| 00:00 | Yeah, no. Yeah, fucked like okay, testing, testing. |
|
| 00:57 | folks. Hello? Hello. Um as you know, or maybe don't |
|
| 01:08 | , cautious schedule is open. So exam is not a week from today |
|
| 01:12 | a week from tomorrow and saturday depending when you scheduled. Let's see, |
|
| 01:21 | stuff. So the blackboard which is unit quiz, which is a little |
|
| 01:25 | , only different in terms of a little bit more comprehensive. It's |
|
| 01:30 | 13 and four material we'll finish for . Well five which we'll do on |
|
| 01:37 | is fairly short, so it's not be a extensive just covering two things |
|
| 01:44 | . One is called aero tolerance among . So there's ways to see this |
|
| 01:50 | the type that can use oxygen cannot 02 can use both etcetera. There's |
|
| 01:56 | to test that. Um and then other part is really just kind of |
|
| 01:59 | basics of, of how you kill . Okay. And how we look |
|
| 02:06 | that um measure it and some examples how we kill these things. |
|
| 02:13 | Um many, many, many terms sure you're familiar with, but there |
|
| 02:17 | be some terms that we have to through. So that's pretty much what |
|
| 02:22 | is about. Okay, I think maybe a total of a dozen slides |
|
| 02:27 | . So anyway, so it's not not super extensive. Something we can |
|
| 02:31 | finish that start and finish in on . Okay, so um what |
|
| 02:39 | Oh so that because five is not part of the, of any of |
|
| 02:43 | quizzes that will have, I will like half a dozen questions relating to |
|
| 02:49 | material on blackboard on monday? So can it will be like just questions |
|
| 02:56 | I'll be like a next you will the answers on it. So if |
|
| 03:00 | want to go through and take the and you'll see the answers at the |
|
| 03:03 | . So just to kind of give a sampling of some questions from from |
|
| 03:07 | chapter. Okay, so again I'll that on monday. Okay, is |
|
| 03:13 | gonna be for great or anything? certainly you know quizzes for for |
|
| 03:16 | Okay so let's see. So alright we need to finish up four so |
|
| 03:27 | . We've gotten through most of these I'm gonna kind of rehash the batch |
|
| 03:33 | concept again a little bit about what call fed batch and bioreactor growth. |
|
| 03:41 | if you are um biotech major, know there's a bunch of you in |
|
| 03:47 | that that is kind of stuff you'll doing if you're not already um in |
|
| 03:54 | I think I know it's part of curriculum, you have bioreactor in you |
|
| 03:59 | you use engineered genetically engineered strains and . But certainly industry, if you |
|
| 04:05 | that route you will definitely be using kinds of tools and techniques um and |
|
| 04:12 | of growth. So that's what we a little bit about at the kind |
|
| 04:16 | the calculations involved. Nothing complex. um about how we measure growth and |
|
| 04:22 | of if you have this many how many do you have at the |
|
| 04:26 | that those kind of problems. And there'll be a couple of those on |
|
| 04:30 | exam. You can use your take hand held calculator. I don't care |
|
| 04:35 | kind tu tu casa, I let know ahead of time that you'll have |
|
| 04:41 | calculator and you can bring it in you. Okay? So so that's |
|
| 04:45 | fine and and I'll remind you again email, so again you can use |
|
| 04:49 | calculator to figure this out. And we're not talking complex math here, |
|
| 04:54 | you can't have a and we'll go a couple of problems today and there's |
|
| 04:57 | extras you can look at on your on blackboard, has the answers all |
|
| 05:03 | out? So you can look at as well. Again it's only taking |
|
| 05:08 | maybe two at most three problems on exam covering this. Okay, likely |
|
| 05:12 | to. So anyway but do take look at those and we'll go through |
|
| 05:17 | basics of that as well. Um before we do that there was one |
|
| 05:22 | thing uh I can't remember. Is any questions cargo? Okay so we'll |
|
| 05:31 | with the question. Okay so this again to kind of the batch growth |
|
| 05:38 | we talked about before. So here we have the first statement when e |
|
| 05:43 | has grown in nutrient broth there's the the formula uh N. B. |
|
| 05:49 | short we grow enough for 24 hours transferred to fresh N. B. |
|
| 05:55 | from one class to a now a one. Um The pattern looks like |
|
| 06:01 | , right so we go from B. Two N. B. |
|
| 06:02 | like a. Okay so if we it on N. B. Again |
|
| 06:07 | then transferred to this other medium you on the right M. Nine A |
|
| 06:12 | , define what do you think the pattern would resemble? A. |
|
| 06:17 | Or C. Okay. Um So a look at that. And uh |
|
| 06:26 | uh while you're looking at this so the phases? Right so the batch |
|
| 06:33 | is basically you've got a flask test , what have you some sort of |
|
| 06:39 | receptacle with your medium? Um You , give it a source of cells |
|
| 06:44 | ? They'll start growing and just following pattern right? Like you see these |
|
| 06:48 | have basically the same pattern. Just differ in different parts. Okay so |
|
| 06:55 | so the different four different stages of process. Okay. The lag log |
|
| 07:03 | death phase. Okay and so all doing is just the only manipulations are |
|
| 07:07 | is taking samples out to measure Remember these of course were all cell |
|
| 07:12 | over time. Okay there's different ways do that. The common ways to |
|
| 07:16 | a sample measure absorbency which you've I'm sure by now in different ways |
|
| 07:22 | different classes you measure absorbent inspector thomas these things as they grow in |
|
| 07:27 | Get cloudy so they will um you measure light absorbent with them and you'll |
|
| 07:32 | a graph like this but that's all doing. Just taking samples and measuring |
|
| 07:37 | that's batch growth just following it from beginning to the end and that's |
|
| 07:41 | Okay. Um and you get these of curves. Okay, so let's |
|
| 07:48 | do a Greece like countdown here. 10 seconds. Okay. So um |
|
| 08:01 | answer as soon as you finish this we'll go Through. Okay. We |
|
| 08:07 | 164 said see um if you said uh you are correct? Who answered |
|
| 08:20 | why? Why do you get Okay. So by lacking things like |
|
| 08:35 | only beef extract, what does that for the cell on the grass is |
|
| 08:42 | it doesn't and what it means obviously have this mode. Well e coli |
|
| 08:51 | can will grow in M. Okay. Right. It's just not |
|
| 08:56 | just it just has this really long phase. Right? Why does it |
|
| 09:01 | a long lag phase here, anybody ? Yeah. Yeah. Right. |
|
| 09:10 | you're on the right track when you're , you're right, it is a |
|
| 09:13 | . And for that reason you said it's in this, Right. So |
|
| 09:18 | is full of preformed nutrients. Okay got vitamins it's got um it's got |
|
| 09:25 | uh amino acids and things. So a lot of materials in here but |
|
| 09:32 | doesn't need to synthesize to get Whereas certainly an m nice to define |
|
| 09:38 | basically to make everything from scratch speak any coal is capable of doing and |
|
| 09:45 | but it takes some time and the is reflected in the lag phase |
|
| 09:49 | Right. So this is a time it's turning these different genes on maybe |
|
| 09:54 | off but you know, making acids whatever else it needs. That's that's |
|
| 10:00 | this is extended because it's it's not a lot of preformed stuff that doesn't |
|
| 10:06 | won't have to synthesize. So that's in the longer lag phase. But |
