bluuebunny/crossref_metadata_2025_split huggingface dataset:
SOME MICROBIOLOGICAL CHARACTERISTICS OF HERBED CHEESES
Authors: ERKAN EMIN M. , CIFTCIOGLU GURHAN , VURAL AYDIN , AKSU HARUN 
Published: April 2007

ABSTRACT Fifty herbed cheese samples, in which herbs (Allium spp.) were used at production, were analyzed for some microbiological quality characteristics. Cheese samples were collected from different retailers in four counties of Eastern Turkey. Presumptive coliform bacteria, generic Escherichia coli, Staphylococcus aureus, lactic acid bacteria, yeast, mold and sulfite‐reducing anaerobic bacteria counts were examined as general microbiologic quality parameters, and the average bacteria counts were 2.1 × 105, 3.1 × 104, 1.1 × 105, 2.2 × 107, 6.8 × 102, 7.0 × 106 and 3.2 × 101 cfu/g, respectively. The number of samples, in which the above selected bacteria have been detected, were 32 (64%), 29 (58%), 23 (46%), 50 (100%), 5 (10%), 46 (92%) and 9 (18%), respectively. Salmonella spp., Listeria monocytogenes and E. coli O157:H7 were targeted as foodborne pathogens, and the presence of those pathogens in samples were 10% (in five samples), 8% (in four samples) and 4% (in two samples), respectively. It was found that herbed cheeses containing foodborne pathogens raise an important risk for consumers’ health. Standardization and modernization of herbed cheese production, in which hygienic conditions and quality controls would be applicable, seems a necessity in order to prevent possible public health risks from herbed cheeses.
APPLICATION OF A DNA‐BASED TEST TO DETECT ADULTERATION OF BREAD WHEAT IN PASTA
Authors: KELLY FIONA , BHAVE MRINAL 
Published: April 2007

ABSTRACT The quality of pasta products is considered the highest if it is made from 100% durum wheat, as the texture of this product is firmer. This characteristic is determined by the hardness (texture) of the wheat grain. Durum wheat is considered genetically “very hard” as a result of having a deletion of two important genes which impart a degree of softness to common wheat; use of the latter can thus compromise the quality characteristics of pasta to some degree. An application of a qualitative test utilizing the polymerase chain reaction based on these genes was applied to DNA extracted from 20 commercially available pasta samples. The results indicate that common wheat is used in a number of pasta products, some of which do not show this as a listed ingredient.
ORGANIC ACIDS PROFILE IN TOMATO JUICE BY HPLC WITH UV DETECTION
Authors: MARCONI OMBRETTA , FLORIDI SIMONA , MONTANARI LUIGI 
Published: April 2007

ABSTRACT A simple method was developed to determine 10 organic acids simultaneously in tomato products using reversed‐phase high‐performance liquid chromatography column with the diode array detector set at 210 nm. After centrifugation and filtration, the samples were passed through an anion exchange resin and the organic acids were released using 0.1‐N HCl. The chromatographic separation was achieved with isocratic analysis in a 20‐min run. The method was reliable and sensitive, the coefficient of determination of the standard calibration curve is 0.9925 ≤ r2 ≤ 0.9999 and the limit of detection ranged from 0.08 to 6.00 mg/kg for trans‐aconitic acid and acetic acid, respectively. The limit of quantification ranged from 0.19 to 15.18 mg/kg for trans‐aconitic and acetic acid, respectively. To establish the efficiency of the anion resin, the procedure was applied to a standard solution of a mixture of organic acids. The organic acids recovery ranged from 87.0% ± 1.9 for citramalic acid to 109.9% ± 5.2 for fumaric acid.
COATED LUPIN BEAN SNACKS*
Authors: JORAY M.L. , RAYAS‐DUARTE P. , MOHAMED A. , VAN SANTEN E. 
Published: April 2007

