6. Which of the following when used in proper concentration stimulates the Ascomycetes fermentation of vitamin B12and can be used to counteract the toxicity of iron in Candida species?
A. Co
B. Ni
C. Zn
D. Ca
7. Pectinase, an enzyme used for increasing yield and for clarifying juice is obtained by
A. A. oryzae
B. A. niger
C. A.flavus
D. all of these
8. The 95% ethanol is equivalent to
A. 190 proof
B. 110 proof
C. 170 proof
D. 120 proof
9. Which species from the following is resistant to methyl tryptophan?
A. Candida utilis
B. E. coli
C. B. subtilis
D. Hansenula anomala
10. Which of the following substance is employed to neutralize the lactic acid as it is produced (because lactic acid bacteria do not tolerate high concentrations of acid?
A. CaCO3
B. (NH4)2HPO4
C. MgSO4
D. Na2SO4