| 00:00 | Yeah, I, no, Yeah. And how we Hey |
|
| 00:29 | Yeah. Right. OK. Um on testing, testing. There we |
|
| 00:40 | . All right, welcome. Uh got a little bit left to finish |
|
| 00:46 | chapter six. OK. So uh yeah. So usual stuff. So |
|
| 00:53 | unit quiz one. OK. That's little more comprehensive. It'll cover many |
|
| 00:59 | the things you talk about for the that we've talked about for these last |
|
| 01:06 | chapters. 145 and six. Uh Another last mastering assignment. Chapter |
|
| 01:15 | on Monday. Uh So this is be like 45 minutes um in duration |
|
| 01:23 | questions total, I think. So, um you know, it |
|
| 01:29 | uh take these quizzes as uh it's to take them as a level of |
|
| 01:36 | an evaluation of assessment to a You can make hundreds on the canvas |
|
| 01:43 | . Doesn't mean you're gonna make 100 the exam. OK. So your |
|
| 01:48 | assessment of how, well, you , the material is not studying |
|
| 01:52 | et cetera. It's more this exercise been trying to get you to do |
|
| 01:57 | . I mean, I'll talk about on day one day one video the |
|
| 02:01 | you understand metabolism. Very super quick check to do glucose, |
|
| 02:07 | Glucose, air co2 and water How much of it can you fill |
|
| 02:11 | ? Remembering not to go into the ? I don't go into detail, |
|
| 02:14 | details on these things, the stages comes in, what comes out how |
|
| 02:18 | you know if you know the chapter stuff on a protic cell? Draw |
|
| 02:22 | freaking circle on a paper. How can you fill in? Right? |
|
| 02:27 | positive. Grand negative. So all I just do a draw, crude |
|
| 02:31 | and, and, and show, myself I know this, that is |
|
| 02:35 | better assessment than just studying questions. . So um because it will identify |
|
| 02:42 | you have a blank page and I can't stress this enough. You're |
|
| 02:46 | the exercise in a vacuum, you a pencil and a paper. That's |
|
| 02:50 | because you need to get an honest of. Do I know this? |
|
| 02:54 | your money where your mouth is and see it on the paper, blank |
|
| 02:58 | after 30 minutes run screaming to my . I don't understand anything. I'm |
|
| 03:03 | getting it. All right. What be a better assessment? You need |
|
| 03:06 | answer one way or the other. it's all 100% correct? Golden. |
|
| 03:12 | fine. Don't, don't need to about it but likely somewhere between half |
|
| 03:16 | 100. So again, if, , if you're just struggling, my |
|
| 03:23 | , why just keep struggling, get help. Ok. So still a |
|
| 03:29 | bit to go. Ok. So you have questions about things, feel |
|
| 03:33 | to come by if you wanna go do that. Ok. But uh |
|
| 03:39 | , so I can only say this many times you either wanna do it |
|
| 03:44 | you don't. So, you it's, but that's my advice. |
|
| 03:49 | , uh what else we got going ? So, um today we |
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| 03:55 | it, it's kind of broken up the two parts of chapter six |
|
| 03:58 | So um so today's kind of focusing growth. Now, there's no no |
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| 04:04 | you have, you're gonna have to no calculations on. OK? Because |
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| 04:08 | you look at on the stuff on , you might go OK? |
|
| 04:11 | they're talking about numbers and growth rates blah, blah, but you're not |
|
| 04:14 | have to do any maths calculations. . So um so with growth, |
|
| 04:23 | different ways to look at it, talking about increases in numbers. |
|
| 04:28 | Um Although we're not gonna get yet into growth, we're willing about a |
|
| 04:33 | slides. But just for now, know, knowing that uh just context |
|
| 04:39 | , right? That if we are cell numbers that obviously represents, you |
|
| 04:45 | , requires energy, right? And goes back to the old chapter five |
|
| 04:48 | metabolism, right? Taking in we're supplying nutrients on this growth |
|
| 04:54 | right? So um cho NPS, ? And you do that and cells |
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| 05:02 | grow on those nutrients, take them metabolize, produce energy and increase their |
|
| 05:09 | . Ok. Now, there is pattern to it as we'll see in |
|
| 05:12 | little bit right from when you add cells to a medium. |
|
| 05:19 | That there will be a pattern and pattern is the same typically. Uh |
|
| 05:25 | what can change are durations of phases change the, the uh inflection. |
|
| 05:32 | other words, maybe it's not, it's faster than faster than that, |
|
| 05:38 | it's slower than that. But you're gonna see these 41234 phases. |
|
| 05:45 | ? And we'll go through what each means and, and whatnot. |
|
| 05:48 | So we already talked about so in, in uh wanting to get |
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| 05:56 | to grow on a medium, of , you supply, they have requirements |
|
| 06:00 | all living things do, right? not just chemical, which we've mentioned |
|
| 06:05 | , right? The elements that make molecules, um maybe extra stuff depending |
|
| 06:11 | their requirements. Some microbes are better to grow with fewer of these um |
|
| 06:18 | uh forms of these elements than Some need to have extra stuff supplied |
|
| 06:23 | they can't do a lot of Like maybe they need to make uh |
|
| 06:27 | have to be supplied certain amino acids whatnot. So you may have to |
|
| 06:31 | that. So it just depends, ? Do you have to supply oxygen |
|
| 06:34 | not? Depends. So, these are all species specific specific but |
|
| 06:39 | , uh if you do fulfill the for the microbe, then you'll get |
|
| 06:44 | like this if you track their Ok. So um ok, so |
|
| 06:50 | again, we've, we, we've talked about this already, right? |
|
| 06:53 | looking at the chemical requirements, different uh things needed in different amounts. |
|
| 06:59 | versus macro, macro, nutrients are what you see there. Carbon, |
|
| 07:05 | ? Phosphorus, sulfur sources. These generally supplied in larger amounts, |
|
| 07:11 | tiny, right? Generally like trace . Uh typically iron, although iron |
|
| 07:17 | kind of on the higher end, things like copper and Cobalt, these |
|
