Gram-negative bacteria Azotobacter

With the advent of gas chromatography the analysis of fatty acids has become a relatively routine task. As a consequence, the fatty adds of a wide variety of bacteria have been analyzed and some correlations with taxonomic classification have become clear. It should be pointed out that fatty acids, as free fatty acids, constitute only a small proportion of the lipids of both the Gram-negative and Gram-positive eubac-teria. For instance, in E. coU, Azotobacter agilis, and Agrobacterium tumefaciens, the free fatty acid content is less than 10% of the total lipid (Kaneshiro and Marr, 1961), while in Sarcina lutea it is 2.1% (Huston et al., 1965). Most analyses of die bacterial fatty adds have been performed on the total fatty adds obtained by hydrolysis of flie total hpid. Four general classes of fatty acid have been found in the eubacteria saturated and unsaturated fatty acids, and branched-chain and cyclopropane fatty adds. 

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