Alkaline-tolerant fungi from Thailand

Abstract

A collection of 490 alkaline-tolerant fungi was made by isolating fungi from natural habitats using Petri-dishes with Potato Dextrose Agar medium buffered at pH 11.0. Alkaline-tolerant fungi were isolated from 51 out of 71 samples collected from different habitats in Thailand. Twenty-eight samples were taken from tree-holes with different pH. The remaining were samples of soil and sand, wood, seeds, rock holes, roots, leaf material or various other substrates. A total of 324 strains (66%) were screened for enzymes which were active at alkaline pH (alkaline enzymes). Arabinanase, amylase, potato-galactanase and protease activity were assayed. Alkaline-tolerant fungi isolated from tree-holes in alkaline and acidic habitats were good sources for alkaline enzyme production. This screening demonstrates that there exists a population of fungi able to tolerate high pH. Importantly, alkaline-tolerant fungi were isolated from acidic environments. Freshwater habitats appear to be a good source of fungi with alkaline enzyme production capability.