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1.
We report the DNA sequence of a 17 933 bp fragment from the left arm of chromosome XIV of Saccharomyces cerevisiae. Analysis of the sequence reveals the presence of ten open reading frames (ORFs) larger than 100 codons. Four of these were previously identified as genes RHO2, TOP2, MKT1 and END3. Additionally, the NH2 end coding region of PMS1 is found in the 3′ end of the sequence. No significant homology to any known protein has been found for the other five ORFs. The nucleotide sequence has been deposited at EMBL, with Accession Number X89016.  相似文献   

2.
BACKGROUND: Traditional kombucha tea (TKT) is produced by mixed tea fungus. We previously proposed Gluconacetobacter sp. A4 as the key functional strain in kombucha culture, because it had strong ability to produce D ‐saccharic acid‐1,4‐lactone (DSL, a crucial functional component in KT). This study investigated the hypocholesterolaemic and antioxidant activities of TKT and modified KT (MKT, tea broth fermented by single Gluconacetobacter sp. A4). RESULTS: In vitro, TKT and MKT, but not DSL equally increased the radical scavenging effects and inhibited low density lipoprotein (LDL) oxidation. In vivo, the total cholesterol and LDL‐cholesterol (LDL‐C) lowering effects were not different between MKT and TKT. Compared with TKT, MKT showed a significantly elevated effect on the increase of antioxidantive enzymes activities (total antioxidant capacity and superoxide dismutase) and the decrease of malondialdehyde. Meanwhile DSL demonstrated an enhanced activity in lipid profile and antioxidant activities. CONCLUSION: KT had the hypocholesterolaemic and antioxidant effects. These effects were largely attributed to DSL. MKT was similar to or even more powerful than TKT in antioxidant and hypocholesterolaemic effects. Thus, Gluconacetobacter sp. A4 was further established as the main functional microorganism in kombucha culture. Moreover, KT may be useful in treating obesity. Copyright © 2008 Society of Chemical Industry  相似文献   

3.
There are only a few reports of successful crosses between cultivated peanut (Arachis hypogaea L., section Arachis) and wild species from sections other than section Arachis. Many of the wild Arachis species harbor important traits necessary for the improvement of peanut. For example, Arachis kretschmeri Krapov., W.C. Gregory & C.E. Simpson (section Procumbentes) can grow under water-logged conditions and has been identified as one of the few wild species of Arachis with resistance to late leaf spot (LLS) and peanut rosette disease. Peanut rosette, caused by a combination of viruses, is an economically important disease only in Africa, while LLS, caused by Cercosporidium personatum, is an important fungal disease in Asia and the Americas as well as Africa. Interspecific hybrids between A. hypogaea and A. kretschmeri were produced by applying growth regulators to pollinated pistils and hybrid plants were obtained by germinating embryos in vitro. A total of seven hybrids were produced and confirmed by Simple Sequence Repeat (SSR) analysis. All hybrids were fertile, although initially slow growing. F1 hybrids were backcrossed to A. hypogaea and all plants in the F1BC1 generation were single-seeded with a prominent beak, characteristic of A. kretschmeri, but many of the F1BC2 pods were double-seeded resembling A. hypogaea. F1BC2 plants were moderately resistant to LLS. When a large number of seeds are obtained, the progeny will be screened for resistance to both LLS and rosette disease. Thus crosses with species outside the section Arachis may not only confer disease resistance but will also broaden the genetic base of cultivated peanut.  相似文献   

4.
This article proposes an approach to determine the level of Pseudomonas spp. in milk, based on the evaluation of the content of oxygen and carbon dioxide produced in the headspace of sealed vials; the research was divided into two phases: model building and preliminary validation. Three different strains of Pseudomonas spp., Ps. putida (wild strain) and Ps. fluorescens (wild and collection isolates), were used as targets. Data of CO2 and O2 were modelled through a modified positive (CO2) or a negative Gompertz equation (O2) to estimate the Minimum Detection Time (MDT), defined as the time to attain 3% of CO2 (MDT1) or a decrease in the content of O2 by 3% (MDT2). Then, MDT1 and MDT2 were submitted to a linear regression procedure, using cell concentration as independent variable; the correlations ‘MDT1/cell concentration’ and ‘MDT2/cell concentration’ showed high determination coefficients (>0.983). Moreover, the regression procedure pointed out that both MDT1 and MDT2 decreased by ca. 3 h for an increase in cell count of 1 log cfu mL?1. Preliminary validation in milk pointed out that the error associated with the regression line ‘MDT2/cell concentration’ was below 5%.  相似文献   

