共查询到20条相似文献，搜索用时 312 毫秒
1.
为克服岸滩溢油生物修复过程中海浪冲刷等不利环境对石油降解菌(群)岸滩定植的影响,本文利用聚乙烯醇(PVA)和海藻酸钠作为载体对石油降解菌群DC10进行固定化,通过研究细菌固定化微球的机械性能、传质性能及石油降解特性等参数,确定石油降解菌群的最优固定化条件。实验结果表明:6%PVA,2%海藻酸钠及0.5%活性炭制备的凝胶可以通过蠕动泵方便快捷制备细菌固定化微球,其粘度小、易成型、机械强度高。海洋石油降解分析表明,与游离菌体(FB)相比,固定化菌群12d石油降解率提高了近7%;GC-MS分析显示,石油烷烃和芳烃降解效果显著。实验证明,石油降解菌群DC10经过固定化处理,其石油降解活性提高,连续降解能力增强,该研究为溢油岸滩的生物修复提供新的技术方法。 相似文献
2.
This study addresses the influence of calcium as hardening agent, on alginate gel bead stability and suitability for the growth of Phaeodactylum tricornutum Bohlin (Bacillariophyceae) in estuarine waters. Alginate beads produced with 1, 2, 4, 5 and 6% of CaCl2 solutions were investigated for stability and suitability for growth of P. tricornutum cells, under mean salinity 27, at 220 and 440 rpm stirring laboratory conditions, and in devices placed under in situ estuarine conditions. Gel stability and suitability for cell growth were evaluated through bead diameter, bead disruption, dissolution and loss of spherical shape, cell viability and specific growth rates. Beads gelled with 5% CaCl2 were found the most suitable to sustain gel stability and cell growth in the estuarine waters. These beads were surveyed during dredging operations in the Tagus estuary, both in situ and in estuarine water under laboratory conditions, showing significantly lowered growth rates possibly due to Mn, Co and As accumulated in the cells. Results confirmed that the monitoring tool presented is reliable and effective for the assessment of anthropogenic impacts. 相似文献
3.
包埋脱水法冷冻保存裙带菜配子体克隆的研究 总被引：6，自引：0，他引：6
将裙带菜配子体克隆包埋在含3%褐藻酸钙的胶球中,研究了预培养中的蔗糖浓度和培养时间,脱水过程中的脱水速率和胶球含水量以及化冻速度对配子体克隆的存活率和发育能力的影响,结果表明含裙带菜配子体克隆的胶球在0.3 mol/dm3的蔗糖培养基中培养9 h可以获得较高的存活率;胶球最适平均脱水速率为含水量的5%每小时,最适含水量为25%;较快的化冻速度可以显著提高配子体克隆的存活率,在优化条件下存活率可高达66%;经过冷冻保存的裙带菜配子体克隆在适合发育的条件下能够正常形成孢子体. 相似文献
4.
Thermal property is one of the most important properties of light-emitting diode (LED). Thermal property of LED packaging material determines the heat dissipations of the phosphor and the chip surface, accordingly having an influence on the light-emitting efficiency and the life-span of the device. In this paper, photoacoustic piezoelectric (PAPE) technique has been employed to investigate the thermal properties of polyvinyl alcohol (PVA) and silicon dioxide, which are the new and the traditional packaging materials in white LED, respectively. Firstly, the theory of PAPE technique has been developed for two-layer model in order to investigate soft materials; secondly, the experimental system has been set up and adjusted by measuring the reference sample; thirdly, the thermal diffusivities of PVA and silicon dioxide are measured and analysed. The experimental results show that PVA has a higher thermal diffusivity than silicon dioxide and is a better packaging material in the sense of thermal diffusivity for white LED. 相似文献
5.
INTRODUCTIONATislowKWCys-rich(aboutonethird)metal-bindingprotein,lackofaromaticaminoacidresidues.AThasbeenfoundinkidneysandliversofmanymammals,andalsoininvertebrates,microorganismsandplants.ThepresenceofanAT-likeproteinhasbeenfoundinanumberofaquaticorganisms,includingtheplaice(Overnelletal.,1977),rock-fish(Olafsonetal.,1974),goldfish(Marafant,1976),andcrabandshrimp(Olafsonetal.,1979).AThasbecomethesubjectofgreatInterestinrecentyearsduetotheirwideexistenceandmetalaffinity.Scientistsha… 相似文献
6.
