Metabolism of aromatic amino acids by lactic acid bacteria is an important source of off-flavor compounds in Cheddar cheese. Previous work has shown that alpha-keto acids produced from Trp, Tyr, and Phe by aminotransferase enzymes are chemically labile and may degrade spontaneously into a variety of off-flavor compounds. However, dairy lactobacilli can convert unstable alpha-keto acids to more-...

Plant-based food products can be modified by fermentation to improve flavour and the concentration of some biologically active compounds, but also to increase the mineral availability by eliminating anti-nutrient substances such as phytates. The objective of this study was to develop a fermented soybean drink with improved nutritional quality and source of probiotic bacteria by including as sta...

Lactobacillus (L. casei) Zhang is a koumiss-originated probiotic strain, which was used as a model in a long-term antibiotics-driven evolution experiment to reveal bacterial evolutionary dynamics; and we isolated gentamycin-resistant L. casei Zhang descendents. To decipher the gentamycin resistance mechanism, here we cultivated the parental L. casei Zhang and its descendent cells in an antibiot...

Nutritional deficiencies are associated with impaired immune response, affecting the body's defence mechanisms. It is also known that Lactic Acid Bacteria (LAB) and fermented products such us yogurt have immunopotentiator activity and nutritional properties, and could thus be used as a valuable supplement in a renutrition diet. The aim of this study was to determine, in a non-severe malnutritio...

Knowledge of the growth factor requirements of various lactic acid bacteria, especially Lactobacillus casei and L. arabinosus 17-5, has led to the development of useful microbiological methods for the quantitative determination of most-of the B vitamins. Recently attention has turned to the amino acid requirements of the lactobacilli. The amino acids necessary for growth of L. casei and L. arab...

A genomic library of Lactobacillus casei DNA containing 10,000 individual clones was constructed in the plasmid pUC13. The gene encoding the L. casei folylpolyglutamate synthetase was isolated from the library by complementation of a folC mutant of Escherichia coli. The gene was expressed in E. coli from its own promoter and produced amplified folylpolyglutamate synthetase activity with propert...

Helicobacter pylori is one of the most common causes of chronic infections in humans. Curing H. pylori infection is difficult because of the habitat of the organism below the mucus adherent layer of gastric mucosa. Lactobacilli are known as acid-resistant bacteria and can remain in stomach for a long time than any other organism, we aimed in this study to examine the efficacy of Lactobacillus c...

The incidence of colon cancer has increased considerably and the intestinal microbiota participate in the development of colon cancer. We showed that the L. casei Zhang or vitamin K2 (Menaquinone-7) intervention significantly alleviated intestinal tumor burden in mice. This was associated with increased serum adiponectin levels in both treatments. But osteocalcin level was only increased by L. ...

Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis) the causative agent of Johne's disease, is one of the most serious infectious diseases in dairy cattle worldwide. Due to the chronic nature of this disease and no feasible control strategy, it is essential to have an efficient animal model which is representative of the natural route of infection as well as a viable treatment opt...

The antimicrobial activity of the intraurethrally administered probiotic Lactobacillus casei strain Shirota against Escherichia coli in a murine urinary tract infection (UTI) model was examined. UTI was induced by intraurethral administration of Escherichia coli strain HU-1 (a clinical isolate from a UTI patient, positive for type 1 and P fimbriae), at a dose of 1 x 10(6) to 2 x 10(6) CFU in 20...