , so in those fours represents a

29:06 of differentiation um are in a initially a growing vegetative state vegetative cells kind

29:18 a normal metabolically functioning cell form. ? Uh If you become stressed in

29:25 case of industry information it can then into this different form. Okay.

29:31 form that allows it to remain essentially and dormant for how long each month

29:39 , thousands of years, Hundreds of of years, millions of years.

29:45 ? So these are a couple of of the extreme millions of years on

29:50 from fossil evidence um and revived. are viable. And those boards that

29:57 able to be revived in the Okay. And in this section are

30:03 number of them. So you see is actually a vegetative cell vegetative cell

30:14 , yep. Here. Okay. that's the actual endospore forming inside

30:23 Right, This would probably be over . These are actual free. And

30:29 four. So when this like for , this cell right here is done

30:33 me, the endospore then this part released from the cell and then you

30:39 something like this or this. this one right here is one that's

30:47 completely vegetative self is not making it those four. Okay. And you're

30:52 see all three types. If you're at a culture of the type that

30:56 form in the sport, you're gonna all three of these in there.

30:59 just the proportions will vary depends on of what stage they're in.

31:04 so obviously in those sports represent a um they're very resistant. Okay,

31:13 to chemicals radiation, um temperature, any kind of stress they're resistant

31:21 Okay. And so there are lots things that former sport across the whole

31:30 animal, the pro cario groups, of things from scores we're all familiar

31:37 fungal spores. Right, mold Um There's there's also cysts which are

31:45 dormant form. Um cysts spores. But the endospore, right, When

31:51 put those four letters right in front sport, you're creating something that's like

31:57 level in terms of resistance. Yeah. Other types of spores and

32:02 can have a certain level of resistance so than a just a vegetative

32:07 But in those four is again another . I don't see anything like

32:12 That's this resistance. Okay. That's we have to use an autoclave sterilized

32:16 kill and those spores. Right? And so the two majors only but

32:23 only two groups on earth that I of that do this. These two

32:30 bacillus clostridium. That's it. Um Both gram positive. Both

32:38 Uh but very different metabolically. The um are obligate anaerobic. Right?

32:45 can't live in the presence of The silvers are mostly um are

32:52 maybe microcephalic, but they use Okay. And so the types,

33:00 probably familiar with the clostridium tetanus, , gas, gangrene. There are

33:05 lot of toxin producers in that Um number of pathogens in that

33:10 But so those are more or less uh anthrax of course. Is that

33:17 exception. But they're both soil Okay. So um and they're gonna

33:24 this characteristic shape. Right? When forming indoors for uh you see the

33:29 club shape at the end. They it. That's the end of the

33:32 forming little refract I'll bodies over These are in those floors forming.

33:38 um so when we look at sports general, So this is a highly

33:46 genetic program to do this, It takes several hours for it to

33:50 uh complete And so you have as cell is undergoing is you have compartmentalization

33:59 in the south. Okay. It's you have the application then you have

34:04 formation of two compartments and they're after when the sport formation occurs.

34:10 Um the ability to be very resistant endospore to be resistant. It has

34:16 do with a large part with the amount of water in the cell.

34:22 cells that are, you know, body uh that undergoes extreme heat,

34:30 ? It's the water in the cell is the most damaging, right?

34:34 water and in vegetative cells. So going to destroy protein function,

34:41 If you can withdraw a lot of water desiccated itself. Not completely.

34:48 goes a long a long way into it very stable. Okay. That's

34:53 happens in speculation, remove a lot the water in the process.

34:58 And so um so as you go this, we're gonna see.

35:04 I've mentioned this before Cell right? just think of that as a doing

35:13 thing. Um And then as mentioned the population of a sport former in

35:18 four former gonna see vegetative cells, producing a spore and free in those

35:23 . Okay. Now again, if seeing if you look at the sample

35:27 the microscope And you're saying 99 of cells. You see 99% of these

35:37 it's really not it's just growing it's not anything stressing it. Okay But

35:42 you see uh 50% 60% 80% of forms then yeah it's clearly undergoing a

35:55 relation process. Something is stressing There's nutrients lacking what have you.

