Production of itaconic acid by Helicobasidium mompa TANAKA.

Abstract

1. The mycelial strand of Helicobasidium mompa TANAKA penetrates the cork layer of sweet potato by breaking through middle lamella of it. The pectic material in contact with the mycelia is gelatinized and has a very low pH value. Following the penetration of the cork layer, the mycelia rapidly macerate the starchy parenchyma and liquefy it. The liquid thus produced is strongly acidic. 2. The optimum pH value for the protopectinase activity of the fungus lies between 2.5 and 3, 0. Above 5.0 the enzyme is almost inactive. 3. From expressed juice of Halicobasidiumrotted sweet potatoes crystalls of itaconic acid were isolated. 4. Itaconic acid was also obtained from culture filtrate of the fungus, yielding 0.5 to 1.0g. of crude crystals from 500ml. of 30 day's culture filtrate. In young culture, for example up to 30 days old, oxalic acid was not detected. The above results suggest that itaconic acid produced by the fungus plays an important role in lowering the pH of the infected tissue, and enhancing the protopectinase activity and intensifing the pathogenic action of the fungus.