Detection and characterization of Bifidobacterium crudilactis and B. mongoliense able to grow during the manufacturing process of French raw milk cheeses.

Background: The study of a production chain of raw milk cheeses (St Marcellin, Vercors area, France) led to the isolation of two Bifidobacterium populations: B. crudilactis and B. mongoliense, that were able to grow along the production chain.

Bifidobacterium pseudolongum are efficient indicators of animal fecal contamination in raw milk cheese industry.

Background: The contamination of raw milk cheeses (St-Marcellin and Brie) from two plants in France was studied at several steps of production (raw milk, after addition of rennet - St-Marcellin - or after second maturation - Brie -, after removal from the mold and during ripening) using bifidobacteria as indicators of fecal contamination.

Results: Bifidobacterium semi-quantitative counts were compared using PCR-RFLP and real-time PCR. B.

Bacteroides sp. strain D8, the first cholesterol-reducing bacterium isolated from human feces.

The microbial community in the human colon contains bacteria that reduce cholesterol to coprostanol, but the species responsible for this conversion are still unknown. We describe here the first isolation and characterization of a cholesterol-reducing bacterium of human intestinal origin. Strain D8 was isolated from a 10(-8) dilution of a fresh stool sample provided by a senior male volunteer with a high capacity to reduce luminal cholesterol to coprostanol.

Clostridium saccharogumia sp. nov. and Lactonifactor longoviformis gen. nov., sp. nov., two novel human faecal bacteria involved in the conversion of the dietary phytoestrogen secoisolariciresinol diglucoside.

Two anaerobic bacteria involved in the conversion of the plant lignan secoisolariciresinol diglucoside were isolated from faeces of a healthy male adult. The first isolate, strain SDG-Mt85-3Db, was a mesophilic strictly anaerobic Gram-positive helically coiled rod. Based on 16S r RNA gene sequence analysis, its nearest relatives were Clostridium cocleatum (96.

Bifidobacterial lipoglycan as a new cause for false-positive platelia Aspergillus enzyme-linked immunosorbent assay reactivity.

We previously hypothesized that a lipoglycan of Bifidobacterium bifidum subsp. pennsylvanicum cross-reacts with the Platelia Aspergillus (PA) enzyme-linked immunosorbent assay (ELISA) based on the presence of galactofuranosyl epitopes in the cell wall (M. A.

Altered ability of Bacillus cereus spores to grow under unfavorable conditions (presence of nisin, low temperature, acidic pH, presence of NaCl) following heat treatment during sporulation.

The effect of thermal treatment on the heat resistance of Bacillus cereus spores and their ability to germinate and grow under more or less adverse conditions during sporulation was investigated. Spores produced by sporulating cells subjected to a mild heat treatment (at a temperature 15 degrees C higher than the growth temperature) were more resistant to heat than were spores produced by untreated cells. Spore germination and growth (the lag time, the maximal growth rate, and the occurrence of a decrease in population) may be greatly affected by adverse environmental conditions brought about by the addition of nisin, low temperatures, acidic pHs, and, to a lesser extent, the addition of NaCl.

Injury and Lethality of Heat Treatment of Bacillus cereus Spores Suspended in Buffer and in Poultry Meat.

The effect was studied of supplementing the recovery medium with lysozyme, glucose, NaCl, and MgSO on the apparent heat resistance of four strains of Bacillus cereus . The composition of an optimal medium (allowing the germination and growth of all surviving spores) and of a selective medium (inhibiting injured spores) was then determined: the optimal medium consisted of nutrient agar supplemented with 50 × 10 g of lysozyme and 0.5 g of MgSO per liter.