bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of combined 16S rDNA and strb1 gene targeted PCR to identify and detect streptomycin‐producing Streptomyces
Authors: Gharaibeh Raad , Saadoun Ismail , Mahasneh Amjad
Published: July 2003

In this study, two designed primers were evaluated to identify soil Streptomyces and to detect streptomycin production by strb1 targeted PCR. Potential Streptomyces‐specific signatures were identified in their 16S rDNA sequences in regions located around nucleotide positions 576 and 995. Primer pair RI7/RI8 derived from these regions was investigated for its specificity in detecting and identifying Streptomyces isolates by PCR assays using DNA from pure cultures. The constructed primer pair showed high specificity in detecting and identifying Streptomyces type strains as well as soil isolates. Streptomycin‐producers were detected by PCR assays through the selective amplification of streptomycin biosynthetic gene (strb1). Results suggest that PCR assay facilitates the differential identification of Streptomyces‐specific antibiotic producers and a resident population of Streptomyces in Jordan with the capacity of streptomycin‐production is present.
Identification of the gene encoding the sole physiological fumarate reductase in Shewanella oneidensis MR‐1
Authors: Maier Tamara M. , Myers Judith M. , Myers Charles R.
Published: July 2003

Shewanella oneidensis MR‐1 is a Gram‐negative, nonfermentative rod with a complex electron transport system which facilitates its ability to use a variety of terminal electron acceptors, including fumarate, for anaerobic respiration. CMTn‐3, a mutant isolated by transposon (TnphoA) mutagenesis, can no longer use fumarate as an electron acceptor; it lacks fumarate reductase activity as well as a 65‐kDa soluble tetraheme flavocytochrome c. The sequence of the TnphoA‐flanking genomic DNA of CMTn‐3 did not align to those for fumarate reductase or related electron transport genes from other bacteria. Sequence analysis of the MR‐1 genomic database demonstrated that an open reading frame encoding a 65‐kDa tetraheme cytochrome c with sequence similarity to the fumarate reductase from S. frigidimarina NCIMB400 was found 8 kb away from the TnphoA‐flanking genomic DNA of CMTn‐3. PCR analysis demonstrated that a large deletion (≥9.2 kb and ≤11 kb) of genomic DNA occurred in CMTn‐3 as a result of TnphoA insertion. This deletion included at least half of the fumarate reductase gene as well as ∼8 kb of upstream DNA. Complementation of CMTn‐3 with the fumarate reductase gene plus 0.5‐kb of upstream DNA restored growth on fumarate. These studies explicitly define the sole physiological fumarate reductase gene from the several possibilities suggested by the genomic sequence of MR‐1. Surprisingly, the fumarate reductase gene plus 0.77‐kb upstream DNA from S. frigidimarina NCIMB400 did not complement CMTn‐3.
Multiplex PCR for the direct detection of Salmonella enterica from chicken, lamb and beef food products
Authors: Malkawi Hanan Issa , Gharaibeh Raad
Published: July 2003

Three sets of known Salmonella enterica‐specific primers were used collectively, for the first time, to evaluate the use of multiplex polymerase chain reaction (m‐PCR) as a diagnostic tool to detect Salmonella enterica in naturally contaminated meat and poultry products. For this purpose a total of 300 samples representing the most frequently used fresh and frozen meat (beef and lamb) and poultry (chicken) products (whole, cut, ground, and processed) were collected from eight locations within Irbid city (Jordan). After an enrichment step, DNA was extracted directly from each food sample and amplified using six Salmonella enterica specific primers. Samples were also analyzed using conventional microbiological methods for the confirmation of Salmonella enterica presence. Out of 300 samples, 93 samples were positive by m‐PCR. On the other hand, 67 samples were positive by conventional microbiological methods and only 26 samples were positive by m‐PCR alone.

The primer pairs, used here, proved to be highly specific for Salmonella enterica. Using m‐PCR, Salmonella enterica detection could be achieved easily and the results had been confirmed effortlessly within a short period of time (24–36 hours) compared to 3–8 days for the conventional microbiological methods. Our findings emphasize the value of using a combination of specific primer pairs instead of a single primer pair in the detection process to minimize any chance for any inherent experimental or natural error.
Studies on the genomic heterogeneity of Micrococcus luteus strains by macro‐restriction analysis using pulsed‐field gel electrophoresis
Authors: Murayama O. , Matsuda M. , Moore J. E.
Published: July 2003

Macro‐restriction analysis by means of double digestion using DraI and VspI demonstrated that they cleaved the genomic DNAs from Micrococcus luteus JCM1464T, JCM3347, and JCM3348 into four to five fragments in a distinguishable manner by pulsed‐field gel electrophoresis (PFGE). Separate digestion with DraI and VspI cleaved the genomic DNA from M. luteus ATCC9341 into a relatively limited number of restriction fragments (six pieces). SspI and XbaI cleaved the genomic DNA from each of the four strains into restriction fragments in a distinctly different and distinguishable manner.

Thus, PFGE profiles after digestion with these four restriction enzymes that recognize six specific base sequences demonstrated the heterogeneity at the whole genomic DNA level among the four strains of M. luteus.

