Fatty acids and carbohydrate-containing lipids in four Micrococcaceae strains.

Fatty acid composition and lipidic carbohydrate to lipidic phosphorus molar ratio of yellow pigmented micrococci are compared to red pigmented ones and may be summarized by three indexes. These bacteria show wide differences in their fatty acid composition: three strains possess saturated branched chain fatty acids and one has unsaturated straight chain ones. A significant increase in 'anteiso/iso indexes' is observed between pink (M. roseus) and yellow colored bacteria (M. lysodeikticus, S. lutea). There is no significant difference (P greater than 0.05) between the 'unsaturation indexes' of the red pigmented parental D. radiodurans strain and its colorless mutant. Radioresistant strains exhibit a higher 'carbohydrate/phosphorus index' than other strains. There seems to be a relationship between a high carbohydrate-containing lipid content and a high resistance to physical and chemical agents, in particular to radiations. These differences observed in the lipid composition have implications in taxonomy and in establishing an evolutionary scheme.