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1.
Summary The influence of temperature on solvent production from whey was investigated by using strains ofClostridium acetobutylicum andbutylicum. Higher yields of solvents were observed at 37°C or at 30°C depending on the strain used. 相似文献
2.
Direct somatic embryogenesis on immature zygotic embryos in vitro has been confirmed for Trifolium pratense and extended to T. resupinatum and T. subterraneum. For all species direct embryo cloning can be achieved on an appropriate basal medium supplemented with 1gl–1 yeast extract and 0.05 mgl–1 BAP. Basal medium/sucrose formulation, level of yeast extract and level of BAP affected the nature of in vitro responses. In particular, for T. pratense and T. subterraneum lowering of the yeast extract level suppressed embryoid initiation, and raising of the BAP level stimulated formation of nodular morphogenic callus. For T. resupinatum alteration of the basal medium/sucrose formulation changed the tissue site of embryoid initiation from hypocotyl to cotyledons or both. Control of embryoid initiation is briefly discussed.Abbreviation BAP
6-benzylaminopurine 相似文献
3.
Summary Nine species of fungi viz.,Aspergillus niger,A. flavus,A. terreus,Fusarium solani,Mucor sp.,Neurospora crassa,Penicillium janthinellum,Trichoderma harzianum andTrichothecium roseum were evaluated for their potential to remove NH3–N from domestic waste water. Of the fungi tested,A. flavus was found to be the most effective in the removal of NH3–N. Maximum reduction (92%) of NH3–N by this organism was observed at pH 8.0 at 20°C. 相似文献
4.
Jacques Mugnier 《Plant cell reports》1988,7(1):9-12
Cultured hairy root lines resulting from infection by Agrobacterium rhizogenes are known for approximately thirty plant species. We extend this range by establishing forty original dicotyledonous hairy root lines with A. rhizogenes strain A4. Hairy roots have been cultured for at least 2–6 years on Murashige & Skoog medium. Some hairy root cultures such as Anagallis arvensis and Antirrhinum majus spontaneously regenerated whole plants. 相似文献
5.
G-matrix FT projection NMR spectroscopy was employed for resonance assignment of the 79-residue subunit c of the Escherichia coli F1F0 ATP synthase embedded in micelles formed by lyso palmitoyl phosphatidyl glycerol (LPPG). Five GFT NMR experiments, that is,
(3,2)D HNNCO, L-(4,3)D HNNC
αβ
C
α, L-(4,3)D HNN(CO)C
αβ
C
α, (4,2)D HACA(CO)NHN and (4,3)D HCCH, were acquired along with simultaneous 3D 15N, 13Caliphatic, 13Caromatic-resolved [1H,1H]-NOESY with a total measurement time of ∼43 h. Data analysis resulted in sequence specific assignments for all routinely
measured backbone and 13Cβ shifts, and for 97% of the side chain shifts. Moreover, the use of two G2FT NMR experiments, that is, (5,3)D HN{N,CO}{C
αβ
C
α} and (5,3)D {C
αβ
C
α}{CON}HN, was explored to break the very high chemical shift degeneracy typically encountered for membrane proteins. It is shown
that the 4D and 5D spectral information obtained rapidly from GFT and G2FT NMR experiments enables one to efficiently obtain (nearly) complete resonance assignments of membrane proteins.
Qi Zhang, Hanudatta S. Atreya, Douglas E. Kamen, Mark E. Girvin and Thomas Szyperski—New York Consortium on Membrane Protein
Structure. 相似文献
6.
Summary
Candida boidinii IAM 12269 andNocardia erythropolis IAM 12122 were useful for the asymmetric reduction of 1,2-diformylferrocene (1) to the planar chiral semialdehyde3 and for the optical resolution of (±)-tricarbonyl(2-methylbenzaldehyde)chromium (4) and (±)-tricarbonyl(1-formyl-2-methylcyclopentadienyl)manganese (6) having planar chirality. 相似文献
7.
The present experimentation compared the best nutrient medium, temperature, and growth hormones for callus induction and growth of various pine species from different seed sources with their effect on growth of Phytophthora cinnamomi. Callus tissues maintained on a modified Murashige and Skoog medium with 10–5M 2,4-D at 26°C in the dark optimized the expression of differential resistance when inoculated with hyphae of P. cinnamomi. High concentration of 2,4-D (5×10–5M) inhibited growth of P. cinnamomi.Abbreviations AL
loblolly pine-Alabama
- PL
South Carolina
- AS
shortleaf pine-Alabama
- CS
Georgia
- AV
Virginia pine-Alabama 相似文献
8.
9.
