Cytobacillus sp. Strain HMBC3 from Saudi Arabian Soil Degrades Low-Density Polyethylene

TL;DR

A new bacteria strain from Saudi Arabian soil can break down low-density polyethylene, offering a potential eco-friendly solution to plastic pollution.

Contribution

Identification of a novel Cytobacillus sp. strain capable of degrading LDPE with significant weight loss and chemical changes.

Findings

HMBC3 caused 20.4% weight loss in LDPE under controlled conditions.

FTIR and GC-MS confirmed chemical changes in LDPE after exposure to HMBC3.

16S rRNA analysis showed 98.9% similarity between HMBC3 and Cytobacillus sp.

Abstract

Considering the dangerous effects on the environment of commonly used packaging materials like low-density polyethylene (LDPE), finding a practical and environmentally safe method for decomposing plastics is crucial. In this study, a bacterial strain (HMBC3) was identified in plastic-contaminated soil samples from eastern Saudi Arabia and showed potential for breaking down LDPE, as revealed by results from weight loss, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and gas chromatography-mass spectrometry (GC-MS). HMBC3 was discovered among bacterial isolates in a mineral nutritional medium (MNM) enhanced with LDPE as the only carbon and energy source. The strain caused changes in the media pH from 7.0 ± 0.03 to 6.23 ± 0.05, while the LDPE also showed 20.4% weight loss. In addition, the 16S rRNA gene similarities revealed a 98.9% homology between HMBC3 and Cytobacillus sp., indicating their close similarity. The high efficiency of strain HMBC3 in biodegrading plastic could potentially lead to its widespread development as an eco-friendly way to eliminate or minimize environmental plastic pollution.

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