| 07:21 | are used in various enzymes but in small small amounts uh growth factors. |
|
| 07:27 | again, those are typically things you that the organs that maybe can't make |
|
| 07:33 | . So you have to kind of these in order to, to let |
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| 07:35 | grow uh essential nutrients. So remember those are basically the things it cannot |
|
| 07:39 | it. All right. So you to supply a carbon source, |
|
| 07:42 | Um in order for it to for example, OK. So, |
|
| 07:47 | then we talk about aero tolerance, ? So oxygen may or may not |
|
| 07:53 | AAA requirement for an organism. It can the the the point here |
|
| 08:00 | all of this really is um living an 02 world, right? So |
|
| 08:08 | microbes, um a bacterium's uh uh is to live in the air. |
|
| 08:18 | ? Um It it is gonna have deal with that because oxygen is very |
|
| 08:24 | . It can create these unwanted side with your metabolism to create these um |
|
| 08:32 | uh reactive compounds. OK. And true. Whether one actively uses |
|
| 08:41 | OK. Like we do or if don't use it, but they still |
|
| 08:47 | live in a world with oxygen, ? They're gonna have to have protection |
|
| 08:52 | whether you one uses it or 02, that oxygen can still interfere |
|
| 08:58 | um enzymes, uh pathways in the and creating these toxic compounds. |
|
| 09:04 | So that's where a robe. So that's on here that lives in an |
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| 09:13 | world, whether they use it or is everything except this one, obligate |
|
| 09:22 | . OK? They have to be away from 02 from air. It |
|
| 09:27 | them. They have no protection. remember the protection, right? These |
|
| 09:32 | sod catalase, right? Peroxidase. so we have these as well because |
|
| 09:42 | need protection from oxygen too. Cells . So um uh so the aero |
|
| 09:49 | micro AOP file the facultative type. can live in 02. And so |
|
| 09:54 | it's got the protection. OK. the only one that doesn't have any |
|
| 09:59 | against it is the obligate A The arrow tolerant one, there's one |
|
| 10:03 | doesn't use 02 ever but it can in the, in the 02 world |
|
| 10:08 | it has the protection, these enzyme . Ok. So, and that's |
|
| 10:14 | what the growth patterns all about is they have um these enzymes? Can |
|
| 10:20 | use oxygen or not use it? it gives you the result in growth |
|
| 10:24 | . OK. So um let's see else we have. So any questions |
|
| 10:31 | aero tolerance at all? OK. If I didn't see your hand, |
|
| 10:39 | , shout, don't scream uh at that's fine. Uh growth meum. |
|
| 10:43 | this is uh we ended here last . So growth medium. So we |
|
| 10:47 | together these CHO npss, right? different forms, right? We don't |
|
| 10:53 | the actual element, we supply them a compound, right? So an |
|
| 10:57 | source would be something like um uh chloride. Here's an N and N |
|
| 11:05 | . OK? Uh And you don't to memorize these chemical formulas, but |
|
| 11:09 | just, this is just for informational here. So um OK. Complex |
|
| 11:16 | . So remember that complex is anything has something like this. OK. |
|
| 11:23 | you got what we call complex So when you see these, you |
|
| 11:28 | that a trip to uh kine which milk protein, um soy tone is |
|
| 11:35 | plant protein and these are just kind trade names, pet tone, soy |
|
| 11:40 | . Um And so, but when , when you see them, just |
|
| 11:44 | of them as being like a plant , uh meat, OK. Uh |
|
| 11:51 | just what you would expect if you a hamburger, right? Complex |
|
| 11:55 | right? You know what it's full uh proteins, you know, it's |
|
| 11:59 | of uh carbohydrates. Um it has and in the course uh it has |
|
| 12:05 | nu- nucleotides in there. OK? all those things are in a |
|
| 12:10 | OK? And so it's gonna provide , right? So media like |
|
| 12:15 | OK? Will provide with these complex . And so does define me, |
|
| 12:21 | both provide these, OK? It's in a complex medium with these components |
|
| 12:27 | krypton, et cetera. Um We those things are in there, |
|
| 12:33 | Uh proteins, fats, carbohydrates, cetera, cho MP S. We |
|
| 12:37 | don't know the exact numbers of OK? The grams per mole of |
|
| 12:42 | , right? We just know it's it right. You know, if |
|
| 12:44 | eat a hamburger, you're gonna get these things, right? But you |
|
| 12:47 | know the exact amounts of atoms, ? But you do it defined meaning |
|
| 12:54 | , that you see it right right? You can get a, |
|
| 12:57 | a calculator and periodic chart and you figure it out, right? And |
|
| 13:01 | the essence of a defined medium. , we saw last time that we |
|
| 13:07 | a medium that looks that had Yes. So remember you can have |
|
| 13:13 | bunch of defined components in your making it a defined medium. But |
|
| 13:20 | we even add just one, if add trip tone to this boom, |
|
| 13:26 | a complex medium. Now, even you have a whole list of, |
|
| 13:31 | know, defined compounds, we've now added this complex nutrient strip to |
|
| 13:37 | Now, it's, now it's a meat game over, right? Complex |
|
| 13:42 | , even if you had just one those. OK. So um |
|
| 13:47 | So now the question of, of OK, two things. So a |
|
| 13:53 | medium by having one or more of complex nutrients, OK. You've got |
|
| 14:02 | material for the cells. In other , if you have Triptone in there |
|
| 14:06 | beef extract, again, think you're a hamburger in there, think of |
|
| 14:11 | that way. OK? That you you're supplying amino acids, right? |
|
| 14:17 | supplying nucleotides and things. So you're supplying a lot of preformed molecules |
|
| 14:23 | the cell itself doesn't have to It's got it right there. |
|
| 14:28 | If you're growing on a strictly defiant , OK? We erase that. |
|
| 14:36 | ? This one, right? You to make protein proteins, lipids, |
|
| 14:45 | , et cetera from scratch literally, ? Because you're only get given, |
|
| 14:50 | given the bare bones, you gotta it all together yourself. OK? |
|
| 14:54 | that compared to growing in a rich where you get a lot of preformed |
|
| 14:57 | that you don't have to make. ? What will uh I'll wait for |
|
| 15:03 | question in a second. So, remember that. OK. The find |
