Biodegradation of chlorpyrifos and its metabolite 3,5,6-trichloro-2- pyridinol (TCP) were studied in aqueous medium and in soil with a novel bacterial strain JAS3. The molecular characterization based on 16S rRNA sequence analysis revealed the strain JAS3 as Sphingobacterium sp. The strain JAS3 was able to grow in minimal salt medium (MSM) supplemented with 300 mg l -1 of chlorpyrifos as sole carbon source. The degradation of chlorpyrifos and its primary metabolite TCP were examined by HPLC. After 5 d, Sphingobacterium sp. JAS3 degraded chlorpyrifos and its metabolite TCP to benzene, 1,3-bis(1,1-dimethylethyl) was analyzed by GCMS. Degradation of chlorpyrifos and TCP in soil with and without addition of nutrients was also studied. The ability to degrade chlorpyrifos makes this strain a useful candidate for remediation of pesticide contaminated sites. © 2013 Elsevier Ltd. All rights reserved.

Jayanthi Abraham

Department of Bio-Medical Sciences

School of Bio Sciences and Technology

Vellore Campus

Silambarasan S.

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Process Biochemistry

The bacterium Serratia marsescens strain JAS16 was isolated from agricultural soil which had prior exposure to monocrotophos for three years. The strain JAS16 tolerated up to 1200 mg L–1 monocrotophos and degraded the insecticide (1000 mg L–1) at a degradation rate constant of 136 d−1 (DT50 = 3.7 d). In soil, the degradation rate constant was 105 d−1 (DT50 = 4.8 d). A schematic pathway is being proposed from the degraded products derived from gas chromatography--mass spectrometry (GC-MS). The phytotoxicity of degradation products to Vigna radiata, Vigna unguiculata, and Macrotyloma uniflorum and the genotoxicity to Allium cepa roots were found to be low. A cost-effective powder-based formulation was achieved with the isolate. The isolate remained viable during the storage and also multiplied with a higher colony forming units (CFU) load g–1 for over a period of seven weeks of storage. © 2015 Taylor &amp; Francis.

Toxicological & Environmental Chemistry

Bacterial degradation of monocrotophos and phyto- and cyto-toxicological evaluation of metabolites

Several researchers have focussed on degradation of pesticides by microorganisms, which is the most viable option in remediation of agricultural soil. However, very few have illustrated the degradation of mixed pesticides. Hence, in the present investigation biodegradation of a mixture of both organophosphorus and organochlorine pesticide directed by microbial consortium was carried out in a fermentor-bioreactor system. The pesticides chosen were chlorpyrifos, monocrotophos (organophosphorus) and endosulfan (organochlorine). In order to accomplish an effective degradation, the microorganisms were isolated from agricultural fields which were previously exposed to the pesticides mentioned above. The bacteria were isolated by minimal meda with the individual pesticide as the only carbon source. The individual strains were identified by morphological, biochemical and 16S rRNA characterization. The bacterial consortium comprised of 10 organisms which were as follows: Alcaligenes sp. JAS1, Ochrobactrum sp. JAS2, Sphingobacterium sp. JAS3 which were screened and selected from chlorpyrifos contaminated soil, Enterobacter ludwigii JAS17, Pseudomonas moraviensis JAS18 and Serratia marcescens JAS16 which were isolated from monocrotophos spiked soil and Klebsiella pneumoniae JAS8, Enterobacter cloacae JAS7, Halophilic bacteria JAS4, Enterobacter asburiae strain JAS5 were obtained from endosulfan persistent soil sample. The fermentor-bioreactor system containing 2L of sterile minimal medium supplemented with 300mgl-1 of chlorpyrifos, 1000mgl-1 of monocrotophos, 1000mgl-1 of endosulfan as the only source of carbon and inoculated with 20ml of bacterial consortium (approximately 3×106cellsml-1). The HPLC and GC-MS studies were performed to record the degradation of mixed pesticides. © 2014 Taiwan Institute of Chemical Engineers.

Journal of the Taiwan Institute of Chemical Engineers

Simultaneous degradation of organophosphorus and organochlorine pesticides by bacterial consortium

JAS1 bacterial strain capable of degrading chlorpyrifos and its major metabolite 3,5,6-trichloro-2-pyridinol (TCP) were isolated from paddy field soil. The isolated bacterial strain was characterized using morphological and biochemical analysis, as well as molecular characterization based on 16S rRNA sequence homology which confirmed its identity as Alcaligenes sp. The isolated bacterial strain efficiently degraded 300mg/l of chlorpyrifos within 12h of incubation and TCP was observed to accumulate in the aqueous medium. In soil studies with nutrients amendment along with chlorpyrifos and Alcaligenes sp. JAS1 showed undetectable level of pesticide in 24h, whereas in the absence of nutrients the pesticide was found to be degraded in 48h. Kinetic studies based on various models were carried out and the results showed a very good compliance with the first and pseudo first order models. TCP degradation process by Alcaligenes sp. JAS1 was characterized by the rate constant (k) of 1.364d-1 and the initial concentration was reduced by 50% (DT50) was 0.5d in the aqueous medium. Studies on biodegradation of TCP in soil with nutrients showed that JAS1 strain exhibited efficient degradation with a rate constant of 1.137d-1, and DT50 was 0.6d. In contrast, degradation of TCP in soil without nutrients was characterized by a rate constant of 0.953d-1 and DT50 was 0.7d. © 2012 Taiwan Institute of Chemical Engineers.

Kinetic studies on enhancement of degradation of chlorpyrifos and its hydrolyzing metabolite TCP by a newly isolated Alcaligenes sp. JAS1

Bioresource Technology

Biodegradation of chlorpyrifos and 3,5,6-trichloro-2-pyridinol by Cupriavidus sp. DT-1

International Biodeterioration & Biodegradation

Simultaneous degradation of the pesticides methyl parathion and chlorpyrifos by an isolated bacterial consortium from a contaminated site

Biology and Fertility of Soils

Fungal degradation of chlorpyrifos by Acremonium sp. strain (GFRC-1) isolated from a laboratory-enriched red agricultural soil

Isolation and characterization of 3,5,6-trichloro-2-pyridinol-degrading Ralstonia sp. strain T6

Biodegradation of chlorpyrifos and its hydrolyzing metabolite 3,5,6-trichloro-2-pyridinol by Sphingobacterium sp. JAS3

Journal	Data powered by TypesetProcess Biochemistry
Publisher	Data powered by TypesetElsevier BV
ISSN	1359-5113
Open Access	0