Effects of white phosphorus on the cellular morphology and protein profile of Aspergillus niger

Abstract

Microorganisms are known for their ability to adapt easily to any environment, forming specific ecosystems capable of surviving in harsh media. White phosphorus is one of the most dangerous and toxic pollutants, whose widespread use for various industrial and military purposes creates conditions for environmental pollution. It has previously been shown that some microbial cultures can adapt to the presence of white phosphorus in the environment, oxidizing it to a phosphate and then using it as a source of biogenic macronutrients. In prior studies, we have demonstrated the possibility of white phosphorus biodegradation by the fungal strains of Aspergillus niger. However, it is important to study the resistance of this species to such a toxic substance as white phosphorus. There may be several probable mechanisms, including the following: the cell wall of the fungus is a barrier to the penetration of white phosphorus into the cell, in which case an increase in the thickness of the cell wall should be observed in response to the impact of the toxicant; a mechanism associated with the expression of stress genes and the production of proteins involved in the disposal of toxins, including white phosphorus. In addition, white phosphorus causes an overall activation of metabolism, accompanied by an increase in the number and size of mitochondria in the cells. It is likely that the active forms of oxygen produced by mitochondria are involved in the detoxification of both white phosphorus and its transformation products. Microscopic and proteomic studies have confirmed the presence of the above-mentioned resistance mechanisms.