|
| 15:07 | complex. OK. And so uh the question we had about what would |
|
| 15:14 | uh uh Hetro for on, what a li go on? What would |
|
| 15:19 | photo go on? Right? These of questions. So all you gotta |
|
| 15:25 | is remember the hetero troph auto right? Is about trope versus |
|
| 15:35 | Ok. That's all about the sea . What is it? That's what |
|
| 15:44 | , how about that? That's what the hetero autotroph. What, what |
|
| 15:49 | of sea source are you using? . These things? You eat |
|
| 15:56 | you eat salads, right? So are gonna be, um, |
|
| 16:03 | complex organic material? Ok. Here's one form of that c six H |
|
| 16:11 | 06 glucose, right? You eat , you can eat proteins, you |
|
| 16:17 | eat all kinds of stuff, You need these large complex organic |
|
| 16:21 | That's the essence of a hetero. ? We learned that already, |
|
| 16:25 | We learned that in metabolism. Now, if you use CO2, |
|
| 16:32 | , that's a different story. Now you're an autotroph, you have |
|
| 16:36 | fix CO2. Remember fixing CO2 takes lot of energy, right? That's |
|
| 16:43 | plants algae photos you light energy, ? To fuel, to fuel that |
|
| 16:51 | . A lit, uses inorganic materials breaks that down and gets energy and |
|
| 16:58 | energy is funneled into fix CO2. right. So if you are an |
|
| 17:03 | fixing CO2 that to fix that, make it into molecules you can |
|
| 17:11 | right? You have to build, is a building block. OK? |
|
| 17:18 | glucose, you're tearing it down, oxidizing it, you're getting energy as |
|
| 17:24 | do it. OK? This thing other way you gotta put it |
|
| 17:28 | you have to take six of Yeah, it's like six of these |
|
| 17:34 | make one of those. Ok. , I know that succeed. All |
|
| 17:40 | . So you gotta build, it energy. OK. Troph Autotroph. |
|
| 17:46 | repeat that 8 million times between now next Friday. Ok. To |
|
| 17:50 | go to bed at night and Dream . Autotroph. OK. Because I |
|
| 17:55 | sure as blank. If I had pole once had an auto, it'd |
|
| 18:01 | 50 50. Ok. So know . Knowx. OK. When you |
|
| 18:10 | U of H and somebody asks you a trophy? You'll know. |
|
| 18:14 | So it's just, it's fundamental to , you know, it's just one |
|
| 18:19 | the things you gotta know like knowing a chromosome is, right? So |
|
| 18:24 | you, especially if you're a science coming out of college, right? |
|
| 18:27 | don't wanna be that person on the on the street interview and they ask |
|
| 18:31 | what's DNA? What? Yeah. that, that was not only the |
|
| 18:37 | makers look bad, you look OK. So you can't be one |
|
| 18:40 | those people just can't um any questions that anything. There's no silly |
|
| 18:49 | OK. Right. And obviously this is gonna be in a test. |
|
| 18:56 | , um, OK. So onward upward. OK. So this is |
|
| 19:02 | um your lab. Well, you'll get a feel for this next |
|
| 19:07 | Uh because we'll be looking at different of, of growth, media, |
|
| 19:12 | , differential media. These two, look at these next week and we |
|
| 19:18 | but uh media can have obviously different , right? Certainly is to grow |
|
| 19:24 | , OK. But you can find certain things about the growth patterns as |
|
| 19:30 | saw with the uh with the fluid media for a tolerance, right? |
|
| 19:35 | a a media that has a specific to it, right? To see |
|
| 19:39 | it behaves in oxygen, right? you might call that type of |
|
| 19:45 | One of these, right? It you something about the metabolism, biochemistry |
|
| 19:51 | the organism based on the result you , whether it's a growth pattern or |
|
| 19:56 | a color change occurs because you added if you add like uh all right |
|
| 20:01 | , right? So here's a light is an enzyme that breaks down |
|
| 20:05 | So you can have a medium that fat in it and you can go |
|
| 20:10 | ? Can it digest it and then go OK, let's, let's inoculate |
|
| 20:15 | . All right. And let's see this case, if it's positive, |
|
| 20:19 | will produce a halo around here, ? Where it's digested the fat, |
|
| 20:25 | , around it and has cleared it and used it. So that tells |
|
| 20:28 | it spot. So again, you have media that, that can show |
|
| 20:31 | different types of things like that. anaerobic growth, that's a whole thing |
|
| 20:37 | itself there. Many anaerobes and you to basically uh remove 02 and there's |
|
| 20:46 | chemical ways to do that. Uh typically displace the, the air with |
|
| 20:51 | use something like nitrogen gas to displace air and that's what you grow them |
|
| 20:56 | . Uh, it's a pain in butt to ana, I, I |
|
| 20:59 | a year of doing that but, , nonetheless, you gotta keep 02 |
|
| 21:03 | , obviously, uh enriched medium. this is a medium that, so |
|
| 21:09 | a subtle difference, I guess you'd between enriched and selective, OK. |
|
| 21:17 | a selective medium, you are actively in a chemical that's inhibitory and uh |
|
| 21:28 | enrichment media, you're not doing OK? In enrichment media, what |
|
| 21:31 | doing is you are just putting together , nutrients that you know, only |
|
| 21:37 | certain type of microbe you're looking for grow on that. OK? Or |
|
| 21:41 | least a very small group will grow it. OK? And so you're |
|
| 21:46 | their grows because they're only capable of it in their way. Whereas the |
|
| 21:52 | ones around it can't, so their increase over the others. OK. |
|
| 21:58 | that's enrichment. So again, you're , you're not adding something to, |
|
| 22:02 | kill other types, but you're just a combination of ingredients that favors their |
|
| 22:08 | , right? So there that is difference. OK? And so um |
|
| 22:13 | so selective you are, you're adding chemical and very common is to add |
|
| 22:18 | that maybe inhibits gram positives or inhibits negatives. OK? There are selective |
|
| 22:25 | like that. That's the kind of you look at next week, you |
|
| 22:28 | a group that select against gram negatives favors gram positives and vice versa. |
|
| 22:35 | . Uh Differential media kind of goes the basket as assay biochemical tests. |
|
| 22:45 | . Uh We see an example OK. So again, selected media |
|
| 22:51 | chemicals that will inhibit certain groups and and thus favor group uh growth of |
