SARMA, K.S(MAJOR)VENKATA REDDY, TPADMANABHA REDDY, VSUDHAMANI, M2018-11-292018-11-291997http://krishikosh.egranth.ac.in/handle/1/5810084735THESESABSTRACT: Raw milk (40) and Dahi (10) samples were used to isolate lactococci. Two hundred isolates from raw milk and 50 isolates from dahi were obtained on M17 agar medium. Of these 167 and 46 isolates from raw milk and dahi rc!spectively proved to be streptococci. Subsequently, 65 and 6 isolates of lortococcc~l.a~c tis subsp. Lactis, 27 and 4 isolates of Lactococrus lactis subsp. rrenoris, and 4 and 4 isolates of Lactococc.us lactis subsp. lactis biovar diacet,vlactis were identified respectively from raw milk and dahi. The range of titrable acidity exhibited by the lactococcal isolates was 0.52% - 0.89% 1.a over 16 h. The range of milk curdling time was 5 - >12h. There was noticeable correlation between acid producing ability and milk curdling time of the lactococcal isolates. Eleven isolates of L. lactis subsp.lactis and 6 isolates of L. lactis subsp, cremoris exhibited antagonism against at least one of the 5 lactococcal indicator strains used. However, none of the lactococcal isolates inhibited any of the 3 pathogens of Escherichia coli, Bacillus cereu.s and Staphylococcus aureus. L. lactis subsp. lactis CI0 was most sensitive lactococcal indicator while Id. lactis subsp. lactis hiovar diacet.ylactis L)RC3 was the least sensitive.ennullThesis