Production of hydroxyectoine from biogas by an engineered strain of Methylomicrobium alcaliphilum using a novel Taylor‐flow bioreactor

Abstract

BACKGROUND: The production of compatible solutes, such as ectoine and hydroxyectoine, is of great interest due to their industrial and biotechnological applications. Methylomicrobium alcaliphilum was genetically engineered to replace a native gene with a heterologous one, aiming to enhance ectoine production. This study focuses on the optimization of bioreactor conditions to maximize the microbial production of these metabolites from methane.

RESULTS: The engineered strain (M. alcaliphilum PstEctD) was cultured in a Taylor flow bioreactor under varying gas recirculation flow rates. Increased flow rates enhanced methane consumption, biomass concentration, and ectoine production. The highest production of ectoine (32 mg/g-VSS) and hydroxyectoine (272 mg/g-VSS) was observed at a flow rate of 0.7 L min−1, while methane removal efficiency improved from 30% to over 60% as flow rates increased.

CONCLUSIONS: Optimizing bioreactor conditions, particularly gas recirculation flow rates, significantly improved both the efficiency of methane consumption and the production of ectoine derivatives. This work provides a scalable approach for the sustainable production of compatible solutes from methane, offering potential applications in biotechnological processes utilizing renewable carbon sources. © 2024 The Author(s). Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).