塔玛亚历山大藻对氮和磷的吸收及