Department of Molecular Ecology, Institute of Aquaculture and Environmental Safety, Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary.
Department of Environmental Safety, Institute of Aquaculture and Environmental Safety, Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary.
Environ Sci Pollut Res Int. 2022 Apr;29(19):28431-28445. doi: 10.1007/s11356-021-18300-w. Epub 2022 Jan 6.
To develop effective bioremediation strategies, it is always important to explore autochthonous microbial community diversity using substrate-specific enrichment. The primary objective of this present study was to reveal the diversity of aerobic xylene-degrading bacteria at a legacy BTEX-contaminated site where xylene is the predominant contaminant, as well as to identify potential indigenous strains that could effectively degrade xylenes, in order to better understand the underlying facts about xylene degradation using a multi-omics approach. Henceforward, parallel aerobic microcosms were set up using different xylene isomers as the sole carbon source to investigate evolved bacterial communities using both culture-dependent and independent methods. Research outcome showed that the autochthonous community of this legacy BTEX-contaminated site has the capability to remove all of the xylene isomers from the environment aerobically employing different bacterial groups for different xylene isomers. Interestingly, polyphasic analysis of the enrichments disclose that the community composition of the o-xylene-degrading enrichment community was utterly distinct from that of the m- and p-xylene-degrading enrichments. Although in each of the enrichments Pseudomonas and Acidovorax were the dominant genera, in the case of o-xylene-degrading enrichment Rhodococcus was the main player. Among the isolates, two Hydogenophaga strains, belonging to the same genomic species, were obtained from p-xylene-degrading enrichment, substantially able to degrade aromatic hydrocarbons including xylene isomers aerobically. Comparative whole-genome analysis of the strains revealed different genomic adaptations to aromatic hydrocarbon degradation, providing an explanation on their different xylene isomer-degrading abilities.
为了开发有效的生物修复策略，使用底物特异性富集探索本土微生物群落多样性始终很重要。本研究的主要目的是揭示在以二甲苯为主要污染物的遗留 BTEX 污染场地中好氧二甲苯降解细菌的多样性，并鉴定出能够有效降解二甲苯的潜在土著菌株，以便更好地了解使用多组学方法进行二甲苯降解的基本事实。因此，使用不同的二甲苯异构体作为唯一碳源平行建立好氧微宇宙，使用培养依赖和非依赖方法来研究进化细菌群落。研究结果表明，该遗留 BTEX 污染场地的本土群落具有在有氧条件下从环境中去除所有二甲苯异构体的能力，不同的细菌群体用于不同的二甲苯异构体。有趣的是，多相分析揭示了邻二甲苯降解富集群落的群落组成与间二甲苯和对二甲苯降解富集群落的群落组成完全不同。虽然在每个富集中假单胞菌和 Acidovorax 都是优势属，但在邻二甲苯降解富集中，节杆菌是主要的优势属。在分离株中，从间二甲苯降解富集中获得了属于同一基因组种的两个 Hydogenophaga 菌株，它们能够在有氧条件下有效地降解芳烃，包括二甲苯异构体。对这些菌株的全基因组比较分析揭示了它们对芳烃降解的不同基因组适应，解释了它们不同的二甲苯异构体降解能力。
