Enzymes of Kombucha

welcome to kombucha cam Academy my name is John if you're new here and our goal with kombucha chem Academy is to demystify all of the chemistry

associated with kombucha and kombucha Brewing so welcome um the topic of today's um presentation is going to be

enzymes in Kombucha Brewing so an enzyme more or less is a biological catalyst and it's enzymes that essentially control regulate and move along all of

the various chemical reactions that happen in Kombucha Brewing one thing to remember is that the yeast and the bacteria that are utilized in the Brewing process are really just little

chemical factories and it's the enzymes that are essentially the workers in those factories that cause the chemicals to be generated in a very efficient manner all right so as a biological

catalyst what is it that an enzyme really does we have to back off and look at the definition of a catalyst by itself so a catalyst is going to be a

chemical agent that speeds up any given chemical reaction but doesn't get used up in the reaction another way of stating this is that the enzyme itself

does not get used up but rather gets regenerated at some point during the mechanism of the reaction so to better understand the

activity of enzymes in Kombucha brewing and fermentation it's a good idea to do a quick review of the actual fermentation process as related to

kombucha Brewing so normally when we Brew kombucha we're going to start out with a disaccharide such as sucros simple table sugar and we can think of

sucrose as essentially a glucose molecule bonded to a fructose molecule that's why we call it a disaccharide It's a combination of two simple sugars

now what ends up happening here in the initial stages of the process is that the yeast itself will secrete an enzyme called

invertase and the job of the invertase is to actually break that chemical bond that exists between the glucose and the fructose to make the sucrose so we see

as the products of that enzyme reaction we get the two simple sugars we have glucose here and fructose as well now the reason why we need to make those

simple sugars thanks to that um enzymatic reaction is that the bacteria and the yeast require those simple sugars themselves as food sources to

continue the fermentation process in other words yeast and bacteria cannot process and utilize sucrose by itself we have to cleave the sucrose into the

glucose and the fructose now once we generate those two simple sugars there are a number of other enzyme driven Pathways that we can rely upon for

example glucose ose can be um utilized by the bacteria in another enzymatic reaction to form cellulose which is the material that forms the pelic that we

see forming on top of the kombucha brw um in another pathway these same bacteria can also generate gluconic acid so that's one of the um acids that we

ultimately um taste in our final product of Kucha as far as the fructose goes that's another important component of our fermentation process um bacteria of

course can um take that fructose as well as some ethyl alcohol that comes about from the fermentation process that continues to happen is facilitated by

the yeast by way of its own enzymatic reactions the bacteria can utilize that ethanol as well as the fructose to generate the other um simple organic

acid that we find in Kombucha which would be acetic acid so the combination of these bacterial and yeast reactions here all driven by enzymes ultimately

give us that concoction of chemicals um that we ultimately end up with to give us a good flavored kombucha base so to better understand how an

individual enzyme Works let's look at one specific example of course as I mentioned before in Kombucha Brewing there are many many different enzymatically driven reactions that

ultimately result in our finish Brew however let's take a look at the inverte step because that's the first step required for us to make Kucha because again what we're doing here is we're

breaking down sucrose into glucose and fructose those simple sugars that are directly utilized by the yeast and bacteria to make the magic happen all

right so how does intaste work well it works like any other enzyme wood and to be specific about this we call this the lock and key model so let's let think

about how a lock and a key work together so the idea here is that we have a lock that we want to um open for example and to do that what we have to do is to insert a very specific key into that

lock so we all know that we can't just put any key into a lock and get that lock unlocked that's just not going to happen we have to have a very specifically cut key to make that happen

Okay so enzymes work in a very similar sort of fashion so if we take a look at the structure of an enzyme as we would find it for example in a kombucha ferment what we're going to find is that

it's going to be a very complex globular pro protein so basically it has a very complex three-dimensional structure um in that water-based environment all

right so inside of this enzyme we have what's called a cleft so that's going to be a little indent in there that has a very specific shape okay pretty much like the insert of a lock that the key

goes into so what ends up happening is the substrate which is the um chemical reagent that we want the enzyme to act upon in our case

sucrose that is shaped in such a way that it can fit beautifully and precisely into that CFT okay so one thing about enzymes is not only do they

speed up reactions but they also give us a tremendous amount of specificity just like a key going into a lock so not just any substrate can fit into that Clift

and have a reaction occur upon it only sucrose can fit in there just like a very specific key will fit into a very specific lock all right so what ends up

happening is the sucrose Works its way into that CFT and then there are some little shape changes that occur which we call confirmational changes once we form

that enzyme substrate complex which is sort of that intermediate version where now the magic is happening here and the reaction occurs where ultimately that

Bond between the glucose and the fructose which makes up the sucrose can be broken and ultimately then that enzyme substrate complex breaks back

apart yielding the individual products which are glucose and fructose and an enzyme of course is a catalyst because what did we say about catalysts well catalysts get regenerated during the

course of the reaction so they're then ready to be utilized again and that's exactly what happens we see that once the glucose and the fructose are spit back out uh we regenerate the enzyme

again and it's ready to take on another sucrose molecule so keep in mind this is the basic mechanism by which enzyme reactions occur and there can be many

many many of these occurring inside of the kombucha reaction and again all of these reactions are meant to um be moved along very efficieny very efficiently by

the enzyme we also rely tremendously upon the degree of Regulation associated with the specificity of the enzyme so this is ultimately a very very finely

tuned series of biochemical reactions that again make kombucha kombucha all right so this ends the presentation we certainly hope that you've enjoyed it and learned something

about enzymes and kombucha brewing and we hope to see you again soon [Music]