Growth and lactic acid production by Bifidobacterium longum and Lactobacillus acidophilus in goat’s milk

The fitness of a particular strains of Bifidobacteria, Lactobacilli and Streptococci for commercial utilization depends on its rapid growth and acidification of milk as well as its acid and oxygen tolerence. From 20 samples of French commercial yoghurt, one species of bifidobacteria was identified as Bifidobacterium longum. Also, Lactobacillus acidophilus was isolated and identified from fermented milk. The rate of growth was 0.37 h-1 on TPY medium and 0.18 h-1 in milk with Bifidobactrium longum. The production of lactic acid was compared with pure and mixed cultures and the values were 90 and 64 mM at 37°C; 82 and 140 mM at 45°C. The maximum rate of lactic acid production was obtained with mixed culture at 45°C.Key words: Bifidobacterium longum, Lactobacillus acidophilus, fermented milk, growth, lactic acid

Identification of cultivable bifidobacterium species isolated from breast-fed infants feces in West-Algeria

Gastrointestinal microflora exerts a high impact on its host mainly by performing a great variety of metabolic activities, protecting the host against colonization by pathogen and stimulating the gut immune system. The integration of bifidobacteria in dairy products is of interest for reinstalling the intestinal microflora. The mother\'s milk is a prebiotic factor which stimulate the bifidobacteria growth in vivo. Results obtained in west Algeria area show that the number of bifidobacteria reach 26 109 cfu/g in breast-fed infant feces. The microbiological, fructose–6-phospho-ketolase and the biochemical tests have revealed Bifidobacterium strains. The most prevalent isolates belong to the species Bifidobacterium longum (75%) and Bifidobacterium breve (25%). In order to evaluate the potential use as a starter culture, the occurrence of some selected properties such as growth and survival in fermented milk were investigated. These strains have a fast growth in glucose, galactose and lactose media compared to reference species. All isolates studied are sensitive to the pH 8. the B. breve strain support the conservation conditions in pure culture better than in mixed culture with Streptococcus thermophilus or Lactobacillus acidophilus.African Journal of Biotechnology Vol. 4 (5), pp. 422-430, 200

Full Length Research Paper - Growth and lactic acid production by Bifidobacterium longum and Lactobacillus acidophilus in goat’s milk

The fitness of a particular strains of Bifidobacteria, Lactobacilli and Streptococci for commercial utilization depends on its rapid growth and acidification of milk as well as its acid and oxygen tolerence. From 20 samples of French commercial yoghurt, one species of bifidobacteria was identified as Bifidobacterium longum . Also, Lactobacillus acidophilus was isolated and identified from fermented milk. The rate of growth was 0.37 h-1 on TPY medium and 0.18 h-1 in milk with Bifidobactrium longum. The production of lactic acid was compared with pure and mixed cultures and the values were 90 and 64 mM at 37°C; 82 and 140 mM at 45°C. The maximum rate of lactic acid production was obtained with mixed culture at 45°C

Characterization of <i>Bifidobacterium asteroides</i> Isolates

Bifidobacteria have long been recognized as bacteria with probiotic and therapeutic features. The aim of this work is to characterize the Bifidobacterium asteroides BA15 and BA17 strains, isolated from honeybee gut, to evaluate its safety for human use. An in-depth assessment was carried out on safety properties (antibiotic resistance profiling, β-hemolytic, DNase and gelatinase activities and virulence factor presence) and other properties (antimicrobial activity, auto-aggregation, co-aggregation and hydrophobicity). Based on phenotypic and genotypic characterization, both strains satisfied all the safety requirements. More specifically, genome analysis showed the absence of genes encoding for glycopeptide (vanA, vanB, vanC-1, vanC-2, vanD, vanE, vanG), resistance to tetracycline (tetM, tetL and tetO) and virulence genes (asa1, gelE, cylA, esp, hyl)