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1.
Summary Novel sugars, oligoglucosyl-inositols, which were synthesized using CGTase fromBacillus ohbensis, stimulated the growth ofBifidobacterium. The enzyme catalyzed transglucosylation from -1,4-maltodextrin (donor) tomyo-inositol (acceptor). Of donors examined, -cyclodextrin gave superior oligoglucosyl-inositol yield of 56.6% (w/w) based on the conversion ratio of incubated inositol. Maltosyl-inositol stimulated growth ofB. adolescentis by 194% when compared with glucose.  相似文献   

2.
Summary E. coli CF3 isolated after the infection ofE. coli K12 C600 with the bacteriophage B278 produces quantities of extracellular exopoly-saccharide characterized by gas chromatography as composed of glucose, galactose and fucose in the molar ratio 111.2 and being partly acetylated. Solutions of the polysaccharide were pseudoplastic and its viscosity is constant at extreme pH (3.5–10) and compatible with temperature (90°C).  相似文献   

3.
Summary Dotted (Dt) is the regulatory element of a two-unit controlling system in maize. Dt causes the inherited change from the recessive a (colorless) to its dominant allele, A (anthocyanin production), during the development of the stalk, leaves, and endosperm. The mutation events are observed as sectors of color in an anthocyaninless background.Since its discovery over 40 years ago, Dt has always been found in the terminal knob of the short arm of chromosome 9. This is puzzling because controlling and regulatory elements in general are not located permanently, but change positions (transpose) within the chromosomal complement. To resolve this seeming discrepancy, transpositions were looked for in a homozygous a Dt stock. Because the frequency of aleurone mutations is exponentially related to Dt dosage, a Dt transposition would result in a greatly increased number of dots if the egg or sperm nucleus contained both the transposed Dt and the Dt remaining on chromosome 9. A total of 6 transposed Dt's (Dt-T) were recovered in this manner. Dt-TA was found linked to the gene Y (yellow endosperm) of chromosome 6. Dt-TB no longer showed linkage with yg2 of chromosome 9, but remains unlocated (the original Dt in this stock is separated from yg2 by 6 or 7 cross-over units.). The remaining transpositions (C-F) assorted independently of Dt on chromosome 9.The transposed Dt's had the same effect as Dt on the frequency and timing of aleurone mutations. An increase in transposition frequency and losses of Dt-T's was characteristic of several of the transposed Dt's. Dt-T's B-F transposed so frequently that testcross ratios of 71 (three Dt' s) and 15 1 (four Dt' s) were observed. No secondary transpositions or losses of Dt-TA were detected. Thus, Dt-TA resembles the original Dt with regard to its transposition frequency and stability.Journal Paper No. J-8333 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa. Project No. 1880.  相似文献   

4.
Summary Streptococcal plasmids pAM1, pVA797, pVA797Tn917 and pAM610 were transferred or mobilized toClostridium acetobútylicum fromStreptococcus sanguis,S. faecalis andS. lactis donors.Clostridum transconjugants were able to retransfer pAM1 and pVA797 to a plasmid-freeS. lactis recipient.  相似文献   

5.
Summary Snake flask experiments were carried out as a preliminary study of fat formation byTrichoderma reesei (formallyviride) QM 9123 using a glucose based medium. The maximum quantity of fat production was 16% of the dry weight. The pH of the medium, as much as its composition, appeared to influence the quantity of fat that was produced. The fatty acids formed by the hydrolysis of the fats were found to be mainly unsaturated, with the 182 (linoleic) acid predominating.  相似文献   

6.
Summary Some 19 strains ofAspergillus niger,A. oryzae, andPaccilomyces spp. are tested for their ability to grow on the supernatant remaining after the expressed juice from sugar beet tops and meadow grass has been heat-treated to precipitate crude leaf protein, and supplemented as required by glucose or ammonium sulphate. With effective strains ofA. niger,A. oryzae,P. elegans orP. variotii and an optimized carbohydrate/nitrogen ratio, over 70% of the organic content of the supernatant is rapidly converted into mycelial biomass of high protein content.  相似文献   

