bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exopolysaccharide and Kestose Production by
Lactobacillus sanfranciscensis
LTH2590
Authors: Korakli Maher , Pavlovic Melanie , Gänzle Michael G. , Vogel Rudi F. 
Published: April 2003

ABSTRACT

The effect was investigated of sucrose concentration on sucrose metabolism and on the formation of exopolysaccharide (EPS) by
Lactobacillus sanfranciscensis
LTH2590 in pH-controlled fermentations with sucrose concentrations ranging from 20 to 160 g liter
−1
. The EPS production increased and the relative sucrose hydrolysis activity decreased by increasing the sucrose concentration in the medium. The carbon recovery decreased from 95% at a sucrose concentration of 30 g liter
−1
to 58% at a sucrose concentration of 160 g liter
−1
because of the production of an unknown metabolite by
L. sanfranciscensis
. This metabolite was characterized as a fructo-oligosaccharide. The oligosaccharide produced by
L. sanfranciscensis
was purified and characterized as a trisaccharide with a glucose/fructose ratio of 1:2. The comparison of the retention time of this oligosaccharide and that of pure oligosaccharide standards using two different chromatography methods revealed that the oligosaccharide produced by
L. sanfranciscensis
LTH2590 is 1-kestose. Kestose production increased concomitantly with the initial sucrose concentration in the medium.
PCR-Restriction Fragment Length Polymorphism Analysis of the Phospholipase B (
PLB1
) Gene for Subtyping of
Cryptococcus neoformans
Isolates
Authors: Latouche G. Nicolas , Huynh Matthew , Sorrell Tania C. , Meyer Wieland 
Published: April 2003

ABSTRACT

Cryptococcus neoformans
is a pathogenic yeast that is currently divided into three varieties, five serotypes, and eight molecular types. The following report describes the use of PCR-restriction fragment length polymorphism (RFLP) analysis of the phospholipase B gene (
PLB1
) as a simple tool to differentiate between
C. neoformans
subgroups. A
PLB1
fragment, 1,970 bp, was amplified and digested with either
Ava
I or
Hin
dIII. Both sets of profiles grouped the isolates into their respective varieties, but only the
Ava
I profiles allowed for the identification of the eight molecular types via the corresponding RFLP profiles A1 to A8. Digestion of the same fragments with
Hin
dIII resulted in RFLP profiles H1 to H5, which distinguished only between serotype A, AD, D, and B/C. Neither enzyme distinguished serotype B from serotype C. The serotype AD profile was a composite of the serotype A and D profiles. Further investigation showed that the serotype AD isolates used in this study are heterozygous, with one allele of
PLB1
originating from a serotype A parent and the other from a serotype D parent.
Secretory Antibodies Do Not Affect the Composition of the Bacterial Microbiota in the Terminal Ileum of 10-Week-Old Mice
Authors: Sait Leanne , Galic Maja , Strugnell Richard A. , Janssen Peter H. 
Published: April 2003

ABSTRACTTerminal restriction fragment length polymorphism (T-RFLP) analysis was conducted on the 16S rRNA genes of the bacterial communities colonizing the epithelial surfaces of the terminal ilea of open conventionally housed mice in an institutional small-animal facility. Polymeric-immunoglobulin-receptor-deficient (pIgR−/−) mice that were unable to secrete antibodies across mucosal surfaces were cohoused with normal and otherwise genetically identical wild-type (C57BL/6) mice for 4 weeks. If secretory antibodies played a role in modeling the gastrointestinal microbiota, C57BL/6 mice would have had a more distinct and uniform microbiota than their pIgR−/−cage mates. The T-RFLP profiles of the bacterial communities were compared by using Sorensen's pairwise similarity coefficient, a newly developed weighted pairwise similarity coefficient, and on the basis of Shannon's and Simpson's diversity indices. No systematic differences were observed between the dominant components of the mucosa-associated bacterial communities of the terminal ileal walls of the two types of mice, indicating that secretory antibodies do not control the composition of this microbiota. Similar analyses of experiments conducted at two different times, between which the bacterial community composition of the mouse colony in the small-animal facility appeared to have changed, showed that differences could have been detected, had they existed.
Cloning, Expression, and Purification of Choline Dehydrogenase from the Moderate Halophile
Halomonas elongata
Authors: Gadda Giovanni , McAllister-Wilkins Elien Elizabeth 
Published: April 2003

