Mouse Model of Anti-Obesity Effects of Blautia hansenii on Diet-Induced Obesity.

Reportedly, a relationship exists between intestinal microflora and obesity-related lifestyle diseases. Blautia spp. a major intestinal microbiota, accounts for 3-11% of human intestinal microflora. Epidemiological reports have described that people with more visceral fat have less Blautia hansenii in their intestinal tract irrespective of age or gender. However, the effect of oral administration of heat-sterilized Blautia hansenii on obesity has not been clarified. Therefore, the aim of this study was to evaluate the effects of dietary Blautia hansenii administration on obesity in high-fat-diet-induced obesity in a mouse model. Heat-sterilized cells of Blautia hansenii were used. C57BL/6J mice (normal mice, n = 7) were fed with each experimental diet for nine weeks. Diets for experimentation were: normal-fat (NF) diets, high-fat (HF) diets, and high-fat + Blautia hansenii (HF + Blautia) diets. The HF + Blautia group was administered about 1 × 109 (CFU/mouse/day) of Blautia hansenii. During the periods of experimentation, body weight, food intake, water consumption, and fecal weight were recorded, and glucose tolerance tests were performed. Subsequently, the white adipose tissue (WAT) weight and serum components were measured. Short-chain fatty acid contents in the feces and cecum were analyzed. Furthermore, changes in the intestinal microflora were analyzed using meta-genomics analysis. Results showed that the total weight of WAT in the HF + Blautia group was significantly lower (13.2%) than that of the HF group. Moreover, the HF + Blautia group exhibited better glucose tolerance than the HF group. Productivity of short-chain fatty acids in the intestinal tract was at a significantly (p < 0.05) low level in the HF group; on the other hand, it recovered in the HF + Blautia group. Furthermore, there was a higher ratio of Blautia (p < 0.05) in the intestinal tracts of the HF + Blautia group than in the HF group. These results suggest that Blautia hansenii administration suppresses obesity induced by a high-fat diet.

Production of reuterin by Lactobacillus coryniformis and its antimicrobial activities.

Reuterin is a broad-spectrum antimicrobial substance produced by lactic acid bacteria, and most previous studies have reported that reuterin is only produced under anaerobic conditions. If there are lactic acid bacteria that also produce it under aerobic conditions, it could be applied to fermented foods. In this study, it was found that Lactobacillus coryniformis WBB05 showed optimal reuterin production (123 mM reuterin from 200 mM glycerol) when incubated aerobically at 20°C. Furthermore, the minimum inhibitory concentration (MIC) of reuterin was determined for starter lactic acid bacteria strains and cheese moulds. MIC toward Penicillium camemberti was 0.125 mM and the white mould starter was much more sensitive than other moulds.

Evaluating the technological properties of lactic acid bacteria in Wagyu cattle milk.

This paper reveals the technological properties of lactic acid bacteria isolated from raw milk (colostrum and mature milk) of Wagyu cattle raised in Okayama Prefecture, Japan. Isolates were identified based on their physiological and biochemical characteristics as well as 16S rDNA sequence analysis. Streptococcus lutetiensis and Lactobacillus plantarum showed high acid and diacetyl-acetoin production in milk after 24 h of incubation at 40 and 30°C, respectively. These strains are thought to have potential for use as starter cultures and adjunct cultures for fermented dairy products.

Time reduction of vitamin B(6) and inositol assay by using lyophilized Saccharomyces cerevisiae ATCC 9080.

The purpose of this study was to improve the efficiency of the microbiological assays for vitamin B(6) and inositol by using lyophilized cells from Saccharomyces cerevisiae ATCC 9080. The use of lyophilized cells as an inoculum was assessed to avoid time-consuming processes like cell precultivation and washing. The authors also examined the effects of various protectants such as skim milk, lactose, maltose, and trehalose on the assay. The viable cell counts of the lyophilized cells were approximately equal. The standard curves for vitamin B(6) and inositol concentrations obtained using lyophilized cells with maltose and intact cells gave similar linear ranges. Furthermore, the measured vitamin concentrations of the standard reference material 1849 were in the range of the established values. Therefore, lyophilized cells with maltose are potential alternative inocula for the turbidimetric method. This will increase the overall convenience associated with microbiological assays.

Biotin, niacin, and pantothenic acid assay using lyophilized lactobacillus plantarum ATCC 8014.

The purpose of this study was to improve the efficiency of the microbiological assays for biotin, niacin, and pantothenic acid by using lyophilized cells from Lactobacillus plantarum ATCC 8014. The use of lyophilized cells as an inoculum was assessed to avoid time-consuming processes like cell precultivation and washing. The authors also examined the effects of various protectants such as skim milk, sucrose, sorbitol, and trehalose on the assay. The viable cell counts of the lyophilized cells were found to be approximately equal for different protectants. The standard curves for biotin, niacin, and pantothenic acid concentrations obtained using lyophilized cells with sucrose and intact cells gave similar linear ranges. Furthermore, the measured vitamin concentrations of the standard reference material 3280 were in the range of the established values. Therefore, lyophilized cells with sucrose are potential alternative inocula for the turbidimetric method. This will increase the overall convenience associated with microbiological assays.

Expression of citrate permease gene of plasmid pCM1 isolated from Lactococcus lactis subsp. lactis biovar diacetylactis NIAI N-7 in Lactobacillus casei L-49-4.

Recombinant vector pJLECit (8,232 bp) was constructed using citrate permease gene contained in the 3,919-bp fragment of plasmid pCM1 (8,280 bp) isolated from Lactococcus lactis subsp. lactis biovar diacetylactis NIAI N-7, repA and ori from pLU1, and pMB1 ori and the erythromycin resistance gene from pJIR418. Lactobacillus casei L-49-4 (plasmid-free mutant of strain L-49) harboring the constructed pJLECit converted citrate into diacetyl/acetoin. Citrate uptake rate of resting cells was the highest at pH 5.5 and 10 mM citrate concentration. Diacetyl formation activity by the cell-free extracts of Lb. casei L-49-4 (pJLECit) grown in de Man-Rogosa-Sharpe (MRS) broth was higher than that of cells grown in MRS broth without citrate. On the other hand, diacetyl reductase activity of cells grown in MRS broth was lower than that of cells grown in MRS broth without citrate.