51. Protease, which is used for flavoring of sake and haze removal in sake is produced by

A. A. oryzae
B. A. flavus
C. B. cereus
D. A. niger

52. The organism B. brevis can be used commercially for the production of

A. gramicidin A
B. tyrothricin(bacitracin tyrocidin complex)
C. tyrocidin
D. all of the above

53. The early assay employed for measuring penicillin activity was based upon the quantity required to prevent the growth of S. aureus over

A. 20 mm diameter zone using the cylinder plate method of assay
B. 24 mm diameter zone using the cylinder plate method of assay
C. 200 mm diameter zone using the cylinder plate method of assay
D. None of the above

54. Penicillin G is also known as

A. hydroxy benzylpenicillin
B. phenoxy methyl penicillin
C. benzylpenicillin
D. 2-pentenyl penicillin

55. A major organic acid produced by a microbial process used in foods is

A. sulfuric acid
B. citric acid
C. oxalic acid
D. uric acid