bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sensory Evaluation of Butterfat‐Vegetable Oil Blend Spread Prepared with Structured Lipid Containing Canola Oil and Caprylic Acid
Authors: Kim Byung Hee , Shewfelt Robert L. , Lee Hyoungil , Akoh Casimir C. 
Published: October 2006

ABSTRACTStructured lipid (SL) was synthesized from canola oil and caprylic acid with sn‐1,3 specific lipase from Rhizomucor miehei. Cold‐spreadable butter was made by blending butterfat with the SL at a weight ratio of 80:20. Its sensory attributes were compared with pure butter and butterfat‐canola oil 80:20 blend spread by headspace solid‐phase microextraction (SPME) procedure and sensory analyses (descriptive analysis and triangle test) to determine the effect of the SL on the sensory profiles of the spread. Butterfat‐SL blend had significantly (P < 0.05) lower contents of hypercholesterolemic fatty acids (FAs) and the lowest atherogenic index (AI) compared with the others. In the volatile compounds analysis, free caprylic acid was detected in the butterfat‐SL blend spread only. Descriptive analysis results indicated that butterfat‐SL blend spread was significantly (P < 0.05) more cold‐spreadable than pure butter, whereas its overall textural profile was very similar to that of butterfat‐canola oil blend spread. However, no significant (P < 0.05) differences were found between all the spread samples in the flavor attributes including caprylic acid flavor. Triangle test results also showed that significant (P < 0.001) difference was found in cold‐spreadability between pure butter and butterfat‐SL blend spread, but there was no significant (P < 0.05) difference between butterfat‐canola oil blend spread and butterfat‐SL blend spread. Our results indicate that SL can counterbalance the hypercholester‐olemic attributes of butterfat as well as improve the cold‐spreadability of the experimental spread without any adverse effect on the flavor attributes of the spread.
Composition and Structure of Fat Bloom in Untempered Chocolate
Authors: Kinta Yasuyoshi , Hatta Tamao 
Published: October 2006

ABSTRACTIt is generally accepted that visual fat bloom is caused by the separation of cocoa butter toward the surface. However, this is not always true for all types of bloom. One type of fat bloom, which can occur due to lack of tempering, has still not been completely elucidated. We performed a compositional and structural study of this type of fat bloom in plain chocolate. More specifically, we performed (1) an investigation of its crystallographic properties, (2) investigation of fat content, (3) analysis of the composition of triacylglycerol (TAG), (4) stereomicroscopic observations, and (5) observation and elemental analysis using a scanning electron microscope with an energy‐dispersive X‐ray spectrometer (SEM‐EDS). In the bloomed chocolate, the fat content in the light brown phase was lower than that in the black phase. Concerning fat composition, the content of sn‐1,3‐saturated acyl, sn‐2‐oleoyl glycerols (Sat‐O‐Sat type TAGs) in the light brown phase was lower. The lower fat content is thought to result in its lighter color. The results of our composition analysis and morphological observations suggest that the mechanism of the bloom generation due to nontempering involves not the separation of fat toward the surface but the crystallization of fat which leads to withdrawal of fat from the vicinity of the growing crystal, leading to differences in fat content.
Effects of Long‐term Storage on Sensory and Nutritional Quality of Rolled Oats
Authors: McEwan Michael , Ogden Lynn V. , Pike Oscar A. 
Published: October 2006

ABSTRACT:Sixteen samples of regular and quick‐cooking rolled oats stored up to 28 y in a reduced oxygen atmosphere in nr 10 cans at ambient temperatures were analyzed for sensory and nutritional quality. A consumer panel evaluated aroma, texture, flavor, aftertaste, and overall acceptability using a 9‐point hedonic scale. Hedonic scores varied from 4.8 to 6.7. Although there was a loss of sensory quality in samples over time, all samples were considered acceptable by at least 3/4 of panelists for use in an emergency. Vitamin B1 amounts ranged from 2.7 to 6.6 μg/g and were highest in some older samples. Vitamin E amounts ranged from 1.3 to 37.8 μg/g and were negatively correlated with headspace hexanal levels. Rolled oats can be included in long‐term food storage regimens because of their sensory and nutritional stability when properly packaged and stored.
Quality Changes of Shrimp (Pandalus borealis) Stored under Different Cooling Conditions
Authors: Zeng Qing Zhu , Thorarinsdottir Kristin A. , Olafsdottir Gudrun 
Published: October 2006

