We previously reported that oral administration of heat-killed cells or fermented milk made by Lactococcus lactis H61 has the potential to improve skin properties during season related with dry skin (i.e. autumn to winter, winter to spring). In this study, we investigated the effects of H61-fermented milk on skin properties during summer by a randomized, double-blind trial. Healthy, middle-aged and aged female volunteers (n=22; age: 40-74y) were given 85g of either conventional yogurt (1011 CFU of both Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus) or fermented milk made by yogurt starter and strain H61 (H61-fermented milk) (1011 CFU of both L. delbrueckii subsp. bulgaricus and S. thermophilus, and 1010 CFU of strain H61) daily for 4 weeks. Before, at the end of the 4-week intake treatment and after 1 month (week 9), we measured skin hydration (inner forearms and cheek) and sebum content (cheek only) and vascular age. At week 4 in both groups, hydration in cheek significantly increased. Hydration in inner forearms and sebum in cheek also increased, although they were not significant. At week 9, those skin parameters decreased. Intake of H61-fermented milk did not affect the skin properties and vascular age, compared with conventional yogurt. At week 4, by self-questionnaire (skin and general health condition), some scores in both groups were improved, and at week 9 some scores were only improved in the H61-fermented milk group. To characterize the beneficial effect of H61-fermented milk on skin properties during summer, it may need larger sample size and longer intake period.
In an investigation of the assimilation of a newly synthesized non-natural N-acetylsucrosamine (SucNAc) by Bifidobacterium spp., we identified one species, Bif. catenulatum, that utilizes SucNAc in the presence of glucose, but not as a sole carbon source, and another species, Bif. pseudocatenulatum, that utilizes SucNAc as a sole carbon source. In culture, Bif. catenulatum growth occurred in two stages, with glucose being utilized in the first stage and SucNAc being used in the second stage (diauxie). Assessment of sugar degradation activity by bacterial extracts revealed that although Bif. catenulatum basically expresses sugar-degrading enzymes at low levels, new enzymatic activity is observed when SucNAc is utilized as a carbon source. In contrast, Bif. pseudocatenulatum basically expresses a variety of sugar-degrading enzymes. Elucidation of the mechanism that allows SucNAc, which is not utilized as a sole carbon source by Bif. catenulatum to be utilized in the presence of glucose will lead to a deeper understanding of sugar utilization by Bifidobacterium spp.
Helicobacter pylori is a Gram-negative spiral-shaped microaerophilic bacterium that infects more than half of the world's population. Probiotic treatment may inhibit H. pylori infection by competition with the pathogen for the same receptor site (s) on the host mucosal surface. We previously found that Lactobacillus reuteri JCM1081 cell surface-associated elongation factor Tu (EF-Tu) was characterized as a sulfated carbohydrate-binding protein and may mediate adhesion of H. pylori to the host gastrointestinal tract. Here, we evaluated the role of EF-Tu in inhibiting H. pylori adhesion, using recombinant EF-Tu protein (His-EF-Tu). The addition of His-EF-Tu showed concentration-dependent inhibitory effects on the adhesion of H. pylori strains to porcine gastric mucin (PGM)-coated wells. Similar inhibitory effects were observed in H. pylori clinical isolates. Interestingly, sulfatase-treated PGM reduced H. pylori adhesion, whereas His-EF-Tu barely affected H. pylori adhesion on sulfatase-treated PGM. The inhibitory rate was similar to that of pretreatment with the sulfated carbohydrate recognition antibody PGM34. Western blotting revealed that EF-Tu was present in cell surface fractions isolated from several Lactobacillus strains. Thus, EF-Tu could inhibit the adhesion of several H. pylori strains, and the inhibitory effect may be mediated through competition of EF-Tu and H. pylori ligands for the same adhesion sites.
The purpose of this paper is to 1) understand the milk processing in Romania, 2) analyze the characteristics of the Romanian milk processing by comparing these techniques with the matured cheeses from Western Europe and the milk products from Southeastern Europe through the case study of the former transhumant households and the semi-pastoral settled households from Romania. Two types of cheeses, brânză de burduf and telemea were made using the rennet coagulant. brânză de burduf is made by draining as much whey as possible from the curds and then left to mature. Once it has matured, the curds are cut finely into small pieces and then mixed with salt. brânză de burduf is comparable to a matured hard cheese and is thought to have possibly developed into the matured hard cheeses found in Western Europe north of the Alps. To make telemea, the curds are pressed to drain whey and immediately soaked in brine without having to set it aside to mature for several days. For this reason, telemea is comparable to a fresh cheese or a matured fresh cheese. The similar cheese such as telemea is also made in Bulgaria, Greece, and Italy, making it a common cheese found throughout the Mediterranean region south of the Alps. The Romanian cheese processing technology provides a very important insight to the history of how the matured cheeses in Europe each developed its own characteristic in the north and the south divided by the Alps mountain range.
Phage attack has always been a major problem in industrial fermentation, especially in the dairy industry. In a monitoring test, a total of five kinds of phage against Streptococcus thermophilus were detected in three yogurt factories located from Kanto to Kansai area of Japan. These phages were found to be derived from a same type of phage harboring a restriction-modification (R/M) system. The occurrence of these phages is possibly caused by the horizontal transmission between factories and the adaption to different starter strains used in each plants via the R/M system. Strategies for prevention of phage contamination in yogurt plants were discussed.