Isolation and Identification of a Starch Assimilating Black Fungus from Sago Palm Stems

Abstract

A black fungus was isolated from sago palm (Meteroxlon sagus) stems imported from Sarawak and identified. Morphological and taxonomic studies revealed the fungus is Chalara paradoxa, Fungi Imperfecti, which has not been reported in Japan. It is suggested that the fungus may have come from Sarawak.
The fungus utilized sago starch better than potato soluble starch, maltose and glucose, and the best among the carbohydrates tested. It was thought that the fungus well produced amylase in the culture medium. The fungus grew in a wide range of pH, namely 2.0 to 7.0, and the best growth rate was obtained 27°C and the fungus grew little at 3 and 41°C. When the fungus was cultured using modified czapek basal medium, yeast extract appeared to be essential for fungus growth.
The fungus grew into the agar medium and spread widely on whole surface of agar medium. It utilized CMC and cellobioe but not cellulose powder and crystalline cellulose (Avicel S. F.) . It suggests that the fungus produced a kind of β-glucosidase. It also produced ethanol and unidentified aromatic substances in the culture medium.
The possibilitis, biotransformation of sago starch to single cell protein by the fungus and the application of the fungus to another starch industry, were mentioned.