Biotechnology is good at taking genes from one organism (a human being, for example) and sticking them into another (yeast, say) in order to churn out large amounts of a desirable protein.

You have to read the ingredients and learn to know the difference between natural ingredients vs. chemical additives like "autolyzed yeast extract" or "hydrolyzed vegetable protein."

"This means we potentially get about 200 litres of ethanol plus 80 to 90 kilograms of excess high-protein yeast per tonne of waste plant material," says Philip Bell of Microbiogen.