BTEX degradation by fungi

Area of Science:

• Environmental Science
• Microbiology
• Bioremediation

Background:

• Aromatic hydrocarbons, including benzene, toluene, ethylbenzene, and xylenes (BTEX), are significant environmental pollutants.
• The Bourgas bay coastal area is particularly vulnerable to BTEX pollution due to its petrochemical industry.

Purpose of the Study:

• To investigate the potential of fungal strains for degrading BTEX compounds.
• To compare the degradation capabilities of two specific fungal genera, Cladophialophora (CPH) and Cladosporium (CS).

Main Methods:

• Experiments were conducted using two fungal strains, CPH and CS, isolated from gasoline-polluted sites.
• Batch reactor experiments were performed to assess the degradation of individual and mixed BTEX compounds.
• Fungal identification confirmed the strains as deuteromycetes.

Main Results:

• Neither fungal strain could degrade benzene.
• Ethylbenzene was readily degraded by both strains.
• Cladophialophora sp. fully degraded o- and m-xylene, while Cladosporium sp. degraded them only in mixtures with toluene.
• p-Xylene showed only partial degradation, with Cladosporium sp. performing slightly better.
• Co-occurrence of ethylbenzene, o-, and m-xylene reduced toluene degradation rates, indicating competitive interactions.

Conclusions:

• Fungal strains CPH and CS demonstrate potential for bioremediating certain BTEX components, particularly ethylbenzene and specific xylene isomers.
• Benzene is recalcitrant to degradation by the tested fungal strains.
• Cladophialophora sp. generally exhibited superior BTEX degradation efficiency compared to Cladosporium sp., with notable exceptions for p-xylene.