THE EFFECT OF TWEEN 80 ON THE FATTY ACID COMPOSITION OF LACTOBACILLUS BUCHNERI AND LACTOBACILLUS BREVIS

Abstract

The effect of Tween 80 on the cellular fatty acid spectra of different strains of two closely related Lactobacillus species, Lactobacillus buchneri and Lactobacillus brevis, was studied. When cultivated in MRS-broth containing Tween 80 all L. buchneri strains contained two different cyclopropane fatty acids, dihydrosterculic and lactobacillic acid, while L. brevis strains contained only dihydrosterculic acid. In contrast, when the cells were cultivated in a modified MRS-broth without Tween 80, only lactobacillic acid was found in the bacteria except in one L. brevis strain that did not contain either lactobacillic acid or dihydrosterculic acid. This L. brevis strain was in contrast to most Lactobacillus strains unable to cyclisize cis-vaccenic acid (cis-11-octadecenoic acid) produced by its own biosynthetic machinery. Still it was able to cyclisize oleic acid (cis-9-octadecenoic acid) supplemented by its growth medium.