Lipid profile of the strains of Agrobacterium tumefaciens in relation to agrocin resistance

Abstract

Studies have been carried out in detail on the lipid make up of Agro-bacterium tumefaciens using virulent agrocin-sensitive and avirulent agrocin-resistant strains. Phosphatidylcholine, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, and phosphatidylglycerol are the major phospholipids present in A. tumefaciens. Although the total lipid content is increased due to development of resistance towards agrocin, the proportion of phospholipids and neutral lipids in the total lipid fraction remains almost the same either in the normal or in the resistant strains. The relative proportion of most of the individual phospholipid and neutral lipid components also remains unaltered due to development of resistance towards agrocin. With the exception of the proportion of neutral lipid, those of total lipid and phospholipid decrease steadily with an increase in the age of the culture. It is further revealed that agrocin resistance brought about an increase in the amount of unsaturated fatty acids with concomitant decrease of saturated fatty acid content in A. tumefaciens as obtained by gas-liquid chromatographic analysis.