Enhancing biohydrogen production from mono-substrates and co-substrates using a novel bacterial strains

The staggering increase in pollution associated with a sharp tightening in global energy demand is a major concern for organic substances. Renewable biofuel production through simultaneous waste reduction is a sustainable approach to meet this energy demand. This study co-fermentation of dairy whey and SCB was performed using mixed and pure bacterial cultures of Salmonella bongori, Escherichia coli, and Shewanella oneidensis by dark fermentation process for hydrogen production. The maximum H₂ production was 202.7 ± 5.5 H₂/mL/L, 237.3 ± 6.0 H₂/mL/L, and 198 ± 9.9 H₂/mL/L obtained in fermentation reactions containing dairy whey, solid and liquid hydrolysis of pretreated sugarcane bagasse as mono-substrates. The H₂ production was greater in co-substrate by 347.3 ± 18.5 H₂/mL/L under optimized conditions (pH 7.0, temperature 37 °C, substrate concentration 30:50 g/L) than expected in mono-substrate conditions, which confirms that co-fermentation of different substrates enhances the H₂ potential. Fermentation medium during bio-H2 production under GC analysis has stated that using mixed cultures in dark fermentation favored acetic acid and butyric acid. Co-substrate degradation produces ethyl alcohol, benzoic acid, propionic acid, and butanol as metabolic by-products. The difference in the treated and untreated substrate and carbon enrichment in the substrates was evaluated by FT-IR analysis. The present study justifies that rather than the usage of mono-substrate for bio-H₂ production, the co-substrate provided highly stable H₂ production by mixed bacterial cultures. Fabricate the homemade single-chamber microbial fuel cell to generate electricity.

The online version contains supplementary material available at 10.1007/s13205-023-03687-9.