Streptococcus thermophilus ATCC 19258, Lactobacillus delbrueckii subsp. bulgaricus T-11, and Lactococcus lactis subsp. lactis IL1403 were transformed with the alpha-amylase gene (amyA) from Streptococcus bovis 148 by using a wide host-range vector, and all the transformants secreted the alpha-amylase successfully. Since the promoter and the secretion signal of the amyA gene were functional in t...

the potential of bulk starter fermentation strategy for production of a cost-effective and safe source of β-galactosidase was investigated. three different bulk starter media with different compositions were selected, and an industrial yogurt starter culture strain, l. bulgaricus dsm 20081 was cultivated in these media under ph-controlled conditions (ph=5.6) at 43°c. the media consisted of 1) b...

The role of starter organisms in the ripening of various cheese varieties has been the subject of extensive study in recent years (Deane, 1951; Peterson et al., 1948; Baribo and Foster, 1952; and Van der Zant and Nelson, 1954a). The accumulation of various free amino compounds during cheese ripening has been attributed primarily to enzymes of bacterial origin (Peterson et al., 1948; Deane, 1951...

Culture filtrates of Lactobacillus lactis and Lactobacillus bulgaricus were observed to contain material inhibitory against Staphylococcus aureus. The concentration of inhibitor increased on storage of the lactobacilli at 5 C, and the maximum was attained af ter five days. A carbohydrate source was necessary for the formation of this inhibitory activity by resting cell suspensions. The inhibito...

The residual activity of Lactobacillus delbrueckii ssp. bulgaricus cultures was analysed using pH and various impedimetric methods (impedance detection time (IDT), conductance and capacitance) to quantify the loss in activity following freeze-drying. The large variation recorded in IDT values for similar levels of activity suggests that IDT is not an adequate parameter for estimating the cultur...

TROJANOVÁ I., RADA V. (2005): Enzymatic activity in fermented milk products containing bifidobacteria. Czech J. Food Sci., 23: 224–229. Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus and Bifidobacterium animalis strains were tested for α-galactosidase, β-galactosidase and α-glucosidase activities. Commercially available yoghurts with bifidobacteria were also tested. Whi...

The stimulation by yeast extract of acid production in milk by various lactobacilli was studied. It was found that supplementing milk with purine and pyrimidine bases and amino acids allowed nearly maximal acid production by Lactobacillus bulgaricus strain 7994, L. acidophilus 4796, 4356, and 4357, and L. leichmannii 326 and 327. Further supplementation with deoxyribotides allowed maximal acid ...