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1.
Isolation of high-quality DNA from rosaceous species is particularly difficult because of their high levels of polyphenols,
polysaccharides, and other compounds. The yields and quality of genomic DNA are considerably affected when the common protocol
for DNA isolation is applied to the chestnut rose (Rosa roxburghii Tratt). A simple, rapid, and efficient protocol for the extraction of DNA from the chestnut rose is described. The modified
hexadecyltrimethylammonium bromide (CTAB) procedure, which uses phenol-absent extraction to enhance the yield, involves a
washing step before extraction for the removal of organic molecules and excessive water; the use of high concentrations of
polyvinylpyrrolidone (2% [w/v]), CTAB (3% [w/v]), and β-mercaptoethanol (3% [v/v]) in the high-salt-concentration extraction
buffer to remove polyphenols and polysaccharides; and the combined use of potassium acetate and chloroform to remove proteins
and polysaccharides. Finally, DNA is precipitated with an equal volume of isopropanol and 0.1 vol of sodium acetate. This
protocol results in high yields of DNA. The average yield of DNA ranged from 980–1800 μg/g of fresh weight of leaves. Downstream
results indicate that DNA quality is sufficient for restriction fragment length polymorphism (RFLP) and polymerase chain reaction
(PCR) analyses. 相似文献
2.
RNA isolation is difficult in some plants and algae because phenolics, polysaccharides, or other compounds can bind or co-precipitate
with RNA, and because the success of RNA isolation can be strain-specific and species-specific. To create an improved RNA
isolation protocol for Laminaria japonica Aresch (Laminariaceae, Phaeophyta), four methods for extracting RNA were tested. A cetyltrimethylammonium bromide (CTAB)-based
RNA extraction protocol was developed that clearly showed 28S and 18S ribosomal RNA bands and produced RNA with high yield
(68 μg g−1 fresh weight) and high quality (A
260/280 ratio 1.96 ± 0.05). The isolated RNA was intact, and RT-PCR analysis confirmed that further molecular application is feasible. 相似文献
3.
Osmotic stress restricts glycolytic flux, growth (rate and yield), d-lactate productivity, and d-lactate tolerance in Escherichia coli B strain SZ132 during batch fermentation in mineral salts medium with 10% (w/v) sugar. Addition of 1 mm betaine, a non-metabolized protective osmolyte, doubled cell yield, increased specific productivity of d-lactate and glycolytic flux by 50%, and tripled volumetric productivity (from 8.6 to 25.7 mmol l−1 h−1; 0.8 to 2.3 g l−1 h−1). Glycolytic flux and specific productivity in mineral salts medium with betaine exceeded that in Luria broth, substantially
eliminating the need for complex nutrients during d-lactate production. In mineral salts medium supplemented with betaine, SZ132 produced approximately 1 mol d-lactate (90 g) per 100 g sugar (glucose or sucrose).
Revisions requested 17 January 2006; Revisions received 7 February 2006 相似文献
4.
Production of poly(3-hydroxybutyrate) by solid-state fermentation with <Emphasis Type="Italic">Ralstonia eutropha</Emphasis> 总被引:1,自引:0,他引:1
The use of solid-state fermentation is examined as a low-cost technology for the production of poly(hydroxyalkanoates) (PHAs) by Ralstonia eutropha. Two agroindustrial residues (babassu and soy cake) were evaluated as culture media. The maximum poly(hydroxybutyrate) (PHB) yield was 1.2 mg g–1 medium on soy cake in 36 h, and 0.7 mg g–1 medium on babassu cake in 84 h. Addition of 2.5% (w/w) sugar cane molasses to soy cake increased PHB production to 4.9 mg g–1 medium in 60 h. Under these conditions, the PHB content of the dry biomass was 39% (w/w). The present results indicate that solid-state fermentation could be a promising alternative for producing biodegradable polymers at low cost.Revisions requested 31 August 2004; Revisions received 12 October 2004 相似文献
5.
Bacillus subtilis(natto) Takahashi, used to prepare the fermented soybean product natto, was grown in a basal medium containing 5% (w/w) sucrose and 1.5% (w/w) l-glutamate and produced 58% (w/w) poly(-glutamic acid) and 42% (w/w) levan simultaneously. After 21 h, 40–50 mg levan ml-1had been produced in medium containing 20% (w/w) sucrose but without l-glutamate. In medium containing l-glutamic acid but without sucrose, mainly poly(-glutamic acid) was produced.
Revisions requested 28 August 2004/14 October 2004; Revisions received 11 October 2004/22 November 2004 相似文献
6.
