Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, 769008, Odisha, India.
Environ Sci Pollut Res Int. 2023 Jul;30(33):79676-79705. doi: 10.1007/s11356-023-28130-7. Epub 2023 Jun 17.
Contamination of soil and natural water bodies driven by increased organic pollutants remains a universal concern. Naturally, organic pollutants contain carcinogenic and toxic properties threatening all known life forms. The conventional physical and chemical methods employed to remove these organic pollutants ironically produce toxic and non-ecofriendly end-products. Whereas microbial-based degradation of organic pollutants provides an edge, they are usually cost-effective and take an eco-friendly approach towards remediation. Bacterial species, including Pseudomonas, Comamonas, Burkholderia, and Xanthomonas, have the unique genetic makeup to metabolically degrade toxic pollutants, conferring their survival in toxic environments. Several catabolic genes, such as alkB, xylE, catA, and nahAc, that encode enzymes and allow bacteria to degrade organic pollutants have been identified, characterized, and even engineered for better efficacy. Aerobic and anaerobic processes are followed by bacteria to metabolize aliphatic saturated and unsaturated hydrocarbons such as alkanes, cycloalkanes, aldehydes, and ethers. Bacteria use a variety of degrading pathways, including catechol, protocatechuate, gentisate, benzoate, and biphenyl, to remove aromatic organic contaminants such as polychlorinated biphenyls, polycyclic aromatic hydrocarbons, and pesticides from the environment. A better understanding of the principle, mechanisms, and genetics would be beneficial for improving the metabolic efficacy of bacteria to such ends. With a focus on comprehending the mechanisms involved in various catabolic pathways and the genetics of the biotransformation of these xenobiotic compounds, the present review offers insight into the various sources and types of known organic pollutants and their toxic effects on health and the environment.
有机污染物的增加导致土壤和天然水体受到污染，这仍然是一个普遍关注的问题。天然有机污染物含有致癌和有毒特性，威胁着所有已知的生命形式。为了去除这些有机污染物，人们采用了传统的物理和化学方法，但这些方法却产生了有毒和不环保的最终产物。相比之下，基于微生物的有机污染物降解方法具有优势，因为它们通常具有成本效益，并且采用了环保的修复方法。假单胞菌、食酸菌、伯克霍尔德菌和黄单胞菌等细菌物种具有独特的遗传组成，可以代谢降解有毒污染物，从而使其能够在有毒环境中生存。已经鉴定、表征甚至工程化了几种编码酶的代谢基因，如 alkB、xylE、catA 和 nahAc 等，这些基因使细菌能够降解有机污染物。细菌通过需氧和厌氧过程来代谢脂肪族饱和和不饱和烃，如烷烃、环烷烃、醛和醚。细菌使用多种降解途径，如儿茶酚、原儿茶酸、龙胆酸、苯甲酸和联苯，来去除环境中的芳香族有机污染物，如多氯联苯、多环芳烃和农药。更好地理解原理、机制和遗传学将有助于提高细菌的代谢效率。本综述重点关注理解各种降解途径中的机制以及这些外来化合物的生物转化的遗传学，深入了解各种已知有机污染物的来源和类型及其对健康和环境的毒性影响。
