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1.
A novel syrup containing neofructo-oligosaccharides was produced from sucrose (Brix 70) by whole cells of Penicillium citrinum. The efficiency of fructo-oligosaccharides production was more than 55% and those of the main carbohydrate components, 1-kestose (Fruf 21Fruf 21 Glc), nystose (Fruf 21Fruf 21 Fruf 21 Glc) and neokestose (Fruf 26 Glc12 Fruf), were 22, 14 and 11%, respectively.  相似文献   

2.
The structure of a new nonasaccharide isolated from human milk has been investigated. By using methylation analysis, FAB-MS and1H-and13C-NMR spectroscopy as basic methods of structural investigation, this oligosaccharide was identified as VI2--Fuc,V4-Fuc,III3--Fuc-p-lacto-n-hexaose: Fuc1-2Gal1-3[Fuc1-4]GlcNAc1-3Gal1-4[Fuc1-3]GlcNAc1-3Gal1-4Glc.Abbreviations COSY correlation spectroscope - DP degree of polymerisation - FAB-MS fast atom bombardment-mass spectrometry - HPLC high performance liquid chromatography - NMR nuclear magnetic resonance - GLC gas-liquid chromatography  相似文献   

3.
Summary Antibodies were raised against a synthetic tetradecameric peptide with an amino acid sequence, DLIQEGNIGLMKAV, which corresponds to the most highly conserved region of bacterial RNA polymerase factors. In a Western-blot analysis of total Escherichia coli proteins, the antiserum reacted specifically with at least three proteins with apparent molecular weights of 75 kDa, 27 kDa and 23 kDa, in addition to the known factors (70 and 32). The majorities of 70 and 32 were recovered as associated forms with the RNA polymerase on glycerol gradient centrifugation, while the other cross-reacting proteins were not. Unambiguous evidence was obtained which indicated that the intracellular level of 32 increased rapidly upon heatshock, at least in the strain containing high copy numbers of the rpoH gene.  相似文献   

4.
The tetrasaccharides GalNAcß1-4[NeuAc2-3]Galß1-4Glc and GalNAcß1-4[NeuAc2-3]Galß1-4GlcNAc were synthesised by enzymic transfer of GalNAc from UDP-GalNAc to 3-sialyllactose (NeuAc2-3Galß1-4Glc) and 3-sialyl-N-acetyllactosamine (NeuAc2-3Galß1-4GlcNAc). The structures of the products were established by methylation and1H-500 MHz NMR spectroscopy. In Sda serological tests the product formed with 3-sialyl-N-acetyllactosamine was highly active whereas that formed with 3-sialyllactose had only weak activity.  相似文献   

5.
The maximal growth rate of the marine cyanobacterium Oscillatoria brevis was reached at 200–400 mM NaCl and pH 9.0–9.6. NaCl was found (i) to stimulate the rate of the light-supported generation across the cytoplasmic membrane of the cells and (ii) to decrease the sensitivity of level and motility of the O. brevis trichomes to protonophorous uncouplers. The Na+/H+ antiporter, monensin, increased both and the uncoupler sensitivity of the cells. The data obtained agree with the assumption that O. brevis possesses a primary Na+ pump in its cytoplasmic membrane.Abbreviations ATP adenosine-5-triphosphate - TTFB tetrachlortrifluoromethylimidazol - CCCP carbonyl cyanide m-chlorophenylhydrazone - Na+ transmembrane electrochemical potential differences of Na+ - transmembrane electric potential difference - pNa transmembrane pNa difference  相似文献   

6.
Summary The affinity of Bacillus subtilis RNA polymerase and subunits to DNA was examined by a non-denaturing polyacrylamide slab gel electrophoresis method which made it possible to resolve DNA-bound and free subunits. The results revealed that subunit, but not subunit had a relatively high affinity for double stranded DNA. The subunit was bound maximally to super-coiled pGR1-3 plasmid DNA at a mass ratio of /DNA of 0.7. With B. subtilis double stranded linear DNA one subunit was bound per approximately 1,000 base pairs. The -DNA complex was sufficiently stable for isolation by a molecular gel filtration column. The subunit had much higher affinity for super-coiled than for linear pGR1-3 DNA or for linear double stranded or denatured DNA from B. subtilis, E. coli, and calf thymus. These results indicate that the free B. subtilis subunit, in contrast to the E. coli subunit, can bind by itself to DNA.  相似文献   