ABSTRACTThe influence of different cooling techniques and storage temperatures (‐1.5 °C or 1.5 °C) to prolong the shelf life of shrimp was evaluated by sensory analysis, physical methods, chemical analysis, and microbial analysis. Storage in liquid ice was more effective than flake ice or brine mixed with flake ice in delaying spoilage of the shrimp by slowing down microbial growth and formation of total volatile basic nitrogen (TVB‐N) and trimethylamine (TMA). Total viable counts (TVC) showed that bacteria grew most quickly in shrimp stored in flake ice and in brine mixed with flake ice, followed by those in liquid ice at 1.5 °C and ‐1.5 °C, respectively. Lowest counts were observed in shrimp stored in liquid ice at ‐1.5 °C where the lag phase of growth was apparently extended at the beginning of storage. Principal component analysis (PCA) showed a good correlation between quality indicators related to microbial growth, TVC, pH, TVB‐N, TMA, responses of an electronic nose and sensory evaluation.
Cloning and nucleotide sequence analysis of the serotype 2 fimbrial subunit gene of Bordetella pertussis
Authors: Livey I. , Duggleby C.J. , Robinson A. 
Published: October 2006

SummaryAn oligonucleotide probe complementary to the beginning of the gene encoding the serotype 2 (ST2) fimbrlal subunit of Bordetella pertussis was synthesized and a cloned DNA fragment hybridizing with the probe identified and sequenced. Several lines of evidence indicate that an open reading frame with coding Information for a polypeptide of 207 amino acids, including a 26‐amino‐acid signal sequence, is the ST2 gene. The protein deduced from the nucleotide sequence shows good agreement with the NH2‐terminal amino acid sequence, amino acid composition and molecular weight of the purified fimbrial subunit. In addition, the proposed ST2 subunit is shown to have homology with other fimbrial subunits.
Reassortment of DNA recognition domains and the evolution of new specificities
Authors: Gann A. A. F. , Campbell A. J. B. , Collins J. F. , Coulson A. F. W. , Murray N. E. 
Published: October 2006

SummaryType I restriction enzymes comprise three subunits only one of which, the S polypeptide, dictates the specificity of the DNA sequence recognized. Recombination between two different hsdS genes, SP and SB, led to the isolation of a system, SQ, which had a different specificity from that of either parent. The finding that the nucleotide sequence recognized by SQ is a hybrid containing components from both the SP and SB target sequences suggested that DNA recognition is carried out by two separable domains within each specificity polypeptide. To test this we have made the recombinant gene of reciprocal structure and demonstrate that it encodes a polypeptide whose recognition sequence, deduced In vivo, is as predicted by this model. We also report the sequence of the SB specificity gene, so that information is now available for the five known members of this family of enzymes. Ali show a similar organization of conserved and variable regions. Comparisons of the predicted amino acid sequences reveal large non‐conserved areas which may not even be structurally similar. This is remarkable since these different S subunits are functionally identical, except for the specificity with respect to the DNA sequence with which they interact. We discuss the correlation of the variation in polypeptide sequence with recognition specificities.
Use of a β‐lactamase fusion vector to investigate the organization of penicillin‐binding protein 1B in the cytoplasmic membrane of Escherichia coli
Authors: Edelman A. , Bowler L. , Broome‐Smith J. K. , Spratt† B. G. 
Published: October 2006

SummaryThe coding region for the mature form of TEM β–lactamase was fused to random positions within the coding region of the penicillin–binding protein 1B (PBP 1B) gene and the nucleotide sequences across the fusion junctions of 100 in–frame fusions were determined. All fusion proteins that contained at least the NH2–terminal 94 residues of PBP 1B provided individual cells of E. coli with substantial levels of ampicillin resistance, suggesting that the β–lactamase moiety had been translocated to the periplasm. Fusion proteins that contained ≤ 63 residues of PBP 1B possessed β–lactamase activity, but could not protect single cells of E. coli from ampicillin, indicating that the 3–lactamase moiety of these fusion proteins remained in the cytoplasm. The β–lactamase fusion approach suggested a model for the organization of PBP 1B in which the protein is embedded in the cytoplasmic membrane by a single hydrophobic trans–membrane segment (residues 64–87), with a short NH2–terminal domain (residues 1–63), and the remainder of the polypeptide (residues 68–844) exposed on the periplasmic side of the cytoplasmic membrane. The proposed model for the organization of PBP 1B was supported by experiments which showed that the protein was completely digested by proteinase K added from the periplasmic side of the cytoplasmic membrane but was only slightly reduced in size by protease attack from the cytoplasmic side of the membrane.
Regulation of alcR, the positive regulatory gene of the ethanol utilization regulon of Aspergillus nidulans
Authors: Locklngton R. , Scazzocchio C. , Sequeval D. , Mathieu M. , Felenbok B. 
Published: October 2006