|
| 22:56 | differential media. Um and, and can be combined, you can have |
|
| 23:01 | , you can have a medium that's selective and differential is just selective or |
|
| 23:08 | just differential. So you can have the combinations. OK. This one |
|
| 23:13 | a medium that is both selective and . It um it uh uh inhibits |
|
| 23:22 | of gram positive. Um and gram are, are preferentially grow on |
|
| 23:29 | And in addition to that, you look for things like lack is for |
|
| 23:34 | fermentation, right? So they produce color reaction. These are often like |
|
| 23:39 | changes and you have dyes that are to ph and they'll change a circuit |
|
| 23:43 | . OK? And so here you like positive is more of a yellowish |
|
| 23:50 | , black negative is more really just and the opaque. Um so that |
|
| 23:56 | you between lack positive like negative, H two S shows up as a |
|
| 24:01 | precipitate. So if it's able to H two S A black precipitate |
|
| 24:05 | so actually, so two things on . So it'll differentiate between the lack |
|
| 24:10 | like positive like negative and the sulfide negative. So 222 things and it's |
|
| 24:18 | for ram negatives. OK. So , just uh a lot of these |
|
| 24:23 | developed, um select the media were really for uh waste water testing. |
|
| 24:29 | . You're looking for, you in, in water to be used |
|
| 24:32 | drinking water. You don't want to what are called fecal contamination in |
|
| 24:38 | right? Per, per water, water quality. So you um |
|
| 24:43 | in the coal, they call these forms. E coli is a coal |
|
| 24:47 | . And so if you find them drinking water, there's a, there |
|
| 24:50 | indicators of, you know, water is not good. We got to |
|
| 24:53 | something in our system, ok? these kind of media are meant to |
|
| 24:57 | of find them. So you take water sample under your system and you |
|
| 25:01 | it on this medium and you see you got, OK? So it |
|
| 25:04 | of helps as a quick way to of show you if you may have |
|
| 25:08 | of these suspected uh fecal contamination in water. Ok. Anyway, so |
|
| 25:15 | this just shows another example of a medium. So this is not |
|
| 25:20 | There's nothing in here to no chemicals here to inhibit anything, but it |
|
| 25:24 | have a blood and this is why red. So you can have different |
|
| 25:31 | by bacteria, depending on what they on this medium. So if they |
|
| 25:36 | clear it out like this, they're lying, the red blood cells |
|
| 25:40 | Ok. Um Some produce like a color. We call that partial |
|
| 25:48 | Um So they're affected. So, of course, has hemoglobin and they |
|
| 25:52 | the hemoglobin turning in green and then have types that don't do anything they |
|
| 25:56 | but they don't produce any kind of change. Ok. And we'll talk |
|
| 26:00 | this later in the context of um different diseases at the end. |
|
| 26:05 | strip the streptococcus is what you use blood for. Ok. Uh Streptococcus |
|
| 26:11 | throat. Are you familiar with that ? And, and other relatives of |
|
| 26:15 | ? So again, just examples of selective and differential meat. |
|
| 26:21 | Um, any question, you'll like I said, if you're in |
|
| 26:25 | lab, you'll be using these things lab as well. OK. |
|
| 26:29 | but so, uh, just one thing I didn't touch on. So |
|
| 26:33 | purpose medium. OK. That's your . If you're a lab, |
|
| 26:39 | you've been using that primarily. it's, it's what we call a |
|
| 26:46 | heterotrophic medium. Lots of, there no one growth medium that will grow |
|
| 26:58 | . OK. You can't satisfy the of all different types of microbes with |
|
| 27:02 | medium. You just can't do it ? Because we know that right. |
|
| 27:05 | know there's photo tropes, there's uh hetero chemo hetero tropes, there's |
|
| 27:11 | tropes and you have, you can't one medium that satisfies everybody's growth. |
|
| 27:16 | . So you can get specific, , OK. This doesn't need to |
|
| 27:23 | much here. Obviously, there's different even beyond liquid and solid. Uh |
|
| 27:29 | , plates are made with solid media adding a solidifying agent, uh |
|
| 27:34 | Uh more. So is the the of each type, OK? You |
|
| 27:40 | do pure culture unless you have a somewhere in the process. OK? |
|
| 27:46 | you know, you, you think may have a pure culture in that |
|
| 27:51 | , OK? You can look under microscope and may may determine that but |
|
| 27:57 | cells can have similar morpho, So you truly can't tell unless you |
|
| 28:03 | this on a plate, you need get kind of a a physical representation |
|
| 28:10 | what's in this liquid on a plate cells will be laid down and where |
|
| 28:18 | are in their lowest concentrations, The individual cell will grow up to |
|
| 28:25 | a colon and then you can see , OK? So that's how you |
|
| 28:28 | get a an idea of what's inside and then physically work with it, |
|
| 28:33 | ? So if you do have contaminants something else, then you'll see |
|
| 28:38 | typically, not always, but usually see different colony types, right? |
|
| 28:42 | you can go oh All right, we go. Uh Let me take |
|
| 28:46 | of that and some of that and and see what these two things |
|
| 28:50 | So again, you can, you get the pure culture unless you have |
|
| 28:53 | . But there's limitations here too, ? Because maybe you want to grow |
|
| 28:58 | up and isolate DNA from them or some protein or something and you want |
|
| 29:05 | of stuff. And so that's where comes in, right? You can |
|
| 29:09 | , you can grow, you can many different volumes of liquid from that |
|
| 29:14 | 100,000 gallons if you want to. ? Depending on how much you wanna |
|
| 29:18 | . Uh, work. So, commercially commercial scale. That's what you |
|
| 29:22 | grow and lots of liquid, Because you can get lots of |
|
| 29:25 | OK? So it will have their . OK. Um All right. |
|
| 29:32 | questions on that? OK. So gonna talk a little bit about growth |
|
| 29:45 | hone in on. So obviously growth this term um generation time. |
|
| 29:53 | So it's pretty obvious you can see ? Uh this one cell dividing into |
|
| 29:59 | that this is one generation. And so that's generally how you measure |