35:59 going through that you can engage and state of the of the cells by

36:05 proportion of the types of C. um Now the um form of the

36:17 . Okay so these these this is specific. Right? You can actually

36:24 the bacillus species. Actually can help identify what type it is by what

36:29 of sport forms. Okay so it be different in location at one end

36:36 the middle maybe between the middle and end. That's those three. That's

36:41 we call terminal sub terminal central. it can be swollen And also be

36:48 the three different locations. So basically different and those warmer pathologies and again

36:54 are species specific. So you can it as an identification tool. Okay

36:59 Now the process uh so we'll Okay that's undergoing some kind of stress

37:12 temperature stress chemicals chemical stress radiation. happened? Okay then that begins a

37:21 where first duplicates D. N. . Okay um And then we get

37:29 in the cell. Okay so one goes to the mother's, sorry goes

37:37 the mother cell and one goes to fourth sport. Okay So the force

37:44 is ultimately where the end those four from. So this guy that's gonna

37:55 the maturity. Okay now the mother . Okay its role is to um

38:06 express jeans that are pretty much what call transcription factors. They will travel

38:13 the fourth board in direct expression of genes to form the endospore. Kind

38:19 controlling controlling what's going on to the of different proteins. Okay that are

38:26 to the fourth board saying turn this and that on what happened become a

38:33 . And so um next what happens that mother cell compartment right begins to

38:43 the force for. And so this now the beginnings of how you get

38:48 very resistant coat around the endospore. so we form a double membrane.

38:55 and inside there we produce pepper look , okay so don't mistake this for

39:04 a now it has two membranes and in the middle. It's now a

39:08 negative. No it's not that okay not this isn't like an out of

39:14 . It's not it's not that okay bacillus apostles. But this in those

39:20 this is how the coke forms. called we call it cortex is

39:25 Okay so um we then add this called acid D. P.

39:35 For short. Okay and then uh buys the D. N.

39:41 Bias the D. N. Kind of helps protect the D.

39:44 . A. In the state calcium deposited into the membrane to kind of

39:49 it. Um Also water is All right so we're gonna remove from

39:56 water. All this kind of helps serve keep that a ultimately viable cell

40:02 this windows for for okay but of you can see how the D.

40:06 . A. And the mother cell kind of just disintegrating. It goes

40:11 . Okay and so we're then left ex operandi um That's kind of a

40:20 structure. I don't really worry that about it but then it goes into

40:23 sport coat right mature sport coat. and then free sport. Okay so

40:29 here two Back to here let's say here these stages here. Okay.

40:45 . Okay that's where it looks like . Okay this form here. Okay

40:52 vegetative cell with the end of So when you're looking at that it's

40:56 one of these um four stages here 1234. So one of these

41:05 Okay that's what it looks like under microscope. Okay and then finally you

41:09 the free free sport released right as rest of the self disintegrates. Okay

41:14 again this this can hang around weeks years thousands hundreds of thousands millions of

41:22 . It all depends. Okay but can germinate. Okay think of germination

41:29 you're taking a seed completely earth and . It grows to a plant and

41:33 what's that's what's happening in those poor germinates into a completely the vegetative form

41:41 stuff. Which is the one that grow and reproduce and et cetera.

41:47 . Um The but you know again are very resistant in the sport.

41:54 why uh on a claim um produces under under steam under pressure and it

42:02 temperatures that are very high. 20 2 b. sub centigrade. Um

42:09 that moist heat is the key. can penetrate the those four code kills

42:17 . Okay and so on the page very effective at doing that.

42:22 Um Any questions Yeah the lack of is what drives it. So it's

42:34 it's not the only thing lots of can be radiation increasing the temperature but

42:41 deprivation of nutrients is a stress. yeah that too. Any other

42:51 Um All right so I think now that's chapter four. Okay we're gonna

42:59 gears a little bit. Of course been talking about growth. So just

43:03 than an extension of that. We'll first with the chapter five. Kind

43:08 two parts. Right? We don't a lot of the first part.

43:13 But the first part is basically uh environmental influences that's the first part.

43:22 second part is this the control So and that's what these for relate

43:32 environmental influences. Okay. We know when we want to grow microbes,

43:38 ? You supply supply C. O. M. P.

