The effects of pesticides on microbial population of saline soils using culture-dependent and next generation sequencing methods

Subject Areas : Microbial Biotechnology

Safoura Hashemi joker ¹ , Mahmoud Shavandi ² , Azam Haddadi ³ , Ebrahim Alaie ⁴

1 - Department of Microbiology, Karaj Branch, Islamic Azad University, Karaj, Iran
2 - Assisstant Professor, Microbiology and Biotechnology Group, Research Institute of Petroleum Industry
3 - Department of Microbiology, Karaj Branch, Islamic Azad University, Karaj, Iran
4 - Environment and Biotechnology Research Division, Research Institute of Petroleum Industry, Tehran, Iran

Received: 2020-12-04 Accepted : 2021-04-11 Published : 2021-05-22

Keywords: Soil salinity, Chlorpyrifos, deltamethrin, Next generation sequencing, Soil microbial composition,

Abstract :

Background & Objectives: Despite of widely use of pesticides in agricultural industry, their ecotoxicological impacts on the environment are not still well understood. In the present study, the effects of chlorpyrifos and deltamethrin pesticides on soil microbial diversity in different salinities were investigated.Materials and methods: Four soil samples with various salinities (0, 1%, 2% and 4%) were contaminated with 200 mg/kg of chlorpyrifos and deltamethrin. Then, the effects of these compounds were investigated by culture-dependent and Next Generation Sequencing (NGS) methods. The dominant bacterial strains were isolated and compared with the results of the NGS method.Results: Remarkable groups of active soil species were destroyed. The main groups at the phylum level were, Firmicutes, Proteobacteria, Bacteroidetes and Actinobacteria. Examination of the   pattern of operational taxonomic unit (OTU) showed that the lowest abundance belonged to the group of soil samples contaminated with chlorpyrifos and the highest abundance belonged to the non-contaminated sample. Alpha diversity analysis revealed that the highest number of strains was observed in non-saline and uncontaminated soil microcosms, and the lowest number of strains was observed in the presence of deltamethrin (1% salinity) and chlorpyrifos (0% salinity).Conclusion: The results indicated that soil salinity had significant impact on the resistance of soil microorganisms to the chlorpyrifos and deltamethrin. Every soil samples will have its own microbial composition based on its physicochemical conditions under the influence of pesticide contamination. By comparison of microbial composition by culture-dependent and molecular-based methods, almost similar findings were obtained.