Methods for controlling acetoclastic microorganisms in acetogenic syngas fermentation processes

摘要

Methods are disclosed for controlling the population of acetoclastic microorganisms in a process for the bioconversion of gas substrate comprising at least one of CO and a mixture of CO₂ and hydrogen to at least one oxygenated organic compound by contact of said gas substrate under acidic, anaerobic fermentation conditions in a bioreactor containing an aqueous fermentation broth having a population of at least one acetogenic microorganism for bioconverting said gas substrate to at least one acetogenic oxygenated organic compound, said fermentation zone defining a head space, said methods comprising continuously or intermittently controlling the partial pressure of carbon dioxide in the head space to provide a desired population ratio of acetoclastic microorganisms to acetogenic microorganisms.