The outer membrane of Spirochaeta aurantia was isolated after cells were extracted with sodium lauryl sarcosinate and was subsequently purified by differential centrifugation and KBr isopycnic gradient centrifugation. The purified outer membrane was obtained in the form of carotenoid-containing vesicles. Four protein species with apparent molecular weights of 26,000 (26K), 36.5K, 41K, and 48.5K...
