Researchers at the Universidade Federal do Rio de Janeiro used brewer's spent grain, the brewing industry's most abundant solid waste, as the primary substrate to produce a protease enzyme via fermentation with the yeast Yarrowia lipolytica, achieving a fivefold increase in enzyme yield after process optimisation.

The food industry generates massive amounts of by-products—fruit peels, grape pomace, and spent grains, to name a few. Many of these end...