|
| 30:06 | growth. OK. So you can at it in terms of that one |
|
| 30:10 | dividing two. But from a more standpoint, it's done by looking at |
|
| 30:16 | time point X and the cell we this many cells in the population then |
|
| 30:22 | time point in the future, how more do we have? And so |
|
| 30:26 | uh a doubling when it doubles, call that also called the generation |
|
| 30:31 | OK. And so um that's generally you do it, you just take |
|
| 30:35 | time point at whenever and then in future and then you do the math |
|
| 30:40 | figure out. OK? Has the doubled or not to give you the |
|
| 30:43 | time? And so, um so growth, OK. Certainly any, |
|
| 30:50 | species on planet earth can have this ? And it basically just means growths |
|
| 30:56 | limitations. OK? But obviously there's finite time to that, right? |
|
| 31:03 | what is it required to get to a high rate of growth? |
|
| 31:07 | So if you, that's what this curve here is, is that |
|
| 31:13 | J shape growth? That's exponential. ? But you can't sustain that |
|
| 31:18 | Eventually it's gonna tip over, Because there's so many people in the |
|
| 31:24 | of the population, you can't, can't possibly feed enough nutrients to everybody |
|
| 31:29 | keep everybody happy, right? And it's gonna, it's going to flatten |
|
| 31:34 | . OK. So uh exponential growth only when the curves is only in |
|
| 31:41 | . OK? It will eventually come to earth, so to speak. |
|
| 31:46 | . So this, I just threw here just to kind of show you |
|
| 31:50 | some basic equation again, you're not have to calculate anything. OK? |
|
| 31:55 | uh one of those equations is really determining population size. OK? Uh |
|
| 32:02 | some time 0.0 while starting at OK. Uh And what uh multiplied |
|
| 32:08 | the generation time that two to the the end generation time? This is |
|
| 32:19 | really, you know how fast you , you can get from few cells |
|
| 32:24 | lots of cells, right? This occur in e coli within uh 8 |
|
| 32:30 | 10 hours under optimal conditions. So that's 20 generations, right? |
|
| 32:35 | about how long it takes humans to 20 generations, right? Probably something |
|
| 32:41 | 400 years, right? To get many, that many generations. |
|
| 32:45 | So uh growth occurs very quickly under conditions. It is certainly in |
|
| 32:51 | OK. And so um if we at here's just a basic example, |
|
| 32:58 | ? So we start with 10 cells a population. How many do we |
|
| 33:02 | after five generations? Right. 320. Well, big deal. |
|
| 33:05 | let's look at this in context of um of the generation time. |
|
| 33:13 | And so this is just an example . OK. So um the starting |
|
| 33:21 | 10 cells, right? So the time and how you may think, |
|
| 33:26 | , four hours, 15. All , that's a difference. But is |
|
| 33:29 | gonna make that much difference in the ? Well, um so we start |
|
| 33:34 | 10 cells, right? Uh at hours. How many do we have |
|
| 33:38 | at both scenarios? Right. So many generations in 20 hours? |
|
| 33:44 | uh due to math, right? generation every four hours, that's what |
|
| 33:50 | that refers to. So times 20 we get five generations, right? |
|
| 33:56 | plug into numbers N zero to the , right? 320 cells like we |
|
| 34:02 | on a previous example. So how in uh with the 15 minute doubling |
|
| 34:08 | . So that's one generation for every hour or 15 minutes, right? |
|
| 34:15 | so compared to one, every four . And so the impact, |
|
| 34:19 | you can see it already two to fifth, two to the 80th, |
|
| 34:24 | ? 80 generations, that's 10 to cells. Big difference between that and |
|
| 34:31 | . Right. So, again, can grow fast. Ok. And |
|
| 34:38 | that's how they can produce 20 generations a few hours, right? So |
|
| 34:44 | and that's really what, you industrial commercial uh rates of growth. |
|
| 34:50 | that's what you're trying to get is there it's all about getting lots of |
|
| 34:54 | typically for the product that you're trying market. OK. So um |
|
| 35:01 | I just threw in because when you're with this kind of growth data, |
|
| 35:07 | ? Because you have numbers just looking , here is zero to a |
|
| 35:13 | right? You have such a wide of numbers in a short time. |
|
| 35:18 | gets crunched in terms of scale, ? So here if you plotted it |
|
| 35:21 | , it would look like this, ? Kind of on a linear |
|
| 35:25 | OK? And you go OK. , zero to 100 and 30,000. |
|
| 35:31 | doesn't seem like that much. Look this. It's, that's, |
|
| 35:34 | but then you have, that's why go into logs there, log scale |
|
| 35:38 | when you have these big, you these big differences in numbers, |
|
| 35:43 | And so that allows you to then the pattern, right? So you |
|
| 35:47 | there's really decent growth there. And that's typical for when you deal |
|
| 35:52 | this kind of data. OK. Ph scales also with logarithmic for that |
|
| 35:58 | . OK. Um OK. So look at this question here. |
|
| 36:03 | a question, Chad um So bacterial batch growth curve. So let me |
|
| 36:12 | here while you read this. So what we'll be focusing on is batch |
|
| 36:16 | . OK. So what does that ? So batch growth would be here |
|
| 36:23 | my growth medium in this bottle. . And all I'm gonna do is |
|
| 36:30 | it and then that's it. Let go and then take samples to monitor |
|
| 36:37 | , right? Typically done through um ways but more convenient ways through |
|
| 36:44 | uh spectrum atomic measuring absorption and getting that way you could measure actual live |
|
| 36:51 | . But in any case, you're taking samples to monitor and that's |
|
| 36:54 | No other manipulations in the batch in batch, in the batch of |
|
| 37:00 | right? Just let it go once inoculate. OK. That's what that |
|
| 37:04 | . And so, and you're gonna this kind of a curse. |
|
| 37:09 | Again, it can be different in of lengths of phases, how steep |
|
| 37:17 | narrow it is. OK. Um talk about that. OK. Each |
|
| 37:23 | has its own name, of right? Yeah. OK. We'll |
|
| 37:57 | . Take a break at 10 Yeah. All right. It's got |
|
| 38:06 | from 10. That so um all , changes in cell size. That |
|
| 38:27 | true. You get changes in cell in both of these phases. |
