Review summarizes comparative data on the intracellular hydrocarbons of different microorganisms (cyanobacteria, aerobic and anaerobic bacteria, yeasts, and mycelial fungi). Certain systematic groups of microorganisms are characterized by specific composition of intracellular hydrocarbons, in particular, cyanobacteria are unique in their ability to produce 7- and 8-methylheptadecanes; photosynthetic bacteria are distinguished by the synthesis of cyclic hydrocarbons (pristane and phytane), whereas in fungi, long-chain hydrocarbons are predominant. The synthesis of hydrocarbons by microorganisms depends considerably on the growth conditions that provides a way for its physiological regulation. The processes for microbiological production of extracellular aliphatic and volatile non-methane hydrocarbons are exemplified. Pathways for the biosynthesis of straight chain-, branched-, volatile non-methane hydrocarbons, and isoprenoids are described. Mechanisms of the hydrocarbon synthesis appear to be different in various microorganisms. The role of hydrocarbons in microorganisms is discussed. (c) 2005 Elsevier Ltd. All rights reserved.