Effects of cigarette smoke condensate on the production and characterization of exopolysaccharides by Bifidobacterium.

The aim of the study was to investigate the effect of cigarette smoke on the production and characterization of exopolysaccharides (EPSs) produced by Bifidobacterium. Cigarettes of Shanhua brand (nicotine: 1.1 mg, tar: 11 mg) were utilized to prepare a cigarette smoke condensate (CSC). The standard strain of Bifidobacterium animalis was cultured in MRS media under anaerobic addition of CSC. The results showed that CSC significantly decreased the growth of B. animalis as well as EPSs and acetic acid production. Furthermore, two EPSs fractions (Fr-I and Fr-II) were isolated and purified for chemical and molecular determination. By comparison with control, CSC was found to be of great impact on EPSs carbohydrate composition. The molecular weight mass of Fr-I changed from 3.33 × 10(5) g/mol (without CSC) to 2.99 × 10(5) (with CSC). In conclusion, in vitro studies revealed that CSC was directly able to affect the production of metabolites for B. animalis, which could be an essential factor in certain pathological disorders.

Nature of the antimicrobial activity of Lactobacillus casei, Bifidobacterium bifidum and Bifidobacterium animalis against foodborne pathogenic and spoilage microorganisms.

The antimicrobial activities as well as the nature of the inhibitory compounds obtained from Lactobacillus casei, Bifidobacterium bifidum and Bifidobacterium animalis strains were assayed on foodborne pathogenic - Staphyloccoccus aureus subsp. aureus (CCUG ATCC® 25926™) and Escherichia coli (ATCC® 25922™) - and spoilage microorganisms - Pseudomonas aeruginosa (ATCC® 27853™). Test producer strains showed inhibitory effect on all indicator microorganisms in diffusion of cell-free concentrated supernatant by agar in well methods (10.0-22.5 mm) in periods of 24, 48 and 72 h. Inhibitory compounds showed no sensitivity to the action of proteolytic enzyme trypsin and were completely inactivated by adjusting the pH of the cell-free 20 × concentrated supernatant to 7.0. The results demonstrated that antimicrobial substances do not have proteinaceous nature and are caused by the action of organic acids with decreasing medium pH.

Adsorção “in vitro” de Ochratoxina A por probióticos utilizados na aquicultura / In vitro adsorption of ochratoxin A by probiotics used in aquaculture

Devido as constantes contaminações de rações comerciais pelas micotoxinas, o presente trabalhoteve por objetivo avaliar in vitro a capacidade de dois produtos comerciais utilizados na aquicultura emadsorverem Ochratoxina A (OTA). Dois tipos de probióticos comerciais, compostos por Bacillus subtilis,Bifidobacterium bifidum, Enterococcus faecium e Lactobacillus acidophilus (Probiótico A) e, Saccharomycescerevisiae provenientes de cervejaria (Probiótico B) foram utilizados no ensaio. Soluções em tampão fosfatosalino (PBS), com pH de 1,5 e 7,5, foram elaborados para simular o pH do estômago e intestino de tilápias doNilo (Oreochromis niloticus). As soluções de PBS foram testadas nas duas faixas de pH (1,5 e 7,5), com asconcentrações dos produtos comerciais de 0%; 25%; 50%; 75% e 100%, para uma concentração de 1.000 ng.mL-1de OTA. As concentrações de OTA foram adicionadas em microtubos para que fosse determinado a capacidadede adsorção dos probióticos utilizados neste estudo. Na detecção e quantificação de OTA, utilizou-se ametodologia de Cromatografia Líquida de Alta Eficiência (CLAE). Os resultados finais mostraram que osprobióticos A e B nas suas concentrações máximas foram capazes de adsorver OTA nas quantidades de 13,78 a76,81 e 301,48 a 317,54 (ng.mL-1), respectivamente. Os dados mostraram que os dois tipos de probióticos sãopromissores para adsorverem OTA nas condições simuladas de pH gastrointestinal de tilápias do Nilo, sendo amaior eficiência verificada para o probiótico B(AU)

