Membrane Lipid Composition of Podospora anserina during a Long-Term Evolutionary Experiment

The paper is devoted to the analysis of aging processes and microevolutionary transformations in a long-term experiment with the model ascomycete fungus Podospora anserina (Rabenh.) Niessl. Wild-type lines of P. anserina develop an “senescence syndrome” after several passages on agar medium, whereas long-term submerged growth with passages every 5–6 days maintains the mycelium in a physiologically young state. The results demonstrated that the aging wild strain exhibited significant changes in sterol composition—an increased proportion of peroxide ergosterol and 9,11-dehydroergosterol, and a complete absence of fungisterol. On the contrary, the experimental lines demonstrated a stable composition of sterols comparable to that of the young wild strain, suggesting the absence of a “senescence syndrome.” Moreover, during long-term submerged cultivation, a complex of changes typical of actively growing juvenile cells developed: an increased glycoceramides level and a high proportion of phospholipids esterified by linolenic C18:3 fatty acid. At the ultrastructural level, the abundance of specific double-membrane vesicles was demonstrated in all independent lines of P. anserina after 400 passages in liquid medium. The potential to control the observed adaptation process gives the study a practical orientation, making it useful in various fields of biotechnology.