Physiological and Biochemical Alterations during the Germination of Aspergillus Niger Conidia

Abstract:

The provided analytical data pertains to the germination of Aspergillus niger van Tieghem spores, focusing on various components measured by dry weight. These components include sugars, organic acids, amino acids, proteins, and lipids. Additionally, indicators of spore activity, such as respiration and permeability changes, were assessed. It is noteworthy that A. niger spores do not initiate germination utilizing their internal reserves. The introduction of glucose triggers heightened oxygen consumption and an increase in the overall concentration of organic acids. The initial 3-hour germination period is characterized by an augmentation in protein synthesis, along with a reduction in free amino acid concentration, which suggests the synthesis of proteins to facilitate germination. Furthermore, changes in permeability are observed to influence the release of various substances from the germinating spores. Significant alterations occur in the concentration of free sterols and the sterol-to-lipid ratio in germinating A. niger spores. During the early stages of germination, there is extensive degradation of phospholipids, particularly phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and their lyso-derivatives. However, these phospholipids are subsequently resynthesized in the later stages of germination. Regarding nonpolar lipids in A. niger spores, they consist primarily of hydrocarbons, triglycerides, fatty acids, sterol esters, and free sterols. Notably, the content of free sterols increases while the content of hydrocarbons decreases during the germination process in A. niger spores.