Tasty Microbes?

[QDragon Leet]

I'm determined to get back into this. This idea is going to be mostly theoretical but we could maybe make some progress.

Any Asimov fans in the house? Well in that science fiction universe the majority of food is made from highly engineered and processed yeast (among other microorganisms)

Seems like a great idea to me! My initial idea was yeast that produces a variety of proteins and fats found in bovine skeletal muscle tissue. Obviously that isn't a starting point, and might not even work.

So to begin... any genes that make a particular flavorful proteins? any proteins to be removed from yeast to make it more palatable? other modifications that would help?

looking forward to your ideas 

[Patrik D'haeseleer]

Yeast extract - autolysed or hydrolyzed -  is often used as a substitute for bouillon. So flavor-wise, you're already doing pretty well. You may be able to make it even more beefy by expressing hemoglobin. Or perhaps actin and myosin for a more "tastes like chicken" experience?

Texture can probabaly be significantly improved by extruding it at temperature, in the same way that Textured Vegetable Protein is made.

[QDragon Leet]

That's what i was thinking but didn't consider hemoglobin. I've even got bovine skeletal muscle myosin bookmarked from an online database.

When yeast is processed to substitute bouillon, what is destroyed and what is purified? Give me the name of this product and i'll look it up.

Was also considering a separate strain to produce certain bovine fats, thoughts? Like mix the protein and fat strains during processing to create different leannesses of "beef".

[Jeswin]

On Sun, Jan 20, 2013 at 3:09 AM, QDragon Leet <dr.qd...@gmail.com> wrote:
> Was also considering a separate strain to produce certain bovine fats,
> thoughts? Like mix the protein and fat strains during processing to create
> different leannesses of "beef".
>

Make sure you don't have to process your products with ammonia or it
may go the way of "pink slime"

[Mega]

Hi,

there is / was an IGEM team producing banana flavour in E.Coli and yeast. (With one idea, producing banana bread without using bananas :D )


Here's the link:
http://openwetware.org/wiki/IGEM:MIT/2006/Blurb

"

Future work

In the future, we envision doing the following ...

1. Porting the biosynthetic device that synthesizes isoamyl acetate to yeast to make banana bread. "
   

[QDragon Leet]

i'll ensure i make the highest quality of extruded meat substitute :P

so straight yeast would be safe to eat eh? if not very tasty

[Patrik D'haeseleer]

On Sunday, January 20, 2013 9:41:38 AM UTC-8, QDragon Leet wrote:

i'll ensure i make the highest quality of extruded meat substitute :P

so straight yeast would be safe to eat eh? if not very tasty

Oh, yeast by itself is definitely safe to eat. You used to be able to buy a chunk of fresh yeast for breadmaking. Looks kinda like a brown-greyish clay and tastes very bland, if I remember correctly - not "meaty" at all. You might still be able to find fresh yeast in a health food store, if you want to do some experimentation. Wonder what a slice of deep fried yeast would taste like...

[QDragon Leet]

i'll avoid tasting until i'm actually modifying some yeast

i'm sure deep-fried it couldn't be much worse than tofu

[Eugen Leitl]

On Sun, Jan 20, 2013 at 10:47:52PM -0800, Patrik D'haeseleer wrote:

> Oh, yeast by itself is definitely safe to eat. You used to be able to buy a
> chunk of fresh yeast for breadmaking. Looks kinda like a brown-greyish clay
> and tastes very bland, if I remember correctly - not "meaty" at all. You
> might still be able to find fresh yeast in a health food store, if you want
> to do some experimentation. Wonder what a slice of deep fried yeast would
> taste like...

Everyone's aware of http://en.wikipedia.org/wiki/Marmite , right?

[Jeswin]

On Mon, Jan 21, 2013 at 6:48 AM, Eugen Leitl <eu...@leitl.org> wrote:
>
> Everyone's aware of http://en.wikipedia.org/wiki/Marmite , right?
>

Just read the wikipedia part of how it's made. Looks like they lyse
the yeast; sieve out the cell walls; and collect the cell's internal
fluids and structures.