ABSTRACT

Choline dehydrogenase (EC 1.1.99.1) catalyzes the four-electron oxidation of choline to glycine-betaine via a betaine-aldehyde intermediate. Such a reaction is of considerable interest for biotechnological applications in that transgenic plants engineered with bacterial glycine-betaine-synthesizing enzymes have been shown to have enhanced tolerance towards various environmental stresses, such as hypersalinity, freezing, and high temperatures. To date, choline dehydrogenase has been poorly characterized in its biochemical and kinetic properties, mainly because its purification has been hampered by instability of the enzyme in vitro. In the present report, we cloned and expressed in
Escherichia coli
the
betA
gene from the moderate halophile
Halomonas elongata
which codes for a hypothetical choline dehydrogenase. The recombinant enzyme was purified to more than 70% homogeneity as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and by treatment with 30 to 50% saturation of ammonium sulfate followed by column chromatography using DEAE-Sepharose. The purified enzyme showed similar substrate specificities with either choline or betaine-aldehyde as the substrate, as indicated by the apparent
V
/
K
values (where
V
is the maximal velocity and
K
is the Michaelis constant) of 0.9 and 0.6 μmol of O
2
min
−1
mg
−1
mM
−1
at pH 7 and 25°C, respectively. With 1 mM phenazine methosulfate as the primary electron acceptor, the apparent
V
max
values for choline and betaine-aldehyde were 10.9 and 5.7 μmol of O
2
min
−1
mg
−1
, respectively. These
V
max
values decreased four- to sevenfold when molecular oxygen was used as the electron acceptor. Altogether, the kinetic data are consistent with the conclusion that
H. elongata betA
codes for a choline dehydrogenase that can also act as an oxidase when electron acceptors other than molecular oxygen are not available.
Bacteriophages ofErwinia amylovora
Authors: Gill J. J. , Svircev A. M. , Smith R. , Castle A. J. 
Published: April 2003

ABSTRACTFifty bacteriophage isolates ofErwinia amylovora, the causal agent of fire blight, were collected from sites in and around the Niagara region of southern Ontario and the Royal Botanical Gardens, Hamilton, Ontario. Forty-two phages survived the isolation, purification, and storage processes. The majority of the phages in the collection were isolated from the soil surrounding trees exhibiting fire blight symptoms. Only five phages were isolated from infected aerial tissue in pear and apple orchards. To avoid any single-host selection bias, six bacterial host strains were used in the initial isolation and enrichment processes. Molecular characterization of the phages with a combination of PCR and restriction endonuclease digestions showed that six distinct phage types, described as groups 1 to 6, were recovered. Ten phage isolates were related to the previously characterizedE. amylovoraPEa1, with some divergence of molecular markers between phages isolated from different sites. A study of the host ranges of the phages revealed that certain types were unable to efficiently lyse someE. amylovorastrains and that some isolates were able to lyse the epiphytic bacteriumPantoea agglomerans. Representatives from the six molecular groups were studied by electron microscopy to determine their morphology. The phages exhibited distinct morphologies when examined by an electron microscope. Group 1 and 2 phages were tailed and contractile, and phages belonging to groups 3 to 6 had short tails or openings with thin appendages. Based on morphotypes, the bacteriophages ofE. amylovorawere placed in the orderCaudovirales, in the familiesMyoviridaeandPodoviridae.
Karyotype Rearrangements in a Wine Yeast Strain by
rad52-
Dependent and
rad52
-Independent Mechanisms
Authors: Carro David , Bartra Enric , Piña Benjamin 
Published: April 2003

ABSTRACT

Yeast strains isolated from the wild may undergo karyotype changes during vegetative growth, a characteristic that compromises their utility in genetic improvement projects for industrial purposes. Karyotype instability is a dominant trait, segregating among meiotic derivatives as if it depended upon only a few genetic elements. We show that disrupting the
RAD52
gene in a hypervariable strain partially stabilizes its karyotype. Specifically,
RAD52
disruption eliminated recombination at telomeric and subtelomeric sequences, had no influence on ribosomal DNA rearrangement rates, and reduced to 30% the rate of changes in chromosomal size. Thus, there are at least three mechanisms related to karyotype instability in wild yeast strains, two of them not requiring
RAD52
-mediated homologous recombination. When utilized for a standard sparkling-wine second fermentation,
Δrad52
strains retained the enological properties of the parental strain, specifically its vigorous fermentation capability. These data increase our understanding of the mechanisms of karyotype instability in yeast strains isolated from the wild and illustrate the feasibility and limitations of genetic remediation to increase the suitability of natural strains for industrial processes.
Survival of
Yersinia pestis
on Environmental Surfaces
Authors: Rose Laura J. , Donlan Rodney , Banerjee Shailen N. , Arduino Matthew J. 
Published: April 2003

