Isolation and characterization of novel bacterial strain from sewage sludge and exploring its potential for hydrogen...

Hydrogen (H₂) energy has garnered significant attention due to its numerous advantages. Nonetheless, for future commercialization, it is imperative to screen and identify strains with enhanced H₂-producing capacities. In order to attain a high and consistent production performance, the conversion of biomass sources into H₂ requires careful selection of the most appropriate H₂-producing bacteria. This study aimed to isolate and identify a highly effective H₂ producing bacteria from local sewage sludge and assess its fermentability for H₂ production. The isolate was first identified by means of morphological, phenotypic, biological, and 16 S rRNA investigations. A facultative anaerobe that produces H₂ and is gram-negative was identified as Alcaligenes ammonioxydans strain SRAM. For the purpose of determining whether the isolate could produce H₂ using glucose as the substrate, its fermentability was evaluated in 500 mL serum bottles. This strain demonstrated the ability to produce H₂ from glucose under anaerobic environment, achieving a maximum H₂ yield of 2.9 mol H₂/mol of glucose. The highest rate of H₂ production, 9.261 mmol H₂/ g dry cell weight per hr, was attained at 37 °C and an initial pH of 6.8. This work effectively illustrated the use of a novel locally isolated strain in the biotechnological conversion of glucose to H₂. This strategy offers an effective remedy for the world's energy instability in addition to addressing environmental issues related to industrial operations.