ABSTRACT The potential of lupin in human nutrition is generally underestimated worldwide and the development of lupin‐based convenient food products needs to be expanded. The objective of this study was to develop savory‐ and sweet‐coated snacks from Lupinus albus grains. Lupin beans were prepared using the traditional Middle Eastern process by cooking, soaking in saltwater, peeling, and either roasting or deep‐frying. Sensory analysis was performed using a 5‐point hedonic scale of four lupin snacks, two savory (Caribbean jerk and fajita) and two sweet (cinnamon and lemon). Overall, sensory attribute scores for the fried savory snacks were better than the roasted, and as expected, the residue on the fingers of panelists after handling the lupin snacks was higher in the fried samples. Higher scores were given to the Caribbean jerk than to the fajita‐flavored lupin snacks for aroma, spiciness and salt level. The panelists gave high (much too strong) crispiness scores to the fried lemon and the roasted cinnamon lupin snacks. Sweet‐coated lupin snacks (combining roasted and fried) received higher than 50% of just about right scores for color, aroma, sugar, spiciness and flavor. Three different samples of L. albus evaluated by consumer panelists were also processed (fried and roasted) to determine color changes using the CIE 1976 L*, a*, b* Color Space color space. The color was recorded in samples of single beans and groups of beans. The darkness (−L*) of the fried and roasted samples increased 28 and 13%, respectively, compared to the raw lupin beans, with a more homogeneous darkness and color in the roasted sample. ΔE suggests that the general change in color was higher in the roasted samples, especially when measured as a group.
Role of the ABC Transporter PRP1 (ABCC7) in Pentamidine Resistance in
Leishmania
Amastigotes
Authors: Coelho Adriano C. , Messier Nadine , Ouellette Marc , Cotrim Paulo C. 
Published: April 2007

ABSTRACT

Pentamidine is a second-line agent in the treatment of leishmaniasis whose mode of action and resistance mechanism are not well understood. In this work, we show that the intracellular ABC protein PRP1 (pentamidine resistance protein 1) (ABCC7) can confer resistance to pentamidine in
Leishmania
sp. parasites in the intracellular stage.
Characterization of SafC, a Catechol 4-O-Methyltransferase Involved in Saframycin Biosynthesis
Authors: Nelson James T. , Lee Jaeheon , Sims James W. , Schmidt Eric W. 
Published: April 2007

ABSTRACTMembers of the saframycin/safracin/ecteinascidin family of peptide natural products are potent antitumor agents currently under clinical development. Saframycin MX1, fromMyxococcus xanthus, is synthesized by a nonribosomal peptide synthetase, SafAB, and anO-methyltransferase, SafC, although other proteins are likely involved in the pathway. SafC was overexpressed inEscherichia coli, purified to homogeneity, and assayed for its ability to methylate a variety of substrates. SafC was able to catalyze the O-methylation of catechol derivatives but not phenols. Among the substrates tested, the best substrate for SafC wasl-dihydroxyphenylalanine (l-dopa), which was methylated specifically in the 4′-O position (kcat/Km= 5.5 × 103M−1s−1). SafC displayed less activity on other catechol derivatives, including catechol, dopamine, and caffeic acid. The more labilel-5′-methyldopa was an extremely poor substrate for SafC (kcat/Km= ∼2.8 × 10−5M−1s−1).l-Dopa thioester derivatives were also much less reactive thanl-dopa. These results indicate that SafC-catalyzed 4′-O-methylation ofl-dopa occurs prior to 5′-C-methylation, suggesting that 4′-O-methylation is likely the first committed step in the biosynthesis of saframycin MX1. SafC has biotechnological potential as a methyltransferase with unique regioselectivity.
Characterization of
Staphylococcus aureus
Isolates from Buffalo, Bovine, Ovine, and Caprine Milk Samples Collected in Rio de Janeiro State, Brazil
Authors: Aires-de-Sousa Marta , Parente Carlos E. S. R. , Vieira-da-Motta Olney , Bonna Isabel C. F. , Silva Denise A. , de Lencastre Hermínia 
Published: April 2007

ABSTRACT

Eighty-four staphylococcal isolates were obtained from milk samples from cows, sheep, goats, and buffalo with subclinical mastitis and from colonization samples from ostriches. The animals were hosted in 18 small dairy herds and an ostrich breeding located in 10 municipalities of the state of Rio de Janeiro, Brazil. Thirty isolates were identified as
Staphylococcus aureus
by biochemical and molecular techniques and were comparatively characterized by phenotypic and genotypic methods. The molecular characterization by pulsed-field gel electrophoresis (PFGE),
spa
typing, and multilocus sequence typing (MLST) revealed five clonal types (PFGE A,
spa
type t359, sequence type 747 [ST747]; PFGE B,
spa
type t1180, ST750; PFGE C,
spa
type t605, ST126; PFGE D,
spa
type t127, ST751; and PFGE F,
spa
type t002, ST5). None of the isolates harbored the Panton-Valentine leukocidin or exfoliative toxin D gene. The detection of major clone A (in 63% of the isolates) in different herds, among all animal species studied, and in infection and colonization samples evidenced its geographical spread among Rio de Janeiro State and no host preference among the animal species. Comparison with
S. aureus
from a human origin suggested that all but one clone found in the present study might be animal specific.
Nitric Oxide Reductase-Targeted Real-Time PCR Quantification of Denitrifier Populations in Soil
Authors: Dandie C. E. , Miller M. N. , Burton D. L. , Zebarth B. J. , Trevors J. T. , Goyer C. 
Published: April 2007

