Biodegradation of anthraquinone dye by Aspergillus niger SA1 in self designed fluidized bed bioreactor

Biodegradation and decolorization of Drimarene blue K2-RL [anthraquinone] dye by a fungal isolate Aspergillus niger SA1 was studied in self designed lab scale bioreactor system with different solid supports. Aspergillus niger SA1, was efficiently immobilized on sand and sodium alginate beads. The immobilized cells were used in the form of fluidized bed reactor for textile dye [Drimarene blue] removal. Both the reactors were operated at room temperature and pH=5.0 in continuous flow mode with increasing concentrations of dye in simulated textile effluent. The reactors were run on fill and draw mode, with hydraulic retention times of 24-72 h. The fluidized bed bioreactor with sand as immobilizing support [FBR1] showed overall better performance as compared to fluidized bed bioreactor with sodium alginate as immobilizing support [FBR2]. The average overall color, BOD and COD removal in the FBR1 system were up to 78.29, 70.81 and 83.07% respectively, with 50 ppm initial dye concentration and HRT of 24 h. While 72.19%, 86.63% and 74.74% removal of color, BOD and COD were observed, respectively, in FBR2 with the same conditions. Reductions in BOD and COD levels along with color removal proved that decolorization and biodegradation occurred simultaneously

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

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