RESPONSE OF PSYCHOACTIVE OLIGOTROPHIC BACTERIA WITH AN UNUSUAL LIPID-COMPOSITION TO CULTIVATION TEMPERATURES

Effect of suboptimum (7 degrees C) and supraoptimum (28 degrees C) cul tivation temperatures on the phospholipid and elemental composition of five oligotrophic bacteria belonging to different genera was studied. The phospholipid composition of two aquatic toroidal bacteria Flectob acillus major and ''Arcocella aquatica,'' which contain up to 30% of a minoacylphosphatidylglycerol (a phospholipid uncommon for prokaryotes) did not change at these cultivation temperatures, whereas P, K, and S contents of these bacteria were lower at 7 degrees C. The responses o f these bacteria to low temperature were assumed to reflect impairment s in their transport and protein-synthesizing systems. Three facultati ve methylotrophs Renobacter vacuolatum, Hyphomicrobium vulgare, and Me thylobacterium organophylum, characterized by an anomalously high cont ent of phosphatidylcholine, responded to low temperature by reducing t he content of this phospholipid and elevating the content of its precu rsor phosphatidylethanolamine. At 7 degrees C, the phosphorus content of cells decreased by 40-60%, while the contents of other elements stu died remained unchanged. These data, together with the absence of an i ncrease in Ca content (which is a typical response of bacteria to stre ss), testified to a high adaptability of lecithin-containing oligotrop hs to suboptimum temperatures.