7.
Summary Transglucosylation byProtaminobacter rubrum using 6-chloro-6-deoxysucrose (1) and methyl -D-arabinofuranoside (2) as donor and acceptor, respectively, were examined. inhibition caused by 6-chloro-6-deoxy-D-fructose (4) was observed and could be greatly lightened in a borate buffer, where the yield of the disaccharide (3) increased by 1.35-fold.  相似文献   

8.
Homologies were searched among the published primary sequences of 51E. coli ribosomal proteins, partly by eye and partly by computer-assisted methods. By employing Moore and Goodman's alignment statistics for evaluating homology levels, 33 out of these 51 ribosomal proteins has been classified into 9 homology groups, some of which being yet tentative and remaining to be further analyzed. Taking it into consideration that most ribosomal protein genes are clustered atstr-stc region,rif region and several other regions, these results strongly suggest that most or all of the contemporary ribosomal proteins must have evolved by repeated gene duplications ofvery few (oronly one) primitive ancestral ribosomal protein gene(s). Thus it is most reasonable to propose that a small ribosome consisting of very few (or only one) ribosomal protein(s) must have existed as a primitive protein-synthesizing apparatus.  相似文献   

9.
Summary Synergistic coculture of an amylolytic yeast (Saccharomycopsis fibuligera) andS. cerevisiae, a non-amylolytic yeast, fermented unhydrolyzed starch to ethanol with conversion efficiencies over 90% of the theoretical maximum. Fermentation was optimal between pH 5.0 to 6.0. Using a starch concentration of 10% (w/v) and a 5% (v/v) inoculum ofS. fibuligera, increasingS. cerevisiae inoculum from 4% to 12% (w/v) resulted in 35–40% (w/v) increase in ethanol yields. Anaerobic or limited aerobic incubation almost doubled ethanol yields.  相似文献   

10.
Summary We have prepared the nucleoamino acids 1-(3-amino, 3-carboxypropyl)uracil (3) and 9-(3-amino, 3-carboxypropyl)adenine (4) as (l)-enantiomers and as racemic mixtures. When3 or4 is suspended in water and treated with N,N-carbonyldiimidazole, peptides are formed in good yield. The products formed from the (l)-enantiomers are hydrolyzed to the monomeric amino acids by pronase.Attempts to improve the efficiency of these oligomerizations by including a polyuridylate template in the reaction mixture were not successful. Similarly, oligomers derived from the (l)-enantiomer of3 did not act as templates to facilitate the oligomerization of4.  相似文献   

11.
Summary A locally isolated oleaginous yeastRhodotorula glutinis IIP-30 was grown on vegetable oils obtained from coconut, ground nut and til. The fatty acid composition of yeast oil was quite similar to that of the substrate oil in case of ground nut and til, while it was different with coconut oil. Utilization of C12 and C14 fatty acids of coconut oil to yield higher proportions of C181 and C182 fatty acids was observed.  相似文献   

12.
Propagation by axillary and multiple axillary bud development was achieved in three native Leptospermum spp. when axillary buds derived from nodal tissues ex mature plants were placed in benzylaminopurine media (0.04–1.0 M) containing macro- and micro-nutrients, sucrose (0.06 M) and a vitamin/amino acid supplement. Reduction of agar concentration from 0.8 to 0.2% greatly stimulated axillary bud development and growth in L. flavescens and L. brachyandrum. Rooting of axillary shoots was stimulated by 2,4-dichlorophenoxyacetic acid and p-chlorophenoxy acetic acid in L. flavescens at concentrations of 5 and 1 M respectively. In L. petersonii ssp. root initiation and development was favoured by -naphthoxyacetic acid (1 M) and in L. brachyandrum indole butyric acid and -naphthalene acetic acid (1 M) were almost equally effective.  相似文献   