The size of the genomic DNA of M. luteus ATCC9341 was estimated to be approximately 2.3 Mb by the summing the lengths of the restriction fragments generated by each three restriction enzymes (DraI, SspI, and VspI) and averaging the results.
In vitro growth response of bread‐spoilage Bacillus strains to selected natural antimicrobials
Authors: Pattison T.L. , Lindsay D. , von Holy A.
Published: July 2003

This study assessed the in vitro responses of Bacillus (B.) strains isolated from ropey bread to natural antimicrobials under optimum growth conditions. The responses of six Bacillus strains [B. subtilis (2), B. licheniformis (2) and B. pumilus (2)] to acetic acid (AA), lactic acid (LA), calcium lactate (CL) and a lactate‐containing cocktail (LCC), singly and in combinations were determined and compared to calcium propionate (CP). Isolates were each inoculated into flasks containing Nutrient Broth (NB) and the respective antimicrobial treatments and pHs were left unadjusted. A duplicate set of flasks, also containing NB and the respective antimicrobials, but adjusted to pH's corresponding to those of baked brown bread containing the same antimicrobials was also inoculated. Growth curves were obtained spectrophotometrically and used to estimate lag times. The organic acids used in this study [0.1% (v/v) AA and 0.25% (v/v) LA] singly and in combination with each other and with CL, CP or LCC, completely inhibited the growth of all six Bacillus strains, but only at non‐adjusted pHs. The efficacies of LA, AA and CL notably decreased when the pH of the test media containing the respective preservatives was adjusted to the corresponding in situ (bread) values. However, the natural antimicrobials were still as effective as CP in retarding growth of the six Bacillus strains at the in situ (bread) pH values.
A sulfate‐reducing bacterium that can detoxify U(VI) and obtain energy via nitrate reduction
Authors: Pietzsch Katja , Babel Wolfgang
Published: July 2003

Bacterial strain UFZ B 490, which was isolated from a uranium dump and is closely related to Desulfovibrio vulgaris oxamicusT (DSM 1925T), is able to detoxify U(VI) in aqueous media. In experiments reported here, U(VI) was used as an electron acceptor and lactate as electron donor. The reduction of soluble U(VI) to solid U(IV) (uraninite) did not provide energy for growth of strain UFZ B 490. However, the isolate is able to grow when supplied with nitrate as sole electron acceptor and nitrogen source, using lactate as a source of carbon and energy. In comparative studies, the strains Desulfovibrio vulgaris oxamicusT (DSM 1925T) and Desulfovibrio vulgaris vulgarisT (DSM 644T), as well as the isolate, all utilized 0.6 mol lactate per mol U(VI) reduced. Strains UFZ B 490 and Desulfovibrio vulgaris oxamicusT (DSM 1925T) were found to consume 2.4 mol lactate per mol nitrate reduced, but Desulfovibrio vulgaris vulgarisT (DSM 644T) did not display dissimilatory nitrate reduction. In further experiments it was found that strain UFZ B 490 preferred sulfate as electron acceptor in the presence of both sulfate and nitrate, irrespective of whether it had been precultivated on sulfate or nitrate.
Effect of natural and controlled fermentation on flatus‐producing compounds of beans (Phaseolus vulgaris)
Authors: Granito Marisela , Champ Martine , Guerra Marisa , Frias Juana
Published: July 2003

Fermentation of grain legumes is an efficient method to reduce the concentration of α‐galactosidic compounds that are known to be flatulence producers. Soluble dietary fibre has also been implicated in flatulence production; however, little information exists about the effectiveness of fermentation in diminishing the effects of these compounds. The objective of this work was to study the effect of natural fermentation (NF) and controlled fermentation (CF) on the content of α‐galactosides and dietary fibre in dry beans (Phaseolus vulgaris) for 24, 48, 72 and 96 h. After 48 h, the pH during NF dropped from 6.15 to 4.00 and the nominal acidity increased six times; for CF, however, although the decrease in pH was similar to that for NF, the nominal acidity increased only three times after 48 h. Insoluble fibre content did not change the pH significantly after 96 h for NF and CF. Soluble fibre suffered an apparent removal after 48 h of NF and underwent a sharp reduction of 66% after 96 h of CF. The concentration of stachyose (the main α‐galactoside in raw beans) diminished notably after 48 h and 96 h NF (72% and 95% respectively), whereas with CF only 11% was removed after 96 h. NF of P vulgaris seems to be more effective than CF in reducing the flatulence‐producer factors (α‐galactosides and soluble dietary fibre). Copyright © 2003 Society of Chemical Industry
A new method for accelerated shelf‐life prediction for frozen foods
Authors: Reid DS , Kotte K , Kilmartin P , Young M
Published: July 2003

Shelf‐life estimation for frozen foods can be a long process because of the long duration of shelf‐life at the lower temperatures of storage. A variety of rapid procedures have been proposed to suggest whether products will have acceptable shelf‐lives at low storage temperatures. These all have limitations. In this paper a new procedure is proposed which involves direct determination of shelf‐lives at the more elevated frozen storage temperatures, where change is more rapid. This is coupled with utilisation of information on the mobility temperature to establish a low‐temperature storage datum. A plot of expected shelf‐life as a function of temperature is produced using these two data sources. The effectiveness of the procedure is validated using existing literature data and newly generated data. The procedure allows for the effective estimation of the low‐temperature storage life of a product utilising data collected on the product in question. It requires around 60 days, while effectively estimating the storage temperatures required to achieve target shelf‐lives of 1 year, 18 months, 2 years or even longer. Copyright © 2003 Society of Chemical Industry
Comparative study of six pear cultivars in terms of their phenolic and vitamin C contents and antioxidant capacity
Authors: Galvis Sánchez Andrea C , Gil‐Izquierdo Angel , Gil María I
Published: July 2003

