POLYAMINE METABOLISM IN THE THERMOTOLERANT MESOPHILIC FUNGUS ASPERGILLUS-FUMIGATUS

Biomass production by Aspergillus fumigatus was greatest at 40-45 degr ees C and was associated with an increase in concentration of the diam ine putrescine and activity of its biosynthetic enzyme ornithine decar boxylase. Concentrations of the other amines, cadaverine, spermidine a nd spermine were considerably lower than putrescine concentration and did not change significantly over the temperature range 20-50 degrees C. This is surprising in view of the greatly increased flux of label f rom ornithine through to spermidine at 45 and 50 degrees C, indicating an increased formation of this triamine. It is suggested that there w as increased formation of spermidine derivatives at these temperatures . Interestingly, there was greatly increased Formation of the higher h omologues of cadaverine, aminopropylcadaverine and N,N'-bis(3-aminopro pyl) cadaverine, in A. fumigatus at 45 and 50 degrees C.