AbstractThe growth of a mixed methane‐utilizing culture in a continuous flow fermenter has been studied under both methane and oxygen limitation. Small additions of methanol have been shown to inhibit the methane‐utilizing moiety in the culture and it has been shown that theHyphomicrobiumsp. in the mixed culture removes any inhibitory methanol. The interaction between the methane‐utilizingPseudomonassp., and theHyphomicrobiumsp. has been explained and a model of the continuous mixed culture under oxygen limitation has been formulated. Qualitative predictions of transient phenomena by the model have been verified experimen