Communautés fongiques associées aux déchets plastiques marins et évaluation de leur potentiel en bioremediation.

Abstract

Marine plastic pollution poses a major threat to marine ecosystems due to the persistence and low biodegradability of synthetic polymers in the environment. The objective of this study is to isolate and identify the fungal community associated with marine plastic waste consisting mainly of cups and bottles collected in April 2026 from three sites along the Mostaganem coastline (Salamandre, Sablettes, and Sidi Medjdoub), and to evaluate its potential for biodegrading polyethylene (PE) and low-density polyethylene (LDPE). An analysis of the macroscopic and microscopic characteristics of the isolated fungal strains revealed a significant diversity of filamentous fungi. A total of 367 isolates were obtained and classified into 13 fungal genera. The isolated community was dominated by Aspergillus versicolor (18.8%), followed by Rhizomucor sp. (12.53%), Trichoderma sp. (10.08%), unidentified sterile mycelia (10.08%), Fusarium moniliforme (8.44%), Absidia sp. (8.17%), Alternaria spp. (7.08%), Aspergillus niger (6.26%), Penicillium spp. (5.44%), Aspergillus fumigatus (4.63%), Acremonium sp. (3.5%), Scytalidium hyalinum (3.27%), and Aspergillus terreus (1.63%). The Sablettes site recorded the highest abundance (125 isolates), followed by Sidi Medjdoub (115), while Salamandre had the lowest abundance (90 isolates). The assessment of the biodegradation potential of PE and LDPE revealed, after 10 days of incubation, the appearance of degradation zones around certain plastic fragments in several fungal strains, notably: Aspergillus niger (2 cm), Alternaria sp. (1.6 cm), Penicillium spp. (1.1 cm), and Scytalidium hyalinum (1 cm). This bioalteration was accompanied by a measurable loss of mass in the plastic material, observed primarily in Alternaria sp., Aspergillus niger, and Penicillium spp., indicating their potential to degrade these polymers. These results highlight the diversity of fungal communities associated with marine plastic waste along the Mostaganem coastline, while also underscoring the potential of these strains to degrade and biodegrade the plastic polymers studied, thereby contributing to the development of bioremediation strategies for contaminated marine environments.