Effect of Pretreatments on Enhanced Degradation of Polyisoprene Rubber by Newly Isolated Bacillus sp. Strain SIO

Abstract

The present investigation was conducted to isolate polyisoprene rubber (latex gloves) degrading microorganisms from soil. Twelve bacterial species were isolated through enrichment technique and were screened for their capacity to degrade rubber. Best growth was observed with Bacillus sp. S10 in terms of diameter of the spot on latex overlay mineral salt agar plates and increase in optical density as determined at 600 nm for liquid culture. The effect of different pretreatments like extraction of rubber pieces with organic solvent (acetone), pretreatment with UV and sunlight, effect of temperature and pH were optimized for Bacillus sp. S10 in liquid MSM with pieces of gloves as the only source of carbon. In case of pretreated rubber best growth was observed in case of acetone pretreated rubber shown by increase in optical density. Bacillus sp. S10 grew best at pH 7 at 37 ºC. Qualitative analysis of degradation of pretreated rubbers, after incubation in liquid MSM with Bacillus sp. S10 was done through FTIR which showed marked differences in transmittance spectra of test and control due to changes in the functional groups. Present study on biodegradation may provide an opportunity for further studies on the applications of biotechnological processes as a tool for rubber waste management.