Given the constant contamination of animals by feed mycotoxins, this study aimed to evaluate invitro the ability of commercial products used in aquaculture as adsorbents of ochratoxin A (OTA). Twocomercial probiotics, composed of Bacillus subtilis, Bifidobacterium bifidum, Enterococcus faecium andLactobacillus acidophilus (Probiotic A) and one made of dry yeast of Saccharomyces cerevisiae from a brewery(Probiotic B) were used in the assay. Phosphate buffered saline solutions (PBS) at pH 1.5 and 7.5 wereformulated to simulate the pH of the stomach and intestine of Nile Tilapia (Oreochromis niloticus). The PBSsolutions were tested at the two pH (1,5 and 7,5) with the probiotics concentrations of 0%; 25%; 50%; 75% and100% for a OTA concentration of 1.000 ng.mL-1. The OTA concentrations were added in microtubes forevaluation of adsorption capacity of the probiotics. The OTA detection and quantification were performed byHigh Performance Liquid Chromatography (HPLC). The final results showed that the probiotics A and B in theirmaximum concentration were capable of adsorbing OTA in amounts from 13.78 to 76.81 and from 301.48 to317.54 (ng.mL-1), respectively. The data showed that this two probiotics were very promissimg at adsorbingOTA under simulated gastrointestinal conditions of pH of tilapias, being more efficient the probiotic B(AU)

Adsorção “in vitro” de Ochratoxina A por probióticos utilizados na aquicultura / In vitro adsorption of ochratoxin A by probiotics used in aquaculture

Devido as constantes contaminações de rações comerciais pelas micotoxinas, o presente trabalhoteve por objetivo avaliar in vitro a capacidade de dois produtos comerciais utilizados na aquicultura emadsorverem Ochratoxina A (OTA). Dois tipos de probióticos comerciais, compostos por Bacillus subtilis,Bifidobacterium bifidum, Enterococcus faecium e Lactobacillus acidophilus (Probiótico A) e, Saccharomycescerevisiae provenientes de cervejaria (Probiótico B) foram utilizados no ensaio. Soluções em tampão fosfatosalino (PBS), com pH de 1,5 e 7,5, foram elaborados para simular o pH do estômago e intestino de tilápias doNilo (Oreochromis niloticus). As soluções de PBS foram testadas nas duas faixas de pH (1,5 e 7,5), com asconcentrações dos produtos comerciais de 0%; 25%; 50%; 75% e 100%, para uma concentração de 1.000 ng.mL-1de OTA. As concentrações de OTA foram adicionadas em microtubos para que fosse determinado a capacidadede adsorção dos probióticos utilizados neste estudo. Na detecção e quantificação de OTA, utilizou-se ametodologia de Cromatografia Líquida de Alta Eficiência (CLAE). Os resultados finais mostraram que osprobióticos A e B nas suas concentrações máximas foram capazes de adsorver OTA nas quantidades de 13,78 a76,81 e 301,48 a 317,54 (ng.mL-1), respectivamente. Os dados mostraram que os dois tipos de probióticos sãopromissores para adsorverem OTA nas condições simuladas de pH gastrointestinal de tilápias do Nilo, sendo amaior eficiência verificada para o probiótico B

Given the constant contamination of animals by feed mycotoxins, this study aimed to evaluate invitro the ability of commercial products used in aquaculture as adsorbents of ochratoxin A (OTA). Twocomercial probiotics, composed of Bacillus subtilis, Bifidobacterium bifidum, Enterococcus faecium andLactobacillus acidophilus (Probiotic A) and one made of dry yeast of Saccharomyces cerevisiae from a brewery(Probiotic B) were used in the assay. Phosphate buffered saline solutions (PBS) at pH 1.5 and 7.5 wereformulated to simulate the pH of the stomach and intestine of Nile Tilapia (Oreochromis niloticus). The PBSsolutions were tested at the two pH (1,5 and 7,5) with the probiotics concentrations of 0%; 25%; 50%; 75% and100% for a OTA concentration of 1.000 ng.mL-1. The OTA concentrations were added in microtubes forevaluation of adsorption capacity of the probiotics. The OTA detection and quantification were performed byHigh Performance Liquid Chromatography (HPLC). The final results showed that the probiotics A and B in theirmaximum concentration were capable of adsorbing OTA in amounts from 13.78 to 76.81 and from 301.48 to317.54 (ng.mL-1), respectively. The data showed that this two probiotics were very promissimg at adsorbingOTA under simulated gastrointestinal conditions of pH of tilapias, being more efficient the probiotic B