Axillary buds from 5 genotypes of mulberry belonging to 4 species were cultured on modified MS basal medium. A total of 30 media combinations were tried for all the genotypes. The response of axillary buds and the requirement for growth regulators varied with genotype. In Morus indica BAP (0.25–0.5 mg/l), and in M. alba and M. rotondifolia GA3 (0.5–1.0 mg/l)were found to induce sprouting. Two genotypes of M. bombycis, namely Schimanochi and Mizusawa, developed healthy shoots on the incorporation of 2,4-D (0.5–1.0 mg/l) and BAP (0.5–2.0 mg/l), respectively. IBA (0.5 mg/l), along with cytokinin/auxin/gibberellin, had no effect on bud growth but helped root induction. Shoots developed from the axillary buds were further multiplied as nodal explants. MS basal medium supplemented with 0.5 mg/l IBA and LS vitamins was found best to produce healthy plantlets in all the genotypes. An average 89% survival was observed on transferring the plantlets to soil.Abbreviations MS
Murashige and Skoog (1962)
- LS
Linsmaier and Skoog (1965)
- IBA
3-indole-butyric acid
- GA3
Gibberellic acid
- BAP
6-Benzylaminopurine
- Kn
Kinetin
- 2,4-D
2,4-Dichlorophenoxyacetic acid 相似文献
10.
A. J. Hacking I. W. F. Taylor C. M. Hanas 《Applied microbiology and biotechnology》1984,19(5):361-363
Summary A total of 55 yeast strains selected from 7 genera known to ferment carbohydrates to ethanol were screened for their ability to ferment glucose to ethanol in shaken flask culture at 37°, 40° and 45°C. Yields of more than 50% of the theoretical maximum were obtained with 28 strains at 37°C, but only 12 at 40°C. Only 6 could grow at 45°C, but they produced poor yields. In general Kluyveromyces strains were more thermotolerant than Saccharomyces and Candida strains, but Saccharomyces strains produced higher ethanol yields. The 8 strains with the highest yields at 40°C were evaluated in batch fermentations. Three of these, two Saccharomyces and one Candida, were able to meet minimum commercial targets set at 8% (v/v) ethanol from 14% (w/v) glucose at 40°C. 相似文献
11.
Jong-Kwon Han Jong-Won Oh Hyune-Hwan Lee Stephen Chung Hyung-Hwan Hyun Jae-Heung Lee 《Biotechnology letters》1991,13(10):721-726
Summary A 2.9 kb DNA fragment encoding s-(2-aminoethyl)-l-cysteine (AEC) resistant aspartokinase ofCorynebacterium
glutamicum was cloned on theC.
glutamicum/E.
coli shuttle vector pECCG117. A recombinant plasmid, designated pAK12, conferred the AEC resistance, the ability to excrete lysine and threonine, and the 3–5 fold increased specific activity of aspartokinase to host strain. 相似文献
12.
Extraction and quantitation of astaxanthin from Phaffia rhodozyma 总被引:32,自引:0,他引:32
Summary The rapid, quantitative release of astaxanthin and other carotenoids from the yeast Phaffia
rhodozyma is described. Hashed cells are ruptured with dimethylsulfoxide (DMSO) and carotenoids extracted into an organic solvent. Extraction and spectrophotometric quantitation of total carotenoids is rapid, reproducible and only small volumes (0.1–2 ml) of culture are required. HPLC analysis in normal phase silica gel column indicates that astaxanthin comprises 65–95% of the total pigmented carotenoids of P.
rhodozyma. 相似文献
13.
Claude P. Champagne 《Biotechnology letters》1990,12(10):771-776
Summary Cells ofLactococcus
lactis orLactobacillus
helveticus were immobilized in calcium-alginate beads, added to raw milk, and incubated 48 h at 7°C. The addition of 2.7×107 immobilizedLc.lactis or 13×107 immobilizedLb.
helveticus cells per mL reduced the development of the psychrotrophic bacteria of raw milk by approximately 50%. The pH of the raw milk dropped 0.10 to 0.22 units under these conditions. Periodic agitation of the seeded raw milk increased the inhibitory activity of the immobilized lactic acid bacteria (LAB). Free LAB cells in the system were only of 0.5% of total LAB. The use of immobilized LAB to inhibit psychrotrophic bacteria might be extended to raw milks destined to the manufacture of non-fermented dairy products. 相似文献
14.
