Antibiotic fermentation residue for biohydrogen production: Inhibitory mechanisms of the inherent antibiotic

• Published in: The Science of the total environment Vol. 944; p. 173986
• Main Authors: Yang, Guang, Xu, Youtong, Wang, Jianlong
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 20.09.2024
• Subjects: Antibiotic fermentation residue; Biohydrogen production; Inhibition; Metagenomics analysis; Microbial community; Inhibition; Metagenomics analysis; Antibiotic fermentation residue; Microbial community; Biohydrogen production
• DOI: 10.1016/j.scitotenv.2024.173986
• ISSN: 0048-9697; 1879-1026

Antibiotic fermentation residue, which is generated from the microbial antibiotic production process, has been a troublesome waste faced by the pharmaceutical industry. Dark fermentation is a potential technology to treat antibiotic fermentation residue in terms of renewable H2 generation and waste management. However, the inherent antibiotic in antibiotic fermentation residue may inhibit its dark fermentation performance, and current understanding on this topic is limited. This investigation examined the impact of the inherent antibiotic on the dark H2 fermentation of Cephalosporin C (CEPC) fermentation residue, and explored the mechanisms from the perspectives of bacterial communities and functional genes. It was found that CEP-C in the antibiotic fermentation residue significantly inhibited the H2 production, with the H2 yield decreasing from 17.2 mL/g-VSadded to 12.5 and 9.6 mL/g-VSadded at CEP-C concentrations of 100 and 200 mg/L, respectively. CEP-C also prolonged the H2-producing lag period. Microbiological analysis indicated that CEP-C remarkably decreased the abundances of high-yielding H2-producing bacteria, as well as downregulated the genes involved in hydrogen generation from the“pyruvate pathway” and“NADH pathway”, essentially leading to the decline of H2 productivity. The present work gains insights into how cephalosporin antibiotics influence the dark H2 fermentation, and provide guidance for mitigating the inhibitory effects. [Display omitted] •Inhibition of CEP-C on bioH2 production from its fermentation residue was examined.•H2 yield decreased by 44.0 % at CEP-C concentration of 200 mg/L.•The inherent CEP-C inhibited the efficiency of organic utilization.•CEP-C remarkably decreased the abundances of high-yielding H2-producing bacteria.•CEP-C down-regulated the genes involved in two crucial H2-producing pathways.