Biodegradation of propiconazole by newly isolated Burkholderia sp. strain BBK_9.
The isolation of propiconazole (PCZ) degrading bacterium BBK_9 strain was done from paddy soil, and it was identified as Burkholderia sp. based on the morphological characteristics and biochemical properties combined with 16S rRNA gene sequencing analysis. It has been seen that the factors such as temperature and pH influence the biodegradation process. The role of plasmid was studied in the degradation process by plasmid curing method. The PCZ acts as the sole carbon source and as energy substrate which can be utilized by the strain for its growth in Mineral salt medium and degraded 8.89 µg ml-1of PCZ at 30 °C and pH 7 within 4 days. During the bioconversion process of PCZ, three metabolite were formed such as 1-(2,4-dichlorophenyl)-2-(1H-1,2,4-triazol-1-yl) ethanone, 1-[2-(4-chlorophenyl) ethyl]-1H-1,2,4-triazole and 1-ethyl-1H-1,2,4-triazole. The LD50 value of BBK_9 strain was determined with acridine orange which resulted in 40 µg ml-1at cell density of 0.243 at 660 nm. Furthermore, plasmid curing was done using LD50 concentration and from that three plasmids got cured in the sixth generation. It was found that, cured strain was able to degrade 7.37 µg ml-1of PCZ, indicating the plasmid encoded gene were not responsible for the PCZ degradation. On the source of these outcomes, strain BBK_9 can be used as potential strain for bioremediation of contaminated sites.
Department of Microbiology and Biotechnology, Karnatak University, Dharwad, Karnataka, India.
Praveen
P
Satapute
Department of Microbiology and Biotechnology, Karnatak University, Dharwad, Karnataka, India. b_kaliwal@yahoo.com.|Department of Microbiology and Biotechnology, Davangere University, Davangere, Karnataka, India. b_kaliwal@yahoo.com.
Basappa
B
Kaliwal
Biodegradation; Burkholderia sp. metabolites; Plasmid curing; Propiconazole