Green synthesis of biohydrogen using Bacillus subtilis BS27 from industrial wastes

Abstract

This study aimed to produce biohydrogen by bacterial isolate through the fermentation of fruit juice waste (FJW). Twenty-seven bacterial isolates were isolated from pretreated of FJW. Isolates were tested for biohydrogen production from the fermentation of FJW. The hydrogen production was confirmed by gas chromatographic (GC) analysis. The bacterial isolate (BS27) from the pretreatment of fruit juice waste by heating at 90 ^oC for 20 min, followed by the addition of 5 M HCl for 24 h, exhibited the highest percentage of biohydrogen production. The isolate (BS27) was identified using 16S RNA gene sequencing and was submitted to GenBank as Bacillus subtilis strain BS27 under accession number OR997671. Incubation periods, dark and light fermentation, pH, inoculum sizes, temperature, shacking, aerobic and anerobic conditions were studied to achieve the maximum production of biohydrogen. The optimum conditions were 48h, a dark condition, pH 7, a temperature of 30 ℃, an inoculum size of 10% (2.5*10⁶ CFU/ml), shacking of 150 and an anaerobic condition. The percentage of biohydrogen production was 100% from GC analysis with an amount of 300 ml/l bioH2 using the water displacement method. From an economic and environmental point of view, biohydrogen using fruit juice waste was produced by Bacillus subtilis.