A Bacillus sp. RE was resistant to chromium and reduced Cr(VI) without accumulating chromium inside the cell. When Cr(VI) was 10 and
40 μg ml−1, >95% of the total Cr(VI) was reduced in 24 and 72 h of growth, respectively, whereas at 80 μg Cr(VI) ml−1 only 50% of Cr(VI) was reduced. However growth was not affected; the cell mass was 0.7–0.8 mg ml−1 in all cases. The cell-free extract showed Cr(VI) reducing enzyme activity which was enhanced (>5 fold) by NADH and NADPH.
Like whole cells the enzyme also reduced Cr(VI) with decreasing efficiency on increasing Cr(VI) concentration. The enzyme
activity was optimal at pH 6.0 and 30 °C. The enzyme was stable up to 30 °C and from pH 5.5 to 8, but from pH 4 to 5 the enzyme
was severely destabilized. Its Km and Vmax were 14 μm and 3.8 nmol min−1 mg−1 respectively. The enzyme activity was enhanced by Cu2+ and Ni2+ and inhibited by Hg2+.
Received 21 September 2005; Revisions requested 5 October 2005; Revisions received 16 November 2005; Accepted 16 November
2005 相似文献
7.
Nostoc muscorum, a heterocystous cyanobacterium, produced poly--hydroxybutyrate ( PHB) up to 8% (w/w) dry cells when grown photoautotrophically but 35% when grown mixotrophically with 0.4% (w/v) glucose and acetate after 21 d. Gas-exchange limitations under mixotrophy and chemoheterotrophy with 0.4% (w/v) acetate enhanced the accumulation up to 40–43% (w/w) dry cells, the value almost 5-fold higher with respect to photoautotrophic condition.Revisions requested/10 September 2004; Revisions received 9 September 2004/11 November 2004 相似文献
8.
The synthesis of optically active (R)-2-trimethylsilyl-2-hydroxyl-ethylcyanide by asymmetric trans-cyanation of acetyltrimethylsilane with acetone cyanohydrin in a biphasic system was achieved using (R)-oxynitrilase from loquat seed meal. Diisopropyl ether was the most suitable organic phase among the organic solvents examined. The optimal concentration of acetyltrimethylsilane, concentration of crude enzyme, volume ratio of the aqueous to the organic phase, temperature and the buffer pH value were 14 mM, 61.4 U ml-1, 13% (v/v), 30 °C and 4, respectively. The substrate conversion and the product enantiomeric excess were 95% and 98% under the optimized conditions. Acetyltrimethylsilane was a better substrate of the enzyme than its carbon counterpart.
Revisions requested 24 August 2004; Revisions received 12 November 2004 相似文献
9.
Laura Jaakola Anna Maria Pirttilä Minna Halonen Anja Hohtola 《Molecular biotechnology》2001,19(2):201-203
A simple and efficient method is described for isolating high quality RNA from bilberry fruit. The procedure is based on the
use of hexadecyltrimethyl ammonium bromide (CTAB), polyvinylpyrrolidone (PVP), and β-mercaptoethanol in an extraction buffer
in order to eliminate the polysaccharides and prevent the oxidation of phenolic compounds. This method is a modification of
the one described for pine trees, and yields high-quality RNA suitable for cDNA based methodologies. This method is applicable
for a variety of plant tissues. 相似文献
10.
Charleson R. Poovaiah Stephen C. Weller Matthew A. Jenks 《In vitro cellular & developmental biology. Plant》2006,42(4):354-358
Summary The effect of different cytokinins on in vitro adventitious shoot regeneration from internodal explants of Menthaxgracilis Sole (scoth spearmint) was investigated. Murashige and Skoog (MS) medium containing 100 mg l−1 myo-inositol, 0.4 mg l−1 thiamine-HCl, 2.0% (w/v) sucrose, 10% (v/v) coconut water and supplemented with 4.5 μM thidiazuron (TDZ) was effective in inducing adventitious shoot formation from callus. The greatest percentage of explants
with shoots (85%) with the highest mean number of shoots per explant (29) was obtained with explants from the 1st and the
2nd internodes from 2-wk-old stock plants growing on a medium containing MS basal salts, 2% sucrose, 100 mg l−1 myo-inositol, 0.4 mg l−1 thiamine-HCl, at TDZ 4.5 μM and 10% (v/v) coconut water and solidified with 0.2% (w/v) phytagel. The regenerated shoots rooted on a medium containing
MS basal salts, 100 mg l−1 myo-inositol, 0.4 mg l−1 thiamine-HCl, 2.0% sucrose, and 0.054 μM naphthalene acetic acid (NAA). Micropropagated plantlets were transplanted into soil and acclimated to greenhouse conditions.
This is the first report describing adventitious shoot regeneration of scotch spearmint. 相似文献