So I guess, you can have yeast express certain amino acids and collect
them. Meat-flavored spread, anyone?

[QDragon Leet]

i'll read up on it but i'm sure highly engineered yeast could be processed into a more solid form. My concern is making sure it wouldn't taste like marmite lol

[Jonathan Cline]

If you engineer yeast or lacto b. or tempeh's Rhizopus oligosporus to produce B-12, you might win a Nobel Prize.

-- 
## Jonathan Cline
## jcl...@ieee.org
## Mobile: +1-805-617-0223
########################

[QDragon Leet]

good idea! always wanted 1 of those

[Patrik D'haeseleer]

On Monday, January 21, 2013 3:48:29 AM UTC-8, eleitl wrote:

Everyone's aware of http://en.wikipedia.org/wiki/Marmite , right?

Yes exactly. Except that Marmite tastes horrible because of all the other crap they add, including tons of salt. However, I've had bouillon cubes made from yeast extract that made for a very passable beef broth substitute.

[QDragon Leet]

Should i just search yeast bouillon?

[Patrik D'haeseleer]

On Tuesday, January 22, 2013 9:24:18 AM UTC-8, QDragon Leet wrote:

Should i just search yeast bouillon?

I'd look into methods to autolyze or hydrolyze yeast. In the manufacture of yeast extract, usually the residual insoluble material (cell walls etc.) is thrown out, but you'd probably want to keep that for nutritional purposes.

[QDragon Leet]

thanks i've got my night reading now 

[QDragon Leet]

seems like hydrolyzing would be better for my purposes, seeing as i don't want the inserted proteins broken down 

[Eugen Leitl]

On Tue, Jan 22, 2013 at 08:55:30PM -0800, QDragon Leet wrote:
> seems like hydrolyzing would be better for my purposes, seeing as i don't
> want the inserted proteins broken down

If you hydrolyze with acid, then neutralize, you will get a salty product.

[QDragon Leet]

how about some kind of heat/enzyme combination?

[Patrik D'haeseleer]

On Tuesday, January 22, 2013 11:40:06 PM UTC-8, QDragon Leet wrote:

how about some kind of heat/enzyme combination?

Yes - sounds like autolysis is typically induced by salt or a heat shock, followed by endogenous enzymes breaking down some of the cellular content. Hydrolysis is typically done by adding exogenous enzymes to break down the cells and proteins.

Breaking down the proteins to peptides and free amino acids may be essential for the meaty "umami" flavor, similar to MSG. So you don't really want to inhibit all protein breakdown. But different proteins will presumably result in a different flavor profile.

[QDragon Leet]

True, perhaps a mix then? certain added proteins may not handle heat well so some sort of strong lipase? mixed with completely broken down yeast until the flavor is right 

[Cathal Garvey (Phone)]

Chitinase plus heat. If you autolyse/hydrolyse your proteins, you'll just end up with a homogenous soup of aminos, whereas you probably want the colour/tang of myoglobin, the texture of collagen, etc.

--
Sent from my Android phone with K-9 Mail. Please excuse my brevity.

[QDragon Leet]

Exactly, but is it possible for just chitinase to work? Again as part of the mix i may not want to expose certain bovine proteins to heat (or much heat) That way it could be cooked similar to real meat, and i like my steak rare :P

[Jeswin]

On Wed, Jan 23, 2013 at 12:38 PM, QDragon Leet <dr.qd...@gmail.com> wrote:
> Exactly, but is it possible for just chitinase to work? Again as part of the
> mix i may not want to expose certain bovine proteins to heat (or much heat)

why not extract those proteins out first and heat the other stuff?
Then mix the proteins back in?

[QDragon Leet]

how would i do that? that's why i was thinking an enzyme to just brake down the cell membrane

have 1 strain that can be heated and 1 that can't, begin processing separately then mix near the end