CHARACTERISATION OF FUNGAL DIVERSITY IN TOXIC CHEMICALS CONTAMINATED SOIL BASED ON ANALYSIS OF I8S rRNA GENE BY SINGLE STRAND CONFORMATION POLYMORPHISM

Abstract

More than 30 years since the Vietnam War passed but some former military bases in central and southern Vietnam were heavily contaminated by toxic chemicals (herbicides) including dioxin and dioxin like-compounds. They are "hot spots" and decomposition of contaminants in these bases is to be solved Bio-stimulation of native microorganisms in order to degrade contaminants is a cost effective and environmental safety method. During biodegradation process of toxicants, soil fungi play an important role. However, estimates suggested that only 5 - 10% fungal species have been described fonnally and cultivated in laboratory conditions. Recently, molecular biological tools based on nucleic acids such as single strand conformation polymorphism (SSCP) were widely applied in study of microbial and fungal diversity. In this study, culture independence fungal diversity in nine soil samples containing different concentrations of dioxin that were collected from former military base in Danang airport, was characterised based on analysis of fingerprinting a part of 18S rRNA gene on SSe? Less contaminated and bordered samples showed lower fungal diversity than heavy contaminated samples collected in the central area. Fungal population is closed to fungal genera such as Penkillium, Aspergillus, Fusarium, Clasdosporium, Conioehaela, Phacidium, Anguillospora, Neelria, Telrachaetum, Exophiala, S'elosphaeria. lvlycosphaella etc. However, dominant fungal genera in these contaminated soils are Penicillium, Aspergillus, Fusarium, Clasdosporinm, Coniochaeta, Phacidium, Anguillospora, Nee/ria, Tefrachaelum.