以本实验室保存的萱藻(Scytosiphon lomentaria)丝状体为材料,用包埋脱水法超低温保存萱藻丝状体,研究了蔗糖预培养浓度和时间、胶球含水量、化冻温度以及胶球恢复时间对萱藻丝状体存活率和冻存后生长发育能力的影响。结果显示:(1)萱藻丝状体胶球在0.4mol/L的蔗糖溶液中预培养6h能获得最高的存活率;(2)萱藻丝状体胶球的最佳含水量较低,为15%左右,当含水量高于27%时,冻存后的存活率为0;(3)40°C为最适的化冻温度;(4)化冻后,将萱藻丝状体胶球在黑暗条件下恢复18h能显著提高存活率;(5)在最佳条件下,萱藻丝状体经冻存后的存活率最高可达54.79%,恢复后的丝状体与冻存前丝状体并无区别,且经诱导后能够产生正常的孢子囊,放散的孢子可以发育成叶状体。 相似文献
7.
不同氮源对微小亚历山大藻生长和毒素产生的影响 总被引：12，自引：0，他引：12
通过尿素、氯化铵、酵母浸出粉和硝酸钠等氮源对微小亚历山大藻(Alexandrium minutum)生长及毒素产生的影响研究,分析了微小亚历山大藻对不同氮源利用状况的差异.结果表明,在氮饥饿条件下,加入硝酸钠和酵母浸出粉能显著促进微小亚历山大藻的生长;高浓度的氯化铵在加入后对微小亚历山大藻有一定的毒性效应,表现为生长停滞,但毒性效应在5 d后消失,并得到与添加硝酸钠及酵母浸出粉相似的增长速率0.21 d-1;添加尿素对微小亚历山大藻的生长没有显著促进作用.在四种氮源中,尿素对微小亚历山大藻毒素产生的刺激作用也最弱,在稳定期每个细胞藻细胞毒素含量维持在6.00~8.00 fmol;添加硝酸钠、氯化铵和酵母浸出粉的藻细胞在稳定期毒素含量分别达到11.85,12.86和14.64 fmol.硝酸钠和氯化铵刺激藻毒素产生的效果比酵母浸出粉更为直接.四种含氮营养盐对微小亚历山大藻毒素组成的影响都很小. 相似文献
8.
在简要评述甲壳素和壳聚糖的资源、产业及其应用特点的同时,着重叙述壳聚糖微孔树脂的制备、性质、功能和应用,从而展示壳聚糖及其微孔树脂的发展前景。 相似文献
9.
Dynamic measurement of sediment grain compressibility at atmospheric pressure: acoustic applications
Richardson N.D. Williams K.L. Briggs K.B. Thorsos E.I. 《Oceanic Engineering, IEEE Journal of》2002,27(3):593-601
Under certain conditions, Wood's equation can be used to predict sound speed in fluid/solid-grain suspensions if the bulk moduli and densities of the grains and fluid are known. In this paper, that relationship is used to estimate grain-bulk moduli in suspensions where sound speed, fluid density, fluid bulk modulus, grain density, and particle concentrations are known or accurately measured. Measured values of grain-bulk moduli for polystyrene beads suspended in water (mean = 4.15 /spl times/ 10/sup 9/ Pa) and soda-lime glass beads suspended in a "heavy liquid" (mean = 3.8 /spl times/ 10/sup 10/ Pa) are consistent with the values of bulk moduli for polystyrene beads and soda-lime glass beads found in the literature (3.6 to 4.2 /spl times/ 10/sup 9/ Pa and 3.4 to 4.0 /spl times/ 10/sup 10/ Pa, respectively). These measurements thus provide controls, which demonstrate the validity of the suspension technique to estimate values of particle bulk modulus. The values of bulk modulus, measured using the same suspension techniques, for Ottawa sand and quartz sand grains collected from the coastal sediments of the northeast Gulf of Mexico ranged between 3.8 and 4.7 /spl times/ 10/sup 10/ Pa, with 95% confidence limits between 3.0-5.7 /spl times/ 10/sup 10/ Pa. These measured values of bulk modulus are consistent with the range of handbook values for polycrystalline quartz (3.6 to 4.0 /spl times/ 10/sup 10/ Pa). The use of the lower bulk modulus (i.e., 7.0 /spl times/ 10/sup 9/ Pa) recently suggested by Chotiros is therefore inappropriate and traditional handbook values of sediment grain-bulk moduli should be used as inputs for sediment acoustic modeling. 相似文献
10.
