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 (<i>q_S</i> ) of the applied microbial production system. Since <i>q_S</i> depends on the growth rate (μ), we highlight the potential of the fastest-growing nonpathogenic bacterium, <i>Vibrio natriegens</i>, as a novel candidate for future biotechnological processes. <i>V. natriegens</i> 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 <i>V. natriegens</i> possesses an exceptionally high <i>q_S</i> 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 <i>V. natriegens</i> 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 <i>V. natriegens</i> a promising new microbial platform for future industrial fermentation processes operating with high productivity.<b>IMPORTANCE</b> 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 <i>V. natriegens</i>, 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, <i>V. natriegens</i> can speed up common laboratory routines, is suitable for already existing production procedures, and forms an excellent foundation for engineering next-generation bioprocesses.