Respiratory quinone composition of some acidophilic bacteria.

Sulfolobus acidocaldarius, S. brierleyi and S. solfataricus possessed caldariellaquinone (6-(3,7,11,15,19,23-hexamethyltetracosyl)-5-methylthiobenzo-[b]-thiophen-4,7-quinone) as their major lipoquinone. Traces of two smaller analogues of caldariellaquinone (containing C(25) and C(20) side-chains) and a 'caldariellaquinone' containing a C(30) side-chain with a single double bond were also detected. Thermoplasma acidopbilum contained unsaturated menaquinones with seven isoprene units (MK-7) as the major isoprenoid quinone. In addition, substantial levels [ca. 20%) of a new quinone, designated thermoplasmaquinone, were detected. Acidiphilium cryptum and some related heterotrophic, acidophilic bacteria contained ubiquinones with ten isoprene units (Q-10) as their major respiratory quinones. Bacillus acidocaldarius possessed unsaturated menaquinones with seven isoprene units (MK-7) as the major component. Copyright © 1983 Gustav Fischer Verlag, Stuttgart/New York. Published by Elsevier GmbH.. All rights reserved.