ABSTRACT

The quantification of denitrifying bacteria is a component in the further understanding of denitrification processes in the environment. Real-time PCR primers were designed to target two segments of the denitrifier population (
cnorB
P
[
Pseudomonas mandelii
and closely related strains] and
cnorB
B
[
Bosea
,
Bradyrhizobium
, and
Ensifer
spp.]) in agricultural soils based on functional
cnorB
(nitric oxide reductase) gene sequences. Total population numbers were measured using 16S rRNA gene real-time PCR. Two soil microcosm experiments were conducted. Experiment 1 examined the response of the indigenous soil microbial population to the addition of 500 mg/kg glucose-C daily over 7 days in soil microcosms. Changes in the total population were correlated (
r
= 0.83) between 16S rRNA gene copy numbers and microbial biomass carbon estimates. Members of the
cnorB
P
population of denitrifiers showed typical r-strategy by being able to increase their proportion in the total population from starting levels of <0.1% to around 2.4% after a daily addition of 500 mg/kg glucose-C. The
cnorB
B
guild was not able to increase its relative percentage of the total population in response to the addition of glucose-C, instead increasing copy numbers only in proportion with the total population measured by 16S rRNA genes. Experiment 2 measured population dynamics in soil after the addition of various amounts of glucose-C (0 to 500 mg/kg) and incubation under denitrifying conditions.
cnorB
P
populations increased proportionally with the amount of glucose-C added (from 0 to 500 mg/kg). In soil microcosms, denitrification rates, respiration, and
cnorB
P
population densities increased significantly with increasing rates of glucose addition.
cnorB
B
guild densities did not increase significantly under denitrifying conditions in response to increasing C additions.
Plant Cell Wall Degradation by Saprophytic
Bacillus subtilis
Strains: Gene Clusters Responsible for Rhamnogalacturonan Depolymerization
Authors: Ochiai Akihito , Itoh Takafumi , Kawamata Akiko , Hashimoto Wataru , Murata Kousaku 
Published: April 2007

ABSTRACT

Plant cell wall degradation is a premier event when
Bacillus subtilis
, a typical saprophytic bacterium, invades plants. Here we show the degradation system of rhamnogalacturonan type I (RG-I), a component of pectin from the plant cell wall, in
B. subtilis
strain 168. Strain 168 cells showed a significant growth on plant cell wall polysaccharides such as pectin, polygalacturonan, and RG-I as a carbon source. DNA microarray analysis indicated that three gene clusters (
yesOPQRSTUVWXYZ
,
ytePQRST
, and
ybcMOPST-ybdABDE
) are inducibly expressed in strain 168 cells grown on RG-I. Cells of an industrially important bacterium,
B. subtilis
strain natto, fermenting soybeans also express the gene cluster including the
yes
series during the assimilation of soybean used as a carbon source. Among proteins encoded in the
yes
cluster, YesW and YesX were found to be novel types of RG lyases releasing disaccharide from RG-I. Genetic and enzymatic properties of YesW and YesX suggest that strain 168 cells secrete YesW, which catalyzes the initial cleavage of the RG-I main chain, and the resultant oligosaccharides are converted to disaccharides through the extracellular exotype YesX reaction. The disaccharide is finally degraded into its constituent monosaccharides through the reaction of intracellular unsaturated galacturonyl hydrolases YesR and YteR. This enzymatic route for RG-I degradation in strain 168 differs significantly from that in plant-pathogenic fungus
Aspergillus aculeatus
. This is, to our knowledge, the first report on the bacterial system for complete RG-I main chain degradation.
Faster, Simpler, More-Specific Methods for Improved Molecular Detection of
Phytophthora ramorum
in the Field
Authors: Tomlinson J. A. , Barker I. , Boonham N. 
Published: April 2007

