Abstract

Lipids are considered a heterogeneous group of organic compounds which contain fats and their derivatives. This chapter achieved the data available on the nature and composition of lipids in filamentous fungi, and their distribution within the cell. The chapter describes some aspects of lipid metabolism, including fatty acid biosynthesis, lipid accumulation mechanisms, and different fermentation strategies. The lipid content of vegetative hyphae varies between 1% and more than 50%, of spores between 1% and 35%, and of yeast cells between 7% and approximately 15% of the tissue dry weights. The amount of lipids produced by a given species of fungus depends on the developmental stage of the growth and on the culture conditions. Culture parameters that influence the growth and the lipid contents of fungi have been found to be temperature, carbon and nitrogen sources, pH, inorganic salts, and others. The qualitative and quantitative nature of the extracellular lipids is influenced by the different growth parameters. The extracellular lipids known in a large number of oleaginous strains include polyol fatty acid esters, glycolipids, hydroxy fatty acids, sugar alcohols, acetylated sphingosines, and acetylated fatty acids. The main purpose of this chapter was to explain the biochemistry behind fungal lipid accumulation in oleaginous filamentous fungi, their distribution and functions, and the current applications of fungal fermentation strategies.