Membranes from Myxococcus fulvus (myxobacterales) containing carotenoid glucosides : I. Isolation and composition

Abstract

1. 1. The isolation and chemical composition of an electronmicroscopically homogeneous membrane fraction from the gliding bacterium Myxococcus fulvus (Gram-negative) was described. 2. 2. The membrane fraction was characterized by the presence of a-, b- and c- type cytochromes, menaquinone, NADH oxidase, NADH dehydrogenase, succinate dehydrogenase. Ubiquinones which are generally found in Gram-negative bacteria were not present. 3. 3. Phospholipids accounted for 25 % of the membrane dry weight. Phosphatidylethanolamine was the main component (72 % of total phospholipid). Phosphatidylglycerol, phosphatidylinositol, phosphatidic acid, and an unknown phospholipid were also present. About 22 % of total phospholipids were identified as alk-1-enyl-acyl derivatives. 4. 4. The carotenoid glucoside myxobacton ester was localized in the membrane (0.14 % of membrane dry weight). The carotenoid glucoside to menaquinone molar ratio was 0.233. This ratio was found for the membrane fraction and for whole bacteria.