ABSTRACT

Phytophthora ramorum
is the causal agent of sudden oak death. The pathogen also affects a wide range of tree, shrub, and herbaceous species in natural and landscaped environments as well as plants in the nursery industry. A TaqMan real-time PCR method for the detection of this pathogen in the field has been described previously; this paper describes the development of a number of assays based on this method which have various advantages for use in the field. A scorpion real-time PCR assay that is twice as fast as TaqMan was developed, allowing the detection of
P. ramorum
in less than 30 min. Also designed was a loop-mediated isothermal amplification (LAMP) assay, which allowed sensitive and specific detection of
P. ramorum
in 45 min using only a heated block. A positive reaction was identified by the detection of the LAMP product by color change visible to the naked eye.
Risk of Handling as a Route of Exposure to Infectious Waterborne
Cryptosporidium parvum
Oocysts via Atlantic Blue Crabs (
Callinectes sapidus
)
Authors: Graczyk Thaddeus K. , McOliver Cynthia , Silbergeld Ellen K. , Tamang Leena , Roberts Jennifer D. 
Published: April 2007

ABSTRACT

Commercial Atlantic blue crabs (
Callinectes sapidus
) were exposed to 2.0 × 10
4
infectious waterborne oocysts of
Cryptosporidium parvum
. The study demonstrated that blue crabs can transfer
C. parvum
oocysts to persons involved in handling or preparing crabs and that they may contaminate other surfaces or products during storage.
Identification of a Gene Cluster EnablingLactobacillus caseiBL23 To Utilizemyo-Inositol
Authors: Yebra María Jesús , Zúñiga Manuel , Beaufils Sophie , Pérez-Martínez Gaspar , Deutscher Josef , Monedero Vicente 
Published: April 2007

ABSTRACTGenome analysis ofLactobacillus caseiBL23 revealed that, compared toL. caseiATCC 334, it carries a 12.8-kb DNA insertion containing genes involved in the catabolism of the cyclic polyolmyo-inositol (MI). Indeed,L. caseiATCC 334 does not ferment MI, whereas strain BL23 is able to utilize this carbon source. The inserted DNA consists of aniolRgene encoding a DeoR family transcriptional repressor and a divergently transcribediolTABCDG1G2EJKoperon, encoding a complete MI catabolic pathway, in which theiolKgene probably codes for a malonate semialdehyde decarboxylase. The presence ofiolKsuggests thatL. caseihas two alternative pathways for the metabolism of malonic semialdehyde: (i) the classical MI catabolic pathway in which IolA (malonate semialdehyde dehydrogenase) catalyzes the formation of acetyl-coenzyme A from malonic semialdehyde and (ii) the conversion of malonic semialdehyde to acetaldehyde catalyzed by the product ofiolK. The function of theiolgenes was verified by the disruption ofiolA,iolT, andiolD, which provided MI-negative strains. By contrast, the disruption ofiolKresulted in a strain with no obvious defect in MI utilization. Transcriptional analyses conducted with different mutant strains showed that theiolTABCDG1G2EJKcluster is regulated by substrate-specific induction mediated by the inactivation of the transcriptional repressor IolR and by carbon catabolite repression mediated by the catabolite control protein A (CcpA). This is the first example of an operon for MI utilization in lactic acid bacteria and illustrates the versatility of carbohydrate utilization inL. caseiBL23.
Protein Engineering of Wzc To Generate New Emulsan Analogs
Authors: Dams-Kozlowska Hanna , Kaplan David L. 
Published: April 2007

ABSTRACTAcinetobacter venetianusRag1 produces an extracellular, polymeric lipoheteropolysaccharide termed apoemulsan. This polymer is putatively produced via a Wzy-dependent pathway. According to this model, the length of the polymer is regulated by polysaccharide-copolymerase (PCP) protein. A highly conserved proline and glycine motif was identified in all members of the PCP family of proteins and is involved in regulation of polymer chain length. In order to control the structure of apoemulsan, defined point mutations in the proline-glycine-rich region of the apoemulsan PCP protein (Wzc) were introduced. Modifiedwzcvariants were introduced into the Rag1 genome via homologous recombination. Stable chromosomal mutants were confirmed by Southern blot analysis. The molecular weight of the polymer was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Five of the eight point mutants produced polymers having molecular weights higher than the molecular weight of the polymer produced by the wild type. Moreover, four of these five polymers had modified biological properties. Replacement of arginine by leucine (R418L) resulted in the most significant change in the molecular weight of the polymer. The R418L mutant was the most hydrophilic mutant, exhibiting decreased adherence to polystyrene, and inhibited biofilm formation. The results described in this report show the functional effect of Wzc modification on the molecular weight of a high-molecular-weight polysaccharide. Moreover, in the present study we developed a genetic system to control polymerization of apoemulsan. The use of selective exogenous fatty acid feeding strategies, as well as genetic manipulation of sugar backbone chain length, is a promising new approach for bioengineering emulsan analogs.
Trehalose Biosynthesis in
Rhizobium leguminosarum
bv.
trifolii
and Its Role in Desiccation Tolerance
Authors: McIntyre Helen J. , Davies Holiday , Hore Timothy A. , Miller Simon H. , Dufour Jean-Pierre , Ronson Clive W. 
Published: April 2007

