title: Optimization of influential nutrients during direct cellulose fermentation into hydrogen by Clostridium thermocellum.
abstract: Combinatorial effects of influential growth nutrients were investigated in order to enhance hydrogen (H2) production during direct conversion of cellulose by Clostridium thermocellum DSM 1237. A central composite face-centered design and response surface methodology (RSM) were applied to optimize concentrations of cellulose, yeast extract (YE), and magnesium chloride (Mg) in culture. The overall optimum composition generated by the desirability function resulted in 57.28 mmol H2/L-culture with 1.30 mol H2/mol glucose and 7.48 mmol/(g·cell·h) when cultures contained 25 g/L cellulose, 2 g/L YE, and 1.75 g/L Mg. Compared with the unaltered medium, the optimized medium produced approximately 3.2-fold more H2 within the same time-frame with 50% higher specific productivity, which are also better than previously reported values from similar studies. Nutrient composition that diverted carbon and electron flux away from H2 promoting ethanol production was also determined. This study represents the first investigation dealing with multifactor optimization with RSM for H2 production during direct cellulose fermentation.
authors: Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB R3T 2N2, Canada. rislam1975@gmail.com.
authors: Rumana
authors: R
authors: Islam
authors: Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada. richard.sparling@umanitoba.ca.
authors: Richard
authors: R
authors: Sparling
authors: Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB R3T 2N2, Canada. nazim.cicek@umanitoba.ca.
authors: Nazim
authors: N
authors: Cicek
authors: Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB R3T 2N2, Canada. david.levin@umanitoba.ca.
authors: David B
authors: DB
authors: Levin
mesh_terms: D061249:Batch Cell Culture Techniques; D018533:Biomass; D002482:Cellulose / Q000378:metabolism*; D048013:Acetivibrio thermocellus / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D003470:Culture Media / Q000494:pharmacology; D000431:Ethanol / Q000378:metabolism; D006859:Hydrogen / Q000378:metabolism*; D015233:Models, Statistical; D010084:Oxidation-Reduction
chemical_list: D003470:Culture Media; D000431:Ethanol; D006859:Hydrogen; D002482:Cellulose
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