Biodegradation of chlorpyrifos by scaling up method in controlled environmental conditions and plant growth enhancement

Abstract

Biodegradation study of chlorpyrifos was done by the bacterial strains of species Pseudomonas aeruginosa. Scaling up the concentration of chlorpyrifos from 15mg/l up to 100mg/l was done, and GC-MS recorded an amount of chlorpyrifos degradation at a constant interval of 15days. The results show that in this scaling up processes 15-50mg/l concentration of chlorpyrifos was readily degraded by Pseudomonas spp. But as we started increasing the level from 75-100mg/l, the biodegradation rate starts decreasing up to 25% at 100 mg/l concentration. Intermediate such as 3, 5, 6 trichloro-2-pyridine,2,4-bis (1, 1 dimethyl ethyl) phenol and 1, 2 Benzenedicarboxylic acid persisted during bioremediation, but after day 18-20 these subsequently get convert to CO2, biomass and nutrients. This strain also shows some significant plant growth promoting activities such as IAA production, p-solubilization, ammonia production both in presence and absence of chlorpyrifos. Confirmed when inoculated with chlorpyrifos degrading strain Pseudomonas aeruginosa, results showed enhanced plant growth in terms of plant height parameters. Thus it is concluded that Pseudomonas aeruginosa easily degrades chlorpyrifos at 50-75mg/l chlorpyrifos concentration, but its potential gets inhibited at a higher level of chlorpyrifos. This study also clearly indicated the role of Pseudomonas aeruginosa (AP2016) in practical bioremediation of chlorpyrifos and simultaneously increasing the production of pesticide-contaminated agricultural fields.