抄録
The intact total lipid from Sulfolobus sp. (99.9% identical to Sulfolobus shibatae by comparison of 16SrRNA) was examined by electrospray ionization/time of flight mass spectrometry (ESI/TOF MS) in negative ion mode with high-resolution. Solution of the total lipid in a mixed solvent of chloroform and methanol (1:3) was injected into the ion source using a loop injection system with an infusion pump. Some ions directly corresponding to phospho-and sulfo-ether lipids isolated from Sulfolobus acidocaldarius were detected. The ions between m/z 1,532 and 1,546 were assigned to phospholipid (PL1), the ions between m/z 1,840 and 1,847 to sulfolipid (SGLII), and the ions between m/z 1,856 and 1,865 to phospholipid (PGLI and/or PGLII). Each group of ions was analyzed as the mixture of the ether lipids containing different number of five-membered ring in the isoprenoid chain with their isotope peaks. Examination of the ether lipids of the bacteria cultivated at different temperatures (65°C and 75°C) indicated that (1) the molecule having four five-membered ring was the major component in the tetraethers; (2) the maximum number of five-membered ring in the tetraethers was six at both growth temperatures; (3) the number of five-membered ring extends toward smaller numbers on cultivation at the lower temperature.
