Aims: Marine-derived fungi are a potential for the search of new compounds with relevant features. Among these, the ligninolytic enzymes have potential applications in a large number of fields, including the environmental and industrial sectors. This work aimed to evaluate the laccase activity of the marine-derived fungus Alternaria alternata, under various cultivation conditions and its application in synthetic dyes decolorization. Methodology and results: Wheat bran prepared with 40 mL sea water proportion was the most suitable substrate for laccase production (114.06±2.24 U/mL) by A. alternata, after 14 days of incubation in submerged fermentation. Laccase production in static cultivation was superior to that in agitated cultures. The simple Boyd and Kohlmeyer medium with supplementation of 2 mM CuSO4·5H2O on day 6, at an incubation period of 14 days and incubation temperature of 28±2°C under static conditions, yielded amounts of laccase (36.13±0.34 U/mL) less than that obtained with submerged fermentation of wheat bran as unique substrate. Furthermore, A. alternata has high decolorization capability toward azo dyes in the absence of redox mediators, 75.47% of the reactive black at 0.01% concentration, was removed after 30 days of incubation. Also has good ability to decolorize the triphenylmethane dye crystal violet, at 0.01% concentration, about 69.35% of the dye was removed after 30 days. Conclusion, significance and impact of study: These unusual properties demonstrate that the marine-derived fungus Alternaria alternata has potentials in specific industrial or environmental applications.

In a screening of fungal isolates associated with marine algae collected from Abou-keer, Alexanderia during the four seasons of 2004, to obtain new biologically active compounds. Varicosporina ramulosa isolate was identified and selected as a producer of 13 compounds. Out of 13 pure compounds produced, compounds 3 and 10 were considered as antibacterial and antifungal compounds, respectively as they were active against gram positive, gram negative bacteria and a fungus. Optimization of conditions (fermentation media, incubation period, temperature, initial pH, aeration levels) which activate compounds 3 and 10 production were studied. Also the spectral properties (UV, MS, GC/MS, IR and 1H-NMR) of the purified compounds were determined. Compound 3 suggested to be dibutyl phthalate and compound 10 may be ergosterol or one of its isomers. Biological evaluation of the two compounds towards 6 different types of tumor cell lines showed weak effect of compound 3 at different concentrations on the viable cell count of the different tumor cell lines. While compound 10 showed different activities against the viable cell count of the 6 different tumor cell lines. It kills 50% of the viable infected liver and lung cells at concentrations equal to 99.7 μg/mL, 74.9μg/mL, respectively. Compound 10 can be recommended as new anticancer compounds.