Screening of Lignocellulose- Degrading Fungi from Mangrove Plant Litter in Samal Island, Davao del Norte

Abstract

Microorganisms such as fungi are being explored as potential sources of lignocellulose-degrading enzymes which are used in industrial applications such as biopulping and biobleaching. Lignocellulose-degrading fungi are found in mangrove habitats. Fungi isolated from decaying wood and leaf litter of the mangrove forest in Samal Island were screened for production of lignocellulose-degrading enzymes using plate enzyme assay. A total of 63 fungal isolates were obtained from mangrove forest using spread plate method. Fourteen fungal isolates have survived the subculturing and were screened for the production of lignocellulose-degrading enzymes, cellulase and polyphenol oxidase using plate assay. Ten (five Aspergillus sp. and five Penicillium sp.) showed positive results for cellulase activity as indicated by the yellow-colored zones around the fungal colony in carboxymethyl cellulose agar plate. Three Penicillium sp. isolates have the ability to produce polyphenol oxidase as indicated by the brown colored zone around the fungal colony in MEA with tannic acid plate. Four isolates showed negative results for both enzymes tested. Fungal isolates that produced cellulase and polyphenol oxidase were then characterized and identified as Aspergillus sp. and Penicillium sp. based on colony morphology, hyphae and reproductive structures. The fungi isolated from leaves and woody litter of the mangrove forest in Samal Island, Davao del Norte serve as potential sources of lignocellulose-degrading enzymes, particularly cellulase.