Recent progress in biodegradation of microplastics by Aspergillus sp. in aquatic environments

Abstract

The potential of Aspergillus sp. for plastic biodegradation is a promising approach for environmentally friendly waste management. Various research studies have been conducted to optimize conditions that enhance the biodegradation of plastics and to understand the genetic basis of Aspergillus species. By performing this investigation, we discussed the role of various species of Aspergillus sp. in the decomposition of plastic polymers. Most Aspergillus sp. grow within the pH range of 4 to 6. 37.5% of the studies showed that Aspergillus sp. grows optimally at 30 °C. Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) tests were used in 34.61% and 32.69% of the different studies, respectively. It has been observed that fungi can biodegrade polymers more effectively within a size range of 20–100 μm. Most studies (34.21%) have focused on the biodegradation of polymers within 21 to 30 days. The highest percentage of studies (44%) focused on the biodegradation of low-density polyethylene (LDPE) by various Aspergillus sp. The dominant Aspergillus sp., including A. niger, A. flavus, and A. oryzae, play a significant role in the biodegradation of microplastics. Enzymes such as laccase, esterase, peroxidase, lipase, and urease play crucial roles in the degradation of plastics. Laccase utilizes oxygen to generate reactive oxygen species, breaking polymer chains. Esterase cleaves polymers into fragments, while peroxidase generates radicals for polymer degradation. Lipases and urease also contribute to the degradation of specific plastic substrates. In general, it can be said that this fungal species has been successful in effectively degrading various polymers.