|
| 10:09 | once it begins making that material, certainly obviously kicks in. Right. |
|
| 10:14 | see that log phase? Of course very steep. Right? So, |
|
| 10:19 | and that's, you know, it and there can be different factors that |
|
| 10:23 | lengthen this, It can be. many cells are you adding? Is |
|
| 10:27 | fewer cells are more cells? Is very old that's going in here um |
|
| 10:34 | are the nutrients different? And so we see the effect there. |
|
| 10:38 | And so if generally if you go if you go from this Okay, |
|
| 10:45 | if I went from here, I cells here and I took an inoculation |
|
| 10:54 | that point And went back again into , would I expect to have the |
|
| 11:01 | long lag period? No, it already acclimated already acclimated to the |
|
| 11:06 | So, so, so it was M9 here. Okay, uh and |
|
| 11:11 | you go into fresh M nine. , that's ok you're not going to |
|
| 11:15 | this extended period because it's already it's geared for it. Okay, already |
|
| 11:21 | , it has all the enzymes and going, it needs to stay on |
|
| 11:25 | minimum media and it can keep going , you know, really the lag |
|
| 11:31 | that would occur because of maybe a temperature variations, slight ph variations, |
|
| 11:36 | be slight osmolarity variations between the That can kind of slow it down |
|
| 11:41 | bit, but it wouldn't be extended it's already geared for that media |
|
| 11:46 | Okay. Um would it, would be a lag phase if it went |
|
| 11:53 | M night into A and B long face? I don't think necessarily would |
|
| 12:05 | there is going going from Oh I I got lots of stuff for |
|
| 12:07 | I can kind of, there may some bit, but I don't think |
|
| 12:11 | would be profound because it's going from from a situation where now it's getting |
|
| 12:17 | of stuff, it doesn't have to okay? And very quickly it will |
|
| 12:21 | down pathways as we'll learn in unit , it can very quickly shut down |
|
| 12:27 | that are on and because I have make anything, it can very likely |
|
| 12:31 | period will not be that long in of lag phase. Okay, by |
|
| 12:35 | to a rich medium. Okay, does that does all that make |
|
| 12:41 | Yeah. All right, alright, so we just kind of went |
|
| 12:47 | I forgot to put that up but think you figured that out. Um |
|
| 12:51 | , so different phases um log let's see, I think I mentioned |
|
| 12:58 | previously. So in log phase here kind of the mid, you often |
|
| 13:04 | the term mid log somewhere in the like around here, that's typically of |
|
| 13:11 | most, you might see the most functioning state of the cells or in |
|
| 13:16 | kind of period here. Often times you zero went on is when you're |
|
| 13:22 | , if your cells are doing something , you know, metabolism you're interested |
|
| 13:27 | and typically it's going to be the active in that period. You may |
|
| 13:31 | to do like samples for enzyme activity something like that and you might do |
|
| 13:36 | there because that represents maybe the most you get the best measurements for those |
|
| 13:40 | the cells are really active and metabolically and growing fast. Maybe that's also |
|
| 13:45 | we want to harvest cells and use for later because you'll know they'll be |
|
| 13:50 | a really good state when you harvest there because they are in a very |
|
| 13:53 | state. So, you know that can be of interest, but not |
|
| 13:56 | everything one does is necessarily geared toward face and maybe something you want in |
|
| 14:01 | phase. So it just depends but very common, you might hear |
|
| 14:04 | Oh yeah, just growing up to log and then run with it or |
|
| 14:08 | like that. That's kind of the behind. Okay um Then of course |
|
| 14:15 | don't forget to sell size differences that here. So uh in late in |
|
| 14:21 | trays of cells generally the biggest So as they kind of get a |
|
| 14:25 | bit bigger that's kind of the the also to then divide. So chromosome |
|
| 14:32 | cell divides so you're gonna have sales kind of the in that duplicating state |
|
| 14:37 | little bit more bigger for that So but then the reverse occurs in |
|
| 14:42 | phase as that becomes kind of a mode. Let's kind of conserve |
|
| 14:48 | becoming a little smaller. Is one those mechanisms uh less material to keep |
|
| 14:53 | with. Um And so kind of let's ride out this storm here. |
|
| 14:58 | this stress occurring here and maybe more become available. You know there is |
|
| 15:04 | some some nutrients do become available here it's it's a source. So if |
|
| 15:12 | let's say they're on the nutrients that in the medium that you made and |
|
| 15:16 | are coming very low, there can to be a slight influx of other |
|
| 15:20 | coming in. What might those be from? Remember? It's surrounded by |
|
| 15:25 | lot of cells right? Dead cells ? Dead cells can actually contribute some |
|
| 15:31 | nutrients to sustain them. So kind cannibalization if you will right there are |
|
| 15:35 | eating each other but as a cell typically license and that stuff is released |
|
| 15:40 | that can actually be nutrients that can them for a bit but not long |
|
| 15:46 | then because not everybody's gonna be satisfied terms of the neutral requirements so it's |
|
| 15:52 | going to reach this tipping point and death increases exponentially. So that's the |
|
| 15:58 | thing to remember that the rate here of course very fast. And so |
|
| 16:03 | will the rate here be fast in phase. And so that's what we'll |
|
| 16:08 | on really monday in that part about killing cells. And how do we |
|
| 16:14 | them? And how can we make go faster? That kind of |
|
| 16:17 | Okay so um okay let's see is any any questions about this? Okay |
|
| 16:27 | okay so let's look at a little about fed batch and bioreactor growth. |
|
| 16:32 | uh fed batch culture. So there see the curve for batch growth. |
|
| 16:37 | remember batch growth you're not really doing with it other than just measuring |
|
| 16:41 | Right? And looking at the Okay and um and that too can |
|
| 16:46 | abuse. What was the use of of getting growth? That's a lot |
|
| 16:49 | uses to that. Right one is . Where is it reached log phase |
|
| 16:53 | is it reached stationary phase? Because are the important points in terms of |
|
| 16:56 | you're doing and studying to know where at for a particular organism. Micro |
|
| 17:03 | Also if you're a uh sometimes you want to you may be at the |
|
| 17:10 | of the maybe you don't want to at the mercy of the bacteria's schedule |
|
| 17:15 | ? And you like not like to in at night and take a sample |
|
| 17:18 | rather wait until the morning. You can also adjust. Right? |
|
| 17:22 | just don't add so many cells at beginning. Have a lower in |
|
| 17:26 | That will kind of stretch out Right? These are just tips I'm |
|
| 17:29 | you right there's gold here. This is stuff you may not want |
|
| 17:33 | your on the job and industry and going to these cells are coming alive |
|
| 17:37 | midnight. I don't want to be . Let me manipulate the conditions of |
|
| 17:41 | growth and get them to be there their best when it's my schedule. |
|
| 17:45 | ? These kind of things. You learn the textbook. Okay so anyway |
|
| 17:50 | trust me I've been up there at and taking samples so I didn't always |
|
| 17:54 | to do that. Um Okay so a question. So back to fed |
|
| 17:59 | . So look at that question. fed batch. Um So generally you |
