Spores of the Aspergillus niger mutant MBU 90, producing high quantities of citric acid under submerged conditions, will keep their viability during a period of 4 years when stored in talc or in lyophilized form (using inactive horse serum or dried milk). When spores are stored in active coal a decrease in spore viability was noted after 3–4 years of storage. Moreover, an increase in the frequency of different morphological modifications was observed.
Musílková M., Fencl Z., Ujcová E., Seichert L. (1979): The viability and physiological activity of spores of Aspergillus niger under different methods of preservation. – Česká Mykologie 33(3): 181–184.