5.
Aflatoxin B1 has been considered as the most potent liver carcinogen for humans. One factor that stimulates the production of aflatoxins in oilseed products, such as sesame seeds and their products is the presence of high levels of fatty acids. This work presents further evidence that sesame is a favorable substrate for aflatoxin B1 production by Aspergillus parasiticus. Moreover, the use of wild artichoke (Cynara cardunculus L.) extract was examined showing inhibition of aflatoxin B1 production in both sesame and yeast extract sucrose medium, inoculated with A. parasiticus. More specifically, the inhibition of aflatoxin B1 production by A. parasiticus in sesame seeds paste was 99.6% and in yeast extract sucrose medium it was 99.4%.  相似文献   

6.
Quality changes of onions (Allium cepa L.) during storage. Part 1. Nutritional Quality Changes in the constituents of one-year old onion bulbs, occurring under outdoor-ventilated (NL) and machine-cooled (KL) conditions over 7 and 8 months of storage (x), have been described averaging 4 to 7 test series. Due to nutrient concentration by weight losses, the content of dry matter showed no changes. The amount of disaccharides including certain oligosaccharides decreased decisively, i.e. by 0.266 and 0.337 g/100 g fresh matter resp. per month of storage. In case of NL, however, the reduction became degressive by the end of storage according to the function y = α0 ? β1x + β2x5. Monosaccharides increased significantly by 19 and 38% resp. till April or May with subsequent slight recession (function y = α0 + β1x ? β2x5). Thus, total saccharides diminished moderately, i.e. linearly in case of NL and progressively growing with KL (y = α0 ? β1x2). The vitamin C total rose linearly and irrespectively of the storage temperature, by about 0.5 mg/100 g fresh matter per month of storage. Detailled consideration is given to physiological effects.  相似文献   

7.
Amylo-maize was crossfertilized with waxy-maize, and bred F1- and F2-seeds were investigated based on phenotype in genetics and on physical and chemical properties of starch. It was elucidated that F1-seeds became normal-type, but F2-seeds were assorted into 4 types, that were normal, amylo, waxy and a novel one. Analysis of all kernels of F2 showed the ratios of the above 4 types to be 9:3:3:1. From the results, the genotypes of endosperm concerned with starch formation were deduced as (Ae - -, Wx - -), (ae ae ae, Wx - -), (Ae - -, wx wx wx), (ae ae ae, wx wx wx) respectively. The novel type was named “amylo-waxy” from its properties that the prepared starch was composed of amylopectin only as waxy, but its iodine stained color reaction was as blue as in amylose.  相似文献   

8.
Polyphenol oxidase (PPO) was extracted from Emir grapes grown in Turkey and its characteristics in terms of pH and temperature optima, thermal inactivation, kinetic parameters and potency of some PPO inhibitors were studied. The optimum pH and temperature for grape PPO were found to be 4.2 and 25 °C respectively using catechol as substrate. Km and Vmax values were found to be 25.1 ± 2.72 mmol L−1 and 0.925 ± 0.04 OD410 min−1 respectively. Of the inhibitors tested, the most potent was sodium metabisulfite, followed by ascorbic acid. The thermal inactivation curve was biphasic. Activation energy (Ea) and Z values were calculated as 251.4 kJ mol−1 (r2 = 0.996) and 8.92 °C (r2 = 0.993) respectively. Copyright © 2006 Society of Chemical Industry  相似文献   

9.
Although a 2S globulin class has been observed in salt extracts from seeds of several lupin species, there have been conflicting reports regarding the importance of this class in Lupinus angustifolius. Conglutin δ, a major sulphur-rich protein extracted from mature seeds of L. angustifolius cv. Uniwhite, was separated by gel-filtration into two oligomeric forms. The sedimentation coefficients of conglutin δ1 (20%) and conglutin δ2 (80%), were 3.2S and 2.0S respectively. The amino acid compositions of both oligomeric forms of conglutin δ were identical and similar to the compositions published for the 2S globulins in other lupin species. Because of the low level of tyrosine and the absence of tryptophan, conglutins δ1 and δ2 showed little absorbance at 280nm (E1%/1 cm?23). They were characterised by unusually high levels of glutamic acid and 1/2 cysteine (38.5 and 8.5 residues percent respectively) while methionine was absent. Gradient SDS-PAGE showed that conglutins δ1 and δ2 were homogeneous single-subunit species. On reduction, with or without S-carboxymethylation, both the conglutin δ1 and δ2 subunits yielded similar pairs of large and small polypeptide chains. Since conglutin δ rarely resolves from conglutin a during electrophoresis on cellulose acetate membranes in phosphate buffer at neutral pH, this method is not as useful for screening lupin cultivars as has been claimed previously.  相似文献   

