Chitosan flocculation associated with biofilms of C. saccharolyticus and C. owensensis enhances biomass retention in a CSTR. (15th June 2021)

• Record Type: Journal Article
• Authors: Vongkampang, Thitiwut; Rao, Nikhil Seshagiri; Grey, Carl; van Niel, Ed W.J.
• Is Part Of: International journal of hydrogen energy. Volume 46:Number 41(2021)
• Page Start: 21338
• Page End: 21347
• Publication Date: 2021-06-15
• Subjects: Caldicellulosiruptor saccharolyticus -- Caldicellulosiruptor owensensis -- Co-culture -- Biofilm -- Immobilization -- Chitosan; D dilution rate (h−1) -- QH2 volumetric hydrogen productivity (mmol·L−1·h−1) -- CSTR continuously stirred tank reactor -- c-di GMP bis-(3′, 5′)-cyclic dimeric guanosine monophosphate -- μmax maximum specific growth rate (h−1) -- ATP adenosine triphosphate; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.03.230
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Cell immobilization and co-culture techniques have gained attention due to its potential to obtain high volumetric hydrogen productivities (QH2 ). Chitosan retained biomass in the fermentation of co-cultures of Caldicellulosiruptor saccharolyticus and C. owensensis efficiently, up to a maximum dilution rate ( D ) of 0.9 h −1 . Without chitosan, wash out of the co-culture occurred earlier, accompanied with approximately 50% drop in QH2 ( D > 0.4 h −1 ). However, butyl rubber did not show as much potential as carrier material; it did neither improve QH2 nor biomass retention in continuous culture. The population dynamics revealed that C. owensensis was the dominant species (95%) in the presence of chitosan, whereas C. saccharolyticus was the predominant (99%) during cultivation without chitosan. In contrast, the co-culture with rubber as carrier maintained the relative population ratios around 1:1. This study highlighted chitosan as an effective potential carrier for immobilization, thereby paving the way for cost – effective hydrogen production. Highlights: Chitosan and biofilm formation could retain biomass during co-culture in a chemostat. The maximum QH2 was 8.4 mmol⋅L −1 ⋅h −1 at a dilution rate ( D ) of 0.8 h −1 . Caldicellulosiruptor species could not utilize chitosan. C. saccharolyticus was the dominant species in the fermentation without chitosan. C. owensensis was the dominant species in the presence of chitosan.