Sewage disposal is a major environmental issue in both developed and developing countries and removal of pollutants such as organic matter, nutrients, heavy metals and persistent organic compounds is required to protect the environment. Novel biological systems using constructed mangrove wetland and immobilized microalgal beads have been developed as alternative systems for treating different types of sewage and pollution at source. The feasibility and efficiency of constructed mangrove wetland to remove organic matter and nutrients from primary settled municipal sewage were demonstrated through a series of greenhouse experiments and a pilot-scale field trial. The treatment efficiency of constructed mangrove wetland was comparable to, or higher than, the conventional constructed wetland. An immobilized microalgal system was developed to remove toxic persistent pollutants from industrial wastewater. Pollutant-resistant microalgal species were selected for culture in domestic wastewater. The harvested biomass was immobilized in alginate beads. Bench-scale experiments showed the algal beads were effective in removing industrial pollutants such as heavy metals (e.g. Cu, Zn, Ni, Cr, etc.), organometallic compounds (e.g. tributyltin, TBT), and persistent organic compounds (e.g. polycyclic aromatic hydrocarbons, PAHs) through biosorption and biodegradation. The adsorbed metals could be recovered by desorption process, and the beads could be used repeatedly for many adsorption–desorption cycles. 相似文献
11.
在海洋环境中的酵母菌分布与多样性 总被引：1，自引：0，他引：1
最近几年作者对不同海洋环境中的酵母资源、分布和多样性进行的大量研究,从中发现了22属63种1051株。并且发现这些广泛分布在海水、海泥、高盐海水、深海、各种大型海藻表面、各种海鱼体表和体内和红树林生态系统中。不同种的酵母可以产生蛋白酶、脂酶、植酸酶、菊糖酶、纤维素酶、β-1,3-葡聚酶、嗜杀因子、核黄素、铁载体等活性产物,所以这些酵母菌具有广泛的实际用途。 相似文献
12.
Isolation and identification of a marine killer yeast strain YF07b and cloning of the gene encoding killer toxin from the yeast 总被引：1，自引：0，他引：1
It was found that the marine yeast strain YF07b could secrete a large amount of killer toxin against a pathogenic yeast strain WCY which could cause milky disease in Portunus trituberculatus.The marine yeast strain YF07b was identified to be Pichia anomala according to the results of routine yeast identification and 18S rDNA and ITS sequences.The gene encoding killer toxin in the marine yeast strain YF07b was amplified by PCR technology.After sequencing,the results show that an open reading frame,consisting of 1 281 bp,encoded a presumed protein of 427 amino acids.The sequence of the cloned gene was found to have 99% match with that of the gene encoding killer toxin in Pichia anomalas strain K.A signal peptide including 17 amino acids appeared in the N-terminal domain of the killer toxin.Therefore,the mature protein consisted of 410 amino acids,its molecular mass was estimated to be 47.4 ku and its isoelctronic point was 4.5. 相似文献
13.
14.
转鲑鱼生长激素基因酵母菌发酵特性的研究 总被引：2，自引：1，他引：1
张培军、Ball等研究表明,外源性生长激素通过注射或浸泡的方法可加快鱼的生长[1]。根据Mclean1987年、Shunsuke等1993年研究发现鱼类后肠具有吸收部分生长激素进入血液循环的特点,本研究室将鲑鱼生长激素基因克隆进无毒无害的酵母菌中,利用可控制的诱导条件,培养出含鲑鱼生长激素的酵母菌,直接掺入饵料,使生长激素通过消化道吸收,以促进鱼的生长。Jacqueline等1989年指出,由于携带外源基因的酵母菌与普通酵母菌的培养要求不同,既要促使菌体快速生长又要保证外源基因的表达,本研究的目的在于选择适宜的培养条件,实现转基因酵母菌的高密度培… 相似文献
15.
