High Substrate Uptake Rates Empower Vibrio natriegens as Production Host for Industrial Biotechnology

Abstract

The productivity of industrial fermentation processes is essentially limited by the biomass-specific substrate consumption rate (q_S ) of the applied microbial production system. Since q_S depends on the growth rate (μ), we highlight the potential of the fastest-growing nonpathogenic bacterium, Vibrio natriegens, as a novel candidate for future biotechnological processes. V. natriegens grows rapidly in BHIN complex medium with a μ of up to 4.43 h^-1 (doubling time of 9.4 min) as well as in minimal medium supplemented with various industrially relevant substrates. Bioreactor cultivations in minimal medium with glucose showed that V. natriegens possesses an exceptionally high q_S under aerobic (3.90 ± 0.08 g g^-1 h^-1) and anaerobic (7.81 ± 0.71 g g^-1 h^-1) conditions. Fermentations with resting cells of genetically engineered V. natriegens under anaerobic conditions yielded an overall volumetric productivity of 0.56 ± 0.10 g alanine liter^-1 min^-1 (i.e., 34 g liter^-1 h^-1). These inherent properties render V. natriegens a promising new microbial platform for future industrial fermentation processes operating with high productivity.IMPORTANCE Low conversion rates are one major challenge to realizing microbial fermentation processes for the production of commodities operating competitively with existing petrochemical approaches. For this reason, we screened for a novel platform organism possessing characteristics superior to those of traditionally employed microbial systems. We identified the fast-growing V. natriegens, which exhibits a versatile metabolism and shows striking growth and conversion rates, as a solid candidate to reach outstanding productivities. Due to these inherent characteristics, V. natriegens can speed up common laboratory routines, is suitable for already existing production procedures, and forms an excellent foundation for engineering next-generation bioprocesses.

Keywords: Vibrio natriegens; alanine production; glucose consumption rate; growth rate; industrial biotechnology; productivity.