Effect of chlorpyrifos on soil microbial diversity and its biotransformation by Streptomyces sp. HP-11

Abstract

The application of pesticides in agricultural fields not only reaches the target pests but also with soil where it interacts with soil microorganisms resulting in change of microbial diversity. Chlorpyrifos (CP) is one such organophosphorous insecticide most widely used against various insects, termites, and beetles throughout the globe. In the present work, the effect of CP on soil microbial population was assessed by the cultivable method. The fertile soil which does not have a history of any pesticide application was treated with 100 and 200 µg/g of CP along with control which received only sterile water and incubated for 1, 7, and 14 days. The soil amended with the insecticide showed decrease in the number of colony forming units (CFU) of bacteria and fungi. However, Streptomyces sp. HP-11 which tolerated high concentration and also inhibited fungal population was further selected for biodegradation studies. After 14 days of incubation in Mineral salt media (MSM), the strain HP-11 biotransformed CP into 3, 5, 6-trichloro-2-pyridinol (TCP) and Diethyl Phosphorothioate (DETP), and its formation was confirmed by the m/z peak of LC–MS analysis, which was later metabolized to unknown polar metabolites. The results obtained highlights that the application of chlorpyrifos favored the Actinomycete growth in the soil, thereby inhibiting other microorganisms and the strain HP-11 harbors metabolic pathway for detoxification of CP and its hydrolysis product TCP into polar metabolites, thus suggesting the strain HP-11 will be a potential bioaugmenting agent for the bioremediation of chlorpyrifos contaminated soil and water.Electronic supplementary materialThe online version of this article (doi:10.1007/s13205-016-0462-2) contains supplementary material, which is available to authorized users.

Effect of Chlorpyrifos and Malathion on Soil Microbial Population and Enzyme Activity

“…Whereas, in some studies rapid decline in number of actinomycetes was observed using different pesticides [16]. The results obtained from the past and our recent studies, highlights that the application of chlorpyrifos and malathion favoured the actinomycetes growth in the soil at low concentration, thereby inhibiting other micro-organisms [17] and higher concentration sight the reduction in actinomycetes populations [18]. Also indicated that soil microbial and actinomycetes populations were inhibited by chlorpyrifos at 10 mg kg -1 [18].…”

Performance of a continuous stirred tank bioreactor employing an immobilized actinobacteria mixed culture for the removal of organophosphorus pesticides

“…Similarly, the lowest germination index values were observed with these flow rates, suggesting that the effluent treated in the bioreactor exerted a moderate inhibitory effect on radishes, possibly due to the presence of CP and DZ residues and phytotoxic substances (Alfonso- Gordillo et al 2016). The metabolites TCP and IMHP were not detected, which could be due to the ability of Streptomyces to remove these compounds in mineral salt media (Briceño et al 2012(Briceño et al , 2016aSupreeth et al 2016). However, the presence of other metabolites, such as CP-oxon, diethyl thiophosphate or diethyl phosphate, produced during CP metabolism is not excluded (Dar et al 2019).…”

Quantifying the economic cost of invertebrate pests to New Zealand’s pastoral industry

“…To date, the efficacy of chlorpyrifos and its effects on natural insect pathogens in New Zealand pastures has not been studied but it has been shown elsewhere to decrease the abundance of bacteria and fungi in soils (e.g. Supreeth et al 2016). Chlorpyrifos has other known non-target effects, e.g.…”