ISOLATION AND MOLECULAR CHARACTERIZATION OF PLASTIC DEGRADING BACTERIA FROM DUMPED GARBAGE SOIL
Keywords:biodegradation, ecosystem, micro-organisms, molecular characterization, plastic
Objective: Plastics are polymers that are widely in application in our day-to-day life. The plastic wastes accumulation is causing threat to the environment as it causes environmental pollution and creates imbalance in the ecosystem. The natural degradation of plastic is too time consuming and the ways to do it are not highly successful. An eco-friendly approach to plastic degradation is using microbial degradation method. Microorganisms play an important role in biological decomposition of various materials in our environment. Thus, the main objective of the present study is isolation and molecular characterization of plastic degrading bacteria from dumped garbage soil.
Methods: The samples were collected from two different locations in Bengaluru and further subcultured to obtain pure culture. Gram’s staining was performed to identify bacterial strains and few tests were conducted to find out the biochemical properties of the bacteria. Molecular characterization of isolated bacteria was performed using 16S rRNA method, BLAST and phylogenetic tree were constructed.
Results: The bacterial isolates were found to be, namely, Aeromonas caviae, Aeromonas hydrophila, Salmonella enterica, and Pseudomonas aeruginosa. The polythene bag biodegradation was analyzed by incubation for a period of 2 months in liquid culture method.
Conclusion: The results of the study ensure that A. hydrophila showed more degrading capability which is followed by A. caviae, whereas Pseudomonas aeruginosa and S. enterica did not contribute in much of the plastic degradation. The weight loss of polythene bag is maximum with higher incubation period rate. From the observation, we conclude that bacteria have more capability to cleave polymer.
Lee B, Pometto AL, Fratzke A, Bailey TB. Biodegradation of degradable plastic polyethylene by phanerochaete and Streptomyces species. Appl Environ Microbiol 1991;57:678-85.
Rivard C, Moens L, Roberts K, Brigham J, Kelley S. Starch esters as biodegradable plastics: Effects of ester group chain length and degree of substitution on anaerobic biodegradation. Enz Microbial Technol 1995;17:848-52.
Shimao M. Biodegradation of plastics. Curr Opin Biotechnol 2001;12:242-7.
Smith WM. Manufacture of Plastic. Vol. 1. United States: Technology and Engineering, Reinhold; 1964.
Gnanavel G, Valli VP, Thirumarimurugan M, Kannadasa T. Degradation of plastics using microorganisms. Int J Pharm Chem Sci 2012;1:691-4.
Spear LB, Ainley DG, Ribic CA. Incidence of plastic in seabirds from the tropical pacific l984-1991: Relation with distribution of species, sex, age, season, year and body weight. Mar Environ Res l995;40:123-46.
Mueller RJ. Biological degradation of synthetic polyesters-enzymes as potential catalysts for polyester recycling. Proc Biochem 2006;41:2124-8.
Singh G, Singh AK, Bhatt K. Biodegradation of polythene by Bacteria isolated from soil. Int J Res Dev Pharm Life Sci 2016;5:2056-62.
Begum MA, Varalakshmi B, Umamagheswari K. Biodegradation of polythene bag using bacteria isolated from soil. Int J Curr Microbiol Appl Sci 2015;4:674-80.
Erin RS. Aseptic laboratory techniques: Plating methods. In: Microbiology, Immunology, and Molecular Genetics. Los Angeles: University of California; 2020.
Khan Academy. Polymerase Chain Reaction. United States: Khan Academy; 2020.
Kahl G. Sanger sequencing (Sanger method, enzymatic method, dideoxy method, dideoxy sequencing, chain terminator method, chain terminator sequencing procedure, enzymatic DNA sequencing, dideoxy mediated chain termination technique). In: The Dictionary of Genomics, Transcriptomics and Proteomics. Germany: Wiley VCH; 2015. p. 1-1.
Kannahi M, Rubini K. Biodegradation of polythene bag by aspergillusoryzae. Biosci Biotechnol Res Asia 2012;9:423-6.
Usha R, Sangeetha T, Palaniswamy M. Screening of polyethylene degrading microorganisms from garbage soil. Libyan Agric Res Cent J Int 2011;2:200-4.
Deepika S, Madhuri RJ. Biodegradation of low density polyethylene by micro-organisms from garbage soil. J Exp Biol Agric Sci 2015;3:15-21.