Lignocellulosic enzymes from Flavodon flavus, a fungus isolated from Western Indian Ocean off the coast of Dar es Salaam, Tanzania

Abstract

Marine basidiomycetes fungus Flavodon flavus (Klotzsch) Ryvarden was isolated from sea grass at Mjimwema in the Western Indian Ocean off the Coast of Dar es Salaam, Tanzania, and cultured in the laboratory. Protein content and lignocellulosic enzyme activities were measured by photometric methods. Desalted and size-separated enzyme filtrates were resolved by sodium docecyl sulphatepolyacrylamide gel electrophoresis (SDS-PAGE) and isoelectric focusing (IEF). The fungal filtrate had maximum lignin peroxidase (LiP), manganese peroxidase (MnP) and Laccase (Lac) activities of 42, 25 and 15 U/mL, respectively. At low carbon medium, F. flavus showed effective (92 - 100%) decolorization of raw textile wastewater and synthetic dyes such as rhemazol brilliant blue-R (RBB-R), Brilliant green, Congo red, Reactive black and Reactive yellow. SDS-PAGE analysis showed major bands of sizeseparated enzymes from F. flavus at relative molecular weights between 45 and 70 kDa. The LiP of F. flavus, purified by ion exchange chromatography, revealed that it has a molecular weight of 46 kDa and isoelectric point (pI) of 3.8. The study confirmed extracellular enzymes from F. flavus to be potential degraders of organic pollutants and showed that facultative marine fungi that live under harsh seawater conditions are suitable for bioremediation of recalcitrant environmental pollutants.