Biological Upgrading of Brewer Spent Grain into high added value products

Brewers spent grain (BSG) is an agro-industrial by-product produced from breweries (~20 kg BSG/hlbeer). Its annual global production is estimated to be 39 million tons, with 3.4 million tons produced in the European Union. Most BSG is currently used as a low-value animal feed (35/ton). In this context, BSG represents a promising feedstock for the production of novel added-value biomolecules. Indeed, this lignocellulosic material is composed of polyphenolic macromolecules such as ferulic (FA) and p-coumaric acids (PA), which have very important physiological functions and a market price of ~ 4000 /Kg. BiOBreW will design novel recombinant enzymes that will allow obtaining high yields of FA and PA extraction from BSG. In addition, the widespread application of FA and PA in pharmaceutical industry is nowadays limited by their low permeability and instability. BiOBreW will overcome this limitation via innovative nano-encapsulation into nanocarriers (biocompatible and biodegradable selective polymers). The pretreated biomass obtained after the enzymatic extraction of FA and PA represents an ideal substrate for biogas production. However, electricity production from biogas will soon became economically non-feasible due to the rapid decrease in the prices of solar or wind power. In this context, the biological conversion of the methane contained in biogas into high added value products represents a novel and cost-competitive platform for biogas valorization. Halotolerant bacteria such as Methylomicrobium alkaliphilum can efficiently synthesize ectoine, one of the most valuable microbial protective compounds (market price ~ 1,300/kg) using CH4 as the sole carbon and energy source. BiOBreW aims at enriching new high-yield ectoine producing strains and developing a new generation of high mass transfer bioreactors. BiOBreW will upgrade BSG using innovative biotechnologies and help creating new value chains in the context of circular economy in the brewery sector.