Biodegradation of thermally treated high-density polyethylene (HDPE) by Klebsiella pneumoniae CH001

Abstract

Biodegradation of plastics, which are the potential source of environmental pollution, has received a great deal of attention in the recent years. We aim to screen, identify, and characterize a bacterial strain capable of degrading high-density polyethylene (HDPE). In the present study, we studied HDPE biodegradation using a laboratory isolate, which was identified as (Accession No MF399051). The HDPE film was characterized by Universal Tensile Machine (UTM), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), and Atomic Force Microscope (AFM) before and after microbial incubation. We observed thatthis strain was capable of adhering strongly on HDPE surface and form a thick biofilm, when incubated in nutrient broth at 30 °C on 120 rpm for 60 days. UTM analysis showed a significant decrease in weight (18.4%) and reduction in tensile strength (60%) of HDPE film. Furthermore, SEM analysis showed the cracks on the HDPE surface, whereas AFM results showed an increase in surface roughness after bacterial incubation. Overall, these results indicate that CH001 can be used as potential candidate for HDPE degradation in eco-friendly and sustainable manner in the environment.

Biodegradation of low-density polyethylene (LDPE) sheet by microalga, Uronema africanum Borge

“…Simultaneously, from FT-IR results, functional groups such as carboxylic acids, esters, nitro compounds, and amino groups were determined in the sample ( U. africanum treated LDPE sheet), but no such functional groups were found in the control (microalga untreated LDPE sheet). Therefore, our results clearly illustrate the biodeterioration of LDPE sheet by microalga U. africanum and found familiar with the results discussed by Vimala and Mathew 37 , and Awasthi et al 36 .…”

“…Gas chromatography and mass spectrometric analysis (GC–MS) and Fourier transform infra-red spectrometry (FT-IR) are the determining factor for biodegradation of polyethylene 35 . When polyethylene was biologically treated with Klebsiella pneumoniae CH001, generation of saturated fatty acids and carboxylic acids were confirmed by both GC–MS and FT-IR analysis respectively 36 , 37 . Similarly, most prominent structural changes were observed by FT-IR while LDPE degradation by a fungus Aspergillus clavatus 38 .…”

Wastewater treatment alters microbial colonization of microplastics

“…Both of these Klebsiella species are part of the normal human microbiome, but they are also common causes of opportunistic and nosocomial infections [ 81 ]. Klebsiella pneumoniae has also been shown to be capable of biodegrading polyethylene [ 82 ]. We are not aware of previous studies reporting the presence of Klebsiella on microplastics, but it’s high abundance on effluent microplastics is noteworthy due to its connections to humans and to plastic breakdown.…”

Plastic Degradation by Extremophilic Bacteria

“…Under laboratory conditions, bacterial isolates cultivated to produce single species biofilms showed variable success in plastic degradation. For example, single species biofilms of Klebsiella pneumoniae CH001 [ 23 ] and Rhodococcus sp. [ 24 ] promoted the degradation of PE, and the corresponding biofilms of Pseudomonas citronellolis and Bacillus flexus showed degradation activity towards PVC [ 25 ]; similarly, B. subtilis ET18 and B. cereus ET30 each formed single species biofilm on nylon and PET, causing damage to the plastic surface [ 26 ].…”