Title:Efficacy of Cavern Isolates for Biodegradation of Synthetic Plastic
Volume: 19
Issue: 3
Author(s): Jamila Tabassum, Muhammad Luqman*, Fariha Hasan, Fariha Arooj, Saif Ur Rehman Kashif and Asma Yousafzai
Affiliation:
- Department of Environmental
Sciences, Faculty of Biosciences, University of Veterinary and Animal Sciences, 54000, Lahore, Pakistan
Keywords:
Polyethylene, FTIR, SEM, LDPE, biodegradation, synthetic plastic.
Abstract: Synthetic plastic waste management is a tenacious environmental concern at global level.
Although all types of synthetic plastics are a nuisance to the environment, however, versatility and one
time use has made polyethylene (PE) a foremost environmental issue. Current study has investigated
cavern bacterial strains isolated from PE samples from San Giovanni cave, Sardinia, Italy for their
efficacy to biodegrade low density polyethylene (LDPE) film. It was an initial effort to use cavern
bacteria in plastic biodegradation studies. Chemical and physical changes in the composition of LDPE
were studied by Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy
(SEM) after incubation with the bacterial consortium for two months. Collected cavern PE plastic
samples were also studied for biodegradation after incubation in nutrient broth for two months. FTIR
revealed obvious signs of degradation with the appearance of two new peaks of functional groups,
nitriles (C≡N) and amines (N-H) in LDPE film, which are intermediate metabolites of β-oxidation
pathway. An increase in various existing peaks of several intermediate metabolites, including
aldehydes, ketones, alcohols, and carboxylic acids, were also observed in experimental LDPE
compared to control. Peaks of alkanes decreased significantly owing to cavern bacterial activity. SEM
revealed biofilm formation on experimental LDPE surface with substantial mechanical damage.
Similar signs of degradation were observed in the cavern PE samples. Four bacterial strains in the
current consortium including Bacillus sonorensis, Bacillus subtilis, Aneurinibacillus spp., and
Alcaligenes faecalis are first time reported to be linked with biodegradation of plastics. The cavern
bacteria under study have the potential to biodegrade LDPE.