Effect of heavy metals and vitamins on urease production and activity by aspergillus fumigatus and fusarium nivale

ABSTRACT

The effect of some microelements and vitamins supplied A either individually or in mixtures to the culture media of Aspergillus fumigatus and Fusarium nivale on their growth and ureolytic activity was studied. Zinc and nikel activated growth and ureolysis either in culture media or reaction mixtures of both fungi. Fe[2+] and Se[2+] activated ureolysis in A. fumigatus only whereas Mo[2+] activated ureolysis in F. nivale. The sequence of activation could be arranged in A. Fumigatus as Fe[2+] [200 microg /I] > Se[2+] [50 microg / L]> Ni[2+] [100 microg/l]> Zn[2+][200 microg / 1]. In F. nivale Mo[2+] [50 microg/l]> Ni[2]+ [200 microg/l]> Zn[2+] [200 microg]l. Hg[2]+, Cd[2+], Co[2+] Fe[3+] and Cu[2+]markedly inhibited growth and ureolysis in both fungal species. Thiamine - HC1 [5 mg/1] and biotin [20 mg/1] activated growth and ureolysis of the tested species, while riboflavin, ascorbic acid and nicotinic acid were inhibitory. Mixture of best microelements and mixture of best vitamins retarded growth and ureolysis in both species, while a mixture containing microelements and vitamins activated urease and growth in both fungi as compared to all other treatments