Microplastics Biodegradation by Aspergillus flavus and Aspergillus versicolor

Abstract

Microplastics (MPs) have indeed raised significant concerns due to their widespread presence and potential adverse effects on both the environment and human health. This study aims to illuminate crucial aspects of MPs, including their origins, migration behavior, and the potential for bioremediation as an effective strategy for their removal. Microplastics can originate from various sources, such as the fragmentation of larger plastics, the presence of microbeads in personal care products, the shedding of fibers from textiles, industrial pellets, and products containing microplastics. These diverse sources contribute to the omnipresence of microplastics in both terrestrial and aquatic ecosystems. This study focuses on observing the biological degradation process of two fungi, Aspergillus flavus, and Aspergillus versicolor when exposed to three different types of microplastics: Polypropylene (PP), Polyethylene (PE), and Polystyrene (PS). After conducting experiments, removal efficiencies of A. flavus and A. versicolor were calculated. Based on the data collected during the 10th week of using these fungi, it was observed that A. flavus exhibited removal efficiencies of 18.3% for PE, 6.8% for PP, and 1.9% for PS. On the other hand, A. versicolor yielded removal efficiencies of 6.7% for PE, 5.1% for PP, and 3.3% for PS. It was determined that A. flavus and A. versicolor exhibited the highest biodegradation efficiency when targeting microplastic PE, while their effectiveness was relatively lower when dealing with microplastic PS.

Keywords

• Aspergillus flavus
• Aspergillus versicolor
• Biodegradation
• Polyethylene
• Polystyrene
• Polypropylene

References

1. Alimi O, Farner Budarz J, Hernandez LM, Tufenkji N. 2018. Microplastics and nanoplastics in aquatic environments: aggregation, deposition, and enhanced contaminant transport. Environ Sci Technol. 52: 1704e1724.
2. Alshehrei F. 2017. Biodegradation of low density polyethylene by fungi isolated from Red sea water. Int J Curr Microbiol App Sci. 6(8): 1703-1709.
3. Ammala A, Bateman S, Dean K, Petinakis E, Sangwan P, Wong S, Yuan Q, Yu L, Patrick C, Leong KH. 2011. An overview of degradable and biodegradable polyolefins. Prog Polym Sci. 36: 1015–1049.
4. Browne MA, Crump P, Niven SJ, Teuten E, Tonkin A, Galloway T, Thompson, R, 2011. Accumulation of microplastic on shorelines worldwide: sources and sinks. Environ Sci Technol. 45: 9175e9179.
5. DSouza GC, Sheriff RS, Ullanat V, Shrikrishna A, Joshi AV, Hiremath L, Entoori K. 2021. Fungal biodegradation of low-density polyethylene using consortium of Aspergillus species under controlled conditions. Heliyon. 7(5): e07008.
6. Gewert B, Plassmann MM, MacLeod M. 2015. Pathways for degradation of plastic polymers floating in the marine environment. Environ Sci Process Impacts. 17: 1513e1521.
7. Hidalgo-Ruz V, Gutow L, Thompson RC, Thiel M. 2012. Microplastics in the marine environment: a review of the methods used for identification and quantification. Environ Sci Technol. 46: 3060e3075.
8. Katija K, Choy CA, Sherlock RE, Sherman AD, Robison BH. 2017. From the surface to the seafloor: how giant larvaceans transport microplastics into the deep sea. J Sci Adv. 3: e1700715.

9. Murphy F, Ewins C, Carbonnier F, Quinn B. 2016. Wastewater treatment Works (WwTW) as a source of microplastics in the aquatic environment. Environ Sci Technol. 50: 5800e5808.
10. Osahon NT, Williams JO. 2021. Assessment of microplastic degrading potential of fungal isolates from an estuary in rivers state, Nigeria. South Asian J Res Microbiol. 9 (2): 11–19.
11. Osman M, Satti SM, Luqman A, Hasan F, Shah Z, Shah AA. 2017. Degradation of polyester polyurethane by Aspergillus sp. strain S45 isolated from soil. J Polym Environ. 26:301–310.
12. Othman AR, Hasan HA, Muhamad MH, Ismail NI, Abdullah SRS. 2021. Microbial degradation of microplastics by enzymatic processes: a review. Environ Chem Lett. 19 (4): 3057–3073.
13. Paco A, Duarte K, da Costa JP, Santos PSM, Pereira R, Pereira ME, Freitas AC, Duarte AC, Rocha-Santos TAP. 2017. Biodegradation of polyethylene microplastics by the marine fungus Zalerion maritimum. Sci Total Environ. 586: 10–15.
14. Rujnic-Sokele M, Pilipovic A. 2017. Challenges and opportunities of biodegradable plastics: a mini-review. Waste Manag Res. 35:132–140.
15. S´anchez C. 2020. Fungal potential for the degradation of petroleum-based polymers: an overview of macro- and microplastics biodegradation. Biotechnol Adv. 40: 107501.
16. Singh B, Sharma N. 2008. Mechanistic implications of plastic degradation. Polym Degrad Stab. 93: 561e584. Singh V, Dubey M, Bhadauria S. 2012. Biodeterioration of polyethylene high density by Aspergillus versicolor and Aspergillus terreus. J Adv Lab Res Biol. 3(1): 47-49.
17. Taghavi N, Singhal N, Zhuang WQ, Baroutian S. 2021. Degradation of plastic waste using stimulated and naturally occurring microbial strains. Chemosphere. 263: 127975.
18. Weithmann N, M€oller JN, L€oder MGJ, Piehl S, Laforsch C, Freitag R. 2018. Organic fertilizer as a vehicle for the entry of microplastic into the environment. Sci Adv. 4: eaap8060.
19. Weinstein JE, Crocker BK, Gray AD. 2016. From macroplastic to microplastic: degradation of high-density polyethylene, polypropylene, and polystyrene in a salt marsh habitat. Environ Toxicol Chem. 35: 1632e1640.
20. Williams JO, Osahon NT. 2021. Assessment of microplastic degrading potential of fungal isolates from an Estuary in Rivers State, Nigeria. South Asian J Res Microbiol. 9(2):11-19.
21. Yuan J, Ma J, Sun Y, Zhou T, Zhao Y, Yu F. 2020. Microbial degradation and other environmental aspects of microplastics/ plastics. Sci Total Environ. 715: 136968.
22. Zhang W, Zhang L, Hua T, Li Y, Zhou X, Wang W, You Z, Wang H, Li M. 2020b. The mechanism for adsorption of Cr(VI) ions by PE microplastics in ternary system of natural water environment. Environ Pollut. 257: 113440.
23. Zhang J, Gao D, Li Q, Zhao Y, Li L, Lin H, Bi Q, Zhao Y. 2020b. Biodegradation of polyethylene microplastic particles by the fungus Aspergillus flavus from the guts of wax moth Galleria mellonella. Sci Total Environ. 704: 135931.