SummaryThe alcR positive control gene is necessary for the expression of both alcA (coding for alcohol dehydro‐genase ADH I.) and aldA (coding for aldehyde dehydro‐genase, AldDH) in Aspergillus nidulans. Using a cloned alcR probe and Northern blots analysis we show that: (1)alcR itself is inducible; (2)alcR inducibility depends on the expression of the alcR gene Itself; and (3) alcR is subject to carbon catabolite repression and its expression Is controlled by the negatively acting creA wide specificity gene. The repression of alcR is sufficient to explain the cariaon catabolite repression of ADH I and AldDH.
Fumarate reductase of Escherichia coli: an investigation of function and assembly using in vivo complementation
Authors: Condon C. , Weiner J. H. 
Published: October 2006

SummaryRecombinant plasmids which carried portions of the Escherichia coli frd operon were constructed and their expression examined by in vivo complementation of E. Coli MI 1443. This strain lacked a chromosomal frd operon and was unable to grow anaerobically on glycerol and fumarate. Introduction of all four fumarate reductase subunits into E. coli MI1443 was essential for the restoration of growth. The FRD A, FRD B dimer (but neither subunit alone) was active in the benzyl viologen oxidase assay. Both FRD C and FRD D were required for membrane association of fumarate reductase and for the oxidation of reduced quinone analogues. Introduction into E. coli MI1443 of the frdABC and frdD genes on two separate plasmid vectors failed to restore anaerobic growth on glycerol and fumarate. Thus separation of the DNA coding for the FRD C and FRD D proteins affected the ability of fumarate reductase to assemble into a functional complex.
Sequence of the nucleoprotein gene from a virulent British field isolate of transmissible gastroenteritis virus and its expression in Saccharomyces cerevisiae
Authors: Britton P. , Cármenes R. S. , Page K. W. , Garwes D. J. , Parral F. 
Published: October 2006

SummarySubgenomic mRNA from a virulent isolate of porcine transmissible gastroenteritis virus (TGEV) was used to produce cDNA which was sequenced. Two non‐overlapping open reading frames (ORFs) were identified. The largest, encoding a polypeptide of 382 amino acids (relative molecular mass (Mr) 43 483), was shown to be the viral nucleoprotein gene. The second ORF, found 3’to the larger ORF, encodes a polypeptide of 78 amino acids (Mr 9068) which has yet to be assigned to a viral product. The nucleoprotein gene was expressed in yeast cells under the control of two types of yeast promoters: the constitutive PGK promoter, and the inducible GAL1 promoter. Yeast cells containing recombinant plasmids, with the nucleoprotein gene in the correct orientation, produced a polypeptide of M, 47000, identical to the viral product, that reacted with a specific monoclonal antibody.
Isolation and molecular characterization of the gene encoding allophycocyanin B, a terminal energy acceptor in cyanobacterial phycobillsomes
Authors: Houmard J. , Capuano V. , Coursin T. , de Marsac N. Tandeau 
Published: October 2006

SummaryPhycobilisomes are the major constituents of the light‐harvesting apparatus in both cyanobacteria and red algae and consist of a central core with radiating rods. From a genomic library of the cyanobacterium Calothrix 7601, a DNA fragment encoding allophycocyanin B, one of the two terminal energy acceptors of the core, was isolated and its nucleotide sequence was determined. Unlike all the other known genes encoding phycobiliproteins, the allophycocyanin B gene, apcD, is transcribed as a monocistronic unit. Mapping of the transcripts was performed and, in contrast to some of the Calothrix genes that encode rod components, transcription was shown to occur regardless of chromatic tight received during cell growth.
Identification and sequencing of the Escherichia coli cet gene which codes for an inner membrane protein, mutation of which causes tolerance to colicin E2
Authors: Drury L. S. , Buxton R. S. 
Published: October 2006