The main phenolic compounds in six pear cultivars were identified and quantified using high‐performance liquid chromatography/diode array detection (HPLC/DAD) and HPLC/electrospray ionisation mass spectrometry (HPLC/ESIMS). Major quantitative differences were found in the phenolic profiles. The peel contained higher concentrations of chlorogenic acid, flavonols and arbutin than the flesh, where only chlorogenic acid was detected. Total phenolics ranged from 1235 to 2005 mg kg−1 in the peel and from 28 to 81 mg k g−1 in the flesh. Ascorbic acid and dehydroascorbic acid were detected in the peel, whereas only dehydroascorbic acid was present in the flesh. The ranges of vitamin C content were from 116 to 228 mg kg−1 in the peel and from 28 to 53 mg kg−1 in the flesh. The antioxidant capacity was correlated with the content of chlorogenic acid (r = 0.46), while ascorbic acid made only a small contribution to the total antioxidant capacity of the fruit. Copyright © 2003 Society of Chemical Industry
Quantification of monomeric and polymeric wheat proteins and the relationship of protein fractions to wheat quality
Authors: Suchy Jerry , Lukow Odean M , Fu Bin X
Published: July 2003

Wheat protein composition is important for understanding the biochemical basis of wheat quality. The objective of this study was to design a simple protein fractionation protocol with low cross‐contamination and to show that these protein fractions were associated with wheat quality. The protocol consists of three sequential extractions from 100 mg of flour with 7.5% propan‐1‐ol and 0.3 M sodium iodide (monomeric‐rich protein), 50% propan‐1‐ol (soluble glutenin‐rich protein) and 40% propan‐1‐ol and 0.2% dithiothreitol (insoluble glutenin‐rich protein). Nitrogen content of protein solubility groups was determined from dry residues using an automated combustion nitrogen analyser. About 90% of the total protein in the flour was solubilised. Cross‐contamination of protein fractions was evaluated by SDS‐PAGE, SE‐HPLC and RP‐HPLC. Variation in nitrogen content of the protein solubility fractions was lowest for monomeric‐rich protein (<2%) and insoluble glutenin‐rich protein (<4%). Three wheats with similar high‐molecular‐weight (HMW) glutenin subunit composition, Alpha 16, Glenlea and Roblin, varied significantly (P ≤ 0.05) in the proportion of monomeric‐rich and insoluble glutenin‐rich protein in the flour. Dough rheological properties were directly related to the proportion of insoluble glutenin‐rich protein and inversely related to the proportion of monomeric‐rich protein. The protocol was validated using an expanded set of 11 wheats which also showed that inter‐cultivar differences in the proportion of monomeric‐rich, insoluble glutenin‐rich protein and glutenin‐to‐gliadin ratio in the flour governed dough rheological properties such as mixograph, farinograph and microextension tests. The protocol has merit for quality screening in wheat‐breeding programmes when the sample size is too small or when time constraints limit the ability to perform traditional rheological tests. For the Department of Agriculture and Agri‐Food, Government of Canada, Copyright © Minister of Public Works and Government Services Canada 2003. Published for SCI by John Wiley & Sons, Ltd.
Effect of drought on polyamine metabolism, yield, protein content and in vitro protein digestibility in tepary (Phaseolus acutifolius) and common (Phaseolus vulgaris) bean seeds
Authors: González de Mejía Elvira , Martínez‐Resendiz Violeta , Castaño‐Tostado Eduardo , Loarca‐Piña Guadalupe
Published: July 2003

The objective of the present study was to investigate the effect of drought on the metabolism of proline, ornithine and polyamines, and the enzymes involved in their synthesis and degradation, in tepary and common bean seeds. Furthermore, the effect on seed yield, protein content and in vitro protein digestibility was also studied. Genotypes of tepary bean (Phaseolus acutifolius) used were: PI‐301‐801 from Nicaragua; G‐400‐35 from Oaxaca, Mexico; L‐242‐24 and L‐242‐36 from Sonora, Mexico; L‐172 from Arizona, USA; and the common bean (Phaseolus vulgaris) variety Flor de Mayo Bajío (FMB) from Mexico. The cultivars were grown in a greenhouse under controlled temperature, light and humidity. Water content in plants (WCP) decreased when irrigation was stopped (1 and 2 weeks after blooming). Common bean had the lowest WCP value (73.75%), while the best genotypes were PI‐301‐801 (91.62%), G‐400‐35 (88.70%) and L‐242‐24 (85.73%). Tepary bean plants had superior water absorption capacity, which helped to increase yield. De novo synthesis of drought proteins may explain the increased protein content present under drought conditions. The results suggest that water stress induced ornithine amino transferase activity and ornithine concentration. Proline also increased under drought conditions (p < 0.05). Genotypes L‐242‐24 and G‐400‐35, which had the highest yield, also had a major concentration of polyamines under water stress. The results also suggest that arginase activity participated in amino acid synthesis such as ornithine and, consequently, in the protein concentration under water stress. Genotypes G‐400‐35 and L‐242‐24 are good alternatives for cultivation in arid zones. Copyright © 2003 Society of Chemical Industry
Bioactivity of falcarinol and the influenceof processing and storage on its content in carrots (Daucus carota L)
Authors: Hansen Susanne L , Purup Stig , Christensen Lars P
Published: July 2003