|
| 38:33 | Uh Actually, their cells are their in uh what we call log |
|
| 38:38 | They are, they kind of tend shrink when they get into stationary |
|
| 38:42 | OK. Uh I'll explain why here a second. Um the exponential |
|
| 38:48 | yeah, there's uh exponential growth occurring two, of course, but also |
|
| 38:53 | a negative fashion in, in phase , right? That phase. So |
|
| 38:59 | both represent, both represent uh exponential or death if you will. |
|
| 39:07 | It's really in I think uh chapter , we talk about controlling growth of |
|
| 39:14 | , disinfectants and sepsis sterilization, These met methods, we're trying to |
|
| 39:21 | really this part of the growth not really calling them gross, but |
|
| 39:25 | trying to maximize how fast you can them when you're, you know, |
|
| 39:28 | antiseptics or disinfectants. It's about that of the curve because they are, |
|
| 39:32 | are dying exponentially. OK. Um phase. That is one, |
|
| 39:39 | So you just inoculated a medium and the cells are in this environment, |
|
| 39:44 | have to get themselves going. Um take some time and then end those |
|
| 39:50 | . So remember end those spores are under stress conditions, right? So |
|
| 39:56 | will typically be within three. It wouldn't be here because by then |
|
| 40:02 | gonna be too late, they're right? So it's gonna kind of |
|
| 40:06 | that in a stationary phase when they're of beginning to really, really kind |
|
| 40:10 | starting here through here. OK. To, to, to form an |
|
| 40:17 | those four, because obviously they're under in that period. OK. So |
|
| 40:21 | would be um none of the, are all true, they all true |
|
| 40:26 | . OK. Um So let's, dig in a little bit deeper on |
|
| 40:31 | , on these phases here. So uh lag phase, right? |
|
| 40:38 | log stationary death. OK. So is, so again, we inoculate |
|
| 40:46 | are in a new environment. Um factors will determine if this is a |
|
| 40:52 | period or is it extended? Um So, um so imagine you're |
|
| 41:01 | cell you've been growing in some other , right? And now you're being |
|
| 41:07 | into this new one. OK. there's gonna be a slight, definitely |
|
| 41:12 | ph temperature changes for sure. Uh um genes turning on and off different |
|
| 41:19 | and we have to turn on different . So think about, think about |
|
| 41:23 | it was growing, it was growing a complex medium, right? And |
|
| 41:28 | you're throwing it into a defined Is that going to shorten or lengthen |
|
| 41:37 | lag phase, Jordan or lengthen going here into here, we gonna go |
|
| 41:47 | , we're gonna get bye. Somebody something at me, right or |
|
| 41:52 | I don't care why, well, don't wanna say why, why it's |
|
| 42:00 | your head? I know it, it out. Why, why just |
|
| 42:05 | , talk, talk. Yeah. . Absolutely. Yeah. I know |
|
| 42:12 | had it, you have to make own nutrients that takes time expressing genes |
|
| 42:17 | happen like that. You gotta do . You gotta, you got |
|
| 42:22 | um, get the signal to transcribe genes, then you have to transcribe |
|
| 42:26 | . You have to make RN you have to get ribosomes involved. |
|
| 42:29 | have to make the protein all takes , right? Maybe you have to |
|
| 42:33 | genes off as well. So you're for a medium that it's basically a |
|
| 42:39 | , you're hanging lots of stuff you have to make, right? You |
|
| 42:43 | grow pretty good, right? But now you're plopped into a medium where |
|
| 42:49 | , there's, you have to make from scratch now. OK? I |
|
| 42:55 | make all my building blocks and I to, I have to do it |
|
| 42:57 | , you know, without having preformed for me, I have to do |
|
| 43:00 | the hard way. OK? That's take time. OK? So that |
|
| 43:05 | face will lengthen. OK? If go from, you go the other |
|
| 43:10 | , right? If you go, in a define and you go this |
|
| 43:14 | . Well, that's gonna shorten right? Because now you're in this |
|
| 43:17 | of, wow, all this stuff already make for me. I can |
|
| 43:19 | gobble it up and grow, It will shorten the lag phase, |
|
| 43:24 | ? Um What's typically done is to both media the same. Ok. |
|
| 43:29 | there, that, that too, at least that it won't lengthen |
|
| 43:32 | but you can be sure it's gonna a reasonable frame, but nonetheless, |
|
| 43:37 | factors, right? Um, uh, how old is your culum |
|
| 43:43 | been growing for like days? There not be any viable cells left when |
|
| 43:48 | ate. Um, again, physical differences in ph temperature, et |
|
| 43:54 | So, cumulatively, these all have effect on, on how long it's |
|
| 43:58 | be sitting here. OK? But it gets out of there black |
|
| 44:03 | it'll take off. OK. So log phase, of course, that's |
|
| 44:07 | be the most active state. So cells, um so when we |
|
| 44:14 | at log phase here, cells are growing. So if this, it's |
|
| 44:21 | rod shaped cell, yeah, let's to COCCUS, let's see here. |
|
| 44:26 | cells that are uh actively dividing, gonna be in these kinds of |
|
| 44:36 | right? So they get, as get a little bit bigger, they |
|
| 44:39 | divide, right? So you're gonna this largest cell size are gonna be |
|
| 44:46 | log face. So they get big they split. So they're gonna, |
|
| 44:50 | gonna be their biggest and most right? So typically, very often |
|
| 44:56 | , you're growing the cells because you , and you know what they call |
|
| 45:07 | log phase or. So that's where really active. You know, they're |
|
| 45:10 | have their highest levels of enzymes And that's when you're gonna get your |
|
| 45:15 | numbers, your best activity. So often when you measure that, um |
|
| 45:20 | if you're gonna going to harvest which means you want to get all |
|
| 45:24 | them and do something with them, do it here around this part here |
|
| 45:30 | you get a compromise between oh lots cells but not yet dying off and |
|
| 45:35 | can even sure maximum yield of when harvest them. OK? Um And |
|
| 45:43 | when we do get to here, , late log. So now we're |
|
| 45:48 | a point where OK, you, , you no longer can sustain everybody |
|
| 45:53 | that growth rate. There's not enough , right? It's bad growth. |
|
