Synergistic removal of methanethiol and other odorant gases by a metabolically complementary synthetic consortia isolated from food waste.

Abstract

Methanethiol (MeSH), a typical volatile sulfur compound, contributes significantly to environmental malodor and poses ecological risks. In this study, three bacterial strains capable of MeSH removal efficiencies exceeding 40% were isolated from food waste. These strains were taxonomically identified asAgrobacterium cavarae,Mycolicibacterium neoaurum, andPseudomonas qingdaonensis. Metagenomic annotation by Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed that all strains possess key enzymes for the methionine and cysteine metabolism pathway, suggesting potential for MeSH degradation. In binary consortia, the combination of A. cavarae R1 and P. qingdaonensis CF (5:1 ratio) exhibited the optimal degradation performance, achieving removal efficiency of 87.2% for MeSH, 98.7% for H₂S, and complete NH₃ elimination (100%) after a 6-day cultivation. Among ternary consortia, the A. cavarae R1/M. neoaurum CD/ P. qingdaonensis CF combination at 3:2:1 and 3:1:2 ratios demonstrated superior removal efficiency for all three target odorants. Specifically, the 3:2:1 ratio consortium achieved 94.7% MeSH degradation, while the 3:1:2 ratio showd 91.7% NH₃ removal efficiency. These results demonstrate the feasibility of using composite microbial agents for odor control in waste management systems.