Engineered yeast for converting plastic and biomass compounds to food additives

To make a fuel or food or other stuff out of it you need to define the microbes set(mixture). Almost every study claiming plastic to X follows hybrid pattern, they break the polymer into smaller molecules by depolymerization either thermally/chemically for polyolefins like PE/PP/PS, since no enzyme is known to break a C-C backbone; enzymatically for ester-linked plastics like PET/PU, via PETase-type enzymes). Then it goes to the fermentation process, resulting small molecules into lipids (most common), PHA, or specific chemicals.

Sometimes a consortium(Mixture of microbes) is used, with different microbes handling different fractions of the breakdown mixture. Any "protein from plastic" claim is the same logic, the depolymerized substrate is just feeding an yeast, and the protein is the yeast biomass itself, harvested and used crude or extracted.

True microbial degradation of intact plastic polymers, no pretreatment, organism doing all the work, is still a challenging task for biologist.

PET consists of repeating C10H8O4 monomers. Glucose is C6H12O6 and starch is a natural polymer containing it. It's not surprising that reactions can turn one into the other, along with other compounds containing hydrogen, carbon, and oxygen.

https://www.nytimes.com/1973/11/10/archives/soviet-plant-to-...

https://www.cia.gov/readingroom/docs/CIA-RDP91T01115R0001000...

The term to search for is "single cell protein."

There are newer approaches to making single cell protein from carbon dioxide and renewable energy instead of fossil oil, like Solein:

https://www.solein.com/

There are a few problems with turning oil into single cell protein:

- Microorganisms have small cells that reproduce quickly, which means a lot of nucleic acids in the dry mass, which is trouble for animals (including humans) that can't tolerate a very high purine level in the diet.

- The abundant cell walls of microorganisms also can cause illness when they're a high proportion of dietary intake.

- Feeding single cell protein directly to people has to overcome traditions of cuisine, even in cases where it doesn't actually make people sick. Indirect usage of SCP (e.g. feeding it to salmon, and then having people eat salmon) can overcome that hurdle, but then the cost per human-edible calorie goes up too.

Again, the ONLY reason there is still anyone, anywhere, who suffers from not enough food, is because people in the richest country on earth aren't even willing to spend a few million sending support to extremely needy countries.

Instead, we take a huge fraction of our entire corn crop, turn it into ethanol, and burn it. The primary reason we do it is to waste corn, so that corn prices are higher. We purposely make food more expensive, as a kickback to some real assholes.

World hunger could have been solved a century ago. No technology is required. Zero. At least until we have to figure out a reasonable way to make fertilizers more sustainable.

You know petroleum is actually expensive for a commodity, right? For the price of one barrel of oil, you could get an entire ton of iron ore, 0.8 tons of coal, 20 bushels of corn (about 1000-1200 pounds), 500 pounds of milk, 500 pounds of refined sugar, etc. Petroleum is an input to agriculture, but it enables staggering yield outputs per gallon of input. No amount of chemistry can ever compete with that for simple thermodynamics reasons.

Mechanized agriculture is so efficient that if you leave it to it's own devices it simply bankrupts itself every other year from oversupply. Damn near every functioning country artificially increases the price of basic agricultural commodities to ensure farms are stable. It's a massive handout to a cohort of people that nowadays are basically just very wealthy capital owners, but it also was the actual solution to famine, at least inside those countries.