WorldWideScience
 
 
1

Impact of Bifidobacterium animalis subsp. lactis BB-12 and, Lactobacillus acidophilus LA-5-containing yoghurt, on fecal bacterial counts of healthy adults  

British Library Electronic Table of Contents (United Kingdom)

This randomized, placebo-controlled, double blind, parallel dose-response study investigated the impact of 4-week commercial yoghurt consumption supplemented with Bifidobacterium animalis subsp. lactis (BB-12) and Lactobacillus acidophilus (LA-5) on fecal bacterial counts of healthy adults. Fifty-eight volunteers were randomly assigned to three different groups: 1. placebo (no probiotic, no starter and no green tea extract); 2. Yoptimal (10^9cfu/100g of BB-12 and LA-5 and 40mg of green tea extract) and 3. Yoptimal-10 (10^1^0cfu/100g of BB-12, 10^9cfu/100g of LA-5 and 40mg of green tea extract). These yoghurt products also contained Lactobacillus delbrueckii subsp. bulgaricus (10^7cfu/100g) and Streptococcus thermophilus (10^1^0cfu/100g). The quantitative PCR (qPCR) results showed that ther...

2011-01-01

2

The characterization of undecaprenol of Lactobacillus plantarum  

UK PubMed Central (United Kingdom)

Evidence for the presence of undecaprenol in the unsaponifiable lipid of Lactobacillus plantarum (N.C.I.B. 6376) is presented. Characterization of the compound was based mainly on...Full Text Available

1970-06-01

6

Silicates as Nonspecific Adsorbents of Bacteriophage: a Model for Purification of Water from Viruses  

UK PubMed Central (United Kingdom)

Amorphous silicates having small particles with a large surface area were found to have high nonspecific adsorption capacity. Investigations with Escherichia coli T4 bacteriophage have...Full Text Available

1980-01-01

7

Organization of Bacteriophage Tail-Like Particles in Cells of Chromobacterium violaceum  

UK PubMed Central (United Kingdom)

A strain of Chromobacterium violaceum has been isolated which produces bacteriophage tail-like particles in high numbers. The extracellular morphology and the intracellular arrangement...Full Text Available

1972-05-01

8

Mutational analysis of bacteriophage lambda lysis gene S.  

UK PubMed Central (United Kingdom)

A plasmid carrying the bacteriophage lambda lysis genes under lac control was subjected to hydroxylamine mutagenesis, and mutations eliminating the host lethality of the S gene were selected. DNA sequence...Full Text Available

1986-09-01

9

Generation of a proton motive force by histidine decarboxylation and electrogenic histidine/histamine antiport in Lactobacillus buchneri.  

UK PubMed Central (United Kingdom)

Lactobacillus buchneri ST2A vigorously decarboxylates histidine to the biogenic amine histamine, which is excreted into the medium. Cells grown in the presence of histidine generate both a transmembrane...Full Text Available

1993-05-01

10

Assay for the enzymatic conversion of indoleacetic acid to 3-methylindole in a ruminal Lactobacillus species.  

UK PubMed Central (United Kingdom)

An assay to measure the rate of enzymatic formation of 3-methylindole (3MI) from indoleacetic acid (IAA) in Lactobacillus sp. strain 11201 was developed. The reaction mixture contained 50 micrograms...Full Text Available

1990-03-01

12

Isolation of a bacterial host selective for bacteriophage T4 containing cytosine in its DNA.  

UK PubMed Central (United Kingdom)

An Escherichia coli B strain, B834 galU56, has been isolated which supports growth of bacteriophage T4 with cytosine in its DNA while restricting growth of T4 with hydroxymethylcytosine. This host is...Full Text Available

1978-09-01

13

Isolation and sequence determination of 5'-terminal oligonucleotide fragments of RNA transcripts synthesized by bacteriophage T3-induced RNA polymerase from T3 DNA.  

UK PubMed Central (United Kingdom)

The nucleotide sequence of the 5'-terminal oligonucleotides produced by pancreatic RNase digestion of bacteriophage T3 RNA polymerase (EC 2.7.7.6) transcripts of T3 DNA has been determined. The sequence...Full Text Available

1980-07-01

14

Genetic Control of Capsid Length in Bacteriophage T4 I. Isolation and Preliminary Description of Four New Mutants  

UK PubMed Central (United Kingdom)

Four new mutants are described whose phenotypic expression affects the length of the head of bacteriophage T4D. All mutants produce some phenotypically normal phage particles. Mutant pt21-34...Full Text Available

1973-08-01

15

Structural aberrations in group A Staphylococcus bacteriophages.  

