Sorn Sovannlaksmy, Matsuura Norihisa, Honda Ryo
Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Ishikawa, Japan.
Faculty of Agricultural and Marine Sciences, Kochi University, Nankoku, Kochi, Japan.
Environ Microbiol. 2025 Apr;27(4):e70087. doi: 10.1111/1462-2920.70087.
Per- and polyfluoroalkyl substances (PFAS) exhibit a widespread distribution across diverse global ecosystems throughout their lifecycle, posing substantial risks to human health. The persistence of PFAS makes biodegradation a challenging yet environmentally friendly solution for their treatment. In the authors' previous study, a bacterial consortium capable of reducing perfluorooctane sulfonate (PFOS) was successfully enriched from activated sludge. This study aimed to investigate the array of genes associated with PFOS reduction via biosorption and biotransformation to elucidate the metabolic pathways. Two metagenome-assembled genomes (MAGs) based on 16S rRNA sequences that share 99.86% and 97.88% similarity with Hyphomicrobium denitrificans and Paracoccus yeei, respectively were obtained. They were found to contain several genes encoding enzymes that potentially regulate biofilm formation of biosorption and facilitate the desulfonation and defluorination processes of biotransformation. Transcriptomic analysis demonstrated the high expression levels of these genes, including alkanesulfonate monooxygenase, catechol dioxygenase, (S)-2-haloacid dehalogenase and putative cytochrome P450, suggesting their involvement in PFOS biotransformation. The expression of these genes supports the presence of candidate metabolites of PFOS biotransformation detected in the previous study. These findings emphasise the significant potential of bacterial consortia and the crucial role played by genes encoding enzymes in facilitating the remediation of PFOS contaminants.
全氟和多氟烷基物质（PFAS）在其整个生命周期中广泛分布于全球不同的生态系统中，对人类健康构成重大风险。PFAS的持久性使得生物降解成为其处理的一项具有挑战性但环境友好的解决方案。在作者之前的研究中，成功从活性污泥中富集了一个能够还原全氟辛烷磺酸（PFOS）的细菌群落。本研究旨在通过生物吸附和生物转化来研究与PFOS还原相关的基因阵列，以阐明代谢途径。基于16S rRNA序列获得了两个宏基因组组装基因组（MAGs），它们分别与反硝化枝孢菌和叶氏副球菌具有99.86%和97.88%的相似性。发现它们含有几个编码酶的基因，这些酶可能调节生物吸附的生物膜形成，并促进生物转化的脱硫和脱氟过程。转录组分析表明这些基因的高表达水平，包括链烷磺酸盐单加氧酶、儿茶酚双加氧酶、（S）-2-卤酸脱卤酶和假定的细胞色素P450，表明它们参与了PFOS的生物转化。这些基因的表达支持了在先前研究中检测到的PFOS生物转化候选代谢物的存在。这些发现强调了细菌群落的巨大潜力以及编码酶的基因在促进PFOS污染物修复中所起的关键作用。
