biocenotic relationships between microorganisms important for dairy industry: 1 streptococci and lactobacilli starters

The biogenotic relationships between single-strain starters of Streptococcus lactis SLI, Str. thermophilus STH6, Str. faecalis SF11, Lactobacillus bulgaricus LB5 and L. casei LC2 were determined in Yeast-Glucose-Extract Agar medium by the auxanographic technique and in milk cultures by the acid development and rate of proteolysis expressed by formol numbers. The results showed that SL1 did not stimulate any other culture tested. STH6 behaved similarly. SF11 could stimulate lactobacilli starters; whereas, partial inhibition -was recorded in the counter screening. The stimulative effect was more frequent in agar rather than in milk. The results suggest the beneficial addition of Str. faecalis with L. casei in starters mixtur

biocenotic relationships between microorganisms important for dairy industry: 2 lactic acid bacteria and micrococci species

The behaviour of conjoint cultures of micrococci and lactic acid bacteria was studied. Relative stimulation or inhibition was expressed by folds increase or decreat in colonies dimensions on agar medium and by acid per cent, as well as, the extent of protein breakdown in milk. The results showed that each of the micrococci tested was unique in its behaviour towards the lactic acid bacteria. The highest stimulation was found between Streprocvccus lactic and micrococci. Five micrococci culture were neutr,-:1 while the rest increaed colonies dimensions of Str. lactic by 3.75 to 5.47 folds than the normal ones. The same strains increased Str. faecalis colonies by 28 to 95%. On the other hand, micrococci inhibited both Str. Thermophilus and Lactobacillus belgaricus starters. For L. casei, only one micrococci culture caused marked stimulation by 2.29 folds. The recorded stimulation does not manifest itself by the same extent in milk. Therefore, it could be concluded from the results that micrococci could be used for composing cheese starters while it is objectionable in fermented milk products

biocenotic relationships between microorganisms important for dairy industry: 3 lactic acid bacteria and microbacterium species

The biocenot relationships between five single-strain streptococci and lactobacilli starters and six microbacterium spp. were determined in Yeast-Glucose-Extract afar medium applying the auxanographic technique. Alt the Microbacterium spp. stimulated the growth of Str. lactis by 30 to 65 Likewise, L, casei colonies increased by 50 to 110,. Less stimulation was recorded with Str. iaecalis; whereas, neutral relationship or inhibitions was observed with Str, thermophilus. On the other hand, Microbacterium spp. tested inhibited the growth of L. bulgaricrs. The results recommend the use of microbacteria cultures to preparing starters for cheese industry. To the conrary, its presence in milk used for fermented dairy products is objectionable Microbacterium spp