The concentration‐dependent activity of the polyacetylene falcarinol ((9Z)‐heptadeca‐1,9‐dien‐4,6‐diyn‐3‐ol), isolated from carrots, was investigated in a bioassay with primary mammary epithelial cells in collagen gels and compared with that of β‐carotene, the orange pigment in carrots. Falcarinol showed biphasic activity, having stimulatory effects between 0.01 and 0.05 µg ml−1 and inhibitory effects between 1 and 10 µg ml−1, whereas β‐carotene showed no effect in the concentration range 0.001–100 µg ml−1. The results are discussed in relation to the health‐promoting effects of carrots and related vegetables. Falcarinol was quantified in the carrot cultivars Bolero, Rodelika and Fancy by analytical reverse phase HPLC, subjected to various processing and storage conditions in order to study how long‐term storage, blanching, freezing and boiling influence the content of falcarinol. Long‐term storage of raw carrot cubes (1 cm3) reduced the falcarinol content by almost 35%. A similar reduction was found in steam‐blanched carrot cubes (1 cm3). Long‐term storage at −24 °C of steam blanched carrot cubes did not reduce the falcarinol content further. A reduction of almost 70% in the falcarinol content was found in carrot pieces boiled in water for 12 min compared with raw carrots. Copyright © 2003 Society of Chemical Industry
Gelatinolytic activities in muscle of Atlantic cod (Gadus morhua), spotted wolffish (Anarhichas minor) and Atlantic salmon (Salmo salar)
Authors: Lødemel Jørgen B , Olsen Ragnar L
Published: July 2003

The gelatinolytic activity in muscle from Atlantic cod (Gadus morhua), spotted wolffish (Anarhichas minor) and Atlantic salmon (Salmo salar) was studied using gelatin SDS‐PAGE, gelatin affinity chromatography and enzyme inhibitors. These fish species are known to differ markedly in fillet softening and gapingpost mortem. Atlantic cod, which is a promising species for cold water marine aquaculture, often shows such negative properties, particularly after being well fed. Gelatinolytic activity bands were present in all three species. Using gelatin chromatography and enzyme inhibitors, both serine proteinases and metalloproteinases were detected in wolffish and cod muscle, while only the latter were found in salmon muscle. Activation of the metalloproteinases byp‐aminophenylmercuric acetate (APMA) resulted in a shift in activity from higher to lower molecular weight, as is known for mammalian matrix metalloproteinases. In all three species the molecular weight of the metalloproteinases was lowered from approximately 80 to about 70 kDa by activating with APMA. Copyright © 2003 Society of Chemical Industry
Solid phase microextraction (SPME) applied to honey quality control
Authors: Piasenzotto Lara , Gracco Luisa , Conte Lanfranco
Published: July 2003

The assessment of the botanical origin of unifloral honeys is an important application in food control. The current official methods mainly use pollen analysis. The aim of this paper is to present an SPME analytical approach to the study of honey volatiles. Honey samples (40) obtained from hive sites in different regions of Italy were analysed. The samples had six different botanical origins: citrus (five), chestnut (10), eucalyptus (eight), lime tree (11), thyme (two) and dandelion (four). Melissopalynological analysis was also performed. Identification of volatile compounds was carried out by SPME/GC/MS analysis, and quantitative evaluation was done by SPME/GC/FID analysis for compounds with well‐resolved peaks. Using the SPME method, all samples with the same botanical origin gave remarkably similar GC profiles. Some volatile compounds were found only in specific floral source honey samples and thus could be interesting for use as markers. Copyright © 2003 Society of Chemical Industry
Interactions between polypeptides derived from barley and other beer components in model foam systems
Authors: Bamforth CW , Kanauchi M
Published: July 2003

The impact of a range of variables on the foaming properties of hordein‐ and albumin‐derived fractions from barley has been investigated. When foamed using nitrogen, the hordein‐derived polypeptides produce the most stable foams. However, when carbon dioxide was the foaming agent, the previously reported observations were repeated, namely that proteolysis weakens the foaming capabilities of albumin, whereas partial hydrolysis enhances the stability of foams derived from hordein. At lower levels of bitterness (iso‐α‐acid) addition there is a reduction in foam stability of albumin‐derived polypeptides, although hordein‐derived polypeptides can withstand this destabilising effect. Higher bitterness levels in both instances lead to a stabilisation of foam. It is likely that this involves ionic interactions between the acid anion (pKof iso‐α‐acids is ca 3.1) and divalent cations, because higher pHs (in the range 3.8–4.6) and the addition of zinc lead to an enhancement of foam stability, particularly of the albumin‐derived fractions. The foaming of the latter, however, is significantly impaired by the presence of ethanol, whereas hordein‐based foams are enhanced by increasing concentrations of ethanol. Copyright © 2003 Society of Chemical Industry
Enhanced coloration reveals high antioxidant potential in new sweetpotato cultivars
Authors: Philpott Martin , Gould Kevin S , Markham Kenneth R , Lewthwaite Steve L , Ferguson Lynnette R
Published: July 2003

