Microbial fermentation for alternative protein production encompasses three at times overlapping processes:

• traditional fermentation, which has been used for thousands of years and includes alternative proteins such as tempeh and tofu;
• biomass fermentation, which uses microorganisms to scale up protein production;
• and precision fermentation, which uses microbes as ‘cell factories’ to produce functional ingredients.[1]

The microbes involved can include fungi, algae and bacteria. For the purposes of this study, we focus primarily on biomass and precision fermentation, as traditionally fermented products are often included under plant-based alternatives since many of these are soya-derived.

The regulatory landscape in the EU for microbially fermented foods is complex and evolving. Precision-fermented products are generally considered to be novel foods under Regulation (EU) 2015/2283.

If the product is obtained through the use of genetically modified organisms (GMOs), it must be authorised under Regulation (EC) No 1829/2003 on genetically modified food and feed if rDNA from the GMO is still present in the fermentation product.

Fungal proteins have for many years been produced from biomass fermentation. Quorn is one of the earliest and most successful producers of microbial proteins for food.[2] In 2017, Quorn sold 22,000 tonnes of its microbial protein product.[3]

Precision fermentation, with the aid of synthetic biology and algal, fungal and bacterial cells, can be optimised to increase yield, quality and the nutritional content of fermented foods.

Precision fermentation has been used for many years in other sectors (e.g. healthcare and industrial applications) and as a food ingredient (notably, the enzyme chymosin, and hemp flavouring for some plant-based meat analogues), but its potential to create alternative protein sources is still emerging.

Microbial protein has shown promise as a fishmeal replacement in aquaculture, and has been tested in terrestrial livestock as feed (i.e. the primary food source) and as a feed additive (e.g. nutritional supplement),[4] although historically low prices for soybean have restricted growth of microbial proteins in this sector.[5]

The most recent estimates available are from 2014-2016 indicating global production volumes for different microbial proteins totalling approximately 3.1M tonnes per year, including both food and feed (compared to approximately 330M tonnes of conventional animal protein in that period).[6]