10.
The principal aim of this study was to estimate the formation of fumonisins (FB1 and FB2), moniliformin (MON), and ergosterol (ERG) by Fusarium oxysporum and Fusarium proliferatum, while the formation of beauvericin (BEA) was estimated by the latter Fusarium species only. Moreover, the effect of temperature on the biosynthesis of mycotoxins was also evaluated. Fumonisins were formed by F. proliferatum, with the highest yield at 18°C (720.0–1976.6 µg g?1 for FB1, 74.2–670.8 µg g?1 for FB2) and only by three of four F. oxysporum strains at a very low level (0.02–4.77 µg g?1 for FB1, 0.02–2.15 µg g?1 for FB2). The amount of MON formed by F. proliferatum was the highest (p < 0.001) at 32°C (3056.87 µg g?1), while MON biosynthesis by F. oxysporum was lower 227.54 µg g?1 (p < 0.001). BEA was produced by F. proliferatum with the highest level at 25°C (p < 0.001). ERG–recognized as an indicator of fungal biomass development and as a consequence of mycotoxin formation–was found at the highest concentration at a biosynthesis temperature of 25°C for F. proliferatum and F. oxysporum (p < 0.001).  相似文献   

11.
Polyphenol oxidase (PPO) was extracted from Sultaniye grapes grown in Turkey, and its characteristics in terms of pH and temperature optima, thermal inactivation, kinetic parameters and potency of some PPO inhibitors were studied. Optimum pH and temperature for grape PPO were found to be 3.4 and 30 °C, using catechol as substrate. Km and Vmax values were found to be 44.5 ± 5.47 mm and 0.695 ± 0.0353 OD410 min?1, respectively. Four inhibitors were tested in this study and the most potent inhibitor was sodium metabisulphite, followed by ascorbic acid. From the thermal inactivation studies in the range of 65–80 °C, the half‐life values of the enzyme ranged between 2.6 and 49.5 min. Activation energy (Ea) and Z values were calculated to be 208.5 kJ mol?1 (r2 = 0.9544) and 10.95 °C (r2 = 0.9517), respectively.  相似文献   

12.
In this study, antioxidant activities of aqueous and ethanolic extracts of Brassica oleracea L. var. italica were investigated. The antioxidant properties of both extracts of Brassica oleracea L. var. italica were evaluated using different antioxidant tests, including 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, superoxide radical scavenging, inhibition of microsomal lipid peroxidation, reduction of power, and metal ion chelating activities. Inhibition of superoxide scavenging by aqueous and ethanolic extracts showed an IC50 of 0.93 and 0.25 mg/ml, respectively. Metal ion chelation showed an IC50 of 0.35 mg/ml of both the extracts and was equipotent to positive control, ethylenediamine tetra-acetic acid. The ethanolic extract of Brassica oleracea L. var. italica exhibited higher antioxidant activity in DPPH radical and superoxide anion scavenging than that of aqueous extract. The results obtained in the in vitro models clearly suggest that, Brassica oleracea L. var. italica is a natural source for antioxidants, which could serve as a nutraceutical with potential applications in reducing the level of oxidative stress and related health benefits. However, comprehensive studies need to be conducted to ascertain the in vivo safety of such extracts in experimental animal models.  相似文献   

13.
The equations theoretically obtained in Part 3 fit well the kinetics of chymotrypsin and protosubtilin hydrolysis of partial casein hydrolysate. The substrate specificity 〈C〉, reciprocal value of Michaelis constant 〈1/KM〉 and fraction of slow enzyme inactivation Ei/Eo were measured.  相似文献   

