Hydrogen production from starch by co-culture of Clostridium acetobutylicum and Rhodobacter sphaeroides in one step hybrid dark- and photofermentation in repeated fed-batch reactor. (January 2017)

• Record Type: Journal Article
• Authors: Zagrodnik, R.; Łaniecki, M.
• Is Part Of: Bioresource technology. Volume 224(2017)
• Page Start: 298
• Page End: 306
• Publication Date: 2017-01
• Subjects: Biohydrogen -- Repeated fed-batch -- Starch -- Co-culture dark and photofermentation; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2016.10.060
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Repeated fed-batch co-culture dark and photofermentation from starch was studied. pH above 6.5 strongly disfavored H2 formation by dark fermentative bacteria. Photo bacteria prefer high acetate/butyrate ratio after dark fermentation process. Cooperation between dark and photobacteria at pH 7.0 was suppressed after few days. Redirection of dark fermentative metabolism led to low H2 yields in the co-culture. Abstract: Hydrogen production from starch by a co-culture hybrid dark and photofermentation under repeated fed-batch conditions at different organic loading rates (OLR) was studied. Effective cooperation between bacteria in co-culture during initial days was observed at controlled pH 7.0. However, at pH above 6.5 dark fermentation phase was redirected from H2 formation towards production of formic acid, lactic acid and ethanol (which are not coupled with hydrogen production) with simultaneous lower starch removal efficiency. This resulted in decrease in the hydrogen production rate. The highest H2 production in co-culture process (3.23 L H2 /Lmedium – after 11 days) was achieved at OLR of 1.5 gstarch /L/day, and it was twofold higher than for dark fermentation process (1.59 L H2 /Lmedium ). The highest H2 yield in the co-culture (2.62 mol H2 /molhexose ) was obtained at the OLR of 0.375 gstarch /L/day. Different pH requirements of bacteria were proven to be a key limitation in co-culture system.