|
| 18:04 | you can continue to increase cell numbers you do fit back to further the |
|
| 18:10 | of the cells. Right. Especially it's what you want to do. |
|
| 18:15 | typically need lots of cells to do so you may and that again is |
|
| 18:20 | where mid log comes in handy to that because that's a good spot to |
|
| 18:23 | more nutrients. So you then begin feed them more before you get the |
|
| 18:28 | log. So they're still in a really functioning state. Given more selves |
|
| 18:33 | then you literally not have that much a plateau occur. It will keep |
|
| 18:39 | . Okay so um but it will even if you if you're off a |
|
| 18:44 | bit and added during even during stationary they'll begin to kick off again. |
|
| 18:49 | if you don't want to have so of a downtime before they kick in |
|
| 18:53 | can always just do it earlier. But in any case you're getting more |
|
| 18:57 | you're gonna grow more. Okay and number one thing so just go back |
|
| 19:02 | quick to this form. So if doing a Fed batch with M. |
|
| 19:09 | , they're growing at M. I wanna feed them to keep them |
|
| 19:14 | growing. What am I gonna add mixture here? Okay carbon pour in |
|
| 19:24 | carbon. Yeah you don't need to the whole medium. Just add |
|
| 19:30 | Right cause there's gonna be plenty of still available. Okay so given the |
|
| 19:35 | and boom. Right that's that's what feed is the whatever the carbon |
|
| 19:39 | Okay so um so the question here is why not add I say all |
|
| 19:47 | why not add, we're just talking adding glucose, defeat it. Why |
|
| 19:50 | add just all the glucose upfront. . You want to get you want |
|
| 19:55 | get to X number of cells and know it takes 100 g of glucose |
|
| 19:59 | liter. But the media recipe only you to add 10 or 15 g |
|
| 20:05 | liter and you have to feed it . Okay. Why not add all |
|
| 20:11 | of it at the beginning? one those basic chemistry fundamental simple things. |
|
| 20:21 | one? Yes. So the reason you don't add everything at the |
|
| 20:28 | There's it's due to a very basic principle. Yeah. Okay one more |
|
| 20:41 | . Yeah you're on the right It's because you greatly increase the osmolarity |
|
| 20:47 | the salute levels greatly increase if you too much. And so you get |
|
| 20:52 | effect of of um these automatic effects you said becomes too hyper tonic as |
|
| 20:59 | result. And that inhibits the cells from growing. So that's why you |
|
| 21:04 | add everything up front. For that the solute concentrations are off too much |
|
| 21:10 | that it becomes too hyper tonic really the cells so that can prevent them |
|
| 21:15 | growing. So that's why you have use the feed strategy or you grow |
|
| 21:20 | in a bioreactor. Okay let me about that. So think about that |
|
| 21:25 | . So here's a bioreactor. So um uh uh I got a picture |
|
| 21:31 | it here so here's I'll come back the previous slide. So this is |
|
| 21:34 | here's a basic shake flask what you and what you would use in a |
|
| 21:39 | . Okay um And here you of course, back up one |
|
| 21:45 | Here's a bioreactor. When you see a it's a computer controlled uh |
|
| 21:51 | Um you see the different pumps you can pump acid and basin all |
|
| 21:56 | controlled. You set parameters, If it gets below uh 6.5 or |
|
| 22:03 | , you add um base. If gets above 7.3 or something, you |
|
| 22:08 | acid. Right? So you keep in that range. Okay? Um |
|
| 22:13 | can also have a pump to feed a regular feed uh your carbon source |
|
| 22:19 | keep growth going. Um And there's ports to make other types of |
|
| 22:24 | If you're doing some kind of experiments things, it's all this is this |
|
| 22:30 | steel jacket jacketed, which means you water cool water circulating. Because one |
|
| 22:36 | the things that happens when this thing and because you're controlling all the parameters |
|
| 22:42 | even oxygen I mentioned the second, are gonna go like nuts. Like |
|
| 22:48 | . Okay, and lots of cells quickly. And when that happens, |
|
| 22:53 | another basic chemical principle that happens. that? Why? You have to |
|
| 23:00 | it with water heat tremendous heat output the cells are dividing and growing like |
|
| 23:06 | . Especially with this volume. This probably about a I think it's about |
|
| 23:12 | liters, I think uh can get hot. So that can kill |
|
| 23:15 | So the temperature control is very Okay, and then uh let's |
|
| 23:21 | so when you're controlling all these I'll come back to this question a |
|
| 23:26 | . So uh let's just look at thing here. I don't expect you |
|
| 23:30 | know the nuts and bolts diagram of bioreactor. I'm just showing you this |
|
| 23:34 | for you know you gotta take majors there. We'll see this um the |
|
| 23:41 | itself. So here you see the coming in. Okay? Um Of |
|
| 23:47 | we're talking about aerobic organism sort of air. Right and disparage? Er |
|
| 23:53 | so why not just bubble Aaron? are we bubbling in through a spark |
|
| 23:57 | ? Makes it super tiny bubbles. the smaller bubbles of gas are easier |
|
| 24:03 | to symbolize in liquid than our big . Okay so the spars are very |
|
| 24:09 | bubbles. Plus this thing let's call impeller basically like a blade that's create |
|
| 24:15 | , right? Spin. Makes things ? And so that plus that helps |
|
| 24:19 | break up the bubbles even more. that allows the oxygen to quickly cybill |
|
| 24:26 | in the liquid. Okay that makes that's accessible to the cells very |
|
| 24:31 | Okay. And you can even control this whole levels of CO. Two |
|
| 24:36 | in. Um And that's done with um This probe there's an oxygen probe |
|
| 24:42 | ph probe to measure ph oxygen probe measure the levels of oxygen and can |
|
| 24:48 | . So if oxygen levels are going well then add more air and increase |
|
| 24:55 | speed of the mixing going on. ? And that can be done |
|
| 24:59 | computer controlled done automatically. Okay. so your complaint ph you get providing |
|
| 25:06 | much air as it can handle. to um feeding it, right. |
|
| 25:11 | you can imagine themselves are gonna be happy under those conditions, right? |
|
| 25:16 | it results in very rapid growth and of cells very quickly. Okay. |
|
| 25:24 | The uh okay the other thing you see in these really these fermentation is |
|
| 25:31 | of lots of foam. So the of gas being pumped in. I'm |
|
| 25:36 | cripple activity. You can get a of foaming going on the top and |
|
| 25:40 | can kind of be disruptive. So have what's called anti foam. Uh |
|
| 25:45 | kind of helps bring that down. know, you have it when you |
|
| 25:47 | a big like a you're too young drink beer in here but I like |
|
| 25:51 | drink beer and you have a big you have again if you have like |
|
| 25:53 | big fat foam on top. So that kinda helps to break that |
|
| 25:58 | . Okay, so these are things encounter in in in in running these |
|
| 26:03 | which I have um uh and the thing, the whole thing you prepare |
|
| 26:08 | medium, fill it up and you to play the whole thing, that's |
|
| 26:11 | you sterilized. Okay now over this guy you don't have as much |
|
| 26:17 | over. Okay, but you can do, there's something you can |
|
| 26:21 | it just becomes a pain because you've to continue to monitor it every few |
|
| 26:26 | and make adjustments but you can do and so you have something like a |
|
