Unsaturated Fatty Acids as Antifungal Substances Effective against “Akagusare” Disease of the Laver Porphyra sp.

Abstract

The mechanism of recovering action of histidine on “akagusare” (red rot disease) of the laver Porphyra sp. was examined. Results showed that the antifungal effect against the responsible fungus Pytium porphyrae is not exerted directly by histidine, but is by some substances produced indirectly in the laver.
The antifungal fraction was separated from the extracts of the recovering laver, by essentially the same methods as for phytoalexins from higher plants. The fraction conained almost exclusively unsaturated fatty acids, suggesting that the antifungal action observed is mostly attributed to those acids whose production is accelerated by added histidine.