A sulfonolipid and novel glucosamidyl glycolipids from the extreme thermoacidophile Bacillus acidocaldarius

Abstract

The total lipid content of the extreme thermoacidophile Bacillus acidocaldarius comprises about 8.1% of the cell dry weight. Total lipid had a distribution of 15.7% neutral linique component initially characterized as an N-acylglucosamine beta-linked to the primary hydroxyl of an unusual fully saturated pentacyclic triterpene derived tetrol(C35H62O4, Mr 546), which appears to be a derivative of the pentacylcic triterpene hopane substituted at C-29 with a 1,2,3,4-tetrahydroxy pentane. Other major glycolipids present were partially characterized as O-beta-D-glucopyranosyl-(1 leads to 4)-O-2-acylamido-2-deoxy-beta D-glucopyranosyldiacylglycerol and O-beta-D-glucopyranosyl-(1 leads to 4)-O-2-acylamido-2-deoxy-beta-D-glucopyranosylmonoacylglycerol. Minor components of the glycolipid fraction included O-beta-D-glucopyranosyl-(1 leads to 4)-O-2-acylamido-2-deoxy-beta-D-glucopyranosylglycerol, O-2-amino-2-deoxy-beta-D-glucopyranosyl pentacyclic tetrol and free pentacyclic tetrol. The distributions of esterified and amide-linked fatty acids were similar, being comprised primarily of branched heptadecanoic, 11-cyclohexyundecanoic and 13-cyclohexyltridecanoic acids. The acid lipids were composed of a sulfonoglycosyldiacylglycerol (43.2%), diphosphatidylglycerol (32.3%), lysodiphosphatidylglycerol (5.3%), phosphatidic acid (5.8%) and phosphatidylglycerol (13.4%).