14.
The synthesis of monomethoxytriphenylmethyl (MMtrityl) starch and the subsequent carboxymethylation of the 6‐O‐functionalized products were investigated. The trityIation both in N,N‐dimethylacetamide (DMA)/LiCl and in dimethyl sulfoxide (DMSO) occurred homogeneously. The highest degree of substitution of trityl groups (DSTrityI) obtained after a single conversion step was 0.77 in both solvents. A complete functionalization of primary OH‐groups was achieved only with unsubstituted triphenylmethyl chloride in these reaction media. In case of monomethoxytriphenylmethyl chloride (MMTMC) as reagent an additional conversion step is necessary to synthesize products with a DSTrityI = 1. The structure of the products was analyzed by FTIR‐ and 13C‐NMR spectroscopy. Subsequent carboxymethylation of the MMtrityl starch samples leads to products with a preferred functionalization of the unprotected secondary OH‐groups. After removal of the trityl moieties, the DSCM and the distribution of carboxymethyl groups within the anhydroglucose unit was investigated by means of HPLC and 1H‐NMR spectroscopy. The carboxymethylation was more effective at O‐2 than at O‐3. In case of ether products with DSTrityl < 1 a partial substitution of the primary OH group took place as well.  相似文献   

15.
The efficacy of NovaSil clay (NS) to reduce aflatoxin (AF) biomarkers of exposure was evaluated in 656 blood samples and 624 urine samples collected from study participants during a 3-month phase IIa clinical intervention trial in Ghana. NS was delivered before meals via capsules. Serum AFB1–albumin adduct was measured by radioimmunoassay and urinary AFM1 metabolites were quantified by immunoaffinity-high-performance liquid chromatography (HPLC)-fluorescence methods. Levels of AFB1–albumin adduct in serum samples collected at baseline and at 1 month were similar (p?=?0.2354 and p?=?0.3645, respectively) among the placebo (PL), low dose (LD, 1.5 g NS day?1), and high dose (HD, 3.0 g NS day?1) groups. However, the levels of AFB1–albumin adduct at 3 months were significantly decreased in both the LD group (p?<?0.0001) and the HD group (p?<?0.0001) compared with levels in the PL group. Levels of AFM1 in urine samples collected at baseline and at 1 month were not statistically different among the three study groups. However, a significant decrease (up to 58%) in the median level of AFM1 in samples collected at 3 months was found in the HD group when compared with the median level in the PL group (p?<?0.0391). In addition, significant effects were found for dose, time, and dose–time interaction with serum AFB1–albumin adduct and dose–time interaction with urinary AFM1 metabolites. The results suggest that capsules containing NS clay can be used to reduce effectively the bioavailability of dietary AF based on a reduction of AF-specific biomarkers.  相似文献   

16.
The DNA sequence of a 2967 bp fragment located near the centromere of chromosome II, between the CEN2 and FUR4 genes, was determined. The segment contains a new open reading frame of 1794 bp. The product encoded by the gene, designated TTP1, is a predicted type II membrane protein of 597 amino acid residues with a short cytoplasmic NH2-terminus, a membrane-spanning region and a large COOH-terminal region containing three potential N-glycosylation sites. Gene disruption indicated that TTP1 is not essential for cell growth. The sequence has been deposited in the GenBank data library under Accession Number U05211.  相似文献   

17.
Zusammenfassung Pyruvatcarboxylase Wurde als Enzym, das inPenicillium camemberti, var. candidum, die C3 + C1-Fixierung katalysiert, nachgewiesen. substrate der Reaktion sind Pyruvat, Hydrogencarbonat und Adenosintriphosphat. Das Enzym ist nur aktiv in Gegenwart von Magnesiumionen. Adenosintriphosphat kann als Donator des energiereichen Phosphates nicht von Cytosin-, Guanosin-oder Inosintriphosphat vertreten Werden. Als Produkt der CO2-Fixierungsreaktion wurde Oxalacetat nachgewiesen. Pyruvatcarboxylase ausPen. camemberti ist ein Biotinenzym, die Enzymaktivität wird durch Avidin gehemmt.
Metabolism of microorganisms important in food technology VIII. Pyruvate carboxylase ofPenicillium camemberti, var. candidium 1. Enzyme determination
Summary Pyruvate carboaylase has been found catalyzing the C3 + C1 fixation inPenicillium camemberti, var. candidum. substrates of the reaction arc pyruvate, hydrogencarbonate, and adenosine-5-triphosphate. The enzyme requires the presence of magnesium ions for the catalytic activity. Adenosine-5-triphosphate is the only donator of the energy rich phosphate in the reaction; the triphosphates of cytosine, guanosine, and inosine cannot replace adenosine triphosphate. The product of the fixation reaction Was found to be oxalacetate. Pyruvate carboaylase fromPenicillium camemberti is a biotin containing enzyme; the activity is inhibited by avidin.