ABSTRACT

The survival of two strains of
Yersinia pestis
(avirulent A1122 and virulent Harbin) on the surfaces of four materials was investigated. Viability was evaluated with epifluorescence microscopy by using the metabolic stain cyanoditolyl tetrazolium chloride and plate counts. Small numbers of cells suspended in phosphate buffer survived 2 to 4 h after visible drying on stainless steel, polyethylene, or glass and beyond 48 h on paper. Cells suspended in brain heart infusion broth (BHI) persisted more than 72 h on stainless steel, polyethylene, and glass. Small numbers of cells suspended in BHI were still viable at 120 h on paper. These data suggest that
Y. pestis
maintains viability for extended periods (last measured at 5 days) under controlled conditions.
Conservation of Ornamental Stone byMyxococcus xanthus-Induced Carbonate Biomineralization
Authors: Rodriguez-Navarro Carlos , Rodriguez-Gallego Manuel , Ben Chekroun Koutar , Gonzalez-Muñoz Maria Teresa 
Published: April 2003

ABSTRACTIncreasing environmental pollution in urban areas has been endangering the survival of carbonate stones in monuments and statuary for many decades. Numerous conservation treatments have been applied for the protection and consolidation of these works of art. Most of them, however, either release dangerous gases during curing or show very little efficacy. Bacterially induced carbonate mineralization has been proposed as a novel and environmentally friendly strategy for the conservation of deteriorated ornamental stone. However, the method appeared to display insufficient consolidation and plugging of pores. Here we report thatMyxococcus xanthus-induced calcium carbonate precipitation efficiently protects and consolidates porous ornamental limestone. The newly formed carbonate cements calcite grains by depositing on the walls of the pores without plugging them. Sonication tests demonstrate that these new carbonate crystals are strongly attached to the substratum, mostly due to epitaxial growth on preexisting calcite grains. The new crystals are more stress resistant than the calcite grains of the original stone because they are organic-inorganic composites. Variations in the phosphate concentrations of the culture medium lead to changes in local pH and bacterial productivity. These affect the structure of the new cement and the type of precipitated CaCO3polymorph (vaterite or calcite). The manipulation of culture medium composition creates new ways of controlling bacterial biomineralization that in the future could be applied to the conservation of ornamental stone.
Killing of
Bacillus
Spores by Aqueous Dissolved Oxygen, Ascorbic Acid, and Copper Ions
Authors: Cross J. B. , Currier R. P. , Torraco D. J. , Vanderberg L. A. , Wagner G. L. , Gladen P. D. 
Published: April 2003

ABSTRACT

An approach to decontamination of biological endospores is discussed. Specifically, the performance of an aqueous modified Fenton reagent is examined. A modified Fenton reagent formulation of cupric chloride, ascorbic acid, and sodium chloride is shown to be an effective sporicide under aerobic conditions. The traditional Fenton reaction involves the conversion of hydrogen peroxide to hydroxyl radical by aqueous ionic catalysts such as the transition metal ions. Our modified Fenton reaction involves the conversion of aqueous dissolved oxygen to hydrogen peroxide by an ionic catalyst (Cu
2+
) and then subsequent conversion to hydroxyl radicals. Results are given for the modified Fenton reagent deactivating spores of
Bacillus globigii
. A biocidal mechanism is proposed that is consistent with our experimental results and independently derived information found in the literature. This mechanism requires diffusion of relatively benign species into the interior of the spore, where dissolved O
2
is then converted through a series of reactions which ultimately produce hydroxyl radicals that perform the killing action.
Rope-Producing Strains of
Bacillus
spp. from Wheat Bread and Strategy for Their Control by Lactic Acid Bacteria
Authors: Pepe Olimpia , Blaiotta Giuseppe , Moschetti Giancarlo , Greco Teresa , Villani Francesco 
Published: April 2003