Sweetpotato is one of the world's most important food crops, particularly in developing countries. The storage roots have high carbohydrate and vitamin A contents and possess strong antioxidant potential, previously attributed to their hydroxycinnamic acid content. We report on several new purple sweetpotatoes developed for their high anthocyanin content. Although the antioxidant activity of purple sweetpotato extracts was greater than that of sweetpotato lacking anthocyanins, anthocyanins alone could not account for all the activity. Extract components were separated by 2D paper chromatography, and their relative contributions to antioxidant activity were determined. The antioxidant activity of the extracts from sweetpotato was shown to be due to both anthocyanins and hydroxycinnamic acids, additively. Neither the anthocyanin content nor the antioxidant activity of sweetpotato flesh was affected by common cooking methods. These findings may be important in the light of the health‐protective properties attributed to both antioxidants and anthocyanins. Copyright © 2003 Society of Chemical Industry
Rheological/textural properties of starch and crude hsian‐tsao leaf gum mixed systems
Authors: Lai Lih‐Shiuh , Liu Ying‐Ling , Lin Pei‐Hsuan
Published: July 2003

The Effects of hsian‐tsao leaf gum (HG) on the rheological/textural properties of non‐waxy starches were studied. Pronounced interactions between starch and HG were observed. The rheological properties, including pseudo‐gel viscosity in the rapid visco‐analyser test, storage and loss moduli in the dynamic rheological test, as well as firmness in the texture analyser test, of the mixed gels generally improved with increasing gum concentration to a certain level, then deteriorated with further increase in gum concentration. The critical gum concentration for the development of optimal rheological properties depended on the starch type and concentration. Within the concentration range studied, mixed systems with wheat starch could generally reach the highest pseudo‐gel viscosity, firmness, and storage modulus if the starch/HG ratio was appropriate, followed by those with corn and tapioca starch. Copyright © 2003 Society of Chemical Industry
Effects of moist heat treatment on ruminal nutrient degradability of sunflower seed
Authors: Mustafa Arif F , Chouinard Yvan P , Ouellet Daniel R , Soita Henry
Published: July 2003

A study was conducted to determine the effects of moist heat treatment (autoclaving at 127 °C with a steam pressure of 117 kPa for 10, 20 and 30 min) of sunflower seed on crude protein (CP) fractions, ruminal dry matter (DM) and CP degradabilities, and ruminal disappearance of amino and fatty acids. Two ruminally fistulated cows were used in a randomised complete block design. Heating of sunflower seed decreased soluble protein and increased neutral detergent‐insoluble protein, with little effect on acid detergent‐insoluble protein. Results of the in sacco study showed that moist heat treatment decreased (cubic effect, P < 0.05) ruminal degradability of DM and CP of sunflower seed. Ruminal undegraded CP of raw sunflower seed was low (84 g kg−1 of CP) and increased (cubic effect, P < 0.05) by 139, 143 and 164% as the heating time increased from 0 to 10, 20 and 30 min respectively. Ruminal disappearance of all amino acids (following 12 h of incubation) was greater (P < 0.05) for raw than for heated sunflower seed. Similar results were also observed for ruminal disappearance of fatty acids. It was concluded that moist heat treatment decreased ruminal DM and CP degradability of sunflower seed (by 17 and 19% respectively) and thus increased the concentrations of amino acids and polyunsaturated fatty acids available for digestion in the small intestine. Copyright © 2003 Society of Chemical Industry
The effect of edible coatings and polymeric packaging films on the quality of minimally processed carrots
Authors: Emmambux Naushad M , Minnaar Amanda
Published: July 2003

Minimally processed carrots have a short shelf‐life because of white blush formation (caused primarily by surface dehydration) and microbiological spoilage (caused mostly by lactic acid bacteria). The use of polymeric packaging films combined with edible coatings might have an additive or synergistic effect to extend the shelf‐life of minimally processed carrots because of the formation of a double barrier to gases and water vapour. A 3 × 3 factorial experiment using a polymeric packaging film of three different levels of permeability and a cellulose‐based edible coating (Nature Seal®) at different concentrations was conducted on minimally processed carrots to investigate any possible synergistic effect over 12 days of storage at 10 °C. No such effect was found. The polymeric packaging film effectively prevented microbiological growth and spoilage but was unable to control white blush formation. On the other hand, the edible coating partially controlled white blush formation but enhanced microbiological spoilage. The polymeric packaging film functioned primarily as a gas barrier, whereas the edible coating probably functioned as a moisture barrier. White blush formation was found to be the most important shelf‐life determinant for minimally processed carrots. Copyright © 2003 Society of Chemical Industry
Fatty acids, sterols and other steroids from seeds of Patagonian Prosopis species
Authors: Mazzuca Marcia , Balzaretti Vilma T
Published: July 2003

Seeds of Prosopis alpataco, P denudans var denudans, P denudans var patagonica and P denudans var stenocarpa were analysed for fatty acids and sterols. The seed lipids contained a relatively large proportion of unsaturated fatty acids, with linoleic and oleic acids being predominant. β‐Sitosterol was the major steroid in all species studied. In P alpataco seeds, stigmasta‐1,3,5‐triene and stigmasta‐4,6‐dien‐3‐one were also identified. Copyright © 2003 Society of Chemical Industry
Oral copper loading test in humans
Authors: Rahmaniyan Mojgan , Johnston Kelley E. , Tamura Tsunenobu
Published: July 2003