| 45:58 | a, we're not adding anything to . We're just taking samples and |
|
| 46:01 | So in that state, you're you're gonna run out of food |
|
| 46:05 | OK? Not yet. It's the food's not at zero in the |
|
| 46:10 | until we're over here. Hold on we're here. This is kind of |
|
| 46:17 | we're approaching zero food. OK? right at the beginning of death |
|
| 46:22 | But uh in any case, so log phase, uh eventually big cells |
|
| 46:27 | then eventually a late log, not food begin, the beginning is becoming |
|
| 46:33 | and then growth slows down, The stationary phase. So kind of |
|
| 46:38 | opposite thing. So, so now you're in a stationary phase and when |
|
| 46:42 | is in that, it's like survival , I got to ride out, |
|
| 46:48 | know, this, this period maybe good things will happen. Maybe |
|
| 46:54 | will fall on top of me and can start growing again. So, |
|
| 46:56 | the meantime, it's survival, survival . Ok. So what do you |
|
| 47:01 | ? You do lots of things, kind of shut down unnecessary processes. |
|
| 47:07 | , you can just kind of hunker . You make yourself smaller a little |
|
| 47:11 | because being smaller means having to keep with less material, a smaller cytoplasm |
|
| 47:16 | less needs. So, again, about survival. OK? And um |
|
| 47:22 | know, gross rate, equally debts , of course, is a flat |
|
| 47:27 | . But after the asterisk here, micro bacteria can be kind of sneaky |
|
| 47:32 | that they can, they're not growing you may think, oh, they're |
|
| 47:37 | , right? But they're actually not , they're actually just kind of sitting |
|
| 47:41 | being, being alive but not Ok. So, you know, |
|
| 47:47 | something to consider. But the um the uh uh so, so certainly |
|
| 47:52 | under stress uh particularly when they get along stationary phase, especially if food |
|
| 47:59 | coming their way, right? Um cells, cells lice they die, |
|
| 48:04 | that do die, that actually can be a food source for |
|
| 48:08 | So, eating each other, Cannibalizing. So, um but that |
|
| 48:13 | only last for so long, And then eventually you're just, you're |
|
| 48:17 | out of it completely and numbers will go down rather rapidly. OK? |
|
| 48:23 | exponential decrease. OK. So, So the life of a cell and |
|
| 48:30 | growth, OK. The um now you can do manipulations, OK. |
|
| 48:36 | this is why we make a distinction batch growth and what we call fed |
|
| 48:42 | . You basically just feeding it is you're doing, right? So what |
|
| 48:45 | can do is uh so here you can, you can be very |
|
| 48:52 | , just have like a, a that you're growing your bacteria. |
|
| 48:58 | And all you do is say like maybe here at time point, we |
|
| 49:06 | some more, I'll add carbon, ? Remember that has the biggest influence |
|
| 49:15 | determining cell numbers. So add some , add some glucose if you can |
|
| 49:20 | glucose, add some more glucose Then you'll see this roast go |
|
| 49:26 | OK? Like that. OK? you can even do it again if |
|
| 49:30 | wanted to and add some more here get it growing some more. |
|
| 49:35 | So you can keep doing this for few times, right? But even |
|
| 49:38 | has those limitations, right? Because still in the, in this closed |
|
| 49:43 | and you're just adding more food and , you know ph changes occurred and |
|
| 49:49 | too much and whatever. So, you can extend it for, for |
|
| 49:53 | while. Now, this is kind a, you know, crude way |
|
| 49:57 | doing it, OK? If you to get super fancy, you can |
|
| 50:00 | do this, OK? So these little pumps, they it's all computer |
|
| 50:06 | So uh you can control uh the of spinning, spinning is what creates |
|
| 50:13 | and mixes in air, right. you can just increase the spinning, |
|
| 50:16 | more air in there, you can ph right uh in a narrow |
|
| 50:23 | Um So doing that uh controlled you can get super high growth rates |
|
| 50:30 | way. OK. Lots of cells and you have to, it's not |
|
| 50:36 | obvious here, but you have this right here. This metal part down |
|
| 50:40 | at the bottom, there's there's called going through. It's a jacket, |
|
| 50:51 | metabolism, energetics producing lots of right? If we didn't have that |
|
| 50:58 | these very high growth rates, burn up. So you have a cooling |
|
| 51:03 | to keep the temperature constant. And under these control and this is |
|
| 51:07 | you do in industrial scale and that you to get lots and lots of |
|
| 51:13 | . OK? Uh So feed create your control, et cetera. |
|
| 51:18 | ? Uh I don't, there's no majors in here, but my other |
|
| 51:21 | has them and that's the kind of they do is is this? |
|
| 51:25 | so uh what about growth, Gross metabolism, right? Um Any |
|
| 51:32 | about that? About growth phases, any of the stages, anything about |
|
| 51:36 | stages? OK. So um I context you know the production of vaccines |
|
| 51:44 | on a commercial growth like this, lots of cells uh for production of |
|
| 51:50 | . OK. Um Your pfizer et . OK. So the last part |
|
| 51:58 | this chapter six is covers this, features are applicable to biofilm formation? |
|
| 52:08 | . So now we're talking about OK. We certainly represents a lot |
|
| 52:14 | growth for sure. OK. Tons , oh, let me open |
|
| 52:21 | Sorry, I forgot something. Yeah, bye. Yeah. |
|
| 53:12 | OK. Counting down from 987 321 paused at one. OK. |
|
| 53:26 | There we go. All right. . The two of the above. |
|
| 53:36 | the two are and right surface and . OK. It's all about |
|
| 53:45 | OK. So we talk about this little bit in the first chapter. |
|
| 53:53 | um examples of biofilm. So some . Ok. Uh They, they |
|
| 54:00 | this with purple dye to show the the plaque. OK. But uh |
|
| 54:05 | pipes or good, good um habitats biofilms um and water. Uh ma |
|
| 54:14 | of algae growth on top of Ok. Uh Your shower curtain. |
|
| 54:18 | a look at that some time. a bio on there maybe. |
|
| 54:22 | Uh bathtub ring. Ok. um and to be honest, there's |
|
| 54:28 | bacteria and archaea probably live mostly in anyway, whether made by themselves or |
|
| 54:36 | of somebody, someone else's biofilm, they're everywhere. And medically important ones |
|
