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 compd. 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 degrdn. 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 concns., and can produce unique enzymes with interesting properties. Therefore, marine-derived fungi have an excellent enzymic 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 ext. agar) in the presence of different concns. (10, 25, 30, 40, and 50 mg L-1) of PCP. Among the tested strains, nine could grow in at least one concn., and Trichoderma harzianum CBMAI 1677 showed optimal growth at the higher evaluated concn. (50 mg L-1), showing toxicity resistance and suggesting its potential for biodegrdn. of PCP. In a later work, it was obsd. that T. harzianum CBMAI 1677 was able to degrade PCP. These results confirmed the efficiency of marine-derived fungi to biodegrade persistent compds. and could enable the development of bioremediation methodologies using these microorganism. [on SciFinder(R)]