Identification of Bacterial Species Capable of Degrading LDPE

Abstract

The Plastic is polymeric material having capability of being molded or shaped by the application of heat and pressure. The low-density polyethylene(LDPE) is the type of plastic which is used in various purpose of our daily life. It is one of the major environmental problems because of its slow degradation rate .To control the pollution caused by low-density polyethylene, microbes are isolated from the dumping site of the Durg region of Chhattisgarh. These microbes are screened by the zone of clearance method for degradation of low-density polyethylene using PEG as substrate. The screened microbes were identified by morphological and biochemical characteristics.Nine bacterial isolates was selected for biodegradation studies.Confirmation of bacterial biodegradation of low-density polyethylene was performed by using weight loss measurement and pH change due to production of acidic product.One potential isolate were further identified through 16S rRNA sequences Alcaligenes faecalis was shown the high degradation rate of low-density polyethylene.

Introduction

I. INTRODUCTION

Plastic is a very big problem for environment because of its slow degradation rate. Plastics are the polymer which can be changed into variety of shapes by heating .It is used in various purposes such as packaging of food materials, cosmetics, pharmaceutical products.Plastics includes polyethylene {Low-density polyethylene(LDPE),High density polyethylene( HDPE)}, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, nylon. Plastic degradation refers to the physical or chemical change in the polymer due to environmental factors like light, heat, moisture, chemical condition and biological activity [1].

 Low-density polyethylene is the most important environmental problem because its chemical structure containing C-C and C-H bonds. Low-density polyethylene degradation is very difficult due to its recalcitrant nature. Recalcitrant nature is due to the hydrophobic property ,high molecular weight and three-dimensional structure [2].

Environmental factors like heat, moisture, light, chemical condition and biological activity results in the physical or chemical change of the polymer .Biodegradation is the process of degradation of substance by using microbes.Microorganism release some enzyme which change the polymer into oligomers, dimers and monomers. In natural condition the degradation rate of polyethylene is quite slow if it is in natural condition.Microorganisms such as Bacillus strain ,Pseudomonas species etc. have been reported to degrade low-density polyethylene.[2],[3],and [10].

The aim of the present study is to isolate and screen the indigenous microbial species   capable of degrading low-density polyethylene.

II. MATERIALS AND METHODS

A. Collection of soil sample

The soil  samples were collected from several sites of Durg district of Chhattisgarh such as  waste dumping sites of potiya , chandkhuri , kolihapuri.

B. Collection of polyethylene films

The low-density polyethylene films (0.910-0.940g/cm3 ) were collected from the local market of  Durg [4] and [5]. 

C. Isolation of LDPE Degrading Bacteria

The low-density polyethylene degrading bacteria was isolated by using the synthetic medium  containing NH4NO3 (1.0g), MgSO4.7H2O (0.2g), K2HPO4 (1.0g), CaCl2.2H2O (0.1 g), KCl (0.15g), Yeast extract (0.1g), FeSO4.6H20(1.0mg),ZnSO4.7H2O(1.0 mg),MnSO4(1.0 mg),Tween 60,or 80 [0.01-0.50%(v/v)], and Agar by serial dilution and spread plate method and incubated at 370  C for 24 hrs.

Conclusion

Microbial-based degradation of environmental pollutants is well known accepted phenomenon as the decomposer nature of naturally occurring microorganisms.In the present study the indigenous bacterial strains which examined for potential biodegradation of low-density polyethylene materials, causing primary pollution in common environments.The study reveals that the study site was having a potential consortium of bacteria capable to degrade low-density polyethylene.Weight loss and pH change studies at time intervals confirmed the biodegradation process. FTIR studies further demonstrated the chemical changes in the pollutant leading formation of simple compounds which can be further used or removed by other invaders from environment.The molecular characterization support for authentic nomenclature of potential isolate as Alcaligenes faecalis.

References

[1] Sharma J,Gurung T,Upadhyay A,Nandy K,Agnihotri P,Mitra AK. Isolation and characterization of plastic degrading bacteria from soil collected from the dumping grounds of an industrial area .International Journal of Advanced and Innovative Research.3(2014): p.225-232. [2] Gupta K K , Devi D, Rana D. Isolation and screening of low-density polyethylene (Ldpe) degrading bacterial strains from waste disposal sites.11(2016): p.1633-1643. [3] Maroof L, Khan I, Yoo H S, Kim Spark H T, Ahmad B, Azam Identification and characterization of low-density polyethylene degrading bacteria isolated from soils of waste disposal sites.Environmental Engineering Research.26(2021): p. 1-9. [4] Gajendiran A, Sharmila Khrishnamoorthy, Jayanthi Abraham. Microbial degradation of Low-density Polyethylene (LDPE) by Aspergillus Clavatus Strain JASK, isolated from landfill soil. Biotech,6 (2016):p 1-6. [5] Priyanka N and Archana T.(2011).Biodegradability of polyethylene and plastic by the help of microorganism ,J Environ Anal Toxicol.1(2011):p. 1-4. [6] Singh G, Singh AK,Bhatt Biodegradation of polyethylene by bacteria isolated from soil .International Journal of Research and Development in Pharmacy and life science.5(2016):p.2056-2062. [7] Ariba Begam M., B. Varalakshmi and K. Umamagheshwari. Biodegradation of polythene Bag using Bacteria Isolated from Soil. International Journal of current Microbiology and Applied Sciences ,11 (2015): p. 674-680.Z [8] Abraham J,Ghosh E, Mukherjee P, and Gajendiran A.Microbial degradation of low-density polyethylene.American Institute of Chemical Engineers, 36 (2016): p.147-152 . [9] Divyalaxmi S, Subhashini A. (2016). Screening and isolation of polyethylene degrading bacteria from various soil environments. IOSR Journal of Environmental Science, Toxicology and Food Technology,10 (2016): p. 01-07. [10] Karthick T, Sumitra B, Bhuvaneshwari K P, Gurujeya B, Jaya barath J. (2016). Biodegradation of plastic by Bacillus subtilis isolated from polythene polluted soil. World Journal of Pharmaceutical Research.5(2016): p.1148-1153.

Copyright

Copyright © 2024 Hempushpa Urwasha, Pragya Kulkarni. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.