ABSTRACT

Two types of white wheat bread (high- and low-type loaves) were investigated for rope spoilage. Thirty of the 56 breads tested developed rope spoilage within 5 days; the high-type loaves were affected by rope spoilage more than the low-type loaves. Sixty-one
Bacillus
strains were isolated from ropy breads and were characterized on the basis of their phenotypic and genotypic traits. All of the isolates were identified as
Bacillus subtilis
by biochemical tests, but molecular assays (randomly amplified polymorphic DNA PCR assay, denaturing gradient gel electrophoresis analysis, and sequencing of the V3 region of 16S ribosomal DNA) revealed greater
Bacillus
species variety in ropy breads. In fact, besides strains of
B. subtilis, Bacillus
licheniformis
,
Bacillus
cereus
, and isolates of
Bacillus
clausii
and
Bacillus
firmus
were also identified. All of the ropy
Bacillus
isolates exhibited amylase activity, whereas only 32.4% of these isolates were able to produce ropiness in bread slices after treatment at 96°C for 10 min. Strains of lactic acid bacteria previously isolated from sourdough were first selected for antirope activity on bread slices and then used as starters for bread-making experiments. Prevention of growth of approximately 10
4
rope-producing
B. subtilis
G1 spores per cm
2
on bread slices for more than 15 days was observed when heat-treated cultures of
Lactobacillus plantarum
E5 and
Leuconostoc mesenteroides
A27 were added. Growth of
B. subtilis
G1 occurred after 7 days in breads started with
Saccharomyces cerevisiae
T22,
L. plantarum
E5, and
L. mesenteroides
A27.
Reconstruction of Mycobacterial Dehalogenase Rv2579 by Cumulative Mutagenesis of Haloalkane Dehalogenase LinB
Authors: Nagata Yuji , Prokop Zbyněk , Marvanová Soňa , Sýkorová Jana , Monincová Marta , Tsuda Masataka , Damborský Jiří 
Published: April 2003

ABSTRACTThe homology model of protein Rv2579 fromMycobacterium tuberculosisH37Rv was compared with the crystal structure of haloalkane dehalogenase LinB fromSphingomonas paucimobilisUT26, and this analysis revealed that 6 of 19 amino acid residues which form an active site and entrance tunnel are different in LinB and Rv2579. To characterize the effect of replacement of these six amino acid residues, mutations were introduced cumulatively into the six amino acid residues of LinB. The sixfold mutant, which was supposed to have the active site of Rv2579, exhibited haloalkane dehalogenase activity with the haloalkanes tested, confirming that Rv2579 is a member of the haloalkane dehalogenase protein family.
Release of Extracellular Transformable Plasmid DNA from
Escherichia coli
Cocultivated with Algae
Authors: Matsui Kazuaki , Ishii Nobuyoshi , Kawabata Zen'ichiro 
Published: April 2003

ABSTRACT

We studied the effects of cocultivation with either
Euglena gracilis
(Euglenophyta),
Microcystis aeruginosa
(Cyanophyta),
Chlamydomonas neglecta
(Chlorophyta), or
Carteria inversa
(Chlorophyta) on the production of extracellular plasmid DNA by
Escherichia coli
LE392(pKZ105). Dot blot hybridization analysis showed a significant release of plasmid DNA by cocultivation with all the algae tested. Further analysis by electrotransformation confirmed the release of transformable plasmid DNA by cocultivation with either
E
.
gracilis
,
M
.
aeruginosa
, or
C
.
inversa
. These results suggest algal involvement in bacterial horizontal gene transfer by stimulating the release of transformable DNA into aquatic environments.
Cyanobacteria Associated with Coral Black Band Disease in Caribbean and Indo-Pacific Reefs
Authors: Frias-Lopez Jorge , Bonheyo George T. , Jin Qusheng , Fouke Bruce W. 
Published: April 2003

ABSTRACT

For 30 years it has been assumed that a single species of cyanobacteria,
Phormidium corallyticum
, is the volumetrically dominant component of all cases of black band disease (BBD) in coral. Cyanobacterium-specific 16S rRNA gene primers and terminal restriction fragment length polymorphism analyses were used to determine the phylogenetic diversity of these BBD cyanobacteria on coral reefs in the Caribbean and Indo-Pacific Seas. These analyses indicate that the cyanobacteria that inhabit BBD bacterial mats collected from the Caribbean and Indo-Pacific Seas belong to at least three different taxa, despite the fact that the corals in each case exhibit similar signs and patterns of BBD mat development.
Detection of poisoning by Impila (Callilepis laureola) in a mother and child
Authors: Steenkamp V , Stewart M J , Zuckerman M 
Published: April 2003

Poisoning with impila (Callilepis laureola) is a recurring phenomenon in South Africa. Cases of poisoning with other plants which contain atractyloside also occur in Europe and the Americas. Since poisoning leads to rapid death from renal and/or hepatic failure, it is suspected that many cases are undiagnosed; this is especially so in South Africa, where patients may die without reaching hospital and do not often admit to ingestion of a traditional remedy. We have developed a thin layer chromatographic method for the detection of impila constituents in urine. We describe the clinical symptoms and the application of the screening method to diagnosis in the case of a mother and child, who both showed symptoms of impila poisoning; the mother died but the child survived. This method is rapid and may be used for the definitive diagnosis in cases of poisoning with atractyloside-containing plants.
Identification of acrolein from the ozone oxidation of unsaturated fatty acids
Authors: Medina-Navarro R , Mercado-Pichardo E , Herńndez-Pérez O , Hicks J J 
Published: April 2003

