Selection and proliferation of rapid growing cell lines from embryo derived cell cultures of yew tree (Taxus cuspidata Sieb. et Zucc)

Calli were induced from 300,000 embryos isolated from immature to mature stage of seeds collected on late September from 14 elite trees. When the embryos were cultured onto plastic Petri-dish containing 20 mL of modified B5 basal medium supplemented with 3% (w/v) sucrose, 500 mg/L casein hydrolysate, 250 mg/L myo-inositol, 0.5% (w/v) polyvinyl polypyrrolidon (PVPP), 2×MS vitamins, 0.5 mg/L gibberellic acid, and 10 mg/L 2,4-D after 2 weeks of culture, yellowish-white calli were immediately formed on the surfaces of embryos, and subcultured for 4 weeks in same culture medium. Because most of calli maintained for more than 3 months were revealed differences in their colors, surface texture, and growth rate, visual selection was made for first round screening. When the size of visually selected calli larger than 19 mm in their diameter were inoculated, persistent proliferation was observed. Among the plating methods tested for the selection of rapid growing cell lines at single cell and/or small cell aggregate level, 2-layer spread plating revealed as the best for single cell cloning. To enhance cell growth and maintain high rate of viability for long-term culture of yew cells in bioreactor, final cell volume less than 50% in SCV seemed to be the best. Time course study revealed that 30% of inoculum density was suitable for fed batch culture. Among the tested conditional media, the rate of 1∶2 (old medium: fresh medium) was recorded at the best for cell growth.     

Effect of oxygen on ethanol fermentation in packed-bed tapered-column reactor

Summary In ethanol production with immobilized yeast a major problem is the provision of nutrients to these highly concentrated cells. O₂ being one of the nutrients of utmost importance to yeast cells, was fed into a column packed with beads with a cell loading of more than 40 g/l. Since addition of large volume of air or O₂ to a cylindrical column reactor would aggravate the problems of pressure build up and channelling caused by the evolving CO₂ gas, a tapered-column reactor and pulsed flow of oxygen gas was used. The supplement of O₂ gas to the tapered column increased the productivity from 21.1 g ethanol x (l gel x h)^-1 to 26.7 g x (l gel x h)^-1, when the ethanol concentration at the outlet was about 80 g/l. The yield coefficient of ethanol was also increased from 0.41 g ethanol/g glucose to 0.43 after O₂ supplement was started. The effects of frequency and duration of O₂ supplement were also determined.     

Macrophytes and flood plain water dynamics in the River Danube ecotone research region (Austria)

In the ecotone research region of the Danube in Austria (Man-and-the-Biosphere (MaB)- project 5/21, Austrian Academy of Science) the macrophytes are one of the most important groups of organisms investigated. The species composition and the plant mass in hydrologically dynamic, and in predominantly stagnant sections of a system of lateral branches and sloughs were studied. This study showed that areas protected from frequent disturbance by floods had a greater number of species and higher biomass of aquatic macrophytes. Some species were shown to be evenly distributed throughout the branch system, whereas other species tended to form rare, but large singular patches. A set of new data elaboration techniques enabled us to describe the distribution pattern of the aquatic vegetation in this large branch system of the River Danube.     

Modification of the Dittmer-Lester reagent for the detection of phospholipid derivatives on thin-layer chromatograms.

A simple modification of the Dittmer-Lester reagent is described that allow the detection of phospholipid derivatives at very low concentrations on silica gel and reversed-phase thin-layer plates. This modification, which involves the addition of acetic acid to the mixture, permits the observation of sharp blue spots on a white background. The specificity and sensitivity of the spray are discussed.     

