Aliphatic compounds are carbon and hydrogen-containing hydrocarbon
complexes and are present in almost every plant, animal and microorganism. In 1929,
aliphatic hydrocarbons were first discovered by crude chemical methods. These
observations were later confirmed and expanded by more sophisticated instruments,
such as gas-liquid chromatography and GLC-mass spectrometry. Aliphatic
hydrocarbons were detected in the wax of most studied organisms and mainly
contained n-alkanes, but may also include n-alkenes, saturated and unsaturated, cyclic
alkanes, and isoprenoid hydrocarbons. Similarly, surfaces of higher plants contain a
complex waxy coating that consists of primary and secondary fatty alcohols, long
chains of fatty acids, ketones, aldehyde, terpenes, diols, waxy esters, glycerides, etc.
The chemical composition of aliphatic hydrocarbons, chain length predominance,
branching, the unsaturation of surface wax and their variation among various
organisms, such as plants, algae, bacteria, animals and particularly in fungi have been
described in the current chapter. The hydrocarbon distribution in animals is reported to
be slightly similar to that of higher plants, while in bacteria, a complex mixture of
normal, single- double branched, saturated, or unsaturated structural isomers are
reported. A brief description of the biotechnological production of various aliphatic
compounds using genetic engineering has also been presented in this chapter. The
biosynthesis of aliphatic hydrocarbons by two common routes, “elongation
decarboxylation” and “head-to-head condensation,” has been studied well in plants and
bacteria and are discussed here in detail. Pathways involved in the degradation of
hydrocarbons by aerobic and anaerobic microbes and the enzymes involved are also
described in this chapter. Aliphatic compounds with different chain lengths have been
of biotechnological interest for the past few decades as they perform various biological
functions in living organisms apart from their role as the chief component of diesel and
jet fuels. The current chapter also highlighted the biological importance of these
aliphatic hydrocarbons.
Keywords: Aliphatic hydrocarbons, Alkanes, Biosynthesis, Biotechnological productions, Carbon chains, Cuticular wax, Degradation, Cesiccation, Elongation decarboxylation, Fungal spores, Head-to-head condensation, Monooxygenases, Odd/even ratios, Oxidation, Paraffin, Predominant.
