The Production of Free Volatile Fatty Acid by Microorganisms Isolated from Stomachs of Marine Little Toothed Whales―I The free volatile fatty acid composition in culture solutions from glucose-peptone media

摘要

In order to ascertain the origin of free isovaleric and other volatile fatty acids which were detected previously in the stomach fluids of porpoises, the free volatile fatty acids in the culture solutions of the microorganisms isolated from the stomachs of marine little toothed whales were studied by GLC. The microorganisms used in experiment were 2 strains of bacteria, Corynebacterium sp. (Cｌ strain: gram positive) and Vibrio sp. (Vl strain: gram negative), and a strain Candida tropicalis-like yeast (Yl strain). Incubations were made by glucose-peptone media (glucose 1.0%, peptone 2.0%, yeast extract 0.1%, sodium chloride 0.5% (Vl strain 2.5%), pH 7.0) for various hours at 37℃. The results obstained are as follows: 1) Although the free volatile fatty acid composition in the culture solutions differ by microorganism and incubation time, all of acetic, propionic, isobutyric, butyric and isovaleric acids were produced in all the culture solutions. 2) Among these acids, acetic and isovaleric acids in both Vibrio sp. and C. tropicalis-like yeast, and acetic, isobutyric and isovaleric acids in Corynebacterium sp. were dominant through various culture hours. 3) It was suggested that in Corynebacterium sp. of gram positive bacteria in addition to acetic acid, isobutyric and other volatile branched-chain fatty acids were largely utilized, but in Vibrio sp. of gram negative bacteria, volatile branched-chain fatty acids were hardly utilized while mostly utilized was acetic acid.