There has been no report of normal responses of plasma copper and/or ceruloplasmin concentrations after an oral loading dose of unlabeled copper in humans. To establish a normal plasma response curve following an oral dose, we performed a copper‐loading test (10 mg elemental copper as copper sulfate) in six healthy adult subjects and monitored plasma copper and ceruloplasmin concentrations for 3.5 h. We found that there were no significant changes in plasma copper and ceruloplasmin concentrations following the oral dose in the subjects. The test was originally intended to evaluate whether there was copper malabsorption in a female patient who developed signs of copper deficiency with her plasma copper levels below 3.0 μmol/l after multiple gastrointestinal surgeries. She did not respond to oral copper sulfate administration but responded to a sublingual application of copper glycinate. These findings suggest that she does not have adequate intestinal copper absorption. In conclusion, the use of unlabeled copper, such as copper sulfate, for an oral loading test, seemingly simple and economical, does not appear to be a suitable means to evaluate copper absorption in humans and is discouraged. In case of copper malabsorption, sublingual administration of copper may be worth trying. J. Trace Elem. Exp. Med. 16: 61–66, 2003. © 2003 Wiley‐Liss, Inc.
Changes of zinc, copper, and iron levels in the lung of male rats after subacute (4‐week) and subchronic (13‐week) exposure to formaldehyde
Authors: Özen Og̊uz Aslan , Songur Ahmet , Sarsılmaz Mustafa , Yaman Mehmet , Kuş İlter
Published: July 2003

The medical use of formaldehyde has focused especially on laboratory use. Harmful effects of formaldehyde inhalation, such as nasal squamous cell carcinoma, are quite well documented. However, detailed studies of the mechanisms of the damaging effects of formaldehyde on lung tissue are quite limited. Amounts of such elements as zinc, copper, and iron within lung tissue indicate whether or not they function physiologically. In this study, 36 adult albino Wistar male rats (6 animals per group) were exposed to 0 (Control), 5, and 10 ppm (1 ppm ≊ 1.2 mg/m3) of formaldehyde gas for subacute (4‐week) and subchronic (13‐week) periods. Whole‐body exposure was continuously carried out for 8 h/day, 5 days/week. Body weights were recorded weekly. Levels of metals mentioned above were measured in lung tissue by atomic absorption spectrometry using wet ashing and were then compared with levels in the control groups. At the end of the study, a gradual decrease in weight gain, a decrease in zinc levels, and an increase in iron levels were observed in both subacute and subchronic groups compared to control groups. Statistically significant increases in tissue Fe levels were seen in the 10 ppm subacute (P < 0.001), 5 ppm subchronic (P < 0.001), and 10 ppm subchronic (P < 0.001) groups. We conclude that subacute or subchronic exposure to cytotoxic concentrations of formaldehyde may cause growth retardation and alter the trace element levels of zinc and iron in the lung tissue. J. Trace Elem. Exp. Med. 16:67–74, 2003. © 2003 Wiley‐Liss, Inc.
Effects of three divalent cations: manganese, zinc, and magnesium on arterial blood pressures in guinea pigs
Authors: Onat Nursen , Süzer Öner
Published: July 2003

Our aim was to compare the effects of the divalent cations, namely magnesium, zinc, and manganese on the arterial blood pressures and heart rate of guinea pigs. Eighteen guinea pigs weighing 500–700 g were divided into three groups (six in each group), and three divalent cations as sulfate salt (MgSO4, ZnSO4, MnSO4) were administered to all animals after 20‐min period of stabilization and at three escalating concentrations (10−6, 10−5, 10−4 mol/kg intravenously, respectively) in 25‐min intervals. Each animal received only one kind of cation. Arterial pressures and heart rate were measured and their derivatives were calculated (dp/dt). Our study showed that divalent cations lowered the arterial blood pressures. No significant differences were between groups for systolic, diastolic, and mean pressures, except that 10−4 mol/kg ZnSO4 was lethal. The heart rates values of ZnSO4 (202 ± 9) was significantly (P < 0.05) lower after 10−6 mol/kg than MgSO4 (230 ± 7). Three divalent cations caused to decrease on arterial pressures. Zn2+ caused cardiac arrest in the highest dose. Intravenous administration of Mn2+ and Mg2+ seems to have similar effects on arterial blood pressures and heart rate. Further work is needed to relate effects on Mn2+ for their possible use in the emergency department. J. Trace Elem. Exp. Med. 16:75–85, 2003. © 2003 Wiley‐Liss, Inc.
Effects of vitamin E and selenium on thyroid status, adrenocorticotropin hormone, and blood serum metabolite and mineral concentrations of Japanese quails reared under heat stress (34°C)
Authors: Ferit Gursu M. , Sahin N. , Kucuk O.
Published: July 2003