SummaryDominant mutations of the cet gene of Escherichia coli result in tolerance to colicin E2 and increased amounts of an inner membrane protein with an Mr of 42 000. We have cloned the cet+ gene and sequenced its DNA, revealing that the gene product, coded by the longest open‐reading frame, has an Mr of 49772, with five predicted transmembrane structures towards its carboxy terminus and one at its amino terminus. We have demonstrated that the cet locus does in fact code for the inner membrane protein that is present in increased amounts in cet mutants, and we have shown that this increased amount of Cet protein is the result of enhanced transcription. The cet gene is shown to be in the same operon as the phoM gene, which is required in a phoR background for expression of the structural gene for alkaline phosphatase, phoA. Although the Cet protein is not required for phoA expression, our experiments suggest that the Cet protein has an enhancing effect on the transcription of phoA. No effect of phosphate concentration on cet or phoM gene expression could be found and thus their primary function may not be connected to the phosphate regulon.
Molecular basis for the spontaneous generation of colonization‐defective mutants of Streptococcus mutans
Authors: Ueda S. , Kuramitsu H. K. 
Published: October 2006

SummarySpontaneous mutants of Streptococcus mutans GS‐5 defective in sucrose‐dependent colonization of smooth surfaces are generated at frequencies above the spontaneous mutation rate. Southern blot analysis of such mutants suggested rearrangement of the genes coding for glucosyltransferase (GTF) activity. Two strain GS‐5 homologous tandem genes, gtfB and gtfC, coding for GTF‐I and GTF‐S activities respectively, were demonstrated to undergo recombination when introduced into recombination‐proficient Escherichia coli transformants. However, the two genes were quite stable when transformed on a single DNA fragment into a recA mutant of E. coli. The DNA fragment coding for GTF activity from one S. mutans colonization‐defective mutant, SP2, was isolated and shown also to have undergone recombination between the gtfB and gtfC genes, resulting in reduced GTF activity. These results are discussed relative to the in vivo generation of colonization‐defective mutants in cultures of S. mutans.
Homology between endoglucanase Z of Erwinia chrysanthemi and endoglucanases of Bacillus subtilis and alkalophilic Bacillus
Authors: Guiseppi A. , Cami B. , Aymeric J.‐L. , Ball G. , Creuzet N. 
Published: October 2006

SummaryNucleotide sequencing of the celZ gene encoding the extracellular endoglucanase Z of Erwinia chrysanthemi indicated the presence of an open reading frame encoding 428 amino acids. The mature protein appeared to be extended by a signal peptide of 43 amino acids; this sequence is unusually long and positively charged (+5). It was shown to function as a signal peptide by fusing it to a truncated phoA gene encoding Escherichia coli alkaline phosphatase. Comparison of the encoded sequence with those of the endoglucanases of Bacillus subtilis and alkalophilic Bacillus revealed the existence of a region of extensive homology occurring in all three proteins at about the same distance from the NH2‐terminal end. These regions may be involved in substrate binding and/or catalytic sites.
Molecular cloning and nucleotide sequence of the pectin methyl esterase gene of Erwinia chrysanthemi B374
Authors: Plastow G. S. 
Published: October 2006

SummaryThe gene encoding pectin methyl esterase (pme) has been cloned from Erwinia chrysanthemi B374. Expression of pme in Escherichia coli allowed the enzyme to be characterized. Pectin methyl esterase (PME) was found to have an apparent molecular weight of 36000 Daltons and an isoelectric point of approximately 9.9. The structural gene was sequenced and consists of a 1098‐bp open reading frame encoding a polypeptide of 39318 Daltons, which includes an amino‐terminal signal peptide. The isolation of the Erwinia gene provides a simple method for the production of PME free from depolymerizing pectinases thereby extending its potential uses.
Mercury and tetracycline resistance genes and flanking repeats associated with methicillin resistance on the chromosome of Staphylococcus aureus
Authors: Skinner S. , Inglis B. , Matthews P. R. , Stewart P. R. 
Published: October 2006

SummarySections of a cloned 27 kb segment of chromosomal DNA, associated with resistance to four antimicrobial agents in a clinical isolate of methicillin‐resistant Staphylococcus aureus (MRSA), were tested for their ability to determine resistance when transformed into a sensitive laboratory strain of S. aureus. This was achieved by inserting the sections into a newly constructed shuttle vector, amplifying the recombinant DNA In E. coli, and transforming protoplasts of the sensitive S. aureus strain. Two sections of the cloned DNA were found to determine resistance separately to mercuric ion and to tetracycline, in both S. aureus and Escherichia coli.
Identification and Characterization of two nitrogen fixation regulatory regions, nifA and nfrX, in Azotobacter vinelandii and Azotobacter chroococcum
Authors: Santero E. , Toukdarian A. , Humphrey R. , Kennedy C. 
Published: October 2006

