ABSTRACT: This work represents the first report on the ability of autochthonous fungi from Tunisia to produce ligninolytic enzymes.
Three hundred and fifteen fungal strains were isolated from different Tunisian biotopes. These fungal strains were firstly
screened on solid media containing Poly R-478 or ABTS as indicator compounds that enabled the detection of lignin-modifying
enzymes as specific color reactions. Of the 315 tested strains, 49 exhibited significant ABTS-oxidation activity expressed
within the first week of incubation and only 18 strains decolorized the Poly R-478. Liquid cultivations and laccase, manganese
peroxidase and lignin peroxidase activity assays of positive strains confirmed that eight efficient enzyme producers were
found in the screening. These strains were attributed to the most closely related species using PCR amplification and sequencing
of the internal transcribed spacer ‘ITS’ regions of the ribosomal DNA. The identification results showed fungal genera such
as Oxyporus, Stereum and Trichoderma which have been only rarely reported as ligninolytic enzyme producers in the literature. Culture conditions and medium composition
were optimized for the laccase producer Trametes trogii CTM 10156. This optimization resulted in high laccase production, 367 times more than in non-optimized conditions and which
reached 110Uml-1 within 15days of incubation.
World Journal of Microbiology and Biotechnology 04/2012; 21(8):1415-1423. · 1.53 Impact Factor