7.
For the structural analysis of the carbohydrate chains ofN-,O-glycoproteins a straightforward strategy was developed based on the cleavage of theN-linked chains with immobilized peptide-N 4-(N-acetyl--glucosaminyl) asparagine amidase-F (PN-Gase-F) fromFlavobacterium meningosepticum, followed by alkaline borohydride treatment of the remainingO-glycoprotein material. This methodology was applied to the isolation of the Asn- and Ser-linked carbohydrate chains of human chorionic gonadotrophin. The structures of the isolated oligosaccharides were verified by 500-MHz1H-NMR spectroscopy. The Asn-linked sugar chains were shown to be: NeuAc2-3Gal1-4GlcNAc1-2Man1-6[NeuAc2-3Gal1-4GlcNAc1-2Man1-3]Man 1-4GlcNAc1-4[Fuc1-6]0-1GlcNAc and Man1-6[NeuAc2-3Gal1-4GlcNAc1-2Man 1-3]Man1-4GlcNAc1-4GlcNAc. Also some minor constituents occurred. The structures of the Ser-linked oligosaccharides were established in the form of their oligosaccharide-alditols as: NeuAc2-3Gal1-3[NeuAc2-6]GalNAc, NeuAc2-3Gal 1-3GalNAc and NeuAc2-3Gal1-3[NeuAc2-3Gal1-4GlcNAc1-6]GalNAc.Abbreviations hCG human chorionic gonadotrophin - hCG- -subunit - hCG- -subunit - ElA enzyme immunoassay - PNGase-F peptide-N 4-(N-acetyl--glucosaminyl)asparagine amidase-F (EC 3.5.1.52) - SDS sodium dodecyl sulphate - GalNAc N-acetylgalactosamine - GlcNAc N-acetylglucosamine - NeuAc N-acetylneuraminic acid - Man mannose - Gal galactose - Fuc fucose  相似文献   

8.
A simple genetic basis for the red/yellow skincolor polymorphism in apple was verified using DNA markers. Bulked segregant analysis identified one 10-base oligomer that generated different fragments in each of the bulks. After testing the primer in four populations, two fragments were found to be associated with red skin color and another two fragments associated with yellow skin color. Three of the fragments (1160, 1180, and 1230 bp) were partly sequenced and found to share high sequence homology, suggesting these were generated from the same locus. A pair of universal primers were designed to amplify the fragments. In the Rome Beauty x White Angel population, two fragments were associated with red skin color; one fragment designated as A1 (1160 bp) was from Rome Beauty and another fragment (A2, 1180 bp) was from White Angel. Progeny possessing both fragments, or either one, had red fruit. Both parents displayed an alternate fragment, a1 (1230 bp), associated with yellowskinned fruit. In three other crosses tested, only fragment A1 co-segregated with red skin color; two fragments, a1 and a2 (1230 bp and 1320 bp), were associated with yellow skin color. Our results are consistent with the hypothesis that the red/yellow dimorphism is controlled by a monogenic system with the presence of the red anthocyanin pigmentation being dominant. There was no indication that other modifier genes could reverse the effect of the locus (R f ) linked to the markers. Examination of amplification products in 56 apple cultivars and advanced breeding selections demonstrated that the universal primers could be used to correctly predict fruit skin color in most cases.  相似文献   

9.
Summary Meiotic pairing in Triticum turgidum cv. Ma (4x) with a mean chiasmata frequency of 27.16 per cell was compared with chiasmata frequencies in its hybrids with several triticale strains, Chinese Spring wheat and its addition lines for Imperial rye chromosomes 4R and 6R. In hybrids between Ma and x Triticosecale cv. Rosner the chiasmata frequency was marginally reduced by an average of 1.25%, by 8.8% in hybrids with x Triticosecale cv. DRIRA HH and by 6.7% with DRIRA EE (lacking 90% telomeric heterochromatin from chromosome arm 7RL). In pentaploid hybrids between Ma and T. aestivum cv. Chinese Spring the reduction was an average of 10.30%, while addition lines with rye chromosome 6R reduced chiasmata frequencies by an average of 7.4% and rye addition line for 4R showed the greatest depression in chiasmata frequency in hybrids by a 25.04% reduction. An interchange difference involving long chromosome segments was observed between Ma and Rosner.Contribution No. 819 Ottawa Research Station  相似文献   

10.
The Streptomyces coelicolor A3(2) gene ssgB belongs to the regulon of stress-response sigma factor H. By integrative transformation via double cross-over, a stable null mutant of ssgB was obtained. This mutation had no obvious effect on vegetative growth, but critically affected aerial mycelium septation. The S. coelicolor ssgB mutant produced aerial hyphae without any signs of septation into spore compartments. The mutation was complemented in trans by wild-type ssgB including the H-dependent ssgBp promoter. The results proved that ssgB belongs a developmental branch of the H regulon.  相似文献   

