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1.
SUMMARY: In detailed studies of the growth of Aspergillus ustus, Penicillium oxalicum, P. frequentans and P. notatum in whey with fat production in view, the first two showed the highest lactose utilization and felt weights in shaken cultures while the last two gave as good or better felt yields in stationary cultures.
When A. ustus was grown in shaken culture in whey with and without the addition of 1·14 g/1. of ammonium nitrate, the extra nitrogen led to the production of larger amounts of fat, but P. frequentans did not form additional fat in these circumstances. A. ustus was the best mould; in whey plus ammonium nitrate it utilized up to 96% of the lactose and formed, per litre of whey, about 17 g of mycelial felt containing 13% of protein and 28% of fat.  相似文献   

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1. The metabolism of chick embryo tissues has been followed by analysis of the culture media after various periods of incubation in roller bottles. 2. The initial rate of glucose utilization is increased by increasing glucose in the medium from 100 to 500 mg. per cent. Total glucose used can be increased in the same way or by daily addition of small amounts. Glucose is used in greatest amount when the medium containing 100 mg. per cent is replaced daily. 3. Although glucose consumption appears necessary for survival of cultures it may be used at a rate far in excess of that required for life and maximal growth. Complete blocking of mitosis by colchicine does not alter the rate of glucose utilization. 4. Proteolytic activity of the cultures is shown by an increase in the amino nitrogen of the peptone medium after incubation with tissue. 5. Utilization of nitrogen from an amino acid medium is shown by a decrease in the amino nitrogen of this medium. Cells obtaining their nitrogen from amino acids proliferate as rapidly as those grown in a medium identical except for the substitution of peptone, but the cell type is markedly different, in that embryo muscle forms cells resembling regenerating adult muscle. 6. Lactic acid was formed in both the presence and absence of glucose. Its formation increased with increased glucose utilization. There is some evidence that lactate may be utilized, and that it favors growth in the absence of glucose. 7. Added pyruvate was rapidly metabolized by the tissues. It, too, favors growth slightly in the absence of glucose.  相似文献   

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本文报道了广东3属14种和变种的小煤炱菌,其中含笑生附丝壳(Appendiculella michelicola Yang)、马比花生小煤炱(Meliola mappianthicola Yang)是新种,其余为国内新记录。文中有种和变种检索表。  相似文献   

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本文报道了广东3属14种和变种的小煤炱菌,其中含笑生附丝壳(Appendiculella michelicola Yang)、马比花生小煤炱(Meliola mappianthicola Yang)是新种,其余为国内新记录。文中有种和变种检索表。  相似文献   

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用Ciprofloxacin去除传代细胞株中的支原体污染的研究   总被引:1,自引:0,他引:1  
在应用细胞培养手段的生物学研究和生物工程产品中,支原体污染仍是一个非常棘手的问题。对Vero和SP2/0-Ag14等细胞,应用Ciprofloxacin,10μg/ml处理14天,支原体检测全部转阴,经4个月的培养、传代、冻存、复苏,每次支原体检测均保持阴性。对去除了支原体的Vero和ISC-116细胞株,测试了其生长特征和功能,均未见受影响。  相似文献   

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A stable colloidal suspension of barium sulfate has been developed and tested in roentgen examination of the gastrointestinal tract. The new material is rather distinctive in radiographic appearance and can usually be differentiated from simple barium-water mixtures by inspection of roentgenograms of the opacified stomach and small intestine. It usually affords a satisfactory demonstration of the mucosal folds of the stomach and duodenal bulb and is considerably more resistant to flocculation and precipitation by retained gastric secretions. In the small intestine, it has little tendency to undergo flocculation and fragmentation, and permits visualization of fine mucosal configurations with unusual clarity. Its motility is about the same as that of conventional suspensions. Air contrast colon examinations with the colloidal preparation exhibit a very uniform, opaque, and stable coating of the bowel wall and are more consistently satisfactory than when simple barium-water mixtures are used.  相似文献   

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来自山东泰安和安徽合肥匍柄霉属的两个新种分别命名为棉匍柄霉Stemphylium gossypii和莴苣匍柄霉Stemphylium lactucae。模式标本保存于山东农业大学植物病理系标本室(HSAUP)。  相似文献   

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Tissue cultures lacking chlorophyll formed porphyrins when fed δ-aminolevulinic acid, a precursor of tetrapyrroles. When grown in the dark tissues from Ginkgo biloba L., Taxus, and Rosa formed protoporphyrin and several unidentified compounds. When grown in the light cultures did not form these pigments. The protoporphyrin was detected in the tissues after 3–6 hours incubation with δ-aminolevulinic acid; it was localized in the plastids by ultraviolet light microscopy and was identified by extraction procedures, chromatography, and absorption spectroscopy. No magnesium protoporphyrins were found, suggesting that chlorophyll synthesis was blocked at this point. Both male and female haploid albino tissues from Ginkgo formed protoporphyrin. The female albino tissue was derived from a chlorophyll-containing tissue culture from the female gametophyte by serially subculturing the green tissue in the dark. Upon exposing the female albino tissue to light, no greening occurred. The treatments used thus far have not caused chloroplasts to develop in the haploid albino tissues, even though the tissues contain many amyloplasts. Concurrent with the loss of chloroplasts, the female tissue loses all capacity to differentiate specialized cells, such as tracheids, resin cells, and chlorenchyma.  相似文献   

