A minimal growth medium containing glucose, acetate, vitamins, and eight amino acids allowed for growth of Lactococcus lactis subsp. lactis, with a specific growth rate in batch culture of mu = 0.3 h. With 19 amino acids added, the growth rate increased to mu = 0.7 h and the exponential growth phase proceeded until high cell concentrations were reached. We show that morpholinepropanesulfonic ac...

BACKGROUND Insulin-like growth factor I (IGF-I) is one important family of growth factors, which plays key role in intestinal growth, regeneration, and damage repair. However, the low natural abundance of IGF-I limits its research opportunities and practical application in the fields of medicine and animal husbandry. In this study, a tandem repeat strategy was used to express three copies of th...

Bacteria can encounter a variety of physical conditions during their life. Bacterial cells are able to survive these (often adverse) conditions by the induction of specific or general protection mechanisms. The lactic acid bacterium Lactococcus lactis is widely used for the production of cheese. Before and during this process as well as in its natural habitats, it is subjected to several stress...

the objective of this study was to evaluate lactic flora identification in fresh (one-day) and ripened (90-day) koozeh cheese samples as one of the raw milk cheeses. in first step, in order to isolate the different genera of lactic acid bacteria (lab), selective and differential (corresponding) media were used as follow: mrs for lactobacilli and pediococci, mrs+ vancomycin for leuconostocs, m17...

In order to develop a new system for the analysis of capsular biosynthetic pathways we have explored the possibility of expressing type 3 capsular polysaccharide (CPS) from the pathogen Streptococcus pneumoniae in Lactococcus lactis, an unencapsulated lactic acid bacterium being developed as a vaccine delivery vehicle for mucosal immunization. Only three of the four type 3 CPS biosynthesis gene...

BACKGROUND Inflammatory bowel diseases (IBD) are intestinal disorders characterized by inflammation in the gastrointestinal tract. Interleukin-10 is one of the most important anti-inflammatory cytokines involved in the intestinal immune system and because of its role in downregulating inflammatory cascades, its potential for IBD therapy is under study. We previously presented the development of...

Previously, we have shown that glutathione can protect Lactococcus lactis against oxidative stress and acid stress. In this study, we show that glutathione taken up by L. lactis SK11 can protect this organism against osmotic stress. When exposed to 5 M NaCl, L. lactis SK11 cells containing glutathione exhibited significantly improved survival compared to the control cells. Transmission electron...

Most inhibitory substances produced by lactic acid bacteria are safe and effective natural inhibitors of pathogenic and food spoilage bacteria in various foods. In this study, bacteriocin nisin producing Lactococcus lactis was isolated from fermented milk and cheese. The test isolate was grown in MRS medium under optimized conditions. Bacteriocin activity of the test isolate was determined by a...

The use of probiotics engineered to express specific enzymes has been the subject of considerable attention in poultry industry because of increased nutrient availability and reduced cost of enzyme supplementation. Phytase enzyme is commonly added to poultry feed to improve digestibility and availability of phosphorus from plant sources. To construct a probiotic with potential of phytate degrad...

BACKGROUND The implementation of novel chassis organisms to be used as microbial cell factories in industrial applications is an intensive research field. Lactococcus lactis, which is one of the most extensively studied model organisms, exhibits superior ability to be used as engineered host for fermentation of desirable products. However, few studies have reported about genome reduction of L. ...