| 26:30 | ph indicator that will turn a So it's getting acid, it turns |
|
| 26:35 | yellow turning basic, it turns red ? And you can go and see |
|
| 26:39 | . Oh my flask is yellow needs be more kind of maybe in between |
|
| 26:43 | orangey color, not yellow. So add some acid to it just you |
|
| 26:48 | with the pipette. Um ah that's you can do that that will promote |
|
| 26:55 | . The other thing here is these these little indentations. Okay, so |
|
| 27:00 | is the last you're used to seeing what you see in chemistry lab which |
|
| 27:03 | a flat bottom. These have a design here, right? This is |
|
| 27:07 | we call baffles is what they Okay, what do you think that |
|
| 27:12 | ? There's a purpose for that? that flask is spinning which it will |
|
| 27:18 | right, you have to mix it so you get air mixed into |
|
| 27:21 | What are the bathroom's gonna do Something. Nothing. Yes. Wild |
|
| 27:32 | hair, guess anything. Yeah. not white but it's it's really easy |
|
| 27:46 | right? Imagine your water, your molecule in here and if it were |
|
| 27:51 | flat compared to having these things, that going to be like? You're |
|
| 27:56 | hit it, create turbulence create more as a result. Okay. And |
|
| 28:02 | you may go really that's gonna make big difference. Trust me, it |
|
| 28:07 | . You do an experiment with a like this versus a flat bottom. |
|
| 28:11 | do see a difference. It grows because it creates more turbulence, turbulence |
|
| 28:16 | more mixing in with 02. So makes a big difference for growing an |
|
| 28:21 | , okay? Because sometimes depending on you end up job you end up |
|
| 28:26 | , that company may not have a lot of money where you can buy |
|
| 28:30 | computer controlled by reactors, right? may be at the mercy of a |
|
| 28:34 | know what you've got on hand and something you can do to improve |
|
| 28:39 | Okay, so better ideas to convince person the company to let's buy a |
|
| 28:45 | controlled by reactor. Okay. Um anyway, so again, for your |
|
| 28:51 | measures this is the kind of things be seeing. Okay, so down |
|
| 28:55 | , if an aerobic bacterium grown in culture is adequately fed, what can |
|
| 29:00 | growth fairly quickly? Key is the work. So what would you have |
|
| 29:10 | do something about very quickly? you have to you have to either |
|
| 29:16 | up the shaker to spin it faster turn up the if you have a |
|
| 29:22 | turn up the level of O to kind of things. So actually becomes |
|
| 29:26 | limiting very quickly in the situation where really controlling the growth and giving it |
|
| 29:32 | it needs, making it nice and , The result is very fast |
|
| 29:36 | but sucking all the auction up and you have to very quickly that will |
|
| 29:41 | out okay. And you know that um you know in a in a |
|
| 29:48 | flask or in a test tube when growing it um you kind of know |
|
| 29:53 | you're in that situation, if you're growth. So you may see a |
|
| 29:59 | used to seeing a pattern like right? But if it's oxygen |
|
| 30:03 | it can very quickly it can do lag exponential, but then kind of |
|
| 30:12 | that it goes quickly. But then it kind of levels off because it's |
|
| 30:17 | oxford limited, That's what kind of to the last level of auction, |
|
| 30:22 | present, Right? So uh e overnight culture, which many of your |
|
| 30:29 | coordinators do for for your labs, chemistry etcetera. That's essentially what happens |
|
| 30:34 | them, you know, in the six hours, they probably get the |
|
| 30:38 | growth. But then after there it's it's kind of linear because they're just |
|
| 30:42 | for auction, but they kind of at that rate. So anyway, |
|
| 30:46 | is none of the stuff I'm gonna you on. But you know, |
|
| 30:50 | to think about, right, Especially you're in the business of growing |
|
| 30:55 | okay. Which I was for a of years. But uh so um |
|
| 31:00 | questions okay, before I went off my tangent? Okay. Um All |
|
| 31:08 | , so that makes it grow. what we're gonna do here is look |
|
| 31:10 | a couple of examples of problems relating there's an equation and you'll be given |
|
| 31:17 | whatever equations you need. There's only really a couple you they're given in |
|
| 31:22 | problem so you don't need to memorize . Okay. But as I've mentioned |
|
| 31:28 | , I think we all know that archaea have the capability of growing very |
|
| 31:34 | . Okay. Under optimal conditions. this concept of generation time, there's |
|
| 31:39 | ways to define it. It can um you know, one way is |
|
| 31:45 | seeing it. Right? So the of one generation, right? The |
|
| 31:48 | to produce a generation cell to divide two more practically. We look at |
|
| 31:54 | in terms of you know what we're these things industrially and otherwise is is |
|
| 31:59 | time for the culture to double take a time point. And then |
|
| 32:03 | see, how long did it take double to get twice? That that's |
|
| 32:06 | that's also generation time. Okay. it doubling time. So all these |
|
| 32:12 | are synonymous. Okay. And so kind of the parameter we look |
|
| 32:17 | You know if we're doing manipulations if looking at the effect of antiseptic or |
|
| 32:23 | on the culture, you may. . How's it affecting growth when I |
|
| 32:27 | a generation time gets longer or is affected or whatever. Okay, so |
|
| 32:33 | ways that um and of course you when you're when you're dealing with cell |
|
| 32:39 | So here's generations, here's number of that equates to when you have such |
|
| 32:45 | wide range of numbers. Okay that over a period of time. You |
|
| 32:50 | of wanted to visualize that better. kind of compress it. So we |
|
| 32:54 | log base 10 to do that and typically what you plot. I'll come |
|
| 32:59 | to that in a second. So a plot. I'm sure you've seen |
|
| 33:02 | before. This is using absorbent spectrum metric measurements to get an optical density |
|
| 33:09 | we convert it to log base 10 you get a video response here. |
|
| 33:15 | so that's that's typical for you again, data whether it sells or |
|
| 33:20 | from the ph scale is also numbers a wide range. A lot of |
|
| 33:25 | base tend to compress that somewhat. the equation basically starts out with this |
|
| 33:32 | . Okay to measure the number of . So this N. T. |
|
| 33:37 | the zero time number cells that your zero is two time beyond their |
|
| 33:46 | Nt how many cells you're having? you start with two cells ends a |
|
| 33:50 | of generations. Okay. It'll end end. And so basic example here |
|
| 33:56 | with two cells. Okay. And is to how many cells that are |
|
| 34:00 | generations to the fourth? 32 These are the kind of problems we're |
|
| 34:04 | do. Okay this is this is pre looping, right We're gonna we're |
|
| 34:08 | manipulate this equation to give us something can better use to do our problems |
|
| 34:15 | . Okay, This is just showing kind of the basics of how to |
|
| 34:17 | this because this only has so much because um you know, you can |
|
| 34:23 | of figure out, okay, if have this member cells here and this |
|
| 34:26 | cells here, you might be able , you know, count using your |
|
| 34:29 | how many generations are in between but can get not very useful very |
|
| 34:34 | So we want to kind of you and set this equation to equal in |
|
| 34:41 | we can calculate indirectly. Alright, number of generations and then we can |
|
| 34:45 | that. Use that number for a of different things and that's what you'll |