11.
Summary The nature and magnitude of variability in the interpopulation cross of Mezcla Amarillo Selection (MAS), an introduction from CIMMYT, Mexico, and J607, a population developed in India using indigenous, American, and Yugoslavian germplasm, were studied. Interpopulation progenies developed by following the North Carolina Design I were evaluated at two locations. The additive genetic variance component in interpopulation cross, A(12) 2 , and in one population assuming the other population as tester, A12 2 and A21 2 were significant for all the traits evaluated, namely ear length, ear girth, kernel rows and days to silk, with one exception. For kernel rows, the dominance variance component, A(12) 2 , was also significant but it was smaller than A(12) 2 . The variance component due to dominance X location interaction, DL(12) 2 , was significant for all traits except kernel rows. In the case of ear length and ear girth, DL(12) 2 was greater than the other components. AL(12) 2 , AL12 2 and AL21 2 were not significant for any trait. Expected genetic advance indicated a superiority of half-sib reciprocal recurrent selection over full-sib reciprocal recurrent selection.  相似文献   

12.
The present paper reports our attempts to determine whether the inclusion of 0.0014 mM Zn++ within a hydroponic culture medium affects the ability of 12-day-old Zea mays, cv. SS-522 to take-up [3H]-aflatoxin B1. Data from the corollary experiment, i.e., whether inclusion of aflatoxin affects the ability of Zea mays, cvs. Truckers White, X-Sweet and Merit to take-up 65ZnCl2 are presented also. This report is a preliminary to one regarding an in-progress analysis of whether pollutant levels of Zn++ affect aflatoxin uptake and distribution. In the absence of irrigating seedlings, which were grown in Perlite containing 65ZnCl2, with a solution containing mixed aflatoxins, the stem contained the greatest amount of label with root plus seed the next highest and the leaf the least for each of the cvs. In contrast, when the seedlings were irrigated with a solution containing mixed aflatoxins, the root plus seed contained either an amount nearly identical to (cv. Truckers White) or in excess of that within the stem (cvs. X-Sweet and Merit). Calculation of the percentages of aflatoxin-induced diminutions in leaf, stem and root label suggested that the aflatoxins interfered with the translocation of 65ZnCl2 from the root to the stem and leaf, at least for cvs X-Sweet and Merit. When 0.0014mM Zn++ as ZnSO4 was added to an incubation medium in which 12-day-old seedlings were suspended and plant growth assessed over 72 hours, a 15% increase (significant at 0.05 level) in seedling height over that of Zn++-deficient plants was observed. No differences in [3H]-aflatoxin B1 uptake were noted between those seedlings which were grown in either Zn++-containing or lacking media. Less than one % of the[3H]-aflatoxin B1 which was taken-up was recovered within chloroform extracts of the seedlings. The distributions of radioactivity from [3H]-aflatoxin B1 for leaf, stem, seed and root were 0, 57, 26 and 19% and 0, 26, 58 and 18% for Zn++-containing and -lacking media, respectively.  相似文献   

13.
Multilocation trials in plant breeding lead to cross-classified data sets with rows=genotypes and columns=environments, where the breeder is particularly interested in the rank orders of the genotypes in the different environments. Non-identical rank orders are the result of genotype x environment interactions. Not every interaction, however, causes rank changes among the genotypes (rank-interaction). From a breeder's point of view, interaction is tolerable only as long as it does not affect the rank orders. Therefore, the question arises of under which circumstances does interaction become rank-interaction. This paper contributes to our understanding of this topic. In our study we emphasized the detection of relationships between the similarity of the rank orders (measured by Kendall's coefficient of concordance W) and the functions of the diverse variance components (genotypes, environments, interaction, error). On the basis of extensive data sets on different agricultural crops (faba bean, fodder beet, sugar beet, oats, winter rape) obtained from registration trials (1985–1989) carried out in the Federal Republic of Germany, we obtained the following as main result: W 2 g /( 2 g + 2 v ) where 2 g =genotypic variance and 2 v = 2 ge + 2 o /L with 2 ge =interaction variance, 2 o =error variance and L=number of replications.  相似文献   