This study was conducted to determine the effects of vitamin E and selenium (Se) on triiodothyronine (T3), thyroxine (T4), thyroid stimulating hormone (TSH), adrenocorticotropin hormone (ACTH), and serum glucose, urea, triglyceride, cholesterol, Ca, P, Na, and K concentrations of Japanese quails reared under heat stress (34°C). One‐hundred twenty 10‐day‐old Japanese quails were randomly assigned to four treatment groups with three replicates of 10 birds each. The birds with a 2 × 2 factorial design received either two levels of vitamin E (125 and 250 mg/kg of diet) or two levels of selenium (0.1 and 0.2 mg/kg of diet). Greater dietary vitamin E and selenium inclusions resulted in a greater (P = 0.001) serum T3, T4, and TSH, but lower (P = 0.001) ACTH concentrations. No interactions between vitamin E and selenium were detected (P ≥ 0.11) for serum concentrations of T3, T4, TSH, and ACTH. Serum glucose, urea, triglyceride, and cholesterol concentrations decreased (P = 0.001), whereas protein concentrations increased (P = 0.001) when both dietary vitamin E and selenium increased. Serum albumin concentrations increased (P = 0.001) with greater dietary vitamin E but did not change with dietary selenium (P = 0.16). No interactions on any blood metabolites were detected (P ≥ 0.11). Serum activities of serum glutamic oxalate transaminase and serum glutamic pyruvate transaminase were not influenced by dietary vitamin E or selenium (P ≥ 0.42). However, serum activity of alkaline phosphatase increased (P = 0.001) with both increasing dietary vitamin E and selenium. There were no interactions detected for the serum enzyme activities (P ≥ 0.09). Increasing both dietary vitamin E and selenium caused an increase in serum concentrations of Ca, P, and K (P = 0.001), but a decrease in serum concentrations of Na (P = 0.001). No interactions were detected for serum mineral concentrations (P ≥ 0.07) except for P (P = 0.001). Results of the present study showed that dietary vitamin E and selenium have synergistic effects, and that supplementing a combination of dietary vitamin E (250 mg) and selenium (0.2 mg) positively influences some blood parameters that may positively influence the performance of Japanese quails under heat stress. J. Trace Elem. Exp. Med. 16:95–104, 2003. © 2003 Wiley‐Liss, Inc.
Association between oxidative stress and selenium levels in patients with breast cancer at different clinical stages
Authors: Sancak Banu , Ünal Adem , Candan Sakine , Coşkun Uḡur , Günel Nazan
Published: July 2003

Oxidative stress has been suggested to play a role in some physiological conditions and in many disease processes, including carcinogenesis. The aim of the study was to investigate the association between the oxidative stress and selenium levels in the erythrocytes of breast cancer patients at different clinical stages. The extent of lipid peroxidation was assessed by measuring thiobarbituric acid reactive substances (TBARS), called malondialdehyde (MDA), in erythrocytes. Glutathione peroxidase activity (GPx) in erythrocyte and serum selenium levels were determined in patients and controls. Thirty‐three female breast cancer patients at different clinical stages were divided into four groups. Ten control subjects were also included in this study. Atomic absorption, spectrophotometry, and colorimetric methods were used to obtain serum selenium and erythrocyte MDA levels, respectively. GPx activities were assessed with kinetic method described by Paglia and Valentine (J Lab Clin Med 1967; 70(1):158–169). All cancer patients (groups A, B, and C) showed significant increases in erythrocyte GPx activities compared with those in control subjects (P < 0.05). No significant differences were found among the cancer patients at different clinical stages (P > 0.05). Although plasma selenium levels did not change among the groups A, B, and C, it was demonstrated that breast cancer patients have lower serum selenium levels than healthy controls (P < 0.05). Significantly increased lipid peroxidation, measured as erythrocyte MDA, was demonstrated in patients with breast cancer compared to the control group (P < 0.05). There were no differences between group A and group B in terms of MDA levels (P > 0.05). Erythrocyte MDA levels were significantly lower (P < 0.05) in breast cancer patients who had had surgery within 1 month (group A) when compared with those levels in breast cancer patients who had just been diagnosed and had not had any surgery yet (group C). Although clinical stage in breast cancer does not have any effect on serum selenium levels or erythrocyte GPx activity, erythrocyte MDA levels changed among the patients at different clinical stages. Increased MDA levels in untreated patients show us increased oxidative stress. If we removed malignant breast tissue by surgery and gave adjuvant therapy, lipid peroxidation product MDA levels in erythrocyte would decrease. Increased GPx enzyme activity in erythrocytes may be a result of a protective mechanism that develops in breast cancer patients against free radical damage. Although an inverse correlation between the serum selenium levels and erythrocyte GPx activity in patients with breast cancer is suggested, there is no correlation at different clinical stages of patients. J Trace Elem. Exp. Med. 16:87–94, 2003. © 2003 Wiley‐Liss, Inc.
Copper retention in intestinal mucosal cells of young men at normal and high copper intakes
Authors: Turnlund Judith R. , Domek Joseph M. , Nair Padmanabhan P. , Bhathena Sam J.
Published: July 2003

The role of intestinal cells in copper homeostasis and storage has not been studied. Homeostasis is regulated by absorption, excretion, and storage. Copper is excreted via the bile, and it has been assumed that the increased excretion into the gastrointestinal tract when diets are high in copper was due to biliary copper. It seemed possible that some of the absorbed copper is sequestered in the intestinal cells. To test this hypothesis we measured the copper content of mucosal epithelial cells isolated from stool samples of 8 young men when consuming their usual diets and after 129 days of supplementation with 7 mg/day copper. The mean copper content of the cells, expressed as mg copper per gram of cell protein, was 0.78 versus 1.65 mg/g (SEM 0.19) (P < 0.02) when the usual and copper‐supplemented diets, respectively, were consumed. In contrast to the copper content of plasma and urine, copper in intestinal cells increased significantly when intake was high. It is likely that copper was sequestered by these cells following absorption and did not get into systemic circulation. Thus, the amount of endogenous copper in stools is probably a combination of biliary copper excretion and copper sequestered in exfoliated intestinal epithelial cells. This suggests that retention of copper by the intestinal cells increases when dietary copper is high and plays a role in copper homeostasis. J. Trace Elem. Exp. Med. 16:105–108, 2003. Published 2003 Wiley–Liss, Inc.
The use of electrochemical techniques for the investigation and monitoring of microbiologically influenced corrosion and its inhibition – a review
Authors: Mansfeld F.
Published: July 2003

