Identification and characterization of low density polyethylene-degrading bacteria isolated from soils of waste disposal sites

Abstract

The current study focused on an environment friendly method for degradation of Low Density Polyethylene (LDPE) using bacteria. A total of 36 bacterial strains were isolated from waste disposal sites in which six strains showed potential biodegradation activities. In this study, we reported 2 new strains i.e. Bacillus siamensis and Bacillus wiedmannii for LDPE degradation. The percent weight loss of LDPE films for isolates was; B. siamensis (8.46 ± 0.3%), B. cereus (6.33 ± 0.2%), B. wiedmannii (5.39 ± 0.3%), B. subtilis (3.75 ± 0.1%), P. aeruginosa (1.15 ± 0.1%) and A. iwoffii (0.76 ± 0.1%) after 90 d of incubation. The LDPE films showed slight surface disruption as observed in Field Emission Scanning Electron Microscopy (FE-SEM) and Fourier Transform Infrared Spectroscopy (FTIR) showed formation of typical carbonyl peaks which were markedly reduced after incubation as measured by carbonyl index. The X-Ray Diffraction (XRD) analysis presented an increase in percent crystallinity and there was no apparent change in total carbon percentage. Different genes responsible for degradation of LDPE like Laccase (167 bp), Alk1 (330 bp) and Alk2 (185 bp) were identified in bacterial isolates and further sequenced. The low degradation values in this study indicate that LDPE degradation is a slow, continuous and time dependent process.

Isolation of Thermophilic Bacteria and Investigation of Their Microplastic Degradation Ability Using Polyethylene Polymers

“…For example, Enterobacter and Pseudomonas exhibited significant biodegradation of plastics, showing up to 15% weight loss in 120 days [74]. Similarly, Maroof et al (2021) also revealed that a new bacterial strain, B. siamensis, showed a degradation ability with a percentage of 8.46% LDPE after 90 d of incubation [75].…”

Biodegradation and detoxification of low-density polyethylene by an indigenous strain Bacillus licheniformis SARR1

“…The amorphous region of LDPE was found disintegrated in the treated sample. Bacillus siamensis and Bacillus wiedmannii decreased the crystallinity percentage of LDPE after 90 days of incubation [46]. The crystallinity of LDPE was decreased by treating with the mixed cultures of Aspergillus sp.…”

Call for biotechnological approach to degrade plastic in the era of COVID-19 pandemic

“…HY-71 Polyester-polyurethane 23.95% Kim et al (2022) 8 Acinetobacter pitti Low-density polyethylene (LDPE) 26.80% Montazer et al (2018) 9 Serratia sp. LDPE 40% Nadeem et al (2021) 10 Bacillus siamensis LDPE 8.46% Maroof et al (2021) 11 Bacillus cereus LDPE 6.33% Maroof et al (2021) 12 Bacillus wiedmannii LDPE 5.39% Maroof et al (2021) 13 Proteus mirabilis LDPE 89.72% Akhiqbe et al (2022) 14 Enterobacter sp. Polypropylene 64% Skariyachan et al (2021) 15 Staphylococcus sp.…”

“…Based on these results, pure cultures of bacteria taken from the environment could adhere to, take over, and break down plastic. Maroof et al (2021) found and described the microorganisms that break down several types of plastic. These microorganisms were Bacillus siamensis , B. cereus , and B. wiedmannii , and they were all found in the soils of waste disposal sites.…”