ABSTRACT

Rhizobium leguminosarum
bv.
trifolii
forms nitrogen-fixing root nodules on the pasture legume
Trifolium repens
, and
T. repens
seed is often coated with a compatible
R. leguminosarum
bv.
trifolii
strain prior to sowing. However, significant losses in bacterial viability occur during the seed-coating process and during storage of the coated seeds, most likely due to desiccation stress. The disaccharide trehalose is known to function as an osmoprotectant, and trehalose accumulation due to de novo biosynthesis is a common response to desiccation stress in bacteria. In this study we investigated the role of endogenous trehalose synthesis in desiccation tolerance in
R. leguminosarum
bv.
trifolii
strain NZP561. Strain NZP561 accumulated trehalose as it entered the stationary phase due to the combined actions of the TreYZ and OtsAB pathways. Mutants deficient in either pathway showed near-wild-type levels of trehalose accumulation, but double
otsA treY
mutants failed to accumulate any trehalose. The double mutants were more sensitive to the effects of drying, and their survival was impaired compared to that of the wild type when glass beads were coated with the organisms and stored at relative humidities of 5 and 32%. The
otsA treY
mutants were also less competitive for nodule occupancy. Gene expression studies showed that the
otsA
and
treY
genes were expressed constitutively and that expression was not influenced by the growth phase, suggesting that trehalose accumulation is controlled at the posttranscriptional level or by control of trehalose breakdown rates. Our results indicate that accumulated trehalose plays an important role in protecting
R. leguminosarum
bv.
trifolii
cells against desiccation stress and against stress encountered during nodulation.
Quantitative Assessment of Contamination of Fresh Food Produce of Various Retail Types by Human-Virulent Microsporidian Spores
Authors: Jedrzejewski Szymon , Graczyk Thaddeus K. , Slodkowicz-Kowalska Anna , Tamang Leena , Majewska Anna C. 
Published: April 2007

ABSTRACT

This study demonstrated that fresh food produce, such as berries, sprouts, and green-leafed vegetables, sold at the retail level can contain potentially viable microsporidian spores of human-virulent species, such as
Enterocytozoon bieneusi
,
Encephalitozoon intestinalis
, and
Encephalitozoon cuniculi
, at quantities representing a threat of food-borne infection.
Desensitization of Feedback Inhibition of the
Saccharomyces cerevisiae
γ-Glutamyl Kinase Enhances Proline Accumulation and Freezing Tolerance
Authors: Sekine Tomoko , Kawaguchi Akari , Hamano Yoshimitsu , Takagi Hiroshi 
Published: April 2007

ABSTRACT

In response to osmotic stress, proline is accumulated in many bacterial and plant cells as an osmoprotectant. The yeast
Saccharomyces cerevisiae
induces trehalose or glycerol synthesis but does not increase intracellular proline levels during various stresses. Using a proline-accumulating mutant, we previously found that proline protects yeast cells from damage by freezing, oxidative, or ethanol stress. This mutant was recently shown to carry an allele of
PRO1
which encodes the Asp154Asn mutant γ-glutamyl kinase (GK), the first enzyme of the proline biosynthetic pathway. Here, enzymatic analysis of recombinant proteins revealed that the GK activity of
S. cerevisiae
is subject to feedback inhibition by proline. The Asp154Asn mutant was less sensitive to feedback inhibition than wild-type GK, leading to proline accumulation. To improve the enzymatic properties of GK, PCR random mutagenesis in
PRO1
was employed. The mutagenized plasmid library was introduced into an
S. cerevisiae
non-proline-utilizing strain, and proline-overproducing mutants were selected on minimal medium containing the toxic proline analogue azetidine-2-carboxylic acid. We successfully isolated several mutant GKs that, due to extreme desensitization to inhibition, enhanced the ability to synthesize proline better than the Asp154Asn mutant. The amino acid changes were localized at the region between positions 142 and 154, probably on the molecular surface, suggesting that this region is involved in allosteric regulation. Furthermore, we found that yeast cells expressing Ile150Thr and Asn142Asp/Ile166Val mutant GKs were more tolerant to freezing stress than cells expressing the Asp154Asn mutant.