Isolation and Characterization of a New High-Yield Hydrogen-Producing Strain, Clostridium sulfidigenes CS3, from Anaerobic Sludge in the To Lich River

Abstract

Hydrogen is a vital gas, recognized for its role as a renewable, clean energy source and its importance as a feedstock in multiple industries, leading to a significant rise in hydrogen production demand in recent years. In this context, a high-yield hydrogen-producing mesophilic bacterium, strain CS3, was isolated from sludge and identified as Clostridium sulfidigenes CS3 through 16S rRNA gene analysis and physio-biochemical testing, revealing novel characteristics of this species. This study systematically investigated various factors influencing biological hydrogen production through fermentation, including medium components (like substrates and nitrogen sources) and environmental conditions (initial pH, incubation temperature, duration, and agitation). The research also explored methods to boost hydrogen yield. The maximum yield of 2.1 mol H₂/mol glucose was obtained under optimal conditions: a medium with 10 g/L glucose, an initial pH of 7.0, incubation at 37°C for 48 hours, and agitation at 200 rpm, with supplementation of organic nitrogen sources (10 g/L peptone and 10 g/L yeast extract). The performance of C. sulfidigenes CS3 was compared with other known hydrogen-producing strains, highlighting the superior hydrogen productivity of this species. This is also considered a new discovery in the hydrogen-producing ability of this species. The findings suggest that C. sulfidigenes CS3 could be a promising candidate for biohydrogen production, providing an environmentally friendly alternative to fossil fuels.