Effects of lycopene, synbiotic and their association on early biomarkers of rat colon carcinogenesis.

This study evaluated whether a synergy exists for the combined treatment with lycopene and synbiotic on early biomarkers of colon carcinogenesis. Male Wistar rats received a diet containing 300 mg/kg of lycopene and/or synbiotic (Bifidobacterium lactisplus oligofructose/inulin) or their combination 2 weeks before and during carcinogen treatment with 1,2-dimethylhydrazine (DMH). Twenty-four hours after the last DMH application, the colons were processed for immunohistochemical analysis of proliferating cell nuclear antigen (PCNA), p53 protein, hematoxylin-eosin staining for apoptosis analysis and genotoxicity of fecal water by comet assay. Eight weeks after the last DMH application, the colons were analyzed for development of classical aberrant crypt foci (ACF) and mucin-negative ACF. Treatment with lycopene, synbiotic or their combination significantly increased apoptosis, reduced the PCNA and p53 labeling indexes and the development of classical ACF and mucin-negative ACF. Furthermore, a lower genotoxicity of fecal water was also detected in the groups treated with the chemopreventive agents. An additive/synergistic effect of the combined treatment with lycopene/synbiotic was observed only for the fecal water genotoxicity and mucin-negative ACF parameters. These results indicate that an additive/synergistic of the combination of chemopreventive agents on the initiation phase of colon carcinogenesis can be detected using selective early biomarkers.

Effect of bile on the lipid composition and surface properties of bifidobacteria.

AIM: The changes produced on the bacterial surface of Bifidobacteria cells when they are grown in bile were compared with those provoked by bile added to bacteria grown in the absence of bile. METHODS AND RESULTS: The adhesive properties, the zeta potential and the lipid composition of Bifidobacterial strains, isolated from human faeces and grown in MRS medium, were determined. Bacteria grown in MRS with bile showed a loss of adherence and autoaggregation in correlation with a decrease in the surface hydrophobicity in comparison to those grown in MRS without bile, concomitant with the absence of two glycolipids, the increase of sugar content and minor changes in fatty acid composition. The surface changes caused by bile shock on bacteria grown in bile-free medium were much less pronounced and, in addition, no effect on the lipid composition was apparent. CONCLUSIONS: The comparison of the results indicates that bile action on surface properties is related to metabolic changes. SIGNIFICANCE AND IMPACT OF THE STUDY: Long-term exposure of bacteria to bile may cause metabolic changes affecting their adhesive properties irreversibly. This may be taken as a criterion to define the probiotic properties of different strains.

Isolation and characterization of Bifidobacterium strains for probiotic formulation.

Twenty-five Bifidobacterium strains isolated from infant feces were identified by sugar fermentation patterns and whole-cell protein analysis. Using gradient SDS-PAGE, six characteristic protein bands of the genus were detected in 40 strains of bifidobacteria but not in lactobacilli. Computerized numerical analysis enabled strains to be grouped in two main clusters. Strains of Bifidobacterium bifidum belong to a well-differentiated cluster that joins the cluster of the remaining species at 0.582 similarity. The predominant species among isolated strains from infant feces were B. bifidum, B. longum, and B. breve. Probiotic and technological indicators such as surface properties, inhibitory capacity, resistance to bile and low pH, and ability to grow under aerobic conditions were studied. Not all desirable characteristics were present in a single strain. In general, adherent and inhibitory strains were not resistant to bile, low pH, and aerobic conditions. Only 10 of 40 strains were resistant to 0.5% bile.