Genetic instability of the short-living ascomycetous fungus <Emphasis Type="Italic">Podospora anserina</Emphasis> induced by prolonged submerged cultivation

Investigation of genetic variability of the short-living filamentous fungus Podospora anserina during its adaptation to conditions of prolonged submerged cultivation has been carried out for the first time. Cultivation of P. anserina under aeration (on a shaker) provides pronounced selective pressure, which makes it possible to obtain isolates with specific features, which are well adapted to cultivation in liquid media and have a life span several times exceeding that of the original strain. Static cultivation did not prevent the ageing of P. anserina. Repeated transfers in the shaker culture resulted in formation of mycelium deprived of the dark pigment melanin and actively producing carotenoids under illumination. The qualitative composition of P. anserina carotenoids was the same as in the closely-related species Neurospora crassa. The features obtained during the shaker cultivation (including changes in the colony morphology and decreased capacity for melanin synthesis) are inherited by their hybrids with the wild type strains, i.e., they resulted from the intragenomic rearrangements occurring during submerged cultivation of the fungus.