Occurrence of isoprenoid compounds in gram-negative methanol-, methane-, and methylamine-utilizing bacteria.

Abstract

The isoprenoid compounds in gram-negative methanol-, methane-, and methylamine-utilizing bacteria were investigated. All strains tested contained ubiquinone, but none contained menaquinone. The ubiquinone types were Q-8, Q-9, or Q-10. The so-called obligate methylotrophs and methanotrophs (genus Methylobacillus, Methylophaga, Methylomonas, Methylococcus, and Methylovibrio) contained ubiquinone Q-8. The Hyphomicrobium strains contained Q-9. The other facultative methylotrophs and methylamine-utilizing bacteria contained Q-10. A large amount of squalene occurred in the Methylobacillus, Methylophaga, Methylomonas, and Methylococcus strains which utilize one-carbon compounds via the ribulose monophosphate pathway. The Protomonas extorquens and Methylobacterium organophilum strains contained a large amount of sterols (Hop-22(29)-ene and Hopan-22-ol), carotenoid pigments, and a small amount of squalene. The Hyphomicrobium strains contained a small amount of squalene and Hop-22(29)-ene. The Xanthobacter strains contained a large amount of carotenoid pigments (zeaxanthin, zeaxanthin monorhamnoside, and zeaxanthin dirhamnoside). The Protomonas and Methylobacterium strains were unique in the existence of sterols and large amounts of total isoprenoid compounds, 4.68 to 7.97 mg/g of dry cell. The distribution of squalene, sterols, quinones, and carotenoid pigments conforms with the morphological, physiological, and other chemotaxonomic characteristics in gram-negative methanol-, methane-, and methylamine-utilizing bacteria.