Biodegradation of isoproturon by Pseudoxanthomonas sp. isolated from herbicide-treated wheat fields of Tarai agro-ecosystem, Pantnagar.
A gram-negative, rod-shaped, isoproturon (IPU) utilizing bacterium was isolated from herbicide-applied wheat fields of Tarai agro-ecosystem, Pantnagar. The phylogenetic sequence analysis based on 16S rRNA sequence revealed that the isolate could be a distinct species within the genus Pseudomonas. The isolate was a close relative of Pseudoxanthomonas japonensis (95 % similarity) and designated as K2. The bacterial isolate showed positive reaction for oxidase, catalase, and 20 carbohydrates using KB009 Part A and B HiCarbohydrate™ Kit. Degradation experiments were conducted using 200 mg l-1initial IPU as a source of carbon at different pH and temperatures. Maximum IPU degradation by K2 was observed at pH 7.0 and 30 °C, while least degradation at 6.5 pH and 25 °C. Addition of dextrose along with IPU as an auxiliary carbon source increased IPU degradation by 4.72 %, as compared to the IPU degradation without dextrose under optimum conditions. 4-isopropylaniline was detected as a degradation by-product in the medium. The present study demonstrated the IPU metabolizing capacity of a novel bacterial isolate K2 that can be a better choice for the remediation of IPU-contaminated sites.
Rain Forest Research Institute, Jorhat, Assam, 785 001, India. krishna.goswami87@gmail.com.
Krishna
K
Giri
Rain Forest Research Institute, Jorhat, Assam, 785 001, India.
Shailseh
S
Pandey
Rain Forest Research Institute, Jorhat, Assam, 785 001, India.
Rajesh
R
Kumar
G. B. Pant University of Agriculture and Technology, Pantnagar, 263145, India.
J P N
JP
Rai
Biodegradation; Herbicide; Isoproturon; Phenylurea; Pseudoxanthomonas