Influence of N,N-bis(3-aminopropyl)dodecylamine on the mycelium growth and the cell wall composition of resistance and sensitive strains belonging to the genus Aspergillus.

Resistance causes of moulds to N,N-bis(3-aminopropyl)dodecylamine (APDA) for selected species of Aspergillus niger and Aspergillus flavus was examined. Control (sensitive) strains and resistant strains, cultured at 0.05% triamine, were used in the experiments. The non-resistant strains did not have growth capacity in this amount of ADPA while the resistant strains were characterised by a smaller biomass increase. Individual stages of the development of the mycelium occurred later than those in the control samples. The participation of the cell wall in the mycelium biomass of the resistant strains was higher by 7.5%. The glucan content in the wall dry mass was lower by 11% than that in the sensitive strains. A 41% increase in the lipid content was recorded in the cell wall of resistant Aspergillus flavus. A 21% protein increase occurred in the wall of Aspergillus niger comparing to the control strain. Infrared spectrophotometric analysis of the cell wall did not reveal the presence of triamine. Most absorption bands disappeared in the wall of Aspergillus flavus while no additional absorption bands were registered in Aspergillus niger; some bands were only stronger than those in the control sample. The resistant strains were characterised by a smaller ergosterol content, the main constituent of cell membranes. Spectrophotometric analysis of the mycelium did not reveal significant qualitative changes; only quantitative changes were observed. It was noticed that the resistance reaction did not occur with the same intensity in both species studied. The resistant strain of Aspergillus niger was characterised by a slightly more intensive absorption within its entire spectrum range in comparison to control strain. In case of Aspergillus flavus the absorption was higher for control strain.