By-products of lipoperoxidation reactions may be associated with the genesis or the progression of several diseases as arteriosclerosis, diabetes and cancer, among many others. Acrolein, at first a widely distributed environmental pollutant, is currently known as a compound capable of being generated as a result of metabolic reactions within biological systems, highly toxic and the most electrophilic of the a, b-unsaturated aldehydes formed during lipoperoxidation. In the present study: 1 The separation of acrolein and malondialdehyde was achieved at alkaline pH with the use of high voltage capillary electrophoresis in uncoated fused-silica capillaries. 2 It was demonstrated how the oxidation of fatty acids (arachidonic/linoleic) with ozone generates, in dose-dependent form, acrolein as one of the by-products of the lipoperoxidation process. The oxidation of open human erythrocyte membranes with ozone also generated acrolein. 3 After aldolic condensation, aldol-acrolein derivative has a positive reaction with 2-thiobarbituric acid (TBA) and shows a maximum absorption at 498 nm. This novel characteristic is used in its identification after the separation of the by-products. 4 It is possible to suggest that in the classic reaction of the denominated thiobarbituric acid reactive substances (TBARS), when used as an indicator of the degree of peroxidation in biological systems, a portion of acrolein could be present but dwarfed by the TBAMDA adduct.
Exposure to environmental tobacco smoke during the first five years of life-results of a prospective birth cohort study
Authors: Luck W. , Kulig M , Bergmann R. L. , Bergmann, K. E. , Bauer C. P. , Wahn V. , Zepp F. , Forster J. , Wahn U. 
Published: April 2003

Objective: To exanine links between environmental tobacco smoke (ETS)-exposure and urnary cotinine excretion during the first five years of life. Design: Prospective birth cohiort study Patients: 307 children from the Genran Multicenter Atopy Study (MAS-90) Measurements and results: ETS-exposure was investigated by questionnaires about the parental smoking habits at home and by analysis of urinary cotinine exacetion by the children at 1 year, 4 years and 5 years of age (capillary gas-chromatography). Results: From age 1 year to age 5 five years, the proportion of children growig up in smoker households remiained nearly constant (42%). However, 17% of the initial smoker households changed to non smoker households and vice versa. Within the smoker housholds the percentage of smoldng mothers increased from 19.9% to 25.7% and the percentage of smoking fathers decreased from 29.7% to 20.7%. 77% of the mothers and 60% of the fathers smoldng in the households when the child was 1 year old smoked continuously until children were 5 years old. The daily number of cigarettes smoked in the smoker households remained nearly constant (mean value: 6 cig/day). Urnary cotinine excretion of the ETS-exposed children was found to peak at 1 year of age, decreasing significantly to 5 years of age (p = 0.02). From age 1 year to age 5 years there was a significant correlation between the urinary cotinine excretion of the children and the number of daily cigarettes smoked in the households (p < 0.01). At age 1 year, cotinine excretion was further influenced by the season of the year, the size of domestic apartment and the presence of an atopic mother. At age 5 years, cotinine excretion of the children living in smoker households and attending a kindergarten was significantly lower than that of children living in smoker households but not attending a kindergarten (< O.000 1). Conclusion: Our results show that ETS-exposure passes through a peak during infancy. This suggests, that the reduced association between ETS-exposure and respiratory symptoms in children after age 2 years reported by earlier studies is due to an agedependent reduction of the ETS-exposure.
Acute basagranTM poisoning mimicking neuroleptic malignant syndrome
Authors: Lin T-J , Hung D-Z , Hu W-H , Yang D-Y , Wu T-C 
Published: April 2003

A 27-year-old robust man, without any medical and surgical history, attempted to commit suicide by consumption of 300 cc (44.1%, 132.3 g) basagranTM, a readily available herbicide. This poisoning resulted in vomiting, fever, sweating, pipe-like muscle rigidity, sinus tachycardia, drowsiness, leukocytosis, rhabdomyolysis and hepatorenal damage. Emperical treatment with bromocriptine was temporally associated with resolution of above signs and symptoms. His clinical presentations and the effect of bromocriptine may be indicative that basagranTm poisoning mimicks neuroleptic malignant syndrome.