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Penicillium simplicissimum was isolated from a local dumpsite of Shivamogga district for use in the biodegradation of polyethylene. Degradation was carried out using autoclaved, UV-treated and surface-sterilized polyethylene. Degradation was monitored by observing weight loss and changes in physical structure by scanning electron microscopy, Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. P. simplicissimum was able to degrade treated polyethylene (38 %) more efficiently than autoclaved (16 %) and surface-sterilized polyethylene (7.7 %). Enzymes responsible for polyethylene degradation were screened from P. simplicissimum. Enzymes were identified as laccase and manganese peroxidase. These enzymes were produced in large amount, enzyme activity was calculated using spectrophotometric method, and crude extraction of enzymes was carried out. Molecular weight of laccase was determined as 66 kDa and that of manganese peroxidase was 60 kDa. Capacity of crude enzymes to degrade polyethylene was also determined. By observing these results, we can conclude that P. simplicissimum may act as solution for the problem caused by polyethylene in nature.

Trichoderma harzianum was isolated from local dumpsites of Shivamogga District for use in the biodegradation of polyethylene. Soil sample of that dumpsite was used for isolation of T. harzianum. Degradation was carried out using autoclaved, UV-treated, and surface-sterilized polyethylene. Degradation was monitored by observing weight loss and changes in physical structure by scanning electron microscopy, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy. T. harzianum was able to degrade treated polyethylene (40%) more efficiently than autoclaved (23%) and surface-sterilized polyethylene (13%). Enzymes responsible for polyethylene degradation were screened from T. harzianum and were identified as laccase and manganese peroxidase. These enzymes were produced in large amount, and their activity was calculated using spectrophotometric method and crude extraction of enzymes was carried out. Molecular weight of laccase was determined as 88 kDa and that of manganese peroxidase was 55 kDa. The capacity of crude enzymes to degrade polyethylene was also determined. By observing these results, we can conclude that this organism may act as solution for the problem caused by polyethylene in nature.

The present study was carried out to isolate rubber degrading bacteria and to check the enzymes responsible for degradation, so that the isolates can be effectively used in rubber degradation. Different bacteria were isolated from soil samples and natural rubber samples collected from a rubber processing unit, and were screened for their ability to degrade natural rubber by plate assay. A biodegradation experiment was carried out in the laboratory to confirm degradation. Enzymes responsible for natural rubber degradation were characterized, crude enzyme was extracted by submerged fermentation process and its activity was determined. After extraction of crude enzyme, it was partially purified by dialysis process, and then, the enzyme activity and specific activity were determined. Then, the ability of these enzymes to degrade natural rubber discs were checked. The ability of natural rubber degrading microorganisms to degrade rubber products such as rubber gloves discs and rubber tire discs, was tested. Among the isolated bacterial species, Bacillus subtilis was predominant and showed growth on the natural rubber discs. The biodegradation experiment showed 48.6 % weight loss. It was screened that laccase and manganese peroxidase enzymes are responsible for natural rubber degradation. When enzyme activity was determined, Bacillus subtilis, showed more manganese peroxidase activity compared to laccase activity. Laccase enzyme activity was 0.0138 IU and manganese peroxidase activity was 0.0155 IU. The molecular weights of laccase enzyme (64 kDa) and of manganese peroxidase enzyme (68 kDa) were determined. Biodegradation of rubber by microorganisms was confirmed by Schiff's staining, SEM, FTIR and NMR studies.The term natural rubber or cahuchu (from Indian, caa = tears, ochu = tree cahuchu = weeping tree) refers to a coagulated or precipitated product obtained from latex of rubber plants (Hevea brasiliensis), which forms non-linked but partially vulcanizable polymer chains having molecular masses of about 10 6 Da with elastic properties. Latex serves as a clogging material during healing of wounds caused by mechanical injury of plants.The natural rubber latex is sticky and viscous in nature and very sensitive to temperature, therefore, it cannot be directly used for the manufacturing of rubber products, unless subjected to vulcanization. Due to the special characters of the rubber it is extensively used worldwide. The global rubber consumption was estimated to be 12.5 million metric tons in 2013 of which 65 % were used for tire production and the other 35 % was used for the production of other rubber products (Tsuchii and Tokiwa 1999).The average composition of the natural rubber latex is 25-30 % polyisoprene, 1-1.8 % proteins, 1-2 % carbohydrates, 0.4-1.1 % neutral lipids, 0.5-0.6 % polar lipids, 0.4-0.6 % inorganic components, 0.4 % aminoacids and other 50-70 % water. Dry weight of the natural rubber latex contains more than 90 % of cis-1, 4-polyisoprene and less than 10 % of nonrubber constituents like proteins, car...