|
| 34:50 | in a couple of problems will do . Okay, so right now, |
|
| 34:54 | just showing you kind of the so N zero N T. We're |
|
| 34:57 | see represents the population size at the time points. Okay, Little |
|
| 35:03 | there's always going to be the number generations and then like I said, |
|
| 35:06 | gonna convert this equation to something we better use Okay, so again, |
|
| 35:11 | going to focus on that and basically gonna rely on the log to the |
|
| 35:16 | 10. Right? So we're just to and I don't expect you you |
|
| 35:18 | have to know how to derive this . Ok. I'm just kind of |
|
| 35:23 | you how we get there. So we're just gonna multiply through by |
|
| 35:27 | to the base 10. Okay. then we're gonna focus on this guy |
|
| 35:32 | first. Right? So that converts remember your log to the base tens |
|
| 35:36 | how you can manipulate those. so this is the same as thing |
|
| 35:44 | times like to the base 10 to . Okay. That directly converts |
|
| 35:51 | Okay, so with the rest of , what we want to do is |
|
| 35:55 | set this equation to two. Little . We want little end equal blah |
|
| 36:01 | . Okay so we're gonna take this and put it over here. |
|
| 36:06 | log to the base 10 of N minus log base 10 of N zero |
|
| 36:11 | putting it over there. Okay. then we can finish the manipulation. |
|
| 36:16 | , so n will equal. So this is the same as saying |
|
| 36:27 | It's the same as doing that log the base 10 of N. |
|
| 36:32 | Over N zero. Right? This just that's how logs work. |
|
| 36:36 | Um and then over 00.301. So think of this as kind of the |
|
| 36:41 | the the the exponential growth, Is the 2 to 4 to 4 |
|
| 36:47 | 88 to 16 and so on. that pattern. So kind of think |
|
| 36:50 | that term is representing kind of that . Okay. Is one way to |
|
| 36:56 | about it. So again this is equation which will do the bulk of |
|
| 37:00 | work force. So the other thing is you notice that there's really no |
|
| 37:05 | element in it. Okay. You also represent this simply putting tea in |
|
| 37:11 | equation right? You see it right . Okay. This now we call |
|
| 37:16 | rate constant because of course it's it's useful to have a time element in |
|
| 37:21 | because you wanna know how fast this is growing and uh you know all |
|
| 37:28 | types um our key appropriates have I all all cells have a growth rate |
|
| 37:35 | of some sort you know and that differ of course depending on what they're |
|
| 37:41 | on. Okay. And the cell . Okay. Um but it should |
|
| 37:46 | consistent. So if you grow Coli on nutrient broth And you grow |
|
| 37:52 | under the best conditions, you can the right temperature right? 37° |
|
| 37:58 | Um and you know giving it what wants, right? And so you'll |
|
| 38:03 | a rate constant. And that number be relatively the same every time you |
|
| 38:07 | E. Coli on on and be the same conditions. Right? So |
|
| 38:11 | should be a constant. And then see or maybe if I grow on |
|
| 38:15 | . B. And add something else it or whatever that may change. |
|
| 38:19 | that can give you some insight into what you're trying to do is working |
|
| 38:23 | not working but regardless. Right, here's our equation then Generation time is |
|
| 38:29 | something we should know probably. And K. This term here again, |
|
| 38:34 | just the same equation. But with time element um equals generations. So |
|
| 38:39 | value we calculate that. That's going give us a number of generations. |
|
| 38:43 | now. The K. Has that time. Okay. And so generation |
|
| 38:49 | itself is really just the inverse of . All right. So one over |
|
| 38:55 | . Went over that. So just it around. That gives you generation |
|
| 38:58 | . Right? So that's so this and that one are kind of the |
|
| 39:03 | we're going to be using in these . Okay, so generation time time |
|
| 39:09 | time for generations. Typically it's in is how you express it. And |
|
| 39:14 | and then the this equation to figure a number of generations. Right. |
|
| 39:16 | those are two things we're gonna use you'll be given this information. |
|
| 39:20 | So don't don't have to memorize But you would be helpful to know |
|
| 39:24 | what these terms represent your middle ends begins. Okay. Um All |
|
| 39:30 | So here's a question. Take a at this. Give it a |
|
| 39:36 | So the bacterium that's not a real , I'm sure you realize has a |
|
| 39:43 | time of 40 minutes. Okay, starting with five cells and log |
|
| 39:50 | How many minutes to produce? About cells. Okay, assume all the |
|
| 39:58 | remain viable. Um Okay, so your equation and see what you |
|
| 40:30 | We don't have a calculator. You work with your neighbor or neighbors. |
|
| 40:40 | . I'm sorry. You will have . Yeah. You'll be able to |
|
| 40:44 | a capital for the test. No , but you have one. You |
|
| 40:49 | use your cell phone now. You to have Okay, cheapo handheld |
|
| 40:52 | It's okay. Mhm. Get the on if you don't get it. |
|
| 41:15 | not sure. It's okay. We're go through it blow by blow. |
|
| 41:44 | . Okay, I didn't set the off, so Alright, go |
|
| 41:50 | And I'm gonna give you 10 seconds point something in 765 was a flurry |
|
| 42:05 | . Okay, here we go. . A little over the map, |
|
| 42:13 | little around the map there. There was a consensus of B Let's |
|
| 42:20 | if that's right. Okay. So , so here's our here's the thought |
|
| 42:26 | . So I kind of that's how map it out here. So uh |
|
| 42:30 | zero is five starting with five We're going to 10,000. That's |
|
| 42:34 | N. T. Okay. Generation . Uh that's Mr generation. So |
|
| 42:42 | us 40 minutes per generation. I this sounds really basic the way I'm |
|
| 42:45 | it, but that's the best way have of just having it all |
|
| 42:50 | What's the logical process here. Ah so you're in a countless number |
|
| 42:54 | generations produced, going from 5 to . Use this value to multiply by |
|
| 43:00 | time to yield minutes. It will out and you'll have minutes. |
|
| 43:04 | so let's go this way. All . So here's where we start. |
|
| 43:10 | long base 10, 10,000 over Right. N. T over N |
|
| 43:14 | . Do have a .301. That us about 11 generations. And then |
|
| 43:22 | generation time is 40 minutes per generation 11 440 minutes Or a little over |
|
| 43:30 | hours. Okay. Okay. So it was d this is not |
|
| 43:40 | . But that's the stop process. , so everybody's good with that. |
|
| 43:47 | , um again uh the the problem also has this one in there as |
|
| 43:55 | . So you can look through it . You need to. Okay, |
|
| 44:00 | the next problem is using the same obviously, but it's asking for something |
|
| 44:07 | little bit different. I think we're for the generation time in the next |
|
| 44:11 | . Okay. So you're counseling a time Of this bacterium if 900 cells |
|
| 44:20 | 15 hours produced over three million. . So there are the different |
|
| 44:29 | So looking for the generation time. . So why is sitting there deciphering |
|
| 44:49 | problem? I will I just got text from colleagues. So this is |
|
| 44:56 | from Merck Merck is a Uh I them as a chemical company but they |
|
| 45:03 | do biology stuff. And so they're interns for summer 2023. So I |
|
| 45:10 | post this on blackboard if you're Okay, so make a note of |
|
| 45:28 | . The other thing. Let me while you're figuring this out. Uh |
|