13.
Leaf protoplasts were isolated from shoot cultures of two hybrid poplar clones (Populus alba × P. grandidentata Crandon, NC-5339 and P. nigra Betulifolia × P. trichocarpa, NC-5331) and the Upright European Aspen (P. tremula Erecta) and were cultured in contact with screen discs floated in liquid medium. Protoplast culture was influenced by the growth medium of the source shoot cultures, the protoplast purification procedure, the plating density, and the presence or absence of a coconut water and casein hydrolysate supplement added to the culture medium. The protoplast-derived cells divided more quickly and with higher incidence than previously reported for hybrid poplars. Shoots were regenerated from the protoplast-derived calli and were maintained as shoot cultures. Plants were developed from microcuttings rooted ex vitro and were grown-on in the greenhouse and field.Abbreviations BA benzyladenine - NAA 1-naphthaleneacetic acid - TDZ thidiazuron - WPM Woody Plant Medium, Lloyd and McCown (1980) - MS Murashige and Skoog Medium (1962) - NC-XXXX North Central Forest Experiment Station accession number assigned to hybrid poplar clones.  相似文献   

14.
Abstract

Several 4-substituted-1-β-D-ribofuranosyl-3-hydroxypyrazoles were prepared as structural analogs of pyrazofurin. Glycosylation of the TMS derivative of ethyl 3(5)-hydroxypyrazole-4-carboxylate (3) with 1-0-acetyl-2,3,5-tri-0-benzoyl-D-ribofuranose in the presence of TMS-triflate gave predominantly ethyl 3-hydroxy-1-(2,3,5-tri-0-benzoyl-β-D-ribofuranosyl)pyrazole-4-carboxylate (4a), which on subsequent ammonolysis furnished 3-hydroxy-1-β-D-ribofuranosylpyrazole-4-carboxamide (5). Benzylation of 4a with benzyl bromide and further ammonolysis gave 3-benzyloxy-1-β-D-ribofuranosylpyrazole-4-carboxamide (8a). Catalytic (Pd/C) hydrogenation of 8a afforded yet another high yield route to 5. Saponification of the ester function of ethyl 3-benzyloxy-1-β-D-ribofuranosylpyrazole-4-carboxylate (7b) gave the corresponding 4-carboxylic acid (6a). Phosphorylation of 8a and subsequent debenzylation of the intermediate 11a gave 3-hydroxy-1-β-D-ribofuranosylpyrazole-4-carboxamide 5′-phosphate (11b). Dehydration of 3-benzyloxy-1-(2,3,5-tri-0-acetyl-β-D-ribofuranosyl)pyrazole-4-carboxamide (8b) with POCl3 provided the corresponding 4-carbonitrile derivative (10a), which on debenzylation with Cl3SiI gave 3-hydroxy-1-(2,3,5-tri-0-acetyl-β-D-ribofuranosyl)pyrazole-4-carbonitrile (13). Reaction of 13 with H2S/pyridine and subsequent deacetylation gave 3-hydroxy-1-β-D-ribofuranosylpyrazole-4-thiocarboxamide (12b). Similarly, treatment of 13 with NH2OH afforded 3-hydroxy-1-β-D-ribofuranosylpyrazole-4-carboxamidoxime (14a), which on catalytic (Pd/C) hydrogenation gave the corresponding 4-carboxamidine derivative (14b). The structural assignment of these pyrazole ribonucleosides was made by single-crystal X-ray analysis of 6a. None of these compounds exhibited any significant antitumor or antiviral activity in cell culture.  相似文献   

15.
Congregado  F.  Estañol  I.  Espuny  M. J.  Fusté  M. C.  Manresa  M. A.  Marqués  A. M.  Guinea  J.  Simon-Pujol  M. D. 《Biotechnology letters》1985,7(12):883-888
Summary Exopolysaccharide production byPseudomonas sp. strain EPS-5028 increased under conditions of high C/N ratios at the pH range 6.7–8 and 25°C. The polymer was formed from a variety of carbon substrates and contains D-glucose, D-galactose and uronic acid in the approximate molar ratio of 325. The polysaccharide produced is of high viscosity (1,600 cP; 1% polymer in D. I. water).  相似文献   