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范亚文  包文姜 《植物研究》1997,17(4):371-376
利用光学显微镜和扫描电镜对东北异极藻科植物3属8个分类单位即:异极藻属2种2变种1变型:细异极藻箭头变处G.sabtile var.saggita(Schum..)Cl.K.,缢缩异极藻头状变种意大利变型G.constrictum var.capitatum f.itallica Mayer.,柔弱异极藻G.tenellum Kutz.,半孔异极藻G.semiapertum Grun.长异极藻延长  相似文献   

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邓春匡   《广西植物》1983,(1):67-76
<正> 广西硅藻羽纹纲的无壳缝目、单壳缝目和短壳缝目的种类及分布情况,过去虽然有许多藻类工作者作了大量工作,但至目前为止,还未见正式报导。现根据本人1978年参加中国孢子植物志《硅藻志》工作以来所采到的标本,选择了103号,进行酸处理及分类鉴定,初步鉴定属于羽纹纲无壳缝目的硅藻有8属11种20变种2变型、短壳缝目1属6种3变种、单壳缝  相似文献   

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本文报道了液体培养灵芝Gl8801菌林产生胞外多糖的最佳发酵条件和胞外多搪的化学组成。适宜的液体培养基(g/L):饴糖40,花生饼粉30,KH_2PO_41.5,(NH_4)_2SO_41.5,MgSO_4·7H_2O_(0.75),CaCO_32,最适起始pH5.5。300ml三角瓶装培养基60ml,发酵温度28℃。摇瓶(165rpm)培养7~8天,发酵液纯多糖含量可达880mg/L。灵芝胞外多糖分为水溶性多糖和水不溶性多糖两种。水溶性多糖的单糖组份为半乳糖、葡萄糖、阿拉伯糖和木糖,所含单糖重量比为6:4:4:1。不溶性多糖为葡聚糖。灵芝胞外多糖的糖环构型为吡喃糖,末端糖基构型,半乳糖为α型,葡萄糖为β型。  相似文献   

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The distribution of Chinese hamster cells with respect to the compartments of the cell generation cycle was studied in cultures in the stationary phase of growth in two different media. A measure of the state of depletion of the nutrient medium was formulated by defining a quantity termed the nutritive capacity of the medium. This quantity was used to verify that the cessation of cell proliferation is due to nutrient deficiencies and not to density dependent growth inhibition. Cell cultures in stationary phase were diluted into fresh medium and as growth resumed, mitotic index, cumulative mitotic index, label index and viability were measured as a function of time. The distribution of cells with respect to compartments of the cell generation cycle in stationary phase populations was reconstructed from these data. Stationary phase populations of Chinese hamster cells that retained the capacity for renewed growth when diluted into fresh medium were found to be arrested in the G1 and G2 portions of the cycle; the relative proportion of these cells in G1 increased with time in the stationary phase, but the sequence differs in the two media. In early stationary phase, in the less rich medium, more cells are in G2 than in G1. Also in this medium a fraction of the population was observed to be synthesizing DNA during stationary phase, but this fraction was not stimulated to renewed growth by dilution into fresh medium.  相似文献   

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为了深入研究七星瓢虫的卵黄发生及其激素调节机理,我们建立了脂肪体的体外培养方法,证明了脂肪体在体外培养条件下能够正常进行卵黄原蛋白的合成与分泌。在体外合成的卵黄原蛋白与体内合成的具有相同的电泳迁移率、免疫学特性和部分水解肽谱。放射性氨基酸在体外参人卵黄原蛋白的动力学与在体内的相似。用脂肪体的体外培养方法,结合放射免疫沉淀、SAS-聚丙烯酰胺凝胶电泳、放射自显影等技术,研究了不同发育期脂肪体的合成能力,以及取食人工饲料的雌虫中保幼激素类似物对卵黄原蛋白合成的促进作用。  相似文献   

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Hot water-soluble polysaccharides were extracted from field colonies and suspension cultures of Nostoc commune Vaucher, Nostoc flagelliforme Berkeley et Curtis, and Nostoc sphaeroides Kützing. Excreted extracellular polymeric substances (EPS) were isolated from the media in which the suspension cultures were grown. The main monosaccharides of the field colony polysaccharides from the three species were glucose, xylose, and galactose, with an approximate ratio of 2:1:1. Mannose was also present, but the levels varied among the species, and arabinose appeared only in N. flagelliforme. The compositions of the cellular polysaccharides and EPS from suspension cultures were more complicated than those of the field samples and varied among the different species. The polysaccharides from the cultures of N. flagelliforme had a relatively simple composition consisting of mannose, galactose, glucose, and glucuronic acid, but no xylose, as was found in the field colony polysaccharides. The polysaccharides from cultures of N. sphaeroides contained glucose (the major component), rhamnose, fucose, xylose, mannose, and galactose. These same sugars were present in the polysaccharides from cultures of N. commune, with xylose as the major component. Combined nitrogen in the media had no qualitative influence on the compositions of the cellular polysaccharides but affected those of the EPS of N. commune and N. flagelliforme. The EPS of N. sphaeroides had a very low total carbohydrate content and thus was not considered to be polysaccharide in nature. The field colony polysaccharides could be separated by anion exchange chromatography into neutral and acidic fractions having similar sugar compositions. Preliminary linkage analysis showed that 1) xylose, glucose, and galactose were 1→4 linked, 2) mannose, galactose, and xylose occurred as terminal residues, and 3) branch points occurred in glucose as 1→3,4 and 1→3,6 linkages and in xylose as a 1→3,4 linkage. The polymer preparations from field colonies had higher kinematic viscosities than those from correspondingsuspension cultures. The high viscosities of the polymers suggested that they might be suitable for industrial uses.  相似文献   

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