The recalcitrant nature of polyvinyl chloride creates serious environmental concerns during manufacturing and waste disposal. The present study was aimed to isolate and screen different soil fungi having potential to biodegrade PVC films. After 10 months of soil burial experiment, it was observed that a number of fungal strains were flourishing on PVC films. On morphological as well as on 18rRNA gene sequence and phylogenetic basis they were identified as Phanerochaete chrysosporium PV1, Lentinus tigrinus PV2, Aspergillus niger PV3, and Aspergillus sydowii PV4. The biodegradation ability of these fungal isolates was further checked in shake flask experiments by taking thin films of PVC (C source) in mineral salt medium. A significant change in color and surface deterioration of PVC films was confirmed through visual observation and Scanning electron microscopy. During shake flask experiments, P. chrysosporium PV1 produced maximum biomass of about 2.57 mg ml(-1) followed by A. niger PV3. P. chrysosporium PV1 showed significant reduction (178,292 Da(-1)) in Molecular weight of the PVC film than control (200,000 Da(-1)) by gel permeation chromatography. Furthermore more Fourier transform infrared spectroscopy and nuclear magnetic resonance also revealed structural changes in the PVC. It was concluded that isolated fungal strains have significant potential for biodegradation of PVC plastics.

The present fluidized bed bioreactor setup with indigenously isolated fungal strain in its immobilized form is efficiently able to convert the parent toxic dye into less toxic by-products.

The accumulation of plastics in the environment is raising great concerns with respect to long-term environmental, economic and waste management problems. The aim of the present research was to investigate the biodegradability of starch blended polyvinyl chloride films in soil burial and controlled laboratory experiments using selective fungal isolates. Clear surface aberrations as color change and minor disintegration in polyvinyl chloride films were observed after 90 days and later confirmed through scanning electron microscopy. The fungal strains showing prominent growth and adherence on plastic films were isolated. One of the strains showing maximum activity was selected and identified as Phanerochaete chrysosporium PV1 by rDNA sequencing. Fourier transform infrared spectroscopy and nuclear magnetic resonance analyses indicated considerable structural changes and transformation in films in terms of appearance of new peaks at 3,077 cm -1 (corresponding to alkenes) and decrease in intensity of peaks at 2,911 cm -1 (C-H stretching). It was supported with a significant decrease in the molecular weight of polymer film from 80,275 to 78,866 Da (treated) through Gel permeation chromatography in shake flask experiment. Moreover, the biodegradation of starch blended polyvinyl chloride films was confirmed through release of higher CO 2 (7.85 g/l) compared to control (2.32 g/l) in respirometric method. So fungal strain P. chrysosporium PV1 has great potential for use in bioremediation of plastic waste.

Polystyrene is considered stable to biological degradation. Lantinus tigrinus isolated from wood sample produced esterase in growth medium under normal conditions. However, acidic medium, 37 degrees C temperature, presence of tween 80; and urea and yeast extract in mineral salt medium enhance the production of esterase and specific activity. Purified esterase was active at broad pH range and 45 degrees C. FTIR analysis confirmed that esterase produced by Lantinus tigrinus effectively degraded polystyrene film and broke macromolecules down to non-toxic molecules. This study concludes that the presence of Lantinus tigrinus at dumping sites can be exploited for waste management containing high molecular weight synthetic polymers.

Context: Endophytic fungi, being a prolific source of bioactive secondary metabolites, are of great interest for natural product discovery. Objective: Isolation and partial characterization of endophytic fungi inhabiting the leaves and woody parts of Taxus fuana Nan Li & R.R. Mill. (Taxaceae) and evaluation of biological activity. Materials and methods: Endophytic fungal isolates were identified by molecular analysis of internal transcribed spacer (ITS) regions of 18S rDNA. Extracts of the endophytic fungi cultured on potato dextrose agar and modified medium were evaluated using cancer chemoprevention bioassays [inhibition of TNF-ainduced NFjB, aromatase and inducible nitric oxide synthase (iNOS); induction of quinone reductase 1 (QR1)] and growth inhibition with MCF-7 cells. Results: Nine of 15 fungal isolates were identified as belonging to Epicoccum, Mucor, Penicillium, Chaetomium, Paraconiothriym, Plectania or Trichoderma. Five of the 15 extracts inhibited NFjB activity (IC 50 values ranging between 0.18 and 17 lg/mL) and five inhibited iNOS (IC 50 values ranging between 0.32 and 12.9 lg/mL). In the aromatase assay, only two isolates mediated inhibition (IC 50 values 12.2 and 10.5 lg/ mL). With QR1 induction, three extracts exhibited significant activity (concentrations to double activity values ranging between 0.20 and 5.5 lg/mL), and five extracts inhibited the growth of MCF-7 cells (IC 50 values ranging from 0.56 to 17.5 lg/mL). Six active cultures were derived from woody parts of the plant material. Conclusion: The endophytic fungi studied are capable of producing pharmacologically active natural compounds. In particular, isolates derived from the wood of Taxus fuana should be prioritized for the isolation and characterization of bioactive constituents. ARTICLE HISTORY