43:41 Right? You put them together in right forums, you know, the

43:46 type of the organism is you provide correct nutrients, then you provide the

43:54 temperature ph right. Osmolarity. These all combined to allow it to

44:01 And so so in this chapter um we read about temperature ph optimal

44:12 you'll see that um for most life earth, right? Where most life

44:20 earth is in the moderate ranges, ? A temperature between 15 and 40

44:29 say centigrade. Right? That's where life lives. A ph of around

44:34 . That's where most living things Okay. Uh Osmolarity. If you're

44:39 marine environment, maybe 3% salt uh terrestrial environment 0.9 point 9 to

44:47 Okay, those are the normal Okay, that's where most living things

44:52 . But you know, we got on the fringes, right, Archaea

44:57 others can live extremes of ph temperature . Okay. Um but regardless of

45:10 , the thing about temperature ph similarity keeping it optimal. Whether you're in

45:18 middle range for most things are already on the extremes, it's about keeping

45:24 proteins in those bodies, whether you're seller something bigger. Keeping the proteins

45:31 . Right, So recall basic protein . Right, tertiary structure of protein

45:37 in a particular way and what keeps folded hydrophobic interactions. Charge attraction,

45:44 cobiella bonds, di sulfide bonds. uh And so osmolarity temperature ph can

45:54 all that. Right. So an optimal conditions of those parameters will keep

46:01 proteins happy. That's what extreme of right, can live that way because

46:07 have adaptations allow them to keep their happy at these extreme conditions.

46:15 So it all boils down to Alright. Whatever the optimum condition is

46:20 particular organism, it's it's a ph and clarity. It's because it's proteins

46:27 optimized for those conditions, right? them in the right shape and

46:31 Okay, so um we oops we're gonna focus on 02.

46:41 so there's gonna be different responses. , um Atmospheric levels of oxygen.

46:52 more or less go to. Um Lots of things are quite happy

46:58 those conditions. Lots of things aren't in those conditions and many are can

47:04 either way. Give me option. give me auction. I don't

47:08 I'm fine. Okay, so there's be a way then to kind of

47:12 know, what are the issues with ? Okay, well that's what we'll

47:17 . So kind of we're just gonna more at this aspect of the department

47:23 influence. Everything else here is about do we kill them basically? How

47:29 we kill them? How do we them fast? Right. So there's

47:32 terms. Well, look at here and in terms relating to the effects

47:40 antimicrobials and then examples of different types ways to kill them both physical and

47:46 . Right? Most of this we leave Tuesday. Right, so let's

47:53 on oxygen right now called zero Okay. So um if one is

48:01 in oxygen world, whether they use or not, we use oxygen as

48:10 of our metabolism, many things Right? But they still live in

48:14 oxygen world. Right? And so oxygen by itself can be very

48:20 Okay, so too is simply just powerful oxidizing agent. Okay, Very

48:27 . Okay, so, um but has a very special property that we

48:35 on, right? And we'll get . We'll get into this in year

48:39 . But it's a terminal electronic right? It's at the end of

48:45 metabolism, right? Of our Very important. You know, the

48:51 to elect very powerful. That's what call a reduction potential has the highest

48:58 potential, Right? And for So for that reason, you

49:03 it allows us to keep electron flow this way. Okay, so we

49:08 food. We oxidize it get electrons it. Then we shut them down

49:14 oxygen because oxygen is very powerful that the electrons. It goes right to

49:19 . It keeps the whole system It as a result of all this

49:23 this process here. It's not really is you get lots of a

49:30 P as a result. Okay, you going. Having an oxygen keeps

49:36 flow going allows you to produce lots 80 p. Okay, now,

49:41 consequence of that is oxygen can also with other components. Okay, so

49:47 can form what is called reactive oxygen . Okay. And that's where the

49:54 effects them. They can interact with . You take acids and damage

50:00 You've probably heard of food labels. foods with antioxidant properties like blueberries or

50:09 like that, among others. That's kind of properties they have. They're

50:13 to so something to mitigate the damaging of these molecules in yourselves because I

50:20 that that's what contributes to aging and . Okay, so and so ourselves

50:29 are in the same boat. We to have protection for that reason.

50:34 . And so how do you do ? Well, it comes through different

50:38 help protect. Okay, so the of them are cattle a's. And

50:46 peroxide eyes and S. O. . Short for super oxide. Disney

50:51 . Okay, so these are what us. Your cells have these three

50:57 . Okay. Um among the bacterial , it varies varies. Okay.

51:05 so the generation of super oxide radical . So F. A.

51:09 Is a component in up here in aerobic respiration process. So it can

51:17 and form this super oxide radical that can be neutralized by the effect of

51:24 . O. D. Okay, two hydrogen peroxide and then by catalyst

51:32 peroxide eyes to water. Okay. of course is harmless. Okay,

51:39 still fairly reactive. So you have have a way to deal with

51:43 It's less reactive to peroxide. But have cataracts and proxies to take care

51:48 that. Okay so those two Right? So again if you're using

51:56 , if you're an aerobic programs use in your metabolism like us,

52:02 Or if you don't don't use Okay. But you still live in

52:08 world of oxygen, you're gonna need , right? So it's irrelevant whether

52:13 actively use the option or not. exposed to it and these these can

52:20 produced so you're gonna need protection from . Okay that's really the essence of

52:26 behaviors bacteria Archaea will have the presence of oxygen is what do they have

52:34 terms of protection? Okay um do have it? Do they not?