14.
The major pentasaccharides Fuc(1-2)[GalNAc(1-3)]Gal(1-4)[Fuc(1-3)]Glc and Fuc(1-2) [Gal(1-3)]Gal(1-4)[Fuc(1-3)]Glc, which are normally present in the urine of bloodgroup A Leb and B Leb healthy subjects, were each found to be contaminated by a minor component when analysed by1H-NMR. The determination of these structures, Fuc(1-2) [GalNAc(1-3)]Gal(1-3)[Fuc(1-4)]Glc and Fuc(1-2) [Gal(1-3)]Gal(1-3)[Fuc(1-4)]Glc, was based on the results of methylation analysis and1H/13C-NMR spectroscopy.Abbreviations HPLC high performance liquid chromatography - GLC gas liquid chromatography - NMR nuclear magnetic resonance - COSY correlation spectroscopy - Gal d-galactopyranose - GalNAc 2-acetamido-2-deoxy-d-galactopyranose - Glc d-glucopyranose - Fuc l-fucopyranose - LNDFH I lacto-N-difucohexaose I (Leb determinant  相似文献   

15.
The complete definition of the chemical structure of GD1b-ganglioside (GD1b) lactone isolated from human brain has been given by means of spectrometric and spectroscopic analyses. GD1h lactone contains a single ester linkage involving the external sialic acid carboxyl group and the C-9 hydroxyl group of the internal sialic acid unit. A synthetic lactone of GD1b prepared treating GD1b with glacial acetic acid characterized in the same way showed an identical chemical structure.Abbreviations: Ganglioside nomenclature is according to Svennerholm [16] and the IUPAC-IUB Recommendations [17] GM1 GM1-ganglioside, II3NeuAc-GgOse4Cer, Gal1-3GalNac1-4[NeuAc2-3]Gal1-4Glc1-1Cer - GD1b GD1b-ganglioside, II3(NeuAc)2GgOse4Cer, Gal1-3GalNAc1-4[NeuAc2-8NeuAc2-3]Gal1-4Glc1-1Cer - GD1b lactone GD1b-L, Gal1-3GalNAc1-4[NeuAc(1-9)2-8NeuAc2-3]Gal1-4Glc1-1Cer - Cer ceramide - FAB-MS fast atom bombardment-mass spectrometry - 1H-NMR proteon nuclear magnetic resonance - 1D-NMR one dimensional NMR - 2D-COSY two dimensional correlated spectroscopy - DMSO-d6 deuterated dimethylsulfoxide  相似文献   

16.
A simple method for stimulating and maintaining high in vitro multiplication of Narcissus shoot clump cultures was developed. Shoot clumps were subjected either to normal cutting where leaves were trimmed to 20 mm in length at the beginning of each culture passage or to severe cutting where shoot clumps were cut down to the basal plate region removing all green tissue. Severe cutting at the beginning of each culture passage initially doubled the leaf multiplication, compared to normal cutting, but the difference between cutting treatments declined in successive passages. The improvement in leaf multiplication was maintained when shoot clumps were subjected to severe cutting only at every other culture passage, with no cutting in the alternate recovery passages. In vitro multiplication was increased by severe cutting in all seven Narcissus cultivars which were tested.Abbreviations NAA-1 naphthylacetic acid - BAP benzylaminopurine  相似文献   

17.
Summary Soluble lead salts and a number of lead-containing minerals catalyze the formation of oligonucleotides from nucleoside 5-phosphorimidazolides. The effectiveness of lead compounds correlates strongly with their solubility. Under optimal conditions we were able to obtain 18% of pentamer and higher oligomers from ImpA. Reactions involving ImpU gave smaller yields.Abbreviations A adenosine - U uridine - Im imidazole - MeIm 1-methyl-imidazole - EDTA ethylenediaminetetraacetic acid - pA adenosine 5-phosphate - pU uridine 5-phosphate - Ap adenosine cyclic 2:3-phosphate - ATP adenosine 5-triphosphate - AppA P1,P2-diadenosine 5-diphosphate - pNp (N = A,U) nucleotide 2(3), 5-diphosphate - ImpA adenosine 5-phosphoreimidazolide - ImpU uridine 5-phosphorimidazolide - A 2pA adenylyl-[25]-adenosine - A 3pA adenylyl-[35]-adenosine - pA 2pA 5-phospho-adenylyl-[25]-adenosine - pA 3pA 5-phospho-adenylyl-[35]-adenosine - pUpU 5-phospho-uridylyl-uridine - pApU 5-phospho-adenylyl-uridine - pUpA 5-phospho-uridylyladenine - (pA)n (n, 2,3,4,) oligoadenylates with 5 terminal phosphate - ImpApA 5-phosphorimidazolide of adenylyl adenosine - (pA) 5+ pentamer and higher oligoadenylates with 5 terminal phosphate - (Ap)nA (n = 2,3,4) oligoadenylates without terminal phosphates In the following we do not specify the nature of the internucleotide linkageIn the following we do not specify the nature of the internucleotide linkage  相似文献   