SummaryFive Tn5‐induced Nif− mutants of Azotobacter vinelandii were characterized as regulatory mutants because they were restored to Nif+ by the introduction of constitutively expressed nifA from Klebsiella pneumoniae. The mutants fell into two different classes on the basis of hybridization to a Rhizobium leguminosarum nifA gene probe and by complementation with cosmids isolated from pLAFRI gene banks of A.vineiandii and Azotobacter chroococcum. One mutant, MV3, was located in or near a nifA gene. The others, MV12, MV16, MV18 and MV26, defined a new regulatory gene, which has been called nfrX. The lack of expression of different nif‐lacZ fusions confirmed the regulatory phenotype of all five mutant strains. The ability of both nifA and nfrX mutants to grow on nitrogen‐free medium with vanadium, but not on medium with molybdenum, suggests that neither gene is required for expression of the alternative V‐containing nitrogenase of A. vinelandii. A fragment carrying Tn5 and flanking DNA from MV3 was used as a probe to isolate the nifA region of A. chroococcum. Ligation of two adjacent EcoRI fragments of A. chroococcum yielded an intact nifA gene that activated expression of nifH‐lac fusions and also restored MV3 to Nif+. The four nfrX mutants were complemented by pLAFRI cosmids pLV163 and pLCI 21. The nfrX gene was subcloned from pLV163 and located within a 3.2 kb fragment. To determine whether nfrX might be found in other nitrogen‐fixing organisms, DNA from 13 different species was hybridized to an nfrX probe. The failure to observe hybridization suggests that nfrX may be specific to nif regulation in Azotobacter.
Multiplicity of §‐endotoxin genes with different insecticidal specificities in Bacillus thuringiensis aizawai 7.29
Authors: Sanchis V. , Lereclus D. , Menou G. , Chaufaux J. , Lecadet M‐M. 
Published: October 2006

SummaryThe hypothesis according to which multiple and different 5‐endotoxin genes could determine the host‐range specificity of the lepidopteran strains of Bacillus thuringiensis is being checked in the case of strains aizawai 7.29 (serotype 7) and entomocidus 601 (serotype 6). From these strains, several crystal protein genes, belonging to different structural types, have been isolated. One of the cloned genes that is not present in strain entomocidus 601 is duplicated in strain aizawai 7.29. This gene belongs to a previously characterized type of crystal protein gene and encodes a protein preferentially active against Pieris brassicae. Two other genes, of presumed chromosomal location, are present In both strains and each displays a unique physical map. In both strains the two genes are in close proximity and in the same orientation. The first, which belongs to a new type of crystal protein gene, encodes a 130–140 kD protein that is not significantly active against the two insect species tested. The other new type of crystal protein gene directs the synthesis of a polypeptide preferentially active against Spodoptera littoralis.
The integral membrane protein from a virulent isolate of transmissible gastroenteritis virus: molecular characterization, sequence and expression in Escherichia coli
Authors: Britton P. , Cármenes R. S. , Page K. W. , Garwes D. J. 
Published: October 2006

SummarySubgenomic mRNA from a virulent isolate of porcine transmissible gastroenteritis virus (TGEV) was used to produce cDNA clones. Part of a new clone and a previously reported clone were sequenced and used to construct the viral gene for integral membrane protein. A single open reading frame (ORF) encoding a polypeptide of 262 amino acids, relative molecular mass (Mr) 29459, was identified. The positive identification of the polypeptide as the integral membrane protein was demonstrated by the production in E. coli of a chimaeric protein comprising most of the ORF encoding the Mr 29459 polypeptide and β‐galactosidase. The chimaeric protein reacted with a specific monoclonal antibody to viral integral membrane protein and antibodies raised against the chimaeric protein immune precipitated the viral protein. Comparison with the sequence of an avirulent isolate indicates amino acid residues that may be important in pathogenicity.
The structure of a plasmid of Chlamydia trachomatis believed to be required for growth within mammalian cells
Authors: Comanducci M. , Ricci S. , Ratti G. 
Published: October 2006

SummarySequence analysis of a 7.5 kb DNA plasmid isolated from Chlamydia trachomatis shows 8 open reading frames (ORFs) regularly spaced along most of the sequence. One of these ORFs encodes a 451‐amino‐acid polypeptide highly homologous to the DnaB protein of Escherichia coli. A region between ORFs 6 and 7 contains a cluster of alternating ATs and a 22 bp sequence tandemly repeated 4 times, suggesting a replication control region. Several ORFs correspond to plasmid‐specific polypeptides that have been described. Codons ending with A or T are more frequent, as might be expected from the high A/T content (64%) of the plasmid, and codon usage is similar to that of the C. trachomatis chromosomal gene, omp1L2.