52:39 don't have it? You have to a different strategy to survive. Okay

52:45 let's um look at how you kind figure this out. So there's a

52:53 type of growth medium you can Okay, fluid flag like flight.

52:59 and so this medium has components in that allow you to create a medium

53:06 an oxygen gradient. Alright so we from high to know. Okay so

53:13 a nutshell it's kind of a semi medium um It has chemicals that will

53:20 up oxygen and when you compare it put it in your table course,

53:26 it kind of boils it. So drives gas out. Okay, as

53:31 take it out and then allow it cool, the gas will kind of

53:34 to seep in, but because it's jelly like matrix, the diffusion of

53:41 gas is somewhat resisted. Okay. what happens is you get a gradient

53:49 auction forming in that tube. And so what you then do and

53:54 red color is due to a dye turns red in front of the

53:58 So you should have bright red at top and none at the bottom and

54:02 gradient in between. Okay, so do you do with this? Well

54:07 you do is you take your wire , right? Here's your plate of

54:13 , Pure culture you want to Right? You take that, don't

54:17 just go like this in the right in and out. It's gonna

54:23 inoculation. Right? And so what basically doing is seeding the length,

54:29 entirety of that tube with itself? now? What you're trying to figure

54:34 which in what location of this tube the cells actually grow? Right?

54:42 they grow? Will it be those the ones that grow? Will it

54:48 these guys in the middle? Will those at the top? Will it

54:52 throughout? It all depends on the document. And did they use

55:01 So you're basically looking at the growth that's gonna tell you in what class

55:07 of zero tolerance idiots. Okay, let's start with a question. So

55:16 it relates to the protective enzymes, to protective enzymes they may have or

55:21 lacking. Okay. How they So let's look at this question

55:28 This up. Okay, this Alright. So we've got five strains

55:37 on that medium I just described. , we knocked out of them and

55:43 looking at the growth pattern results. ? So based on the results which

55:50 A through E. Uh is not not lacking these protective enzymes. So

55:57 has them but big but it has levels of these enzymes or maybe is

56:05 one or two of them. So they've got they have some

56:09 Just not the full complement. So might something like that grow? What

56:15 would it show you? Okay. . Remember how the Grady goes?

56:26 auction to none. Mm. Hi . Okay counting down 10 9

57:24 Right? Yeah. Okay. Um , so let's go through if you

57:34 answer. Okay. Who answered As an eagle? Why'd you have

57:41 eat? Okay. Oh right. , like business. Yes.

58:00 So correct. So e. Is correct answer. So e uh so

58:05 a reminder here. So let's So there was 02 max 02 at

58:12 top. Right? And then 002 here. Right, so it has

58:21 protection. Okay, so it means can it won't be able to grow

58:26 here. Right? So it's gonna at some level below. Okay,

58:30 it's not gonna be at the Right? This guy is that's the

58:34 . And a rope, right? actually kills it. Can't even grow

58:39 auction is present. Okay, So let's go through different types of what

58:44 are. Okay. E is what call a micro aero file.

58:48 So we'll break this down in terms uh, Arab and Arab faculty.

58:57 , So you're a robe. Um use oxygen. Is partner metabolism.

59:05 aerobic respirators like us. Okay. so there's two types. There's

59:12 We're out of the Arabs. And then there's micro arrow files.

59:18 , So auction is toxic to them atmospheric levels. They have to grow

59:23 like 10%, 1%, 5% or like that because they don't have the

59:30 protection if you have lower levels of protective enzymes or missing one or

59:36 So, they can't handle the full . About two that you get at

59:41 levels. So, the micro era . Okay. The so the other

59:47 to remember is, oh, to . Okay, get you more

59:54 Right, So everybody capitalism translates to ADP translates to more heroics.

60:02 so as we look at the ana . Okay, They don't use oxygen

60:08 there fermenters, they could be what called anaerobic. There's fires There reads

60:13 things other than 02. Okay. they can be obligate anna rose where

60:19 toxic. So they can only live areas where there's no 02.

60:24 Um The aero tolerant. Arab that's one that's probably the most confusing.

