Importance of lipidic acyl chains in the process of biochemical thermal adaptation of <Emphasis Type="Italic">Cunninghamella japonica</Emphasis> mucoraceous fungus

The temperature of C. japonica cultivation influences the lipid content and composition of acyl chains, especially the content of such polyunsaturated acids as linoleic and linolenic. Thermal adaptation is accompanied by the modulation of fatty acid isomeric composition and acyl chain length and, at low temperatures, promotes the appearance of fatty acids uncommon to the fungus, in particular, arachidonic acid. The changes occur on a background of significant alterations in the fungus metabolism (in glucose uptake, ATP content, economic coefficient value, etc.). In experiments on the inhibition of translation with cycloheximide, abrupt temperature change (supraoptimal to cold) did not lead to desaturase de novo synthesis, but rather stimulated the activity of the named enzymes, except for palmitoleoyl-CoA desaturase. In the process of temperature adaptation, polar lipid microviscosity modulating compounds influenced fatty acid acyl chain composition. Microviscosity differences between polar and neutral lipids and correlation to the degree of fatty acid unsaturation during temperature fluctuation were established.