Poly-cis-isoprene Degradation by Nocardia sp. BSTN01 Isolated from Industrial Waste

The natural and synthetic rubber (NR and SR) products are made up of poly-cis-isoprene which are estimated as one of the major solid-wastes and need to be cleared through bacterial bioremediation. The present research reports isolation and characterization of a gram-positive, non-spore forming, filamentous actinomycete Nocardia sp. BSTN01 from the waste of a rubber processing industry. We found NR- and SR-dependent growth of BSTN01 over a period of time. BSTN01 has been found to degrade NR by 55.3% and SR by 45.9% in 6 weeks. We have found an increase in the total protein of BSTN01 cells up to 623.6 and 573.9 µg/ml for NR and SR, respectively, after 6 weeks of growth in rubber-supplemented MSM medium. Scanning electron microscopy revealed adhesive growth of BSTN01 on the surface of NR and SR. Formation of aldehyde groups due to the degradation was indicated by Schiff's test and confirmed by FTIR-ATR analysis. The genome sequence of BSTN01 revealed the gene responsible for rubber degradation. The presence of lcp gene and structural analysis of the latex clearing protein further confirmed the reliability. Studies on quantification of rubber degradation capability by the isolated strain prove it to be an efficient degrader of NR and SR. This study revealed the genome sequence and structural analysis of the proteins responsible for degradation of rubber. A new fast-growing Nocardia strain can degrade both NR and SR with higher efficiency and have future potential for rubber solid-waste management either alone or in consortia.