60:31 , so this guy does not use but it has the enzymes to

60:38 It actually has a full complement of to protect it. Okay. So

60:44 you look at the faculty type, , you call it is calculated.

60:50 . You can live with without Yeah. And if oxygen is

60:57 it can grow like crazy. So it will grow throughout the

61:01 Both the faculty native and the aero grow throughout the tube. Right?

61:08 there's one key difference. Right? right here. Is that alright,

61:14 at the top? So go to lose oxygen. Using more energy.

61:23 growth. Right? That's why there's growth here at the top compared to

61:27 air a teller and a rope. . And so that's the difference between

61:32 two. They're both grow throughout their against it. But the faculty can

61:39 oxygen and where its highest at that different interface, more gross is more

61:46 less homogeneous throughout the whole to write more growth here, is there because

61:53 doesn't use oxygen. Okay. Um that's that's those five types.

62:00 Any questions? Yeah. Yeah. it? The answer is because there's

62:15 be less auction in the middle number . Right. It still has the

62:21 that there's it has a protected some the protective enzymes that allow it to

62:28 auction. So that tells you it's going to be at the max

62:32 Okay. And so that will enable then it has to use remember where

62:38 file use the auction. So it's have to have some source of

62:41 Just not maximum and it's gonna go below the top level because they they

62:50 have oxygen to grow. They're they're like us except they just can't tolerate

62:57 levels of oxygen. So they have option to grow without it. They

63:00 grow if we don't have any capability ferment or respond without oxygen.

63:07 Um So I mean in the microbial , in the bacterial archaea world,

63:15 . To be honest, there's there's of these types of Arabs in fact

63:21 is in fact the types of anything really. Right. Anaerobic and aerobic

63:26 aerobic metabolism is not is not is the majority. Right? It's typically

63:36 faculty actively anaerobic aero tolerant. If anything, probably MicroAire files are

63:42 prevalent than than Arabs in the bacterial world. Okay. We have to

63:48 of you know when you think of that's anaerobic, you might think,

63:52 . It's gonna be in this really off environment. Right. Where the

63:57 can't even get into it at That's not the case right there.

64:01 . Right. You have to think micro environments because they're in your

64:05 All right. You have to open mouth because fermentation goes on your mouth

64:10 cavities. Right? So they're kind occupying the nooks and crannies like in

64:14 guns or you know where there's gonna less less oxygen. Okay.

64:20 uh micro environments can vary widely in around your body. Right? Where

64:26 less auction in some places, more others. So, and there was

64:30 environments you can have and it is Okay. Obviously your gut is one

64:36 one huge in a robe factory. . So anyway, uh the so

64:43 gears here a little bit just for second, a couple of minutes.

64:47 uh this is kind of the second of Chapter five. This is kind

64:50 the how do we kill to get of it? Okay, so basically

64:55 on that part of the growth curve death phase. Right? So,

65:01 remember, death can occur just as almost as long growth. Okay,

65:08 that's what we're trying to emphasize here controlling growth with different types of physical

65:12 agents. And so this is just you, you know, if you

65:15 your favorite disinfectant, right. A disinfectants are gonna have um they're all

65:23 of similar in terms of how they're , but there's a pretty much a

65:29 set of microbes that you test Right. Different types of viruses?

65:34 even fungi showing different bacterial types. you see the oldest ones here.

65:40 . Uh, usually medically important Right. And so, um,

65:46 , you read the label and it you this and that this affects hundreds

65:50 services. This is marketing stuff. , but uh, my interest here

65:56 that they always have typically a big lettering, 99.9% killed, 99.999%

66:05 killed. Right? Or microbes So what does that actually mean?

66:10 that's really what somebody's we're looking for are we counting these things how much

66:15 how fast? Right. So we look at and when they do these

66:18 of studies, they typically have a template that's like maybe too much by

66:23 and square and put it on the or something. And they'll swab it

66:28 see how many bacteria actually there. many microbes are there. And then

66:32 take another square and apply disinfectant and see you know what percent has been

66:39 . Right? And so if you a million cells and then you kill

66:44 as Lysol claims to do, Then should have killed 999,000 of them.