The background of several electrochemical techniques – recording of the corrosion potential Ecorr, electrochemical impedance spectroscopy (EIS), electrochemical noise analysis (ENA) and recording of potentiodynamic polarization curves – has been discussed and examples of the use of these techniques in studies of microbiologically influenced corrosion (MIC) and MIC inhibition have been presented. These examples range from the use of the polarization resistance Rp and the noise resistance Rn in corrosion monitoring in a sewer environment and a gas production field, respectively, to the application of EIS and ENA in the evaluation of the interaction of bacteria with protective coatings on steel exposed to natural seawater (NS). A more detailed analysis based on EIS and ENA of Corrosion protection of Al 2024, mild steel and brass in artificial seawater (AS) by bacteria such as B. subtilis, B. licheniformis, E. coli and Shewanella has been presented. Determination of the changes of Rp and Rn as well as Ecorr allows to propose appropriate mechanisms of MIC inhibition. These mechanisms have been confirmed in the case of S. algae by recording of anodic and cathodic potentiodynamic polarization curves after exposure to AS containing the bacteria for extended time periods.
Microbiologically influenced corrosion of stainless steels – What is required for pitting?
Authors: Hakkarainen T. J.
Published: July 2003

Pitting of stainless steels in environments normally regarded as completely harmless is often attributed to microbial activity. In this paper, attention is drawn on one hand to the basic requirements for pitting of stainless steels to be possible, and on the other hand to various ways how microbial activity could contribute to a fulfilment of these requirements. For pit growth to be possible, three basic requirements must be fulfilled: 1) the environment must contain anions that can form an aggressive solution into the pit, 2) there must be a potential difference between the interior of the pit and the open surface outside the pit, 3) the temperature must exceed a critical value. The main factors that normally influence the possibility of pitting are the chloride content and the oxidising power of the environment, presence of anions other than chloride, temperature, possible presence of deposits on the steel surface, and the composition of the steel. Anions other than chloride in the bulk solution, including sulphate, usually have an inhibiting effect. Thiosulphate, however, is known to promote pitting under certain conditions. The possible ways of microbial activity to enhance pitting could include deposit formation leading to crevice type of attack, local modification of the composition of the environment to a more concentrated one, raising the electrode potential of the steel surface (“ennoblement”), or formation of reaction products that permit active dissolution inside a pit at lower potentials. Special attention is drawn to the possible action of thiosulphate by enhancing the anodic reaction at low potentials of the dissolving surface inside the pits.
Advanced studies on the influence of manganese on the potential increase of stainless steels
Authors: Kreikenbohm R. , Eisenbeis M. , Gümpel P. , Linhardt P.
Published: July 2003

The influence of manganese on the time course and on the final value of the open‐circuit potential of microbially influenced stainless steel (SS) has been examined by variation of the concentration of manganese in the aqueous phase and on the surface of the metal sample. Under the influence of bacteria stable final values of the open‐circuit potential are attained at 540 mV or 620 mV depending on the manganese concentration in the aqueous phase, the duration of the experiment, and the supply of oxygen. These potential values can also be fixed electrochemically by anodic deposition of MnO2on the metal surface.

According to the results obtained with different techniques, the electron flow from the metal towards the oxygen is a combination of biotic and abiotic processes. Besides the microbial oxidation of manganese the electron flow via a Mn‐based redox enzyme system has to be discussed.
Effects of Leptothrix discophora on the potential behavior of stainless steel
Authors: Carpén L. , Raaska L. , Kujanpää K. , Hakkarainen T.
Published: July 2003

Biofilm formation and electrochemical behavior of stainless steel have been studied in well water, in tap water and in water taken from fire extinguishing system. Some of the waters have been modified by adding manganese ions as well as in some cases acetate and yeast extract as a nutrient. Manganese oxidizing bacteria Leptothrix discophora has been used in these studies. To eliminate crevices in the specimen holder and to simulate reasonably well the conditions in fire‐extinguishing systems where the water is stagnant most of the time, a tape test arrangement with very slow flowing rate has been used in most of these studies. Also specimens with heat tint areas produced by heating inductively a small section of the specimen under flowing argon shielding gas were used in these studies. The results of these tape tests show that manganese oxidizing bacteria are able to increase the potential of both the base material (stainless steel UNS S30400) and of specimens with heat tint areas in well water, in tap water and in water taken from fire extinguishing system. Manganese oxidizing bacteria are also able to increase the cathodic reaction and thus enhance the initiation of corrosion. However, the increase of potential is not alone enough to start the corrosion. In these tests corrosion was initiated only in the specimens with heat tint areas in one of the waters taken from fire extinguishing system. No corrosion was detected in the specimens exposed to the well water or to the tap water used in these tests.
Biofouling control in industrial water systems: What we know and what we need to know
Authors: Cloete T. E.
Published: July 2003

Biofouling contributes substantially to economic losses in industry. Although much progress has been made in understanding biofouling and its implications in industrial water systems, many questions remain unanswered.

The cost of biofouling has not been enumerated. A prerequisite for this is research to elucidate the contribution that microbiologically influenced corrosion makes, to the overall corrosion process. Surface characteristics play a major role in the initial stages of microbial attachment. Ways of preventing preferential attachment to certain areas, i.e. grain boundaries and welds need further investigation. Biocides are routinely used to control biofouling. Due to the problem of resistance and potential environmental impact, alternative strategies for biofouling control need to be investigated and put to practice. These should focus on an integrated approach with the minimum impact on the environment. A number of biofouling monitoring devices have been developed. The advantages of biofouling monitoring needs to be demonstrated and monitors should become commercially available.