ABSTRACT

Among the organophosphate pesticides, the wide and indiscriminate use of profenofos (PFF) in agricultural and horticultural crops has resulted in serious environmental and animal health concerns and therefore demands an urgent need to develop a biological solution for its effective removal from the environment. For the bioremediation of PFF, a strain PF1, capable of utilizing profenofos as the sole source of carbon and energy was isolated from the soil samples of apple orchards of Shimla region of Himachal Pradesh, India. Based on the biochemical, FAME, and 16S rRNA gene analysis the bacterium PF1 was identified as Bacillus altitudinis (GenBank: MH986176). The strain was able to degrade 50μg mL⁻¹ PFF up to 93% within 30 days of incubation at 28°C, pH 7.0. A linear regression analysis performed on the data-set revealed the statistical significance of the relationship between the growth of the bacterial population and the degradation of pesticides. The compound 4-Bromo-2-chlorophenol (BCP) was detected as one of the pathway metabolites which further were completely degraded to lower pathway metabolites. A probable PFF degradation pathway has been proposed which follows the path from PFF to BCP and ultimately enters into the TCA cycle. To the best of our knowledge, this is the first report of PFF biodegradation by any Bacillus species of western Himalayan origin exhibiting close phylogenetic association with Bacillus altitudinis. This indigenous bacterium can be useful to bio-remediate the PFF contaminated soil as this pesticide is extensively used in the different horticulture fields in Himachal Pradesh, India.

摘要

在有机磷农药中，丙溴磷 (PFF) 在农业和园艺作物中的广泛和滥用导致了严重的环境和动物健康问题，因此迫切需要开发一种生物解决方案，以有效地将其从环境中去除。对于 PFF 的生物修复，从印度喜马偕尔邦西姆拉地区苹果园的土壤样本中分离出一株能够利用丙溴磷作为唯一碳源和能源的菌株 PF1。基于生化、FAME 和 16S rRNA 基因分析，细菌 PF1 被鉴定为高原芽孢杆菌(GenBank: MH986176)。该菌株能够降解 50μg mL ^-1在 28°C、pH 7.0 下孵育 30 天内，PFF 高达 93%。对数据集进行的线性回归分析揭示了细菌种群增长与农药降解之间关系的统计显着性。化合物 4-Bromo-2-chlorophenol (BCP) 被检测为途径代谢物之一，其进一步完全降解为较低途径代谢物。已经提出了一个可能的 PFF 降解途径，它遵循从 PF​​F 到 BCP 的路径，并最终进入 TCA 循环。据我们所知，这是西喜马拉雅起源的任何芽孢杆菌属物种的 PFF 生物降解的第一份报告，显示出与高原芽孢杆菌密切的系统发育关联. 这种本地细菌可用于生物修复 PFF 污染的土壤，因为这种杀虫剂广泛用于印度喜马偕尔邦的不同园艺领域。