Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Animal, Dairy, and Veterinary Sciences

Department name when degree awarded

Dairy Manufacturing


This study was designed to answer a three-fold purpose. Primarily, it has endeavored to measure the inhibitory effect of three antibiotics (potassium pencillin, dihydrostreptomycin, and oxytetracycline) on lactic acid producing organisms. The lactic acid-producing organisms include Streptococcus lactis, Streptococcus thermophilis, and Lactobacillus bulgaricus.

The determination of an effective dose of a given antibiotic which will inhibit 50 percent of the lactic acid-producing organism (E.D.50) will be established. A 50 percent cut in acid development will certainly lead to an inferior product.

The secondary purpose has related to the detection of inhibitory substances (antibiotics) in milk. What is the possibility of detecting the concentration of antibiotic which correlates to the E.D.50 established in the first phase of the problem?

The third purpose embraces a study of the sensitivity of tests for detecting inhibitory substances.



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