Determination of Biodegradation Potential of Aspergillus niger, Candida albicans, and Acremonium sclerotigenum on Polyethylene, Polyethylene Terephthalate, and Polystyrene Microplastics

Plastics are used widely in almost every field of life, but their synthetic and persistent nature makes them harmful for the environment. The aim of this research was to evaluate the degradation abilities of Aspergillus niger, Candida albicans, and Acremonium sclerotigenum on microplastics (MPs). MP pieces of 4 +/- 1 mm, including polyethylene, polyethylene terephthalate, and polystyrene, were incubated with fungal inoculums for 30 days. The degradation of treated MPs was determined by biofilm formation, weight loss, scanning electron microscopy (SEM), and Fourier transform analyses. The results indicated that the polyethylene MPs treated with Aspergillus niger exhibited the highest level of biofilm formation (optical density 1.595) and percentage weight loss (16%). In the case of polyethylene terephthalate and polystyrene MPs, Acremonium sclerotigenum and co-culture showed weight loss of 6% and 10%, respectively. Candida albicans was observed to be the least effective in biodegradation analyses. SEM observation revealed the surface modifications as holes, pits, cracks, and increased roughness in treated MPs. Fourier transform infrared (FTIR) spectroscopy showed that the chemical structure of each polymer exhibited some variations. The study concluded that the fungal strains play an important role in the biodegradation of plastics and can be utilized to mitigate environmental pollution.