| 45:34 | lab is crazy lab today and today yesterday. Simple staying microscope. |
|
| 45:42 | So it would behoove yourself to make microscope your you know what? |
|
| 45:48 | Which means become efficient with it. microscopes are all Service a month |
|
| 45:57 | spent something $1,000 on their all in order. So if you don't see |
|
| 46:04 | it's your eyes that aren't working Okay. So become efficient at |
|
| 46:10 | Okay is my best advice. Oh and uh work gloves? You |
|
| 46:19 | have pink hands and purple hands and kinds of colors on your hands. |
|
| 46:24 | . All right, counting down Okay. Here we go, stragglers |
|
| 46:39 | now. Okay let's see. consensus says B. Let's see. |
|
| 46:49 | . Alright. So there's our basics zero in t terms equation number generations |
|
| 46:59 | so plug it in To get generation , right time, 15 hours, |
|
| 47:04 | minutes divided by that many generations, . So B. B. As |
|
| 47:09 | boy. That's correct. So again we're gonna move on from this but |
|
| 47:14 | know there's there's a problem set of five including these two. So if |
|
| 47:19 | need to look at the kind of they're all laid out in the same |
|
| 47:22 | kind of giving you the thought process the logic behind it. Okay. |
|
| 47:26 | mean you obviously have the choices going it. I don't know how to |
|
| 47:29 | it. I'm not gonna worry about because we have two problems on the |
|
| 47:32 | . Right? That's one approach. . But you know, it's not |
|
| 47:37 | hard. I don't think it's just setting it up in the logic. |
|
| 47:41 | . Um Many questions. Okay. alright, now the last part of |
|
| 47:50 | relates to two phenomena. Right? again, here's another question. It's |
|
| 47:54 | math. All right, believe me was never great at math. |
|
| 48:02 | you know I I that's why I to do with all that kind of |
|
| 48:04 | basic way and map it all I made season calculus one or |
|
| 48:08 | so Mhm. Uh Actually made season chemistry too, but I survived. |
|
| 48:21 | I'm actually end up teaching organic chemistry in my metabolism. How crazy is |
|
| 48:26 | ? Right? Probably not any good it. Right, I'm average at |
|
| 48:33 | . Um All right. All I think that's a pretty basic |
|
| 48:44 | I'm sure everybody knows this one. . You do, Huh? |
|
| 48:57 | We'll see if you're right trying to everybody else. You're right. A |
|
| 49:08 | mm. Okay. 21 stragglers jump . What's that and the answer? |
|
| 49:22 | goodness ! You really are taking advantage . Its only two points. I |
|
| 49:26 | it whether it's right or wrong, don't care. All right. Don't |
|
| 49:29 | that. Okay. Um Who picked . Are you? Right. Are |
|
| 49:39 | wrong? Yes, you're wrong. It's B. And those sports |
|
| 49:48 | Okay, so um this is not clicker question, that one fits what |
|
| 50:00 | biofilm formation. Okay? And as it's the opposite it's nutrients. It's |
|
| 50:06 | that plus lots of nutrients equals Okay so surface attachment, lots of |
|
| 50:15 | , biofilm, lack of nutrients or stress. Let's make an indoor |
|
| 50:22 | Okay? And I'll resist the lack nutrients and the radiation bombarding me and |
|
| 50:30 | come back to life at some point the road. Right? That's the |
|
| 50:33 | of sport. Okay? Um So we'll talk about biofilms. Um So |
|
| 50:42 | the biofilm of course represents, this going clockwise 12 o'clock is the beginning |
|
| 50:50 | the full blown biofilm at nine Okay. So obviously represents a massive |
|
| 50:57 | of growth, Both initially like in dimensions. If you will then here |
|
| 51:05 | almost like a volcano, you coming out of the ground, |
|
| 51:08 | You can see the three dimensionality of . So it becomes flat and then |
|
| 51:12 | upward. Okay, representing of course of cells. Okay, so and |
|
| 51:19 | on the way here uh you know around 11 25 I took a picture |
|
| 51:26 | a couple of biofilms on campus. that that's over uh you walk right |
|
| 51:33 | that door, it's right in front you on that wall. Okay so |
|
| 51:38 | see so there was a wooden board here and somebody moved it but that |
|
| 51:44 | really had that you can really see but if you look right in the |
|
| 51:48 | that you can see that of course a window on STL building. So |
|
| 51:53 | a and there's always precipitation running down . Uh So that kind of feeds |
|
| 51:59 | biofilm, there's this this is always as you can tell. So that's |
|
| 52:03 | going along quite nicely. Okay, um so yeah, lots lots of |
|
| 52:10 | . The and of course in a context, whereas these are fairly common |
|
| 52:16 | see these in various places. You see them on water as well called |
|
| 52:21 | mats of growth can occur various rocks and things and it's fairly common |
|
| 52:27 | nature. But the end, you , and of course in human structures |
|
| 52:32 | sculptures, you can also see them in other places. But from a |
|
| 52:37 | standpoint they can be quite serious. , so this is a catheter. |
|
| 52:43 | any kind of medical devices like a tube called intubation, breathing tube, |
|
| 52:51 | the nasal tubes, not so much , but certainly things that comes in |
|
| 52:58 | packaging, but you then put in on the body. And so when |
|
| 53:03 | care workers mishandle those because your hands staff and mucous membranes and things right |
|
| 53:09 | they can become contaminated. And so can sort of contaminated catheter into somebody |
|
| 53:13 | then that biofilm can grow and grow a biofilm and coat that device. |
|
| 53:19 | can then of course break off and get to other parts of the body |
|
| 53:24 | can be quite serious to deal with that very thick film of growth restrict |
|
| 53:30 | movement of antibiotics that are trying to it. And so that's what really |
|
| 53:33 | it problematic. And so you have biofilm infection that takes that can take |
|
| 53:39 | , weeks if not months of treatment really deal with it. So, |
|
| 53:44 | these these aren't as uncommon as you in the hospital setting. Okay. |
|
| 53:52 | , so nature of a biofilm. let's focus on that. Again, |
|
| 53:56 | biofilm examples, there's somebody's teeth. right as black, but that's been |
|
| 54:04 | . So they put some kind of kind of diet to kind of enhance |
|
| 54:07 | . Right? Normally it wouldn't be it wouldn't look like that normally. |
|
| 54:11 | you would feel it because you have sticky feeling you have on your |
|
| 54:14 | Right? This is uh I've dealt this type before. This is what |
|
| 54:18 | see in a restaurant. The dispensers you get your soda the tubing that |
|
| 54:25 | full of syrup. Right? That to the, to the dispenser. |
|
| 54:30 | in that environment you can form these polymers are really in there and code |
|
| 54:35 | the block up the tubing. Call it the sugar snake. So |
|
| 54:42 | right. So the there are several , but the main thing is the |
|
| 54:47 | , our surface attachment and nutrient Okay. And the other thing is |
|
| 54:53 | information is not a random process of , let's grow a lot. And |
|
| 55:00 | we all come together and there we . No, okay, it's a |
|
| 55:05 | specific phenomenon. Not all bacteria can biofilms. Those that do have the |
|
| 55:12 | that enable them to do it. , it's an orchestrated process. So |
|
| 55:16 | like it's a chemical signals between cells um that then that then trigger the |
|
| 55:26 | of the biofilm. So it's by from being a random process. |
|
| 55:31 | so the the coli 0157 always mentioned chipotle E coli. Right. That |
