Microbial Biotechnology Laboratory, Life Science Division, Institute of Advanced Study in Science and Technology (IASST), Paschim Boragaon, Garchuk, Guwahati, Assam, 781035, India.
Department of Molecular Biology and Biotechnology, Cotton University, Guwahati, Assam, India.
Curr Microbiol. 2024 Aug 28;81(10):332. doi: 10.1007/s00284-024-03859-7.
Pesticides employed for controlling domestic and agricultural pests are among the most dangerous environmental contaminants. Nevertheless, negligent usage and a lack of technical expertise have led to the contamination and pollution of various ecological niches. The extensive utilization of the organophosphate chlorpyrifos (CPs) for insect infestation control, coupled with its detrimental effects and persistence in the ecosystem, has led to calls for its removal from contaminated sites. The study is mainly focused on degradation of CPs; using viz. Bacillus wiedmannii A3 and Bacillus cereus P14 isolated from tea rhizosphere soil having pesticide contamination in Sonitpur district, Assam, India. These two bacterial strains were able to degrade CPs in vitro within 3 days. Reverse-phase HPLC analysis suggested about 96% reduction of CPs concentration upon bacterial treatment. Again, in case of A3, GC-MS analysis revealed that CPs was modified to 2-hydroxy-3,5,6-trichloropyridine and chlorpyrifos-oxon, thus finally metabolized into non-toxic products. While analyzing P14, silane, dimethyl (2,2,2-trichloroethoxy) propoxy, and 3-aminobenzoic acid, N-trimethylsilyl-, trimethylsilyl ester were identified. These compounds were subsequently transformed into non-toxic products. In addition to this, they demonstrated a significant boost of plant growth-promoting traits in both absence and presence of CPs; also showed growth development in nursery scale condition. Moreover, they functioned as biocontrol agents against Phellinus lamaensis and Colletotrichum gloeosporioides, responsible for brown root rot and anthracnose in North East India tea plantations, respectively. Thus, the pesticide-tolerant Bacilli strains A3 and P14 could be used as bioremediation of contaminated sites and also as biostimulants, and biocontrols in tea crop production.
用于控制家庭和农业害虫的农药是最危险的环境污染物之一。然而，由于疏忽使用和缺乏技术专业知识，导致各种生态位受到污染和破坏。由于有机磷毒死蜱 (CPs) 广泛用于防治虫害，加上其对生态系统的有害影响和持久性，因此呼吁将其从受污染的地点清除。本研究主要集中在 CPs 的降解上；使用从印度阿萨姆邦索尼特布尔地区受到农药污染的茶根际土壤中分离到的 Bacillus wiedmannii A3 和 Bacillus cereus P14。这两种细菌菌株能够在体外 3 天内降解 CPs。反相高效液相色谱分析表明，经过细菌处理后，CPs 的浓度降低了约 96%。再次，对于 A3，GC-MS 分析表明 CPs 被修饰为 2-羟基-3,5,6-三氯吡啶和毒死蜱氧，最终代谢为无毒产物。在分析 P14 时，鉴定出硅烷、二甲基（2,2,2-三氯乙氧基）丙氧基和 3-氨基苯甲酸、N-三甲基甲硅烷基-、三甲基硅烷基酯。这些化合物随后被转化为无毒产物。除此之外，它们在有或没有 CPs 的情况下都表现出对植物生长促进特性的显著促进作用；在苗圃规模条件下也显示出生长发育。此外，它们还可以作为生物防治剂，对抗分别导致印度东北部茶园褐根腐烂和炭疽病的 Phellinus lamaensis 和 Colletotrichum gloeosporioides。因此，具有农药耐受性的 Bacillus 菌株 A3 和 P14 可用于受污染地点的生物修复，也可用于茶作物生产中的生物刺激素和生物防治。