16.
Plant regeneration through shoot bud formation was induced in cultured hypocotyl explants of diploid and tetraploid varieties of Solanum khasianum. Optimum regeneration of multiple shoot buds accompanied by rooting occurred on Murashige and Skoog's medium supplemented with IAA (1 mg/1) and kinetin or benzyladenine (1 mg/1). Plantlets obtained in vitro were successfully established in soil.Part of a thesis entitled Morphogenetic studies in tissue and organ cultures of certain Solanaceous plants: Capsicum, Lycopersicon and Solanum submitted by A.L. Gunay and approved for Master's degree in Botany by research of the University of Bombay.  相似文献   

17.
Abstract

The reaction of the 2′,3′-lyxoepoxide (1) with ammonium azide gives two products; namely, the 3′-arabino azide (2a) and in low yield 2′-xylo azide (3a). After debenzoylation and reduction the resulting mixture of amines was resolved by chromatography on a weak cation exchanger, Amberlite IRC-50, and afforded crystalline 1-(3-amino-3-deoxy-β-D-arabinofuranosyl)uracil (2c) and 1-(2-amino-2-deoxy-β-D-xylofuranosyl)uracil (3c) in the ratio of 4:1.  相似文献   

18.
Abstract

Treatment of D-xylose (1) with 0.5% methanolic hydrogen chloride under controlled conditions followed by benzoylation and acetolysis afforded crystalline 1-O-acetyl-2, 3, 5-tri-O-benzoyl-α-D-xylofuranose (4) in good yield. Coupling of 4 with 2, 4-bis-trimethylsilyl derivatives of 5-alkyluracils (methyl, ethyl, propyl and butyl) (5a-5d), 5-fluorouracil (5e) and uracil (5f) in acetonitrile in the presence of stannic chloride gave 1-(2,3,5-tri-O-benzoyl-β-D-xylofuranosyl)-nucleosides (6a-6f). Saponification of 6 with sodium methoxide afforded 1-β-D-xylofuranosyl-5-substituted uracils (7a-7f). Condensation of 4 with free adenine in similar fashion and deblocking gave carcinostatic 9-β-D-xylofuranosyladenine (7g).  相似文献   

19.
Hypocotyl explants of three leguminous forest tree species, Albizia amara, A. lucida and A. richardiana, have differentiated shoot buds on B5 basal medium. Maximum number of shoots per explant developed on basal medium augmented with 2,4-D (0.1 M) in A. amara (2) and BA (10 M) for both A. lucida (2) and A. richardiana (1.6). Higher concentrations of auxins in the medium, in general, enhanced rooting and callusing but cytokinins promoted the growth of green calli. BA enchanced the differentiation of shoots in the three species. The in vitro grown shoots of A. amara and A. richardiana, after subculturing on B5+1 M IAA developed roots (up to 30–40%). These plants have been successfully transferred to the field.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - BA 6-benzylaminopurine - BM Gamborg's B5 medium with 0.9% agar+3% sucrose - IAA Indole-3-acetic acid - IBA Indole-3-butyric acid - Kn Kinetin - NAA -naphthaleneacetic acid  相似文献   

20.
Summary Genetically transformed kiwi fruit (Actinidia deliciosa) plants were obtained from hypocotyl and stem segments co-cultured with Agrobacterium tumefaciens strain EHA101 harboring a binary vector, pLAN411 or pLAN421, which contained the neomycin phosphotransferase II (nptII) gene and the -glucuronidase (GUS) gene. After co-culturing with the A. tumefaciens, the hypocotyl or stem segments were cultured on a selection medium containing 25g/ml kanamycin and 500g/ml Claforan. After one month in culture, shoots had regenerated from the cuttings. Green shoots were analyzed for NPTII activity and GUS activity. Eighty-five percent of the green shoots examined expressed the nptII and GUS genes. GUS histochemical assays revealed strong GUS expression in guard cells, mesophyll cells, and trichomes.  相似文献   

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