title: Biohydrogen production from sugarcane bagasse hydrolysate: effects of pH, S/X, Fe2+, and magnetite nanoparticles.
abstract: Batch dark fermentation experiments were conducted to investigate the effects of initial pH, substrate-to-biomass (S/X) ratio, and concentrations of Fe2+and magnetite nanoparticles on biohydrogen production from sugarcane bagasse (SCB) hydrolysate. By applying the response surface methodology, the optimum condition of steam-acid hydrolysis was 0.64% (v/v) H2SO4for 55.7 min, which obtained a sugar yield of 274 mg g-1. The maximum hydrogen yield (HY) of 0.874 mol (mol glucose-1) was detected at the optimum pH of 5.0 and S/X ratio of 0.5 g chemical oxygen demand (COD, g VSS-1). The addition of Fe2+200 mg L-1and magnetite nanoparticles 200 mg L-1to the inoculum enhanced the HY by 62.1% and 69.6%, respectively. The kinetics of hydrogen production was estimated by fitting the experimental data to the modified Gompertz model. The inhibitory effects of adding Fe2+and magnetite nanoparticles to the fermentative hydrogen production were examined by applying Andrew's inhibition model. COD mass balance and full stoichiometric reactions, including soluble metabolic products, cell synthesis, and H2production, indicated the reliability of the experimental results. A qPCR-based analysis was conducted to assess the microbial community structure using Enterobacteriaceae, Clostridium spp., and hydrogenase-specific gene activity. Results from the microbial analysis revealed the dominance of hydrogen producers in the inoculum immobilized on magnetite nanoparticles, followed by the inoculum supplemented with Fe2+concentration. Graphical abstract ᅟ.
authors.affiliation: Institute for Water and Wastewater Technology, Durban University of Technology, Durban, 4000, South Africa.
authors.forename: Karen
authors.initials: K
authors.lastname: Reddy
authors.affiliation: Sanitary Engineering Department, Faculty of Engineering, Alexandria University, Alexandria, 21544, Egypt.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Nasr
authors.affiliation: Institute for Water and Wastewater Technology, Durban University of Technology, Durban, 4000, South Africa.
authors.forename: Sheena
authors.initials: S
authors.lastname: Kumari
authors.affiliation: Department of Biotechnology and Food Technology, Durban University of Technology, Durban, 4000, South Africa.
authors.forename: Santhosh
authors.initials: S
authors.lastname: Kumar
authors.affiliation: Institute for Water and Wastewater Technology, Durban University of Technology, Durban, 4000, South Africa.
authors.forename: Sanjay Kumar
authors.initials: SK
authors.lastname: Gupta
authors.affiliation: Institute for Water and Wastewater Technology, Durban University of Technology, Durban, 4000, South Africa.
authors.forename: Abimbola Motunrayo
authors.initials: AM
authors.lastname: Enitan
authors.affiliation: Institute for Water and Wastewater Technology, Durban University of Technology, Durban, 4000, South Africa. faizalb@dut.ac.za.
authors.forename: Faizal
authors.initials: F
authors.lastname: Bux
mesh_terms: D000693:Anaerobiosis; D056804:Biofuels / Q000032:analysis*; D057919:Biological Oxygen Demand Analysis; D018533:Biomass; D018914:Cells, Immobilized / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism*; D003013:Clostridium / Q000378:metabolism; D004755:Enterobacteriaceae / Q000378:metabolism; D005285:Fermentation; D006859:Hydrogen / Q000032:analysis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000382:microbiology; D031786:Saccharum / Q000254:growth & development / Q000378:metabolism*; D013019:South Africa; D013499:Surface Properties
chemical_list: D056804:Biofuels; D058185:Magnetite Nanoparticles; D006859:Hydrogen; D002482:Cellulose; C027433:bagasse
keywords: Biohydrogen; Dark fermentation; Full stoichiometry; Hydrogen-producing microbes; Magnetite nanoparticles; Sugarcane bagasse hydrolysate