Screening of Marine-derived Fungi Isolated from the sponge Didemnun ligulum for Biodegradation of Pentachlorophenol

Abstract

Contamination by pesticides employed in agriculture has caused serious environmental harm. Pentachlorophenol (PCP) is a phenolic organochlorine compound and a dangerous pollutant which was banned from Brazil since 1985; however, there are still many contaminated areas. This pesticide is a serious problem because it has high toxicity and persistence at the environment due to its resistance to biotic and abiotic degradation. The use of microorganisms as degrading agents is considered an efficient method to reduce the adverse effects of environmental contaminants. It is noteworthy that fungi from marine environment are adapted to extreme conditions, including high chlorine concentrations, and can produce unique enzymes with interesting properties. Therefore, marine-derived fungi have an excellent enzymatic potential for the biotransformation of xenobiotics such as organochlorine pesticides. In this work, fifteen fungi strains isolated from a marine invertebrate, the ascidian Didemnun ligulum, were evaluated according to their ability to grow in solid culture media (3% malt extract agar) in the presence of different concentrations (10, 25, 30, 40, and 50 mg L-1) of PCP. Among the tested strains, nine could grow in at least one concentration, and Trichoderma harzianum CBMAI 1677 showed optimal growth at the higher evaluated concentration (50 mg L-1), showing toxicity resistance and suggesting its potential for biodegradation of PCP. In a later work, it was observed that T. harzia

Marine-derived fungi as biocatalysts

“…After 7 days, this pesticide was biotransformed into pentachloroanisole by biomethylation, which was subsequently dechlorinated to 2,3,4,6-tetrachloroanisole. Their biodegradation products were also partially metabolized by this strain, preventing their accumulation in the environment (Vacondio et al, 2015b).…”

“…Pesticides, despite having a beneficial effect on agricultural production, may be one of the most dangerous contaminants to the environment since they are very toxic and have adverse effects on human and animal health. They can also bioaccumulate, remaining in the soil at the application site, or may be transported to different parts of the environment such as sediments, plants, surface and ground waters, marine environments and even volatilized into the atmosphere, depending on their physical-chemical properties (Vacondio et al, 2015b). Among the techniques employed to remove these contaminants, bioremediation emerges as a safe, low-cost, and environmentally friendly alternative technology.…”