Long-term H 2 photoproduction from starch by co-culture of Clostridium butyricum and Rhodobacter sphaeroides in a repeated batch process

• Published in: Biotechnology letters 2018-02, Vol.40 (2), p.309
• Main Authors: Laurinavichene, Tatyana, Laurinavichius, Kestutis, Shastik, Evgeny, Tsygankov, Anatoly
• Format: Article
• Language: English
• Subjects: Batch Cell Culture Techniques - methods; Clostridium butyricum - metabolism; Coculture Techniques - methods; Fermentation; Hydrogen - analysis; Hydrogen - metabolism; Kinetics; Photobioreactors - microbiology; Photochemical Processes; Rhodobacter sphaeroides - metabolism; Starch - metabolism
• ISSN: 1573-6776
• DOI: 10.1007/s10529-017-2486-z

To prove the possibility of efficient starch photofermentation in co-culture of heterotrophic and phototrophic bacteria over prolonged period. Repeated batch photofermentation of starch was demonstrated in co-culture Clostridium butyricum and Rhodobacter sphaeroides under microaerobic conditions. It continued 15 months without addition of new inoculum or pH regulation when using 4-5 g starch l and 0.04 g yeast extract l . The complete degradation of starch without volatile fatty acids accumulation was shown in this co-culture. The average H yield of 5.2 mol/mol glucose was much higher than that in Clostridium monoculture. The species composition of co-culture was studied by q-PCR assay. The concentration of Clostridium cells in prolonged co-culture was lower than in monoculture and even in a single batch co-culture. This means that Clostridia growth was significantly limited whereas starch hydrolysis still took place. The prolonged repeated batch photofermentation of starch by co-culture C. butyricum and R. sphaeroides provided efficient H production without accumulation of organic acids under conditions of Clostridia limitation.