Journal of Applied Biosciences (J. Appl. Biosci.) [ISSN 1997 - 5902]
Volume 12: 657 - 660. Published December 11, 2008.
Bioremediation of Chlorpyrifos by Pseudomonas aeruginosa using scale up technique
M. H. Fulekar and M. Geetha
Environmental Biotechnology Laboratory, Department of Life Sciences, University of Mumbai, Mumbai, India
^Corresponding author e–mail:mhfulekar@yahoo.com
ABSTRACT
Objective: To assess the bioremediation potential of Pseudomonas aeruginosa (NCIM 2074) by improving its adaptability to increasing concentration of chlorpyrifos using scale up process.
Methodology and results: Pseudomonas aeruginosa isolate NCIM 2074 was adapted by subjecting to varying concentrations of chlorpyrifos, i.e. 10, 20, 50, 75 and 100 mg/l in incubator shaker at 37 °C and 150 rpm. An initial 10 mg/l concentration of chlorpyrifos was supplied in minimal salt medium (MSM) under controlled environmental conditions for 14 days. The culture was subsequently scaled up to higher concentrations of chlorpyrifos by transferring one milliliter from the medium with 10mg/L to 25 mg/l of the compound. After every 14 days this process was repeated, each time using medium with higher chlorpyrifos concentration. The entire scale up process continued for a period of 70 days. Pseudomonas aeruginosa (NCIM 2074) was adapted to increasing chlorpyrifos upto 50 mg/l, but 75 and 100 mg/l was inhibitory to the organism. The biodegradation of chlorpyrifos, as assessed by GC-MS, showed that chlorpyrifos at 10, 25, 50 mg/l degraded completely over a period of 1, 5 and 7 days, respectively. The intermediate 3, 5, 6 trichloro-2-pyridion, 2, 4-bis (1, 1 dimethyiethyl) phenol and 1, 2 Benzenedicarboxylic acid persised during bioremediation, but in the long run these convert to CO2, biomass and nutrients.
Conclusion and application of findings: Pseudomonas aeruginosa (NCIM 2074) has been potential use in bioremediation of chlorpyrifos at concentrations upto 50 mg/l, but the organism is inhibited by higher concentrations.
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