18.
Summary Carbon isotope composition, photosynthetic gas exchange, and nitrogen content were measured in leaves of three varieties of Metrosideros polymorpha growing in sites presenting a variety of precipitation, temperature and edaphic regimes. The eight populations studied could be divided into two groups on the basis of their mean foliar 13C values, one group consisting of three populations with mean 13C values ca.-26 and another group with 13C values ca.-28. Less negative 13C values appeared to be associated with reduced physiological availability of soil moisture resulting from hypoxic conditions at a poorly drained high elevation bog site and from low precipitation at a welldrained, low elevation leeward site. Gas exchange measurements indicated that foliar 13C and intrinsic wateruse efficiency were positively correlated. Maximum photosynthetic rates were nearly constant while maximum stomatal conductance varied substantially in individuals with foliar 13C ranging from-29 to-24. In contrast with the patterns of 13C observed, leaf nitrogen content appeared to be genetically determined and independent of site characteristics. Photosynthetic nitrogenuse efficiency was nearly constant over the range of 13C observed, suggesting that a compromise between intrinsic water- and N-use efficiency did not occur. In one population variations in foliar 13C and gas exchange with leaf cohort age, caused the ratio of intercellular to atmospheric partial pressure of CO2 predicted from gas exchange and that calculated from 13C to be in close agreement only in the two youngest cohorts of fully expanded leaves. The results indicated that with suitable precautions concerning measurement protocol, foliar 13C and gas exchange measurements were reliable indicators of potential resource use efficiency by M. polymorpha along environmental gradients.  相似文献   

19.
Summary The fluorescent intercalation complex of ethidium bromide (ETB) with DNA was used as a probe to compare the effects of various radicals with respect to impairment of the DNA base-pair region.OH radicals inhibit up to 0.7 dye intercalations perOH at low salt concentration, and for various oxidizing species the effect decreases in the orderOH > Br 2 > N 3 > $$ " align="middle" border="0"> (SCN) 2 . DNA impairment by theOH product of Met-Gly is comparable to that of N 3 , but no effect was found due to the interaction between DNA and Lys-Tyr-Lys phenoxyl radicals. The reducing speciese aq , H, O 2 , and CO 2 hardly affect the DNA-ETB intercalation.  相似文献   

20.
Transitions in growth irradiance level from 92 to 7 Em-2 s-1 and vice versa caused changes in the pigment contents and photosynthesis of Oscillatoria agardhii. The changes in chlorophyll a and C-phycocyanin contents during the transition from high to low irradiance (HL) were reflected in photosynthetic parameters. In the LH transition light utilization efficiencies of the cells changed faster than pigment contents. This appeared to be related to the lowering of light utilization efficiencies of photosynthesis. As a possible explanation it was hypothesized that excess photosynthate production led to feed back inhibition of photosynthesis. Time-scales of changes in the maximal rate of O2 evolution were discussed as changes in the number of reaction centers of photosystem II in relation to photosynthetic electron transport. Parameters that were subject to change during irradiance transitions obeyed first order kinetics, but hysteresis occurred when comparing HL with LH transients. Interpretation of first order kinetic analysis was discussed in terms of adaptive response vs changes in growth rate.Non-standard abbreviations Chla chlorophyll a - CPC C-phycocyanin - PS II photosystem II - PS I photosystem I - RC II reaction center of photosystem II - P photosynthetic O2-evolution - I irradiance, Em-2 s-1 - light utilization efficiency of cells, mmol O2·mg dry wt-1·h-1/Em-2 s-1 - light utilization efficiency of photosynthetic apparatus, mol O2·mol Chla -1·h-1/Em-2 s-1 - Pmax maximal rate of O2 evolution by cells, mol O2·mg dry wt-1·h-1 - Pmax maximal rate of O2 evolution by photosynthetic apparatus, mol O2·mol·Chla -1·h-1 - LL low light, E m-2 s-1 - HL high light, E m-2 s-1 - LH low to high light transition - HL high to low light transition - k specific rate of adaptation, h-1 - specific growth rate, h-1 - Q pool size of cell constituent, mol·mg dry wt-1 - q net synthesis rate of cell constituent, mol·mg dry wt-1·h-1  相似文献   

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