B. Rao 《Prostaglandins & other lipid mediators》1979,18(1):93-100
In vitro synthesis of progesterone and estradiol-17β from endogenous precursors was studied in the placenta from women in early stage of gestation (< 7 weeks). Radioimmunoassay techniques were used to measure progesterone and estradiol-17β.It was shown that placental tissue from as early as six weeks of gestation can synthesize both progesterone and estradiol-17β in vitro. Prostaglandins F2α and E2 in concentration of 100 μg/ml of the incubation media did not have any significant effect on the in vitro synthesis of progesterone and estradiol-17β in the placental tissue.It seems unlikely that the abortifacient effect of natural prostaglandins PGE2 and PGF2α is due to their direct action on the synthesis of progesterone and estradiol-17β in the placenta. 相似文献
15.
The Neuronal Kv4 Channel Complex 总被引:1,自引:0,他引:1
Covarrubias M Bhattacharji A De Santiago-Castillo JA Dougherty K Kaulin YA Na-Phuket TR Wang G 《Neurochemical research》2008,33(8):1558-1567
Kv4 channel complexes mediate the neuronal somatodendritic A-type K+ current (ISA), which plays pivotal roles in dendritic signal integration. These complexes are composed of pore-forming voltage-gated α-subunits
(Shal/Kv4) and at least two classes of auxiliary β-subunits: KChIPs (K
+-Channel-Interacting-Proteins) and DPLPs (Dipeptidyl-Peptidase-Like-Proteins). Here, we review our investigations of Kv4 gating mechanisms and functional remodeling by specific auxiliary β-subunits.
Namely, we have concluded that: (1) the Kv4 channel complex employs novel alternative mechanisms of closed-state inactivation;
(2) the intracellular Zn2+ site in the T1 domain undergoes a conformational change tightly coupled to voltage-dependent gating and is targeted by nitrosative
modulation; and (3) discrete and specific interactions mediate the effects of KChIPs and DPLPs on activation, inactivation
and permeation of Kv4 channels. These studies are shedding new light on the molecular bases of ISA function and regulation.
Special issue article in honor of Dr. Ricardo Tapia. 相似文献
16.
Summary A method for the quantitative enantioselective bioreduction of ethyl acetoacetate [1] to optically pure (+)-S-ethyl-3 hydroxybutyrate [II] usingSclerotium
rolfsii mycelium is described. In a synthetic medium 1 g mycelium (dry weight) could convert 1 g of I to II within 2–3 days of fermentation (pH 5.8, 30°C). This is the first report demonstrating use ofS.
rolfsii biomass for asymmetric reduction to get chiral building blocks. 相似文献
17.
Eeva Levonen-Munoz Derek H. Bone Andrew J. Daugulis 《Applied microbiology and biotechnology》1983,18(2):120-123
Summary Seventee white-rot and brown-rot fungi were screened for their ability to fractionate the lignocellulose structure of oat straw through the preferential attack of lignin or cellulose. Fermentations were carried out under solid-state conditions with 25 g quantities of straw. The fermented straw was analyzed for weight loss, Klason lignin loss and cellulase digestion. All the fungi attacked both lignin and carbohydrate fractions causing 3–28% weight losses and 26–34 g/100 g enzymatic digestibility. Polyporus
tulipiferae, Phanerochaete
chrysosporium and Polyporus sp. were tested for the effects of various nitrogen, phosphate and carbon levels, incubation temperatures and incubation time. The three fungi had different responses to these factors. 相似文献
18.
Summary Two thermophilic strains of Lactobacillus were transformed by electroporation; L.fermentum with a maximum of frequency of 1×105/ug of plasmid vector pPSC20DNA and 1.4×103/ug pSA3DNA. L.helveticus showed a very low frequency of transformation, from 9 to 26 transformants/ug DNA in all the experiments carried out with both the vectors. While L.fermentum transformants were very stable, in L.helveticus the acquired plasmid was lost after 30–50 generations. 相似文献
19.
Summary From continuous culture studies it has been shown that the protein concentrations of strains of Z. mobilis (62–68%) were appreciably higher than for the yeast S.uvarum (45–50%). The DNA and RNA contents were similar for the two species. Comparison of the essential amino acids indicated that Z.mobilis did not exhibit the deficiency in methionine which was apparent in the yeast. Such a study of the macromolecular composition of cells of Z.mobilis is important in assessing its by-product nutritional value for animal feed supplementation. 相似文献
20.
Nelson Duran Jaime Rodriguez Andre Ferraz Victoriano Campos 《Biotechnology letters》1987,9(5):357-360
Summary
C. sitophila strain TFB-27441 showed 2–3 times higher lignolytic activity thanPhanerochaete chrysosporium (BKM-F-1767 strain). Lignin had a marked effect on the ligninase activity indicating that some induction or activation mechanism is involved in lignin degradation byC. sitophila. 相似文献