Investigation of biodegradation potentials of high density polyethylene degrading marine bacteria isolated from the coastal regions of Tamil Nadu, India.

Plastics constitute an important part of our life for many decades. All the wastes produced from human activities finally enters into the aquatic ecosystem. Microbial degradation of plastic is a promising eco-friendly strategy which represents a great opportunity to manage waste plastic materials with minimum adverse impacts. In this present study, totally 248 bacterial isolates were isolated from the plastic waste dumped sites in the coastal region districts of Tamil Nadu, India and screened for HDPE degradation. Based on the results obtained from the weight loss, viability and FT-IR, 10 bacterial isolates were considered to be potent HDPE degraders. The identification of efficient HDPE degrading isolates confirms that most of the bacterial isolates belong to the genus Bacillus spp. and Pseudomonas spp. The present study suggests that the isolated efficient bacterial strains can be used as cost-effective, eco-friendly and safe approach for the elimination of plastic wastes from the environment.

High-density polyethylene (HDPE)-degrading potential bacteria from marine ecosystem of Gulf of Mannar, India.

AIMS: Assessment of high-density polyethylene (HDPE)-degrading bacteria isolated from plastic waste dumpsites of Gulf of Mannar. METHODS AND RESULTS: Rationally, 15 bacteria (GMB1-GMB15) were isolated by enrichment technique. GMB5 and GMB7 were selected for further studies based on their efficiency to degrade the HDPE and identified as Arthrobacter sp. and Pseudomonas sp., respectively. Assessed weight loss of HDPE after 30 days of incubation was nearly 12% for Arthrobacter sp. and 15% for Pseudomonas sp. The bacterial adhesion to hydrocarbon (BATH) assay showed that the cell surface hydrophobicity of Pseudomonas sp. was higher than Arthrobacter sp. Both fluorescein diacetate hydrolysis and protein content of the biofilm were used to test the viability and protein density of the biomass. Acute peak elevation was observed between 2 and 5 days of inoculation for both bacteria. Fourier transform infrared (FT-IR) spectrum showed that keto carbonyl bond index (KCBI), Ester carbonyl bond index (ECBI) and Vinyl bond index (VBI) were increased indicating changes in functional group(s) and/or side chain modification confirming the biodegradation. CONCLUSION: The results pose us to suggest that both Pseudomonas sp. and Arthrobacter sp. were proven efficient to degrade HDPE, albeit the former was more efficacious, yet the ability of latter cannot be neglected. SIGNIFICANCE AND IMPACT OF THE STUDY: Recent alarm on ecological threats to marine system is dumping plastic waste in the marine ecosystem and coastal arena by anthropogenic activity. In maintenance phase of the plastic-derived polyethylene waste, the microbial degradation plays a major role; the information accomplished in this work will be the initiating point for the degradation of polyethylene by indigenous bacterial population in the marine ecosystem and provides a novel eco-friendly solution in eco-management.

Synthesis, antimicrobial activities and cytogenetic studies of newer diazepino quinoline derivatives via Vilsmeier-Haack reaction.

The study of the Vilsmeier-Haack reagent on 4-hydroxyquinaldines resulted in a new versatile intermediate 4-chloro-3-formyl-2-(2-hydroxy-ethene-1-yl)quinolines, which on further treatment with hydrazine hydrate yielded the desired diazepino quinoline derivatives. All the synthesized diazepino quinoline derivatives are screened for their antibacterial and antifungal activities. Cytogenetic analysis of the samples is also reported.