We describe, for the first time, a detailed electroporation procedure for Lactobacillus delbrueckii. Three L. delbrueckii strains were successfully transformed. Under optimal conditions, the transformation efficiency was 10(4) transformants per microg of DNA. Using this procedure, we identified several plasmids able to replicate in L. delbrueckii and integrated an integrative vector based on ph...

Cell growth and lactose consumption profile of five Lactobacillus Strains: bulgaricus, casei, lactis, delbrueckii and fermentum has been investigated. Experiments of cell growth and substrate utilization were conducted in batch submerged culture of whey with added lactose and some other growth factors. Fitness assessment of experimental data on the cell growth and lactose consumption by Monod k...

Ldl1 is a virulent phage infecting the dairy starter Lactobacillus delbrueckii subsp. lactis LdlS. Electron microscopy analysis revealed that this phage exhibits a large head and a long tail and bears little resemblance to other characterized phages infecting Lactobacillus delbrueckii. In vitro propagation of this phage revealed a latent period of 30 to 40 min and a burst size of 59.9 +/- 1.9 p...

background and aims: probiotics are defined as live microorganisms that are beneficial to human health. probiotics are commonly found in some foods such as dairy products or complementary tablets. a recent research shows that probiotics have a significant role in diabetes type 1 and 2 treatment. among the variety of lactic acid bacteria, lactobacillus strains are well known in probiotics for th...

The concentrations of gamma-aminobutyric acid (GABA) in 22 Italian cheese varieties that differ in several technological traits markedly varied from 0.26 to 391 mg kg(-1). Presumptive lactic acid bacteria were isolated from each cheese variety (total of 440 isolates) and screened for the capacity to synthesize GABA. Only 61 isolates showed this activity and were identified by partial sequencing...

Objective: The objective of the present study was to collect different Lactic acid bacterial strains from culture collection centers and screen their functional probiotic characteristics such as acid tolerance, bile tolerance, antibacterial activity and antibiotic sensitivity for their commercial use. Materials and Methods: Acid and bile tolerence of selected LAB(Lactic acid bacteria) was deter...

Azoreductase activity in the ceca of mice lacking lactobacilli as members of the normal microflora (reconstituted-lactobacillus-free [RLF] mice) was compared with that of RLF mice whose gastrointestinal tracts were colonized by strains of Lactobacillus delbrueckii and Lactobacillus fermentum. Azoreductase activity was 31% lower in the ceca of mice colonized by lactobacilli.

In the present study, the effects of milk supplementation on growth and viability of yogurt (Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus) and probiotic bacteria (Lactobacillus acidophilus and bifidobacteria) were studied during yogurt production and 33 days of refrigerated storage. The incubation time to reach pH = 4.5 was greatly affected by the addition of milk ...

Lipoteichoic acids (LTAs) were purified from Lactobacillus delbrueckii subsp. lactis ATCC 15808 and its LL-H adsorption-resistant mutant, Ads-5, by hydrophobic interaction chromatography. L. delbrueckii phages (LL-H, the LL-H host range mutant, and JCL1032) were inactivated by these poly(glycerophosphate) type of LTAs in vitro in accordance to their adsorption to intact ATCC 15808 and Ads-5 cells.

The complete genome sequence of Lactobacillus bacteriophage LL-H was determined in 1996. Accordingly, LL-H has been used as a model phage for the infection of dairy Lactobacillus, specifically for thermophilic Lactobacillus delbrueckii ssp. lactis host strains, such as ATCC 15808. One of the major goals of phage LL-H research consisted of the characterization of the first phage-host interaction...