Essential Oils Against Foodborne Pathogens and Spoilage Bacteria in Minced Meat

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The midgut of Cephalotes ants (Formicidae: Myrmicinae): Ultrastructure of the epithelium and symbiotic bacteria

The ultrastructural analysis of the midgut of Cephalotes atratus. C. clypeatus, and C. pusillus reveled that the midgut epithelium lays on a basal lamina and is composed basically of three cell types: digestive cells, regenerative cells, and goblet cells. In these ants, the rough endoplasmic reticulum, in addition to producing digestive enzymes, is involved in the formation of concretions and ion storage in specialized vacuoles present in the midgut. These concretions are spherocrystals and may contribute to stabilize the pH and to maintain symbiotic bacteria found between microvilli. The ultrastructure analysis of these bacteria revealed the presence of a double envelope typical of gram-negative bacteria. For the three species examined, the ultrastructure similarities are conspicuous, suggesting that this may be the pattern for the genus Cephalotes. Details of the relationship between bacteria and microvilli were examined. (C) 2010 Elsevier Ltd. All rights reserved.

A new strategy of endosymbiont midgut bacteria in ant (Ponerinae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Symbiotic bacteria and the structural specializations in the ileum of Cephalotes ants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

BTEX biodegradation by bacteria from effluents of petroleum refinery

Groundwater contamination with benzene, toluene, ethylbenzene and xylene (BTEX) has been increasing, thus requiring an urgent development of methodologies that are able to remove or minimize the damages these compounds can cause to the environment. The biodegradation process using microorganisms has been regarded as an efficient technology to treat places contaminated with hydrocarbons, since they are able to biotransform and/or biodegrade target pollutants. To prove the efficiency of this process, besides chemical analysis, the use of biological assessments has been indicated. This work identified and selected BTEX-biodegrading microorganisms present in effluents from petroleum refinery, and evaluated the efficiency of microorganism biodegradation process for reducing genotoxic and mutagenic BTEX damage through two test-systems: Allium cepa and hepatoma tissue culture (HTC) cells. Five different non-biodegraded BTEX concentrations were evaluated in relation to biodegraded concentrations. The biodegradation process was performed in a BOO Trak Apparatus (HACH) for 20 days, using microorganisms pre-selected through enrichment. Although the biodegradation usually occurs by a consortium of different microorganisms, the consortium in this study was composed exclusively of five bacteria species and the bacteria Pseudomonas putida was held responsible for the BTEX biodegradation. The chemical analyses showed that BTEX was reduced in the biodegraded concentrations. The results obtained with genotoxicity assays, carried out with both A. cepa and HTC cells, showed that the biodegradation process was able to decrease the genotoxic damages of BTEX. By mutagenic tests, we observed a decrease in damage only to the A. cepa organism. Although no decrease in mutagenicity was observed for HTC cells, no increase of this effect after the biodegradation process was observed either. The application of pre-selected bacteria in biodegradation processes can represent a reliable and effective tool in the treatment of water contaminated with BTEX mixture. Therefore, the raw petroleum refinery effluent might be a source of hydrocarbon-biodegrading microorganisms. (c) 2010 Elsevier B.A. All rights reserved.

COEVOLUTION BETWEEN ATTINE ANTS and ACTINOMYCETE BACTERIA: A REEVALUATION

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Surfactin reduces the adhesion of food-borne pathogenic bacteria to solid surfaces

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito do teor de soro, açúcar e de frutooligossacarídeos sobre a população de bactérias lácticas probióticas em bebidas fermentadas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Optimization of polysaccharides production by bacteria isolated from soil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bacteriocin-like substances production by Streptococcus-salivarius against oral bacteria

Samples of tongue and bucal mucosa surfaces were obtained from six healthy subjects with the purpose of isolating S. salivarius. It was verified that 47 out of 48 S. salivarius strains produced bacteriocin-like substances against at least one of the indicator species: Actinomyces viscosus, Rothia dentocariosa, Streptococcus pyogenes, Staphylococcus aureus, Streptococcus mutans and Streptococcus sanguis. The method employed to test for bacteriocin production was that of deferred antagonism. The results showed that there was a high antagonism against R. dentocariosa, S. pyogenes and A. viscosus; extremely low against S. mutans and S. sanguis and no inhibition for S. aureus.

