Biodegradation of cypermethrin by immobilized cells of <italic>Micrococcus</italic> sp. strain CPN 1

Tallur, Preeti NMulla, Sikandar IMegadi, Veena BTalwar, Manjunatha PNinnekar, Harichandra Z

<p>Pyrethroid pesticide cypermethrin is a environmental pollutant because of its widespread use, toxicity and persistence. Biodegradation of such chemicals by microorganisms may provide an cost-effective method for their detoxification. We have investigated the degradation of cypermethrin by immobilized cells of <italic>Micrococcus</italic> sp. strain CPN 1 in various matrices such as, polyurethane foam (PUF), polyacrylamide, sodium alginate and agar. The optimum temperature and pH for the degradation of cypermethrin by immobilized cells of <italic>Micrococcus</italic> sp. were found to be 30 °C and 7.0, respectively. The rate of degradation of 10 and 20 mM of cypermethrin by freely suspended cells were compared with that of immobilized cells in batches and semi-continuous with shaken cultures. PUF-immobilized cells showed higher degradation of cypermethrin (10 mM and 20 mM) than freely suspended cells and cells immobilized in other matrices. The PUF-immobilized cells of <italic>Micrococcus</italic> sp. strain CPN 1 were retain their degradation capacity. Thus, they can be reused for more than 32 cycles, without losing their degradation capacity. Hence, the PUF-immobilized cells of <italic>Micrococcus</italic> sp. could potentially be used in the bioremediation of cypermethrin contaminated water.</p>.(AU)

1. Immobilization
2. Cypermethrin
3. <italic>Micrococcus</italic> sp. strain CPN 1
4. Degradation
5. Polyurethane foam