|
| 55:39 | is a biofilm former. Okay. uh the only the mutants of that |
|
| 55:46 | that lack don't form aren't pathogenic, the ones that have the friendly. |
|
| 55:52 | do. Ok, so friend brad an important thing because attachment. |
|
| 55:56 | So here's the kind of the five process. Right? So initiation. |
|
| 56:01 | so we differentiate between cells that are swimming, the colors plank, tonic |
|
| 56:07 | those that are called stickers. they stick to the surface. |
|
| 56:12 | that's these guys. Right. So why tonic cells are kind of the |
|
| 56:18 | if you want scouting out an area form a biofilm which is predicated on |
|
| 56:24 | a nutrient source present. Okay. having a favorable environment. Okay, |
|
| 56:28 | that's kind of what their job And then if there is a favorable |
|
| 56:32 | then they develop into the swimmers into . Okay pot stickers, not pot |
|
| 56:39 | . Um The so they basically lose flagellum and then the finsbury I take |
|
| 56:46 | and promote adhesion. Okay then, maturation involves kind of building the glue |
|
| 56:55 | gonna hold everything together and that's the place aka right? So they so |
|
| 56:59 | will secrete that um that will enable to kind of form the biofilm. |
|
| 57:05 | then maintain the biofilm requires of course supply of nutrients. And then as |
|
| 57:11 | thing gets massive, you have to of create a situation where everybody can |
|
| 57:18 | fed as best as possible. And why you see biofilm towers and you'll |
|
| 57:23 | holds so that nutrients can flow through everybody, I'll show you a picture |
|
| 57:28 | in a second. Then then of most of these don't last forever. |
|
| 57:33 | there's a period of time when nutrients out, right? That picture of |
|
| 57:37 | drain pipe, you know if if water supply is cut off. All |
|
| 57:42 | , and stop then that thing of is going to die eventually there's no |
|
| 57:45 | feeding it and you can get this . All right, so it breaks |
|
| 57:49 | and again, this is a nutrient phenomenon. It's got to be a |
|
| 57:54 | of nutrients and you're not going to all these cells dividing and making the |
|
| 58:01 | . So then they revert back to swimmer state because that's how they can |
|
| 58:03 | around and find another spot to make bio. Okay, so in terms |
|
| 58:08 | what it looks like, basic terms , here's where playing tonic cells and |
|
| 58:14 | are communicating, right? there's chemical going on. Okay so you may |
|
| 58:20 | types that are not yet in the mode. Okay. Kind of on |
|
| 58:25 | surface you may see that twitching motility going on. Okay. Um but |
|
| 58:31 | signals are being produced and there there's threshold. So the quorum sensing thing |
|
| 58:39 | if you're familiar with parliamentary procedures and , if they have a minimum number |
|
| 58:44 | people to hold the meeting kind of . So if you have a number |
|
| 58:49 | enough cells are present okay then enough is produced and that's a signal that |
|
| 58:55 | okay there's enough cells there. So you have presumably if you reach a |
|
| 59:00 | that means it's a favorable environment and good enough then trigger the process. |
|
| 59:07 | if not then cells won't accumulate and a signal for okay this is maybe |
|
| 59:12 | good place to form a biofilm. not enough nutrients here. If there |
|
| 59:16 | then you'll reach the threshold level and you'll promote the biofilm formation which then |
|
| 59:22 | the exact policy accurate production. And um and then growth growth of |
|
| 59:28 | of course on the surface then begins go up right so three D. |
|
| 59:31 | dimensionally and then in order to kind be able to to adequately feed everybody |
|
| 59:39 | here reckons there's gonna be several layers . Right one way to do that |
|
| 59:44 | to create holes in the in the the in the biofilm towers so that |
|
| 59:49 | can flow in and around. But , if it's not enough to sustain |
|
| 59:54 | , okay then you'll get breaking off biofilm cells will then revert back to |
|
| 60:00 | multiple stage and seek a different Okay? But again, if you |
|
| 60:06 | a flow of nutrients going through they can sustain that thing for quite |
|
| 60:10 | time. Right? That thing over that took a picture of has been |
|
| 60:13 | for since last semester probably even longer that. Okay, so um it |
|
| 60:21 | depends. So again it's enough nutrients feed everybody then it'll keep going. |
|
| 60:27 | . Um Any questions about Okay. , the main effect from that is |
|
| 60:41 | that in the restaurant where it's you'll notice odors occurring. That's the |
|
| 60:48 | clue that something is not right. when that happens then people are called |
|
| 60:52 | to take care of up to that . And even the spigot where it |
|
| 60:58 | out will be very kind of sticky not very good flow. And so |
|
| 61:03 | those begin to happen is when something be done about it because I, |
|
| 61:08 | experience, I haven't seen anybody get , but it doesn't mean that people |
|
| 61:14 | get like an upset stomach or something that. They just didn't report |
|
| 61:18 | So, but because what we actually to fix it was, you know |
|
| 61:22 | things you have in the in a , in the men's room on the |
|
| 61:27 | dispenser thingy that goes and scores out of the material that we put one |
|
| 61:32 | those in by the tubing and it actually escort this enzyme that would break |
|
| 61:36 | the sugar. Think so. But don't, people, people that own |
|
| 61:42 | restaurant or run the restaurant, I want to deal with problems unless the |
|
| 61:46 | are going, hey what's going And of course they smelled the |
|
| 61:50 | Then you have to come in and with it. Right. They would |
|
| 61:52 | preventative done it before. Right then wouldn't have the issue at all. |
|
| 61:56 | but anyway, that's that answer the . Okay else. Okay. |
|
| 62:03 | So alright and those spores. So those spores I said these guys can |
|
| 62:12 | for a long time. So here evidence of that. So the top |
|
| 62:17 | is a 250 million years old sample um It's the Ancient Sea Salt Beneath |
|
| 62:25 | New Mexico. It's like a sedimentary . Um but you see I forget |
|
| 62:34 | picture, I can't remember which picture which description but doesn't matter down below |
|
| 62:38 | million year old bacteria found in And so the point being they were |
|
| 62:45 | . And we also see these things there's no reports of ancient Egyptian |
|
| 62:52 | So the confidence of pharaohs and things buried in. They've opened those things |
|
| 62:56 | and found in those sports in there well and revived them. But time |
|
| 63:01 | . These are certainly much older than those would be. And so the |
|
| 63:05 | of the sports here are shown by cells containing the white blobs. So |
|
| 63:12 | right here are your in those sports . That these lots of them in |
|
| 63:24 | actually. And you will see in four forming type, you're gonna see |
|
| 63:29 | cross section of forms. You're going see types that are this is actually |
|
| 63:33 | cell containing in those four. Then also see just free call free in |
|
| 63:38 | pores like this and something like which would be just completely just what |
|
| 63:43 | call vegetative cell not making it in four. So you always see proportions |
|
| 63:48 | all three in any in any any of one of these types. And |
|
| 63:54 | two types of any sport formers. I think I mentioned this in the |
