الفهرس 
Literature ReviewOnly 14 pages are availabe for public view
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Abstract
The solid waste management is a serious challenge around the world, in particular for developing countries. In Egypt due to the poverty of effective management of wastes, solid waste management becomes one of the most critical issues. With special interest in plastic waste management which resemble (13%) of the total solid waste generated annually in Egypt, only small portion could be recycled (30%) and the rest either be landfilled or incinerated, leading to production of many pollutants which threatened both human health and environment. Therefore, nowadays the global goal is using alternative methods for plastic waste remediation to reduce the hazards produced by traditional methods. So, our study aims to recover fungal isolates from soil contaminated by plastic waste and investigate their efficiency in plastic degradation. 33 fungal isolates were recovered from soil samples which collected from plastic contaminated sites from different location (Ismailia, Portsaid, EL-Sharqia, Damietta and Saint Katherine). Screening of fungal isolates for degrading enzymes production were revealed that 66.7% of fungal isolates were able to produce protease and esterase, 72.7% were able to produce lipase, while only one isolate was able to excrete laccase and the same for polyurethanase. While 6 isolates out of 33 fungal isolates were characterized by high affinity to produce acid. However, 11 fungal isolates were characterized by moderate ability in acid production. The results reveled that factors (e.g. pH, organic matter content and heavy metals) have a great end product on the enzyme biosynthesis by fungi. The obtained results showed a great variation in their capacity in enzymes and acid production.11 isolates, varied between weak to high capacity in enzymes and acid production, were selected to investigate their degradation efficiency in PUR degradation in its liquid form (Impranil dln). These isolates identified by molecular techniques as Lichtheimia ramosa, Monascus ruber, Monascus sp., Monascus sanguineus, Aspergillus sclerotiorum, Aspergillus flavus, Aspergillus sydowii, Gymnoascus dankaliensis, Aspergillus tritici, Aspergillus candidus and Aspergillus sp. The results showed that there are three isolates could degrade Impranil dln completely; these isolates were Aspergillus flavus, Aspergillus sydowii and Aspergillus sp. from our findings, fungal isolates depend on different mechanisms in biodegradation of polymer, not only single mechanisms. These mechanisms include mainly adsorption, excretion of degrading enzymes and acid production. Finally, the most efficient isolates in both biofilm formation plus degrading enzymes excretion were selected for investigate their degradation capability of polymer film (PVC and PUR). Both isolates Aspergillus flavus and Aspergillus candidus were able to reduce the weight of plastic film. In case of Aspergillus candidus, reductions in weight of PVC films were 21.5%, while in PUR films weight were 6.1%. But in case of Aspergillus flavus there was a higher reduction in the weight of both PVC and PUR films 24.2% and 7.4 % respectively. SEM and FTIR analysis revealed the ability of both isolates in change the structure of PVC and PUR which may result in degradation with the time.