Impact of Waste as a Substrate on Biomass Formation, and Optimization of Spent Microbial Biomass Re-Use by Sustainable Metabolic Engineering

Biomass residue and waste stream bioconversion is a key pillar for successful transition toward sustainable bioeconomy. Spent microbial biomass (SMB) unique type of nutrient-rich generated from fermentation. This study addresses the waste–SMB–substrate cycle in Data range published fermentation processes using non-waste substrates are analyzed variety products including alcohols biofuels, amino acids, polymers (PHA), organic acids. On average, produces similar, or up to two–three times higher, amounts SMB compared purified substrates. production further illustrated with data PHA production. The acid composition 6 industrially relevant microorganisms shows relatively low (2–8%). return as (co-)substrate then considered by building upon novel concept metabolic engineering (SME). SME incorporates economic, environmental, social sustainability criteria its optimization algorithm select strain designs resulting most products. An example application re-use engineered Escherichia coli demonstrated discussed. A design dual succinate ethanol was found be sustainable.