title: Isolation and Characterization of Fipronil Degrading Acinetobacter calcoaceticus and Acinetobacter oleivorans from Rhizospheric Zone of Zea mays.
abstract: An enrichment culture technique was used for the isolation of bacteria capable of utilizing fipronil as a sole source of carbon and energy. Based on morphological, biochemical characteristics and phylogenetic analysis of 16S rRNA sequence, the bacterial strains were identified as Acinetobacter calcoaceticus and Acinetobacter oleivorans. Biodegradation experiments were conducted in loamy sand soil samples fortified with fipronil (50 µg kg(-1)) and inoculated with Acinetobacter sp. cells (45 × 10(7) CFU mL(-1)) for 90 days. Soil samples were periodically analyzed by gas liquid chromatography equipped with electron capture detector. Biodegradation of fipronil fitted well with the pseudo first-order kinetics, with rate constant value between 0.041 and 0.051 days(-1). In pot experiments, fipronil and its metabolites fipronil sulfide, fipronil sulfone and fipronil amide were found below quantifiable limit in soil and root, shoot and leaves of Zea mays. These results demonstrated that A. calcoaceticus and A. oleivorans may serve as promising strains in the bioremediation of fipronil-contaminated soils.
authors.affiliation: Department of Environmental Science, Swami Ramtirth Campus Badshahithaul, Hemwati Nandan Bahuguna Garhwal University, Srinagar Garhwal, Uttarakhand, India. shivi273@gmail.com.
authors.forename: Shivani
authors.initials: S
authors.lastname: Uniyal
authors.affiliation: Ecotechnology Laboratory, Department of Environmental Science, G. B. Pant University of Agriculture and Technology, Pantnagar, India.
authors.forename: Rashmi
authors.initials: R
authors.lastname: Paliwal
authors.affiliation: Ecotechnology Laboratory, Department of Environmental Science, G. B. Pant University of Agriculture and Technology, Pantnagar, India.
authors.forename: Megha
authors.initials: M
authors.lastname: Verma
authors.affiliation: G. B. Pant Institute of Himalayan Environment and Development, Himachal Unit, Mohal-Kullu, Himachal Pradesh, India.
authors.forename: R K
authors.initials: RK
authors.lastname: Sharma
authors.affiliation: Ecotechnology Laboratory, Department of Environmental Science, G. B. Pant University of Agriculture and Technology, Pantnagar, India.
authors.forename: J P N
authors.initials: JP
authors.lastname: Rai
mesh_terms: D016954:Acinetobacter calcoaceticus / Q000302:isolation & purification* / Q000378:metabolism; D001673:Biodegradation, Environmental; D002849:Chromatography, Gas; D007306:Insecticides / Q000737:chemistry; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology; D011720:Pyrazoles / Q000737:chemistry*; D012336:RNA, Ribosomal, 16S / Q000235:genetics / Q000302:isolation & purification; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis; D003313:Zea mays / Q000382:microbiology*
chemical_list: D007306:Insecticides; D011720:Pyrazoles; D012336:RNA, Ribosomal, 16S; D012987:Soil; D012989:Soil Pollutants; C534368:fipronil sulfone; C082360:fipronil
keywords: Acinetobacter; Biodegradation; Fipronil; Kinetics; Metabolites