Phân lập và tuyển chọn các dòng vi khuẩn có khả năng phân huỷ hoạt chất carbosulfan từ đất trồng lúa chuyên canh ở tỉnh Hậu Giang

Abstract

The study was carried out on the basis of isolating and selecting of high activity bacteria strains for degrading carbosulfan from 3 rice crop soils in Hau Giang province. Investigating the ability of bacterial isolates to grow on the minimal mineral medium (MM) supplemented with carbosulfan concentration gradually increasing from 30 mg.L-1 to 60 mg.L-1 based on colony count method. Quantification of carbosulfan residues in liquid medium was done by mass chromatography technique. The research results showed that a total of 31 bacterial strains were isolated from rice-growing soils in Hau Giang province. Most of bacterial strains were short rods, negative Gram and move slowly. Sixteen bacterial strains could grow well in liquid MM supplemented with 20 mg.L-1 carbosulfan. Among them, 8, 6, 7 and 6 bacterial strains showed their well-growing in liquid culture media supplemented with 30, 40, 50, and 60 mg.L-1 carbosulfa after seventy-two hours of incubation, respectively. In particular, two bacterial strains designated as NB02 and NB04 could grow well in the liquid culture media containing 60 mg.L-1carbosulfan. They were identified as Stenotrophomonas panacihumi and Acinetobacter calcoaceticus, respectively. These two strains, in turn, degraded 82.3% and 75.0% of innitial concentration of carbosulfan in the liquid MSM after 7 incubation days under the laboratory conditions, respectively, with an initial concentration of 60 mg.L-1 carbosulfan.