|
| 64:01 | of Tyndall tyndall pasture back then. So spores just the words term sport |
|
| 64:12 | are widespread across all domains. fungi produce spores. Um uh there's |
|
| 64:20 | dormant forms. So what's common of ? Are there dormant forms? Think |
|
| 64:26 | them as a seed kind of And um assist as another type of proto |
|
| 64:32 | can form cysts. Um to assist spore. These are all just kind |
|
| 64:37 | dormant forms. Think of them as that under my conditions they'll reproduce. |
|
| 64:43 | , so now the endo spore is whole other level. Okay. |
|
| 64:50 | these other types are somewhat resistant. , but nothing not even close to |
|
| 64:57 | end those four is. Okay, it has that unique kind of really |
|
| 65:01 | coat that enables it to handle, know, radiation to handle, you |
|
| 65:07 | , not just one boiling will typically them. Okay. Um extremes of |
|
| 65:14 | etcetera. So they're very resistant. . And the two groups are both |
|
| 65:19 | domain bacteria bacillus and clostridium bacillus for most part are fairly benign, just |
|
| 65:25 | dwelling organisms. They're both soil bacillus and Clostridium clostridium is the one |
|
| 65:30 | has the number of pathogens in Okay. You know of tetanus and |
|
| 65:36 | of course, uh their toxin producers that group. Okay. Um gas |
|
| 65:44 | basically the it was a common cause death, you know, for the |
|
| 65:48 | time. In terms of military a wound would occur, dirt in |
|
| 65:55 | wound, couldn't clean it. And the bacteria grow toxin produced and that |
|
| 66:00 | actually killed the tissue. And so gangrene was very common uh for the |
|
| 66:07 | time in terms of battlefield wounds and people dying from them. Um but |
|
| 66:12 | , so the you know, they're in those performers metabolically quite different. |
|
| 66:18 | are an Arabs they don't use oxygen does. Okay. And so um |
|
| 66:26 | we'll talk more about clostridium later in semester in the context of diseases, |
|
| 66:32 | the sport process of like biofilm Was it was a orchestrated process. |
|
| 66:41 | , to a speculation. So it a lot of genes And it's not |
|
| 66:46 | it's not a trivial thing to Right? And so um it takes |
|
| 66:52 | while to do it here. You eight hours can be up to 12 |
|
| 66:56 | depending on and again you're gonna see not it's not a if if they're |
|
| 67:01 | make in those spores that all sales making in the sports all at once |
|
| 67:05 | the same time. Okay. It's continuum. Right? That's why you're |
|
| 67:09 | to see a proportion of types. . Those forming the sport, those |
|
| 67:14 | beginning the process, those that haven't yet. Okay. Um And in |
|
| 67:21 | of the things that distinguishes um in poor formation is it's it involves replication |
|
| 67:28 | D. N. A. Step And step two is to compartmentalize that |
|
| 67:34 | forming cell. We're gonna make two . One compartment in those four |
|
| 67:39 | the other ones surrounding it, the compartment surrounding it is kind of directing |
|
| 67:45 | events of the process. Okay. eventually that bigger compartment that's directing things |
|
| 67:52 | disintegrate and go away. And you're with the mature maturing finally mature endospore |
|
| 67:59 | then becomes its own thing. And so that's what we refer to |
|
| 68:03 | the mother cell. And the fourth . Right? So the mother cell |
|
| 68:07 | the the one directing the events, ? That of course means producing proteins |
|
| 68:14 | that that are involved in in turning two different genes at different times of |
|
| 68:19 | formation. Okay. And so the for is kind of where is receiving |
|
| 68:23 | instructions and is becoming the sport. . And so when we look at |
|
| 68:30 | uh so this is just to reiterate different types. You see um a |
|
| 68:37 | section. So of course if this is is nearing the end then everything |
|
| 68:43 | formed in those spores, the proportion free and those spores will be much |
|
| 68:48 | . Right? There only be a of types that look like that completely |
|
| 68:55 | . So the proportions will differ and proportions will tell you where they're at |
|
| 69:00 | the process. Is everybody becoming in four yet? They're gonna see tons |
|
| 69:04 | these free sports. Okay. If then you're gonna be somewhere in |
|
| 69:09 | Right? If it's not really forming the sports at all, You're only |
|
| 69:13 | to see a few. So the proportions you see under the microscope |
|
| 69:19 | how far along they are, if are at all. Okay. So |
|
| 69:25 | in a culture where you're not even to induce speculation, you'll see a |
|
| 69:31 | in there because all cells are kind on their own timetable in a |
|
| 69:36 | Okay, So um and don't worry the descriptors here, but um you |
|
| 69:45 | identify spores species that different species by sport. They form that where it's |
|
| 69:52 | middle And is it swell up the ? These are ways to identify |
|
| 69:57 | Okay. And so the process Okay relies on replicating the chromosome forming |
|
| 70:07 | two compartments. Okay. And here's mother's cell. Here's your 4th |
|
| 70:12 | So there's there's proteins being regulation of turning on genes. Those kind of |
|
| 70:19 | are being passed from mothers health to for and eventually the mother so kind |
|
| 70:25 | engulfs it. And that's the process making a double membrane. Right? |
|
| 70:31 | what the beginnings of that really thick coat. Okay then the D. |
|
| 70:37 | . A. And the mother. disintegrates. Okay. And we deposit |
|
| 70:42 | chemicals di piccoli like acid and calcium serves to kind of strengthen as |
|
| 70:48 | Peptidoglycan is formed in there. So can you have these chemicals that serves |
|
| 70:53 | strengthen the sport coat. Draw out of the water. Right? Kind |
|
| 70:58 | dry it out a little bit. completely. And that serves to make |
|
| 71:02 | highly resistant form. Okay. And eventually the free sport. Okay and |
|
| 71:10 | this could hang around for a long as we saw. But like a |
|
| 71:15 | you just put it in soil and water and it grows you just give |
|
| 71:18 | the right conditions and it will it germinate into a viable cells and cells |
|
| 71:24 | they'll divide and and the spores Okay, now there may be a |
|
| 71:29 | where maybe some something adverse happened to end of those four and maybe you |
|
| 71:34 | if you have a handful of maybe not all are able to survive |
|
| 71:38 | certainly I would guess that there will a few that will okay, but |
|
| 71:42 | the right conditions will revive it and , it's now back to a full |
|
| 71:46 | vegetative self. Right? So the cell itself just real quick is I |
|
| 71:52 | that kind of the the normal functioning right? Under happy conditions. That's |
|
| 71:58 | vegetative cells when something begins to happen them stress or other than they can |
|
| 72:04 | the end those four and be in process and so they can be in |
|
| 72:07 | middle of it, right, vegetative within those four until they get to |
|
| 72:11 | state. Okay? So, but this kind of state here they're kind |
|
| 72:16 | that's the normal functioning south form the state. Okay? Just like you |
|
| 72:22 | there or in a vegetative state. , no, that's not quite |
|
| 72:25 | That's not right. Maybe you I used to be like, I |
|
| 72:30 | sometimes. But anyway, so any , folks, so we'll finish this |
|
| 72:35 | on Tuesday, So have a good |
|