66:51 ? So the point is you still cells left on your little area

66:56 You're not sterilizing the service when you this as a disinfectant. You're reducing

67:02 numbers greatly. Okay, you still have viable cells there. Okay and

67:08 we begin to talk about you know disinfectants and antiseptics work and kill its

67:15 of death. That's what manufacturers of things. That's the parameters typically use

67:21 of death. How how long to One longer death in many. And

67:26 parameter varies from manufacturer to manufacturer. rely on 12 blocks. Uh

67:31 And what time frame? Okay. the point is here this is what

67:35 trying to do. Kill them and them fast. Right? So um

67:42 let's look at this. You're you're aware of my pet peeve of misuse

67:48 the word sterilization. So we had similar to this before a few weeks

67:55 , see if we remember that. And so as we go through this

68:02 more so next time. Yes. any of these treatments. Whether it's

68:09 acceptance disaffection, whatever you are reducing numbers of everything. Okay but obviously

68:17 looking at, are you affecting Right? Because you know certain that's

68:22 you want to try to reduce levels . Okay so uh the time around

68:34 . Yeah I predict 98%. I'll it right, 99%, Right?

68:46 the lifestyle can says okay That's Not correct anyway. Alright.

68:59 Not quite Alright even close. sterilization is none of the above this

69:07 . Okay so what is sterilization? is destruction in my little two inch

69:15 there by sterilizing there would be no sell spore or virus in that

69:22 0 99.99990 is what it would Okay. Um disinfection and acceptance where

69:32 know what those are ready. That's has to do with what you are

69:38 it to applying it to a living . That's anti sepsis, inanimate

69:44 Walls, bench top, that's Okay. Um so by you know

69:51 can infer from that that disinfectants can be harsher. Right? Think bleach

69:58 as a problem alcohol which is a harsher chemical but it can be quite

70:04 disinfectant. Um And so of course and sepsis. Yes, all microbes

70:13 gonna be affected by this. They're be reduced a number. But

70:16 trying to see what what about the are they the ones being produced?

70:20 are the ones that are human health obviously. Okay, sanitation is kind

70:25 a little different. It is an reduction micro but more surely as to

70:33 you carry out your practices. Think of restaurant reviews, right.

70:39 you have used to be a guy Houston or if you remember him maybe

70:44 . His thing was slime in the machine. So the restaurant reports and

70:50 first one that started this in Houston . So you know food at improper

70:55 um messy floors with food around uh food out at the wrong temperature.

71:03 kind of things are all practices that lead to foodborne illnesses. Right.

71:08 you do things like where the loves clean up, you have proper refrigeration

71:13 and that. These are hygienic You do to reduce numbers.

71:17 But what numbers but the numbers you have to get to this is typically

71:22 by your county or state Health Department that they're the ones that come around

71:28 check on these things. Okay, that kind of, what is what

71:32 is? Okay, um Any questions that? Yeah. Okay, pasteurization

71:41 um is a temperature process to reduce in foods and beverages to relate to

71:50 and beverages. Pasteurization talked about that Tuesday. Okay, let me uh

71:57 since something is coming up on I have to finish with this question

72:01 . Okay, so I realized that is a football fan. So there

72:10 no right answer. Whatever you you get credit for, Right?

72:17 assuming everybody knows what Kansas city home is that refers to. Okay,

72:49 see what I think it's gonna E it's a favorite answer, I

72:54 my guess or see maybe it's c , so well there's no Chiefs

73:08 I see that. Eagles Texans. . Okay, Texans. Yes.

73:16 put any money on that one. , seven. We can see

73:34 you can put a title on the . What about the protection? You

73:41 put yeah, they should be there on the video points lecture they put

73:48 stuff in there. Yeah because there something wrong with your video points

73:55 So they fixed it. So I it and so I posted it today

73:59 you should see the version. That's should be the right version.

74:04 Yeah you will now because it's gone the right thing now. So you'll

74:10 . Yeah. Yeah. Yeah they're they can't sexually reproduce right or.

74:21 they can. Yeah itself. No will begin to then come out of

74:26 state under favorable conditions would be the of nutrients. No stress. Yes

74:42 . Whether it's nutrient deprivation or favorable which will be anything that will enhance

74:50 growth. Yeah. Question. Well the the basically the D.

75:05 . A. Of the of the becomes engulfed in a sport coat is

75:11 around it. Okay so when it's then then that then the into a

75:20 form social by. Yeah. Yeah is a it's a version of

75:30 But yeah it is different. That's right. Sure let's see.

75:42 . Okay. Yeah I wanted to you something. I would say grill

76:02 and look at the day one lecture 17 January and there was like a

76:08 minute or 10 minute section in That explains exactly that question. So

76:14 a combination of stuff it gives you little here's here's how here's what to

76:18 . Um I would say give that look and you have questions, let

76:22 know, look at that first and that makes sense. And then uh

76:27 then um if you you need just let me know. Okay.

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