Comparative genomic analysis of plant-associated bacteria

This review deals with a comparative analysis of seven genome sequences from plant-associated bacteria. These are the genomes of Agrobacterium tumefaciens, Mesorhizobium loti, Sinorhizobium meliloti, Xanthomonas campestris pv campestris, Xanthomonas axonopodis pv citri, Xylella fastidiosa, and Ralstonia solanacearum. Genome structure and the metabolism pathways available highlight the compromise between the genome size and lifestyle. Despite the recognized importance of the type III secretion system in controlling host compatibility, its presence is not universal in all necrogenic pathogens. Hemolysins, hemagglutinins, and some adhesins, previously reported only for mammalian pathogens, are present in most organisms discussed. Different numbers and combinations of cell wall degrading enzymes and genes to overcome the oxidative burst generally induced by the plant host are characterized in these genomes. A total of 19 genes not involved in housekeeping functions were found common to all these bacteria.

Use of vaccine and probiotic in the control of swine diarrhea caused by enterotoxigenic Escherichia coli

A total of 42 pregnant sows were divided into eight groups and submitted to the following treatments: group I with seven unvaccinated sows whose piglets did not receive probiotic, was used as control, group II with five vaccinated sows whose piglets did not receive probiotic, groups III, IV and V with five vaccinated sows each whose piglets received probiotic for 5, 15 and 28 days, respectively, and groups VI, VII and VIII with five unvaccinated sows each whose piglets received probiotic for 5, 15 and 28 days, respectively. Each animal in the vaccinated groups received subcutaneously Two doses of 5.0ml of vaccine containing pill K88, K99, 987P and F42 of Escherichia coli. The probiotic contained Lactobacillus acidophilus at the dose of 2.0x10(8) live cells in 20ml of milk and was administered orally. All animals were observed clinically and bacteriologically and the titers of anti-K88, anti-K99, anti-987P and anti-F42 antibodies were determined in serum and colostrum. The results showed that the vaccine associated to the probiotic administered for 28 days was the most effective treatment for the control of diarrhea caused by enterotoxigenic Escherichia coli.

Atividade antimicrobiana de Lactobacillus acidophilus, contra microrganismos patogênicos veiculados por alimentos

The antimicrobial activity of a commercial probiotic culture, Lactobacillus acidophilus (La5), was tested against two foodborne pathogens, Escherichia coli and Staphylococcus aureus. The antagonistic effect of the probiotic culture in vitro was performed by applying both Multilayer Agar Plate and Agar Well Diffusion methods. The results indicated that the inhibitory substance present on 72 hours culture broth supernatant was extracellular and diffusible. The incubation period of the lactic acid bacteria on MRS Broth, at 3 7 degrees C in aerobic conditions, for the highest lactic acid production (1,08 g/%) was 72 hours, which gave a minimum pH value of the supernatant (3,90) and the best inhibition results by the Well Diffusion Agar Assay, showing inhibition zone diameters of 14,75mm and 15,0mm for E. coli and S. aureus, respectively. The inhibitor compound was not sensitive to proteolytic enzyme and freezing, but was totally inactivated when the supernatant was neutralized with NaOH 1 N solution. The results suggest that the inhibitory activity was due to the lactic acid concentration and the low pH of the probiotic culture broth.

Effect of 3,4,4 '-trichlorocarbanilide on growth of lactic acid bacteria contaminants in alcoholic fermentation

3,4,4'-trichlorocarbanilide (TCC) was rested as a new method of bacterial growth control for S. cerevisiae alcoholic fermentations of diluted high test molasses (HTM). Minimal inhibitory concentration (MIC) was tested to determine the necessary concentration of TCC to control bacterial growth. The fed-batch alcoholic fermentation process was used with cell recycle similar to industrial conditions and Lactobacillus fermentum CCT 1407 was mixed in the first inoculum to grow with the yeast. Yeast extract was added into the must to stimulate bacterial growth. The best results of TCC's MIC to bacterial growth of Lactobacillus fermentum and Leuconostoc mesenteroides (< 0.125-1.0 mu g/ml) and Saccharomyces cerevisiae (16 mu g/ml) occurred when it was combined with sodium dodecylsulphate (SDS) in a 1: 4 TCC/SDS ratio (wt/wt) in distilled water solution. 1.8 g/l TCC entrapped in calcium alginate added to the must with yeast extract inhibited the growth of Lactobacillus fermentum CCT 1407 maintaining a controlled acidity, higher yeast viability and up to 20.8% of improvement in the average of alcoholic efficiency. Addition of 0.075 g/l TCC entrapped in calcium alginate and 1.67 mg/l SDS in the wort with yeast extract (0-5.0 g/l), inhibited and controlled the extensive bacterial contamination for 19 cycles of fermentation. (C) 1998 Published by Elsevier B.V. Ltd.