Assessment of potential plastic-degrading fungi in Jordanian habitats

Authors: IBRAHIM N. IBRAHIM, ANWAR MARAQA, KHALID M. HAMEED, ISMAIL M. SAADOUN, HAMZAH M. MASWADEH

Abstract: Out of 70 fungal isolates recovered from soil, wall paints (Latex), and pieces of plastic debris from different habitats in Jordan and plastic shields of street light posts on campus, 35 isolates showed varied potential to degrade polyester-polyurethane (PS-PUR). Six of these isolates (Fusarium solani, Alternaria solani, Spicaria spp., Aspergillus fumigatus, Aspergillus terreus, and Aspergillus flavus) were selected on the basis of their growth rates on basal salt media amended with PS-PUR as the sole source of carbon. Isolates were further evaluated utilizing 3 different methods: 1) direct plating, 2) clear zone in a 2-layered agar media, and 3) liquid shaking culture. These isolates caused significant weight loss in the PS-PUR blocks in the shaken cultures, reaching up to 100% in case of the isolate Fusarium solani. The petri dish test method revealed a maximum degradation activity achieved by the isolate Aspergillus flavus, which caused 94% loss in weight of PS-PUR pieces. However, only 4 isolates (Fusarium solani, Spicaria spp., Alternaria solani, and Aspergillus flavus) yielded positive results of biodegradation, indicated by clear zones created due to PS-PUR hydrolysis in 2-layered agar culture plate media. Out of the 6 fungal isolates reported here, 2 novel organisms have not been previously reported, Alternaria solani and Spicaria spp. Overall, these findings helped identify predominant as well as novel fungi in Jordanian habitats that play a key role in PS-PUR degradation.

Keywords: Polyurethane (PUR), Fusarium solani, Alternaria solani, Spicaria spp., Aspergillus fumigatus, Aspergillus terreus, Aspergillus flavus

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