Auszug aus der Promotionsarbeit vonH.-J. Stan: Pyruvatearboxylase ausPenicillium camemberti, var. candidum — Funktion und Eigenschaften. Diss. Techn. Univ. Berlin 1968 (D 83).  相似文献   

18.
The eradication of apple mildew caused by Podosphaera leucotricha (Ell. and Everh.) Salm. with 2-(C4 to C13 α-branched alkyl)-4,6-dinitrophenols and 4-(C4 to C13 α-branched alkyl)-2,6-dinitrophenols was examined. 4-(1-Ethylbutyl)- and most 4-(C7 to C12 α-branched alkyl)-2,6-dinitrophenols were significantly more active than their 2-alkyl-4,6-dinitrophenol analogues. Compounds containing 4-C13 alkyls did not show significant activity. Activity generally increased as the α-alkyl branch lengthened. Methyl carbonates did not show lower activity than the parent phenols, but esterification of 4-(C12 or C13 α-branched alkyl)-2,6-dinitrophenols to ethyl carbonates or crotonates gave compounds with reduced activity. Methyl-, ethyl- or isopropyl-carbonates and crotonates of 4-(1-ethylhexyl)-2,6-dinitrophenol had much higher activity than the corresponding esters of the 4-(1-methylheptyl) isomer or of 2-(1-ethyl-hexyl)-4,6-dinitrophenol. Compounds containing long ester chains (C7 or C8) had less activity than 4-(1-ethylhexyl)-2,6-dinitrophenol. O-Methylation produced compounds with less activity than the parent 4-(1-ethylhexyl)- and 4-(1-propyl-pentyl)-2,6-dinitrophenols.  相似文献   

19.
Fishmeals with different moisture contents, having water activities (aw) ranging from 0.34 to 0.71, were infected with strains of Salmonella oranienburg or S. senftenberg and were stored at 15, 20 and 30°c, packed in nitrogen or air. The initial death rates (calculated over storage periods of 70 days) were not appreciably influenced by reduction of aw from 0.71 to 0.54. Further reduction of aw to 0.34 caused a decrease of the initial death rate, in particular in meals stored at 15 or 20°c. As compared with fishmeals packed in air, meals packed in nitrogen showed a decrease of initial death rates, especially in meals with the lowest aw and stored at 15 and 20°c. Death rates calculated over longer storage periods were smaller than initial death rates, in particular in meals with aw 0.54 stored at 15 and 20°c and meals with aw 0.34 stored at 15, 20 and 30°c. Pelletisation of meals with aw 0.72-0.74 caused a 102-103-fold reduction of initial Salmonella counts. The death rates of salmonellae which survived the pelletisation treatments were of about the same order as found for the initial death rates of salmonellae in non-pelletised meals with about the same aw.  相似文献   

20.
The studies of the eradication of barley mildew due to Erysiphe graminis Mérat with alkyldinitrophenols reported earlier1 were continued. The degree of eradication was highest with 4-(C9 α-branched alkyl)-2,6-dinitrophenols. 4-Alkyl-2,6-dinitrophenols containing a heptyl or higher alkyl branch were significantly less active, and compounds containing the C12 or C13 alkyls were not active since the most compact of the C12 α-branched alkyls is 1-pentylheptyl. 2-(1-Methylheptyl)- and 2-(1-propylpentyl)-4,6-dinitrophenols had high activity, but their esters showed reduced activity. Esterification of 4-(α-branched alkyl)-2,6-dinitrophenols to methyl carbonates did not affect the activity shown by the compounds, but when certain 4-C10 and C11 alkyl-2,6-dinitrophenols were esterified to ethyl carbonates the activity of the products was reduced. Also activity was diminished by conversion of some 4-C9 and C10 alkyl-2,6-dinitrophenols to crotonates. Whereas the methyl- and ethyl- carbonates of 4-(1-ethylhexyl)-2,6-dinitrophenol gave consistently high degrees of eradication of barley mildew, the performance of the crotonate of this phenol was not consistent. Lower aliphatic esters of the active C8-alkyl phenols were themselves active. Esterification of 4-(1-ethylhexyl)-2,6-dinitrophenol to the benzoate, isopropyl carbonate or S-methyl thiolocarbonate gave compounds with substantially reduced activity. 2-t-Butyl-4,6-dinitrophenyl or 4-t-butyl- or t-octyl-2,6-dinitrophenyl esters gave little or no significant eradication.  相似文献   

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