A bioreactor system is provided for continuous fermentation of a gaseous substrate, said system comprising two or more primary bioreactors and one or more secondary bioreactors connected by a central bleed line. Further provided is a process for inoculating multiple bioreactors utilizing a central bleed line, said process comprising passing fermentation broth from a first primary bioreactor to other primary bioreactors and/or secondary bioreactors via a central bleed line. Further provided is a process for maintaining stable fermentation of a gaseous substrate across multiple bioreactors, said process comprising providing fermentation broth from one or more operational primary bioreactors to one or more secondary bioreactors via a central bleed line.