Screening for Ligninolytic Enzyme Production by Diverse Fungi from Tunisia

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 110 U ml -1 within 15 days of incubation.

Screening for ligninolytic enzymes from autochthonous fungi and applications for decolorization of Remazole Marine Blue

“…Several screening works about ligninolytic enzymes have been carried out mainly in white-rot basidiomycetes (9). In these studies fungal strains were searched for detecting the ability to produce lignin-modifying enzymes (9,28).…”

“…Several screening works about ligninolytic enzymes have been carried out mainly in white-rot basidiomycetes (9). In these studies fungal strains were searched for detecting the ability to produce lignin-modifying enzymes (9,28). This study presents an initial screening method for detecting ligninolytic enzymes in a little while and suggests an estimation whether fungal strain will secrete these enzymes or not.…”

“…Literature about geographical and climatic repartition of autochthonous fungal flora or describing biodiversity in a given region for ligninolytic enzymes production is scarce (9). In this study, thirty autochthonous fungal strains were harvested from Bornova-Izmir in Turkey and identified in Ege University, Faculty of Science Microbiology Section according to their macroscopic and microscopic properties.…”

Characterization of the Oxidative Enzyme Potential in Wild White Rot Fungi From Misiones (Argentina)

“…It should be however noted that, as previously emphasized, if detected ligninolytic activities were constitutive, titers may be subjected to the influence of inducers such as aromatic compounds or Cu 2+ (Saparrat et al, 2002;Dhouib et al, 2005). These results were in agreement with others previously reported by Tekere et al (2001a), Saparrat et al (2002), Matos et al (2007), Lin et al (2003) and Basto et al (2006) who also described high ligninolytic activities in closely related fungal specimens such as T. villosa, C. versicolor, G. applanatum and P. sanguineus, consequently proposed for different biotechnological applications.…”

Wood production, wood technology, and biotechnological impacts

“…that enzymes are not produced in such high amounts as required for industrial application, or iii. that available enzymes are not as ideal for specific applications, screenings are also ongoing for the other main types of fungal enzymes acting in lignocellulose degradation [e.g., see receent publications of Kiiskinen et al (2004), Krogh et al (2004), Dhouib et al (2005), Kabe et al (2005), Chairattanamanokorn et al (2006), Guimaraes et al (2006), Songulashvili et al (2007)]. …”