Genetic recombination in Micromonospora rosaria by protoplast fusion

Auxotrophic strains of Micromonospora rosaria were isolated by N-methyl-N'-nitro-N'-nitrosoguanidine mutagenesis and used in intraspecific recombination by protoplast fusion. High-frequency fusion of protoplasts of M. rosaria strains was induced by polyethylene glycol (molecular weight, 1,000) (PEG 1,000). The optimum concentration of PEG 1,000 for fusion of M. rosaria was 50% (wt/vol). PEG 4,000 was slightly better than PEG 1,000 at concentrations lower than 50% (wt/vol). The recombinant frequency did not increase after treatment with PEG 1,000 (50% [wt/vol]) for longer than 20 min. Under these conditions, fusion with many auxotrophic strains of M. rosaria resulted in a high frequency of formation of true recombinants (sometimes more than 10%). Additionally, when ros (rosamicin nonproducing) strains were crossed by protoplast fusion; about 5% of the resultant prototrophic recombinants were shown to have the ros+ (rosamicin producing) characteristic restored. Rosamicin production by M. rosaria colonies was clearly distinguished by the broth overlay method. The results of fusion experiments between ros and ros+ strains indicated that either the chromosomal mutation or pleiotrophic effect of some auxotrophic markers is involved.     

Purification and some properties of a phospholipase A2 from bovine platelets

An intracellular form of phospholipase A2 was purified about 47,500-fold to near homogeneity from bovine platelets 100,000 x g supernatant by sequential use of column chromatographies on Heparin-Sepharose, DEAE-Sephacel, Butyl-Toyopearl, Sephacryl S-300, DEAE-5PW HPLC, TSK G 3000 SW HPLC and Mono Q FPLC. The final preparation showed a single band on SDS-polyacrylamide gel, and its molecular mass was estimated to be approximately 100,000 daltons. The purified PLA2 showed maximal activity at alkaline pH(pH 9.0-10.0) and considerable activity at 0.3-1.0 microM calcium concentration. It hydrolyzed phosphatidylcholine containing arachidonate at sn-2 position with high selectivity in comparison to linoleate.     

GDSL lipase-like 1 regulates systemic resistance associated with ethylene signaling in Arabidopsis

Systemic resistance is induced by necrotizing pathogenic microbes and non-pathogenic rhizobacteria and confers protection against a broad range of pathogens. Here we show that Arabidopsis GDSL LIPASE-LIKE 1 (GLIP1) plays an important role in plant immunity, eliciting both local and systemic resistance in plants. GLIP1 functions independently of salicylic acid but requires ethylene signaling. Enhancement of GLIP1 expression in plants increases resistance to pathogens including Alternaria brassicicola , Erwinia carotovora and Pseudomonas syringae , and limits their growth at the infection site. Furthermore, local treatment with GLIP1 proteins is sufficient for the activation of systemic resistance, inducing both resistance gene expression and pathogen resistance in systemic leaves. The PDF1.2 -inducing activity accumulates in petiole exudates in a GLIP1-dependent manner and is fractionated in the size range of less than 10 kDa as determined by size exclusion chromatography. Our results demonstrate that GLIP1-elicited systemic resistance is dependent on ethylene signaling and provide evidence that GLIP1 may mediate the production of a systemic signaling molecule(s).     

Comparative analysis of the anxiety-related behaviors in four inbred mice

An anxiety-related behavior is an emotional response of an organism, which is quantitatively measured by several behavioral paradigms. We employed two most frequently used behavioral tests, the open field and light-dark exploration, to comparatively analyze the anxiety-like behaviors in four inbred mice. For an accurate recording of movement, motion analysis software was developed that acquires a real-time video input to generate a behavioral path. Effects of the strains on the test results were evaluated by ANOVA with the Newman-Keuls post hoc comparison. Eight different behavioral indices, four from each tests, were grouped into two classes; the results of duration, center crossing, transition, rearing, and ambulation indicate strain differences of FVB/N>C57BL/6J>/=BALB/cA>/=CBA/N (I), while stretched-attend posture, peeping, and defecation show the tendency of FVB/N=C57BL/6J相似文献