In vitro study on the cell adhesion ability of immobilized lactobacilli on natural supports

The aim of the present study was to investigate the effect of probiotic immobilization onto wheat grains, both wet and freeze dried, on the adhesion properties of the probiotic cells and make comparisons with wet and freeze dried free cells. Lactobacillus casei ATCC 393 and Lactobacillus plantarum NCIMB 8826 were used as model probiotic strains. The results showed satisfactory adhesion ability of free cells to a monolayer of Caco-2 cells (> 1000 CFU/100 Caco-2 cells for wet cells). Cell immobilization resulted in a significant decrease in adhesion, for both wet and freeze dried formulations, most likely because immobilized cells did not have direct access to the Caco-2 cells, but it still remained in adequate levels (> 100 CFU/100 Caco-2 cells for wet cells). No clear correlation could be observed between cell adhesion and the hydrophobicity of the bacterial cells, measured by the hexadecane adhesion assay. Most notably, immobilization enhanced the monolayer integrity of Caco-2 cells, demonstrated by a more than 2-fold increase in transepithelial electrical resistance (TEER) compared to free cells. SEM micrographs ascertained the adhesion of both immobilized and free cells to the brush border microvilli. Finally, the impact of the food matrix on the adhesion properties of probiotic bacteria and on the design of novel functional products is discussed.

Dunford-Pettis properties, Hilbert spaces and projective tensor products

We study complete continuity properties of operators onto ℓ2 and prove several results in the Dunford–Pettis theory of JB∗-triples and their projective tensor products, culminating in characterisations of the alternative Dunford–Pettis property for where E and F are JB∗-triples.

Enhanced aglycone production of fermented soybean products by Bacillus species

This study evaluated the effect of starter culture and fermentation period on the isoflavone content of protein-rich soybeans variety TG145. Initially, soybeans were washed, soaked in water for 16 h and autoclaved at 121°C for 40min. Three different bacterial starter cultures (~104 CFU/g) namely Bacillus subtilis BEST195, B. subtilis Asaichiban and B. subtilis TN51 were then added and the fermentation was allowed to proceed at 42°C for 24 h (natto-style) and 72 h (thua nao-style). The quantities of six major isoflavones (daidzin, genistin, glycitin, daidzein, genistein, and glycitein) were then determined in these fermented soybean products using reverse phase HPLC technique. Generally, our results clearly showed that the content of total isoflavones in the fermented products prepared by Bacillus starter cultures greatly increased ranging from 43 to 99% compared to that of the unfermented autoclaved soybeans. In addition, a dramatic increase of aglycones was also observed (> 400%) in the soybean products fermented by Bacillus subtilis strain TN51. This present study suggests a promising use of Bacillus starter cultures in improving isoflavone compounds especially the aglycones which would benefit for novel functional food development.

Rapid parallel expression in E-coli and insect cells: Analysis of five lef gene products of the Autographa californica multiple nuclear polyhedrosis virus (AcMNPV)

A number of strategies are emerging for the high throughput (HTP) expression of recombinant proteins to enable structural and functional study. Here we describe a workable HTP strategy based on parallel protein expression in E. coli and insect cells. Using this system we provide comparative expression data for five proteins derived from the Autographa californica polyhedrosis virus genome that vary in amino acid composition and in molecular weight. Although the proteins are part of a set of factors known to be required for viral late gene expression, the precise function of three of the five, late expression factors (lefs) 6, 7 and 10, is unknown. Rapid expression and characterisation has allowed the determination of their ability to bind DNA and shown a cellular location consistent with their properties. Our data point to the utility of a parallel expression strategy to rapidly obtain workable protein expression levels from many open reading frames (ORFs).

Functional food, blood lipids and cardiovascular disease. Part 1: probiotics

For the past 20 years, the focuses of public health strategies for reducing the risk of cardiovascular disease (CVD) have been aimed at lowering cholesterol levels. However recent findings have highlighted not only cholesterol but also triacylglycerol as a lipid risk factor for CVD. Dietary strategies which are able to reduce these circulating lipid levels, but which are able to offer long-term efficacy comparable with effective drug treatments, are currently being sought. One dietary strategy that has been proposed to benefit the lipid profile involves the supplementation of the diet with probiotics (Part 1), prebiotics and synbiotics (Part 2), which are mechanisms to improve the health of the host by supplementation and/or fortification of certain health promoting gut bacteria. Probiotics in the form of fermented milk products have been shown to have cholesterol-lowering properties, whereas non-digestible fermentable prebiotics have been shown to reduce triacylglycerol levels in animal studies. However in humans studies, there have been inconsistent findings with respect to changes in lipid levels with both prebiotics and probiotics although on the whole there have been favourable outcomes.

