Identificación y evaluación de algunos hongos con actividad celulásica aislados en Ecuador

Abstract

Fungal samples were collected in the Western and Eastern Andean foothills of Ecuador in the provinces of Pichincha, Sucumbíos, Orellana and Santo Domingo de los Tsáchilas. The fungi were aseptically isolated and increased on Potato Dextrose Agar (PDA) or Malt Agar (MA). Their growth characteristics were recorded, and molecularly identified on the basis of ribosomal RNA internal transcribed spacer (ITS) region. The sequences were compared with other similar sequences on GenBank for phylogenetic analysis and identification. The isolated and identified strains were plated on Carboxymethylcellulose (CMC) to evaluate their enzymatic capabilities to degrade cellulose. Diameters (in mm) of the halos of hydrolysis were continuously monitored during 7-14 days of growth. The halos in strains H23.2 and H24 of the genus Pestalotiopsis and of L4 of the genus Neonothopanus had halo diameters significantly bigger than most of the other fungal samples tested. Increased extracellulolytic activity was recorded in the supernatants extracted from the genera Pestalotiopsis, Neonothopanus, and Gymnopilus after 14 days of culture in the 24-hour interval. This enzyme activity, in some cases, was not proportional to the protein concentration in μg/ml of the supernatants extracted from the different cultures