三株海洋酵母的生化营养成分分析 总被引：1，自引：0，他引：1
海洋酵母是一种重要的水产生物饵料.实验对3株海洋酵母菌德巴利酵母Debaryomyces sp.、克鲁维酵母Kluyveromyces sp. 和虫道酵母Ambrosiozyma sp.的基础营养成分进行了研究和分析.3株海洋酵母菌的粗蛋白含量分别为56.87%、46.75%、51.80%;脂肪分别为4.67%、6.35%、6.35%;碳水化合物分别为31.28%、41.55%、35.96%;灰分分别为7.18%、5.35%、6.37%.3株海洋酵母菌具有较高的蛋白含量水平以及优良的氨基酸和脂肪酸组成,表明该3株海洋酵母菌具有用作水产饵料生物的营养价值.但是,3株海洋酵母菌均缺乏多不饱和脂肪酸EPA和DHA,用其作为水产饲料源料,需要在配合饲料中添加多不饱和脂肪酸或与富含多不饱和脂肪酸的藻类一起使用. 相似文献
16.
采用磁珠富集法及利用生物素标记的(CA)15寡核苷酸探针从波纹唇鱼(Cheilinus undulatus)基因组DNA Bsp143Ⅰ酶切位点的400~1000 bp片段中筛选CA/GT微卫星位点。洗脱的杂交片段克隆到PMD18-T载体上构建富集微卫星基因组文库后,通过PCR筛选出阳性克隆进行测序。在120条序列中有88条序列包含有重复次数不少于5次的微卫星位点,阳性序列比例达到73.33%。其中完美型(perfect)类型微卫星最多的重复次数为26次。在88条非冗长序列中,共有28条(31.82%)微卫星重复序列两端有侧翼序列能够进行引物设计。用波纹唇鱼3个个体的混合基因进行引物筛选,其中的24对具有清晰的扩增条带。将筛选的24对引物对波纹唇鱼1个群体的39个个体进行遗传多样性分析,其中4对引物扩增产物为单态,20对扩增产物呈多态性;20对扩增多态的引物在39个个体中扩增出等位基因数为2~12,平均有效等位基因数为3.5。该波纹唇鱼群体的PIC、Ho、He的平均值分别为0.0782、0.8513、0.5667。这20个微卫星位点适于波纹唇鱼群体遗传结构的研究分析。 相似文献
17.
利用酒精酵母细胞表面展示技术制备活疫苗及其潜在应用 总被引：1，自引：0，他引：1
最近几年，出现把有关的基因在宿主表达之后的目的蛋白分泌并固定在细菌、病毒和酵母菌细胞表面上的技术一表面展示技术。在这些宿主中，酒精酵母菌是最佳的微生物。本文对利用酒精酵母细胞表面展示技术制备活疫苗的基本原理，在酵母细胞表面展示蛋白质的优点，以及哈维氏弧菌溶血素蛋白在酵母菌细胞表面上展示及其作为活疫苗的潜在应用作了综述。研究结果表明在酒精酵母菌细胞表面上展示的哈维氏弧菌溶血素蛋白在海洋动物中具有很好的免疫原性和免疫保护性。 相似文献
18.
Abstract. Organic substances are suspected to influence the unpredictable, episodic blooms which characterize the planktonic pennate diatom Asterionella glacialis in certain coastal waters. Experiments to test its general responsiveness to organic enrichments in terms of growth rate and colony formation were carried out. An axenic clone was grown at 10° C, 0.039 l min-1 ,12:12 LD cycle in G uillard's f/2 medium enriched with eight different organic substances. Growth rates in organically-enriched media during exponential phase usually exceeded those in f/2 medium alone. Cell yields after 12 days in media enriched with glycyl-glycin and trypticase + yeast extract were significantly greater than in the other treatments. Longer chain lengths accompanied organic enrichment, notably with trypticase + yeast extract and 100ppm soil extract. These results suggest that Asterionella glacialis is positively responsive to elevated levels of certain organic substances. A potential effect of organic substance - trace metal - silica interactions on colony-size is suggested. 相似文献
19.
20.
酵母双杂交系统是一种新兴的体内研究蛋白质之间相互作用以及筛选cDNA文库的技术手段,自建立以来得到了不断的改进与发展。在此基础上又相继出现了单杂交、三杂交、反向双杂交以及SOS富集系统等多种衍生系统,它们在功能基因组学、蛋白质组学以及药物开发研究中发挥了重要作用。本文拟就双杂交系统的原理、改进、发展及应用做一综述。 相似文献