Functional food, blood lipids and cardiovascular disease. Part 2: prebiotics and synbiotics

For the past 20 years, the focuses of public health strategies for reducing the risk of cardiovascular disease (CVD) have been aimed at lowering cholesterol levels. However, recent findings have highlighted not only cholesterol but also triacylglycerol as a lipid risk factor for CVD. Dietary strategies which are able to reduce these Circulating lipid levels, but which are able to offer longterm efficacy comparable with effective drug treatments, are currently being sought. One dietary strategy that has been proposed to benefit the lipid profile involves the supplementation of the diet with probiotics (Part 1) prebiotics and synbiotics (Part 2), which are mechanisms to improve the health of the host by supplementation and/or fortification of certain health promoting gut bacteria. Probiotics in the form of fermented milk products have been shown to have cholesterol-lowering properties, whereas non-digestible fermentable prebiotics have been shown to reduce triacylglycerol levels in animal studies, However, in human studies, there have been inconsistent findings with respect to changes in lipid levels with both prebiotics and probiotics although on the whole there have been favourable outcomes.

Functional petit-suisse cheese: measure of the prebiotic effect

Prebiotics and probiotics are increasingly being used to produce potentially synbiotic foods, particularly through dairy products as vehicles. It is well known that both ingredients may offer benefits to improve the host health. This research aimed to evaluate the prebiotic potential of novel petit-suisse cheeses using an in vitro fermentation model. Five petit-suisse cheese formulations combining candidate prebiotics (inulin. oligofructose. hone) and probiotics (Lactobacillus acidophilus, Bifidobacterium lactis) were tested in vitro using, sterile. stirred, batch culture fermentations with human faecal slurry. Measurement of prebiotic effect (MPE) values were generated comparing bacterial changes through determination of maximum growth rates of groups, rate of substrate assimilation and production of lactate and short chain fatty acids. Fastest fermentation and high lactic acid production, promoting increased growth rates of bifidobacteria and lactobacilli. were achieved with addition of prebiotics to a probiotic cheese (made using starter + probiotics). Addition of probiotic strains to control cheese (made using just a starter culture) also resulted in high lactic acid production. Highest MPE values were obtained with addition of prebiotics to a probiotic cheese, followed by addition of prebiotics and/or probiotics to a control cheese. Under the in vitro conditions used, cheese made with the combination of different prebiotics and probiotics resulted in the most promising functional petit-suisse cheese. The study allowed comparison of potentially functional petit-suisse cheeses and screening of preferred synbiotic potential for future market use. (c) 2007 Elsevier Ltd. All rights reserved.

Language dominance and lexical diversity: how bilinguals and L2 learners differ in their knowledge and use of French lexical and functional items

This chapter compares lexical diversity of French words used by Dutch-French bilinguals, English-French bilinguals and Flemish L2 learners of French.

Bifidobacteria in milk products: An overview of physiological and biochemical properties, exopolysaccharide production, selection criteria of milk products and health benefits

Research and commercial interest in the genus Bifidobacterium have increased in the last decade due to their potential health benefits in probiotic functional foods, especially in dairy products. However, cultivation of bifidobacteria in milk is a difficult task compared with that of conventional starters because milk is not a good medium for growth of these nutritionally fastidious microorganisms. Therefore, suitable strains of Bifidobacterium for dairy products should be selected based on their safety and technological and functional properties. There are a number of milk products containing bifidobacteria in the world market and the demand for new products is increasing with the awareness of the potential health benefits of the consumption of products blended with bifidobacteria. Some strains of Bifidobacterium, which produce exopolysaccharide, have been isolated and characterised. This review will discuss the general characteristics of bifidobacteria, exopolysaccharide production, the selection criteria of bacterial strains for milk products, current applications of bifidobacteria in milk products, and their nutritional and beneficial health properties.