| 54:42 | those that are various types of implants a heart valve replacement, a knee |
|
| 54:49 | , hip replacement, uh breathing uh catheter, all these provide surfaces |
|
| 54:57 | biofilm formation and there are medically important informers, staff can do that right |
|
| 55:05 | others. OK. And so, and of course, it really comes |
|
| 55:10 | to the typically to the mishandling of device where it becomes, it's sterilely |
|
| 55:17 | , it becomes compromised as it's not correctly and leading to contamination. And |
|
| 55:22 | in the patient formation occurs. um but you know, they all |
|
| 55:28 | in common is the surface, I'll, I'll have the surface in |
|
| 55:31 | . So um I would say biofilms probably uh a a nutrient nutrient driven |
|
| 55:40 | . OK. Uh In a way of the opposite of in those four |
|
| 55:45 | . So in those four formation is about, in many cases, it |
|
| 55:48 | be deprivation of nutrients, indus EndoSeal . Here. It's like you gotta |
|
| 55:56 | lots of nutrients and then that will a biofilm because obviously that's a ton |
|
| 56:01 | growth, right? Lots of So you have to have lots of |
|
| 56:04 | to support it, right? um so kind of the basic process |
|
| 56:11 | see here is so 22 views. here's one view, one, it |
|
| 56:18 | out as a growth on the So let's just kind of look uh |
|
| 56:21 | of the 123 steps here. So what we call planktonic cells are |
|
| 56:28 | free swimming forms of this, of species. OK. Truly swimming with |
|
| 56:34 | , with the OK. Um they adhere to a surface. OK. |
|
| 56:41 | , this is all about chemicals being , that's what induces this being on |
|
| 56:48 | surface have to have those. And that allows for attachment. You |
|
| 57:00 | see twitching motility on the surface, might be moving around through that kind |
|
| 57:04 | motion. Now, what happens from just some cells plopping down on the |
|
| 57:11 | , they then may begin to collect micro colonies. OK. Chemical |
|
| 57:17 | it's all driven. It's just, not just a random process where they |
|
| 57:20 | plop down and begin growing. It's chemically driven, right? And gene |
|
| 57:26 | encoded process. OK. So it's a random assembly. It is a |
|
| 57:32 | process, a favorable environment because why are they staying there? Right. |
|
| 57:45 | as a result, the chemicals accumulate they're sending off, bringing more cells |
|
| 57:50 | , hey, this is a good , let's hang out, right? |
|
| 57:53 | so growth, of course, First, we gotta make the glue |
|
| 58:04 | holds it together so that this this the chemicals or signals to say, |
|
| 58:09 | , let's make this exo polysaccharide. is the kind of the glue that |
|
| 58:13 | it together. OK? And so you get lots of growth. So |
|
| 58:19 | it expands three dimensionally o off the , right, actually called these biofilm |
|
| 58:25 | , right? And so then you're have fluid as you see up here |
|
| 58:31 | throughout the whole, all these little clumpy things, right? These |
|
| 58:37 | OK? And you know, to this level of growth, you're gonna |
|
| 58:41 | a lot of nutrients, this this a lot of cells, ok? |
|
| 58:45 | so not surprisingly a pipe, You have a constant flow of liquid |
|
| 58:49 | a pipe, nutrients, right? environment for it to sustain this |
|
| 58:53 | ok? Uh shower curtain, Nice moist and human in there most |
|
| 58:58 | the time, right? So um you have to have that to sustain |
|
| 59:02 | . Ok. Uh what can happen is eventually, well, even if |
|
| 59:09 | , even if it doesn't fall apart of lack of nutrients, it can |
|
| 59:13 | a healthy, runs out of it will begin to dissolve, |
|
| 59:24 | And it will revert back from from this uh non uh losing their |
|
| 59:32 | form to regaining it is. it's got to swim off and find |
|
| 59:36 | new, a new home, A new healthy uh habitat with lots |
|
| 59:40 | food and start over again. So, um but again, you |
|
| 59:45 | , these are thought to be very throughout all nature, right? Uh |
|
| 59:52 | both in water and on s surfaces in terrestrial environments, uh et |
|
| 59:58 | And um now the thing is within biofilms, OK. You'll have micro |
|
| 60:07 | , right? You'll have cells out on the surface, right? Compared |
|
| 60:11 | cells in the middle. OK. these can tend to become somewhat different |
|
| 60:18 | because they don't have as much access the food out here as the ones |
|
| 60:22 | the periphery do. So you can some differences within the biofilm and differences |
|
| 60:29 | antibiotic resistance. OK. And so why these biofilm ones that are medically |
|
| 60:38 | can be such a problem, One, the thickness of this, |
|
| 60:44 | ? Imagine antibiotics trying to penetrate, , uh penetrate this this film, |
|
| 60:51 | ? And then the differences in antibiotic uh resistance can develop uh more easily |
|
| 60:57 | this scenario. And so um so like a uh catheter that's inserted that |
|
| 61:05 | then you have a bio formation due staff. OK. That can be |
|
| 61:10 | , these things have a hard time rid of it. Uh You |
|
| 61:14 | but it's not like a week, week's worth of antibiotics. It's more |
|
| 61:17 | months. Ok? Because these things persist, um can be hard to |
|
| 61:23 | at and, and then migrate right? So these are really uh |
|
| 61:29 | and more in health care. These , are an issue, you |
|
| 61:32 | you know, again, cat breathing , et cetera, but certainly |
|
| 61:37 | handling these devices when you putting him the patient is, is where the |
|
| 61:43 | begin. So, doing that Ok. Um All right. Any |
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| 61:51 | about that, right? So you need to worry about. Oh, |
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| 61:56 | I need to know each of the of bio formation? No, just |
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| 61:59 | what the basics of it, You know, surface attachment, |
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| 62:03 | Lots of growth is occurring, supply that, that much. Ok. |
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| 62:09 | . Folks. Uh that's it for start unit two next week. |
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