UK PubMed Central (United Kingdom)

Six related Staphylococcus phages spontaneously produced various abnormal head and tail structures: (i) giant capsids which were tailed and apparently contained nucleic acid; (ii) regular and irregular...Full Text Available

1976-05-01

16

Experimental Differential Light-Scattering Correction to the Circular Dichroism of Bacteriophage T2  

UK PubMed Central (United Kingdom)

Experimental techniques are presented that can be used to assay and correct for differential light scattering effects in circular dichroism spectra of biological macrostructures. The assay is based...Full Text Available

1973-01-01

17

Characterization of T-Even Bacteriophage Substructures  

UK PubMed Central (United Kingdom)

Tail plates obtained from T4D amber mutants were examined with respect to sedimentation behavior, subunit molecular weights, amino acid composition, isoelectric points, and morphology. Intact plates...Full Text Available

1970-10-01

18

Probiotic Lactobacillus spp. Diminish Helicobacter hepaticus-Induced Inflammatory Bowel Disease in Interleukin-10-Deficient Mice  

UK PubMed Central (United Kingdom)

Clinical and experimental evidence has demonstrated the potential role of probiotics in the prevention or treatment of inflammatory bowel disease. Probiotic clones with direct immunomodulatory activity...Full Text Available

2005-02-01

19

Metabolic Engineering of Lactobacillus plantarum for Production of l-Ribulose?  

UK PubMed Central (United Kingdom)

l-Ribulose is a rare and expensive sugar that can be used as a precursor for the production of other rare sugars of high market value such as l-ribose. In this work we describe a production...Full Text Available

2007-11-01

20

Bacteriophage P22 capsid size determination: Roles for the coat protein telokin-like domain and the scaffolding protein amino-terminus  

British Library Electronic Table of Contents (United Kingdom)

Assembly of icosahedral capsids of proper size and symmetry is not understood. Residue F170 in bacteriophage P22 coat protein is critical for conformational switching during assembly. Substitutions at this site cause assembly of tubes of hexamerically arranged coat protein. Intragenic suppressors of the ts phenotype of F170A and F170K coat protein mutants were isolated. Suppressors were repeatedly found in the coat protein telokin-like domain at position 285, which caused coat protein to assemble into petite procapsids and capsids. Petite capsid assembly strongly correlated to the side chain volume of the substituted amino acid. We hypothesize that larger side chains at position 285 torque the telokin-like domain, changing flexibility of the subunit and intercapsomer contacts. Thus, a sing...

2011-01-01

 
 
 
 
21

Homo-d-lactic acid production from mixed sugars using xylose-assimilating operon-integrated Lactobacillus plantarum  

British Library Electronic Table of Contents (United Kingdom)

In order to achieve efficient d-lactic acid fermentation from a mixture of xylose and glucose, the xylose-assimilating xylAB operon from Lactobacillus pentosus (PXylAB) was introduced into an l-lactate dehydrogenase gene (ldhL1)-deficient Lactobacillus plantarum (?ldhL1-xpk1::tkt-?xpk2) strain in which the phosphoketolase 1 gene (xpk1) was replaced with the transketolase gene (tkt) from Lactococcus lactis, and the phosphoketolase 2 (xpk2) gene was deleted. Two copies of xylAB introduced into the genome significantly improved the xylose fermentation ability, raising it to the same level as that of ?ldhL1-xpk1::tkt-?xpk2 harboring a xylAB operon-expressing plasmid. Using the two-copy xylAB integrated strain, successful homo-d-lactic acid production was achieved from a mixture of 25?g/l xylos...

2011-01-01

22

Mannose-specific interaction of Lactobacillus plantarum with porcine jejunal epithelium  

British Library Electronic Table of Contents (United Kingdom)

Abstract Host-microorganism interactions in the intestinal tract are complex, and little is known about specific nonpathogenic microbial factors triggering host responses in the gut. In this study, mannose-specific interactions of Lactobacillus plantarum 299v with jejunal epithelium were investigated using an in situ pig Small Intestinal Segment Perfusion model. The effects of L. plantarum 299v wild-type strain were compared with those of two corresponding mutant strains either lacking the gene encoding for the mannose-specific adhesin (msa) or sortase (srtA; responsible for anchoring of cell surface proteins like Msa to the cell wall). A slight enrichment of the wild-type strain associated with the intestinal surface could be observed after 8 h of perfusion when a mixture of wild-type and...

2008-01-01

23

Termination of transcription by bacteriophage T3 RNA polymerase: homogeneous 3'-terminal oligonucleotide sequence of in vitro T3 RNA polymerase transcripts.  

UK PubMed Central (United Kingdom)

RNA was synthesized in vitro from a T3 DNA template by T3 RNA polymerase and subsequently separated into seven discrete size classes (molecular weights ranging between 0.21 x 10(6) and 6.2 x 10(6))...Full Text Available

1979-10-01

24

Model system using coliphage phi X174 for testing virus removal by air filters.  

UK PubMed Central (United Kingdom)

Short-term (15-min-duration) and long-term (5- to 6-day-duration) test procedures have been developed for determining the efficiency of the removal of bacteriophage phi X174 by air-sterilizing filters....Full Text Available

1992-03-01

25

High-cell Density Shake-flask Expression and Rapid Purification of the Large Fragment of Thermus aquaticus DNA Polymerase I Using a New Chemically and Temperature Inducible Expression Plasmid in Escherichia coli*  

UK PubMed Central (United Kingdom)

We have developed a new expression vector, pcIts ind+, based upon the powerful rightward promoter of bacteriophage lambda, which is controlled by a temperature-sensitive...Full Text Available

2009-02-01

26

Effect of Lactobacillus supplementation with and without arginine on liver damage and bacterial translocation in an acute liver injury model in the rat.  

Science.gov (United States)

In acute liver failure following hepatitis, toxic insults, or after major liver surgery, there is an increased bacterial translocation from the gut. This may explain some of the infectious complications seen in these conditions. To elucidate mechanisms and find possible preventive measures, we investigated the effect of rectal administration of arginine and probiotic bacteria (Lactobacillus spp.) on bacterial translocation and the extent of liver failure. Sprague-Dawley rats were used and five different Lactobacillus strains (Lb. reuteri R2LC, Lb. rhamnosus DSM 6594 (= strain 271), Lb. plantarum DSM 9843 (= strain 299v), Lb. fermentum 8704:3 (= strain 245), and Lb. reuteri (= strain 108) were administered rectally once daily for 8 days with and without 2% arginine. Acute liver injury (ALI) was induced on the eighth day by intraperitoneal injection of D-galactosamine (1.1 g/kg body weight), and samples were collected after 24 and 48 hours. ...

1997-03-01

27

Probiotics inhibit enteropathogenic E. coli adherence in vitro by inducing intestinal mucin gene expression.  

Science.gov (United States)

Probiotic agents, live microorganisms with beneficial effects for the host, may offer an alternative to conventional antimicrobials in the treatment and prevention of enteric infections. The probiotic agents Lactobacillus plantarum 299v and Lactobacillus rhamnosus GG quantitatively inhibited the adherence of an attaching and effacing pathogenic Escherichia coli to HT-29 intestinal epithelial cells but did not inhibit adherence to nonintestinal HEp-2 cells. HT-29 cells were grown under conditions that induced high levels of either MUC2 or MUC3 mRNA, but HEp-2 cells expressed only minimal levels of MUC2 and no MUC3 mRNA. Media enriched for MUC2 and MUC3 mucin were added exogenously to binding assays and were shown to be capable of inhibiting enteropathogen adherence to HEp-2 cells. Incubation of L. plantarum 299v with HT-29 cells increased MUC2 and MUC3 mRNA expression levels. From these in vitro studies, we propose the hypothesis that the ...

1999-04-01

28

Quantitative variations in the vaginal bacterial population associated with asymptomatic infections: a real-time polymerase chain reaction study.  

Science.gov (United States)

The real-time polymerase chain reaction (PCR) quantification of several vaginal bacterial groups in healthy women and patients developing asymptomatic bacterial vaginosis (BV) and candidiasis (CA) was performed. Statistical analysis revealed that the BV condition is characterised by a great variability among subjects and that it is associated with a significant increase of Prevotella, Atopobium, Veillonella and Gardnerella vaginalis, and a drop in Lactobacillus. On the contrary, the vaginal microflora of healthy women and patients developing CA was found to be homogeneous and stable over time. PMID:18762999

2008-09-02

29

Quantitative variations in the vaginal bacterial population associated with asymptomatic infections: a real-time polymerase chain reaction study  

British Library Electronic Table of Contents (United Kingdom)

The real-time polymerase chain reaction (PCR) quantification of several vaginal bacterial groups in healthy women and patients developing asymptomatic bacterial vaginosis (BV) and candidiasis (CA) was performed. Statistical analysis revealed that the BV condition is characterised by a great variability among subjects and that it is associated with a significant increase of Prevotella, Atopobium, Veillonella and Gardnerella vaginalis, and a drop in Lactobacillus. On the contrary, the vaginal microflora of healthy women and patients developing CA was found to be homogeneous and stable over time.

2009-01-01

30

Probiotic-Induced Priming of Innate Immunity to Protect Against Rotaviral Infection  

British Library Electronic Table of Contents (United Kingdom)

Understanding of probiotic-induced regulatory gene expression and networking is critical to further explore their roles in controlling infection. Transcriptional profile of selected innate immune genes in primary bovine intestinal epithelial cells was assessed over a time course of incubation with the probiotic Lactobacillus plantarum 299v. Based on gene expression results, a time point was chosen to prime epithelial cells with the probiotic prior to infection with rotavirus. Plaque assays and genomic analysis provided the basis for establishing the efficacy of probiotics in preventing a rotaviral infection. Plaque assays revealed that the probiotic is capable of decreasing (at least by 100-fold) the levels of live virus when the cells were primed with the probiotic. Results from gene expr...

2010-01-01

31

In vitro competitive adhesion and production of antagonistic compounds by lactic acid bacteria against fish pathogens  

British Library Electronic Table of Contents (United Kingdom)

The present study describes the screening of five lactic acid bacteria (LAB) for use as probiotics based on their competitive adhesion and production of antagonistic substances against some fish pathogens. A reduction of adhesion of all pathogenic strains tested was obtained with three of the LAB strains (Lactococcus lactis subsp. lactis CLFP100, Lactococcus lactis subsp. cremoris CLFP102 and Lactobacillus curvatus CLFP150). With the exception of fish pathogens Flavobacterium psychrophilum and Renibacterium salmoninarum that were not inhibited by LAB strains, production of antagonistic compounds by all tested LAB was observed against at least one of the indicator strains. Based on mucus adhesion, competitive exclusion, and suppression of fish pathogen growth, the selected LAB strains can b...

2007-01-01

32

Food-grade gene expression in lactic acid bacteria  

British Library Electronic Table of Contents (United Kingdom)

Abstract In the 1990s, significant efforts were invested in the research and development of food-grade expression systems in lactic acid bacteria (LAB). At this time, Lactococcus lactis in particular was demonstrated to be an ideal cell factory for the food-grade production of recombinant proteins. Steady progress has since been made in research on LAB, including Lactococcus, Lactobacillus and Streptococcus, in the areas of recombinant enzyme production, industrial food fermentation, and gene and metabolic pathway regulation. Over the past decade, this work has also led to new approaches on chromosomal integration vectors and host/vector systems. These newly constructed food-grade gene expression systems were designed with specific attention to self-cloning strategies, food-grade selection...

2011-01-01

33

Bioconvertion of spent cellulose sausage casings  

British Library Electronic Table of Contents (United Kingdom)

Cellulose sausage cellulose casings are used extensively in the manufacture of sausages in meat packaging. After stripping the meat, spent casings mainly contain cellulose and residual meat juice with salt, nitrate and nitrite. Disposal of spent sausage casings has serious economic and environmental concerns for the sausage industry. This work describes bioconversion of spent cellulose casings (SCC) into enzymes, lactic acid and ethanol by using cellulolytic fungi, lactobacillus and yeasts. The solid substrate cultivation (SSC) of Trichoderma reesei RUT C-30 on SCC and blends gave a maximum of 152 filter paper cellulase (FPase) activity and about 100 carboxymethylcellulase activity (CMCase)/g dry weight substrate. The SSC produced enzyme-rich casing with 50 FPase when directly mixed as suc...

2008-01-01

34

A lytic enzyme cocktail from Streptomyces sp. B578 for the control of lactic and acetic acid bacteria in wine  

British Library Electronic Table of Contents (United Kingdom)

Beside yeasts, lactic acid bacteria (LAB) are the most abundant microbes in must during vinification. Whereas Oenococcos oeni is commercially used as a starter culture for the biological acid reduction in wines, other species are responsible for different types of wine spoilage. Members of the genera Pediococcus, Weissella, Leuconostoc, and Lactobacillus are producers of exopolysaccharide slimes, biogenic amines, acetic acid, and other off-flavors. In order to control microbial growth, different procedures such as heating of must and addition of sulfite or lysozyme from egg white are generally applied. Yet, because of health risks, the application of sulfite should be reduced and lysozyme is not effective against all LAB. In this study, we describe exoenzymes from a Streptomyces sp. strain...

2009-01-01

35

DNA alterations photosensitized by tetracycline and some of its derivatives  

Energy Technology Data Exchange (ETDEWEB)

Bacteriophage M13 mp10 DNA were irradiated with near-UV light in the presence of tetracycline derivatives and primed with synthetic oligonucleotide to be used for DNA synthesis using Escherichia coli DNA polymerase. Chain terminations were observed by denaturing polyacrylamide gel electrophoresis and mapped precisely. All the synthesis stops occurred before or at the level of guanine residues, showing that the photoreaction mediated by tetracycline derivatives led to a preferential alteration of guanine residues. These lesions were demonstrated to be induced in DNA through a pathway involving singlet oxygen. Tetracycline derivatives also photoinduced the breakage of the DNA sugar-phosphate backbone monitored by the conversion of supercoiled phi X174 DNA to a relaxed form. This lesion was shown to be initiated by hydroxyl radicals. The production of this free radical has been confirmed by electron paramagnetic resonance (EPR) spin trapping experiments using ...

1986-06-01

36

Analysis of forward mutations induced by N-methyl-N'-nitro-N-nitrosoguanidine in the bacteriophage P22 mnt repressor gene  

Energy Technology Data Exchange (ETDEWEB)

We describe the isolation and genetic characterization of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced mutations in the phage P22 mnt repressor gene cloned in plasmid pBR322. Mutations in the mnt repressor gene or its operator on this plasmid, pPY98, confer a tetracycline resistance phenotype, whereas the wild-type plasmid confers tetracycline sensitivity. Cells carrying pPY98 were briefly exposed to MNNG to give 20 to 40% survival and a 50- to 100-fold increase in tetracycline-resistant cells. DNA sequence analysis showed that 29 to 30 MNNG-induced mutations were GC-to-AT transitions and one was an AT-to-GC transition. About 80% of the mutations are in three hotspots. This mutation spectrum is consistent with the proposed mechanism of mutagenic action of MNNG, which involves mispairing of an alkylated base, O/sup 6/-methylguanine. The mnt gene may be a useful target for determining mutagenic specificity at the nucleotide level because (i) forward mutations are easily ...

1986-04-01

37

In vitro and in vivo activities of T4 endonuclease V mutants altered in the C-terminal aromatic region  

International Nuclear Information System (INIS)

Genes encoding mutants of the thymine photodimer repair enzyme from bacteriophage T4 (T4 endonuclease V) having an amino acid substitution (T127M, W128A, W128S, Y129A, K130L, Y131A, Y132A) were constructed by use of a previously obtained synthetic gene and expressed in Escherichia coli under the control of the E. coli tryptophan promoter. An in vitro assay of partially fractionated mutant proteins for glycosylase activity was performed with chemically synthesized substrates containing a thymine photodimer. T127M and K130L showed almost the same activity as the wild-type protein. Although W128S, Y131A, and Y132A were slightly active, W128A and Y129A lost activity. The results indicated that the aromatic amino acids around position 130 may be important for the glycosylase activity. Mutant T127M was purified, and the Km value was found to be of the same order as that of the wild type (10(-8) M). In vivo activities for all mutants were characterized with UV-sensitive ...