Screening of some marine-derived fungal isolates for lignin degrading enzymes (LDEs) production

A study was carried out to establish the lignin-degrading enzymes (LDEs) activity of a large number of diverse marine ascomycetes. Eighty eight fungal isolates obtained from different algae, sea grasses and decaying wood samples collected from Abou-keer, Alexanderia, Egypt, were screened for the presence of laccase (Lac), lignin-peroxidase (LiP) and manganese-dependent peroxidase (MnP) activities. Results obtained from both qualitative and quantitative assay showed that the marine fungal isolate Trematosphaeria mangrovei measured the highest zone diameter and colony diameter in agar plate screening test with guaiacol and showed a final specific activity of 82.51 U/mg protein with higher laccase activity 14.03 U/ml when grown in low nitrogen (LN) medium with half-strength sea water, initial pH 4.5 for 14 days. The other two ligninolytic activities could not be detected. It was recommended that the marine fungal isolate Trematosphaeria mangrovei was the most promising one for laccase enzyme production.