Abstract:In the present investigation we evaluate methods for the isolation and growth of marine-derived fungal strains in artificial media for the production of secondary metabolites. Inoculation of marine macroorganisms fragments in Petri dishes proved to be the most convenient procedure for the isolation of the largest number of strains. Among the growth media used, 3% malt extract showed the best result for strains isolation and growth, and yielded the largest number of strains from marine macroorganisms. The percentage of strains isolated using each of the growth media which yielded cytotoxic and/or antibiotic extracts was in the range of 23-35%, regardless of the growth media used. Further investigation of extracts obtained from different marine-derived fungal strains yielded several bioactive secondary metabolites, among which (E)-4-methoxy-5-(3-methoxybut-1-enyl)-6-methyl-2H-pyran-2-one is a new metabolite isolated from the Penicillium paxilli strain Ma(G)K.

No abstract

No abstract

No abstract

No abstract

The growth and biodegradation potential of marine-derived fungi were evaluated by measuring the radial growth of colonies. It was observed that Penicillium raistrickii CBMAI 931, Aspergillus sydowii CBMAI 935, Cladosporium sp. CBMAI 1237, Microsphaeropsis sp. Dr(A)6, Acremonium sp. Dr(F)1, Westerdykella sp. Dr(M2)4 and Cladosporium sp. Dr(M2)2 were able to grow and develop in the presence of the pyrethroid insecticide esfenvalerate (S,Sfenvalerate) and its main metabolites (3-phenoxybenzaldehyde, 3-phenoxybenzoic acid, 3-phenoxybenzyl alcohol and 2-(4-chlorophenyl)-3-methylbutyric acid), showing the possibility of esfenvalerate biodegradation by these strains. The presence of technical grade esfenvalerate and its metabolites caused significant growthinhibition, while fungal development was not affected by the presence of the commercial insecticide SUMIDAN 150 SC in the culture medium. This fact might show that the biodegradation of the esfenvalerate in the commercial insecticide is slower than that of the technical grade active ingredient, since slower biodegradation of esfenvalerate would reduce the concentration of phenolic compounds and thus the growth inhibition. Future studies will focus on the quantitative biodegradation analysis of technical grade esfenvalerate and active ingredient in the commercial insecticide.

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