Bioremediation of ε-Caprolactam from Nylon-6 Waste Water by Use of Pseudomonas aeruginosa MCM B-407

Abstract.

Nylon-6, a man-made polymer that finds its application in the manufacture of car tires, ropes, fabrics, automobile parts etc., is manufactured with ε-caprolactam. Waste water generated during production of nylon-6 contains the unreacted monomer. Owing to the polluting and toxic nature of ε-caprolactam, its removal from waste streams is necessary. Pseudomonas aeruginosa MCM B-407 was isolated from activated sludge used to treat waste from a factory producing nylon-6. This organism was able to remove ε-caprolactam with simultaneous reduction in chemical oxygen demand (COD). The degradation of ε-caprolactam in waste water was found to be optimal over a wide range of pH from 5.0 to 9.0, temperature of 30°C, and under shake or aerated conditions, with an inoculum density of 10⁵ cells/ml and with an incubation period of 24 – 48 h. Thus, Pseudomonas aeruginosa MCM B-407 isolated from the activated sludge exposed to ε-caprolactam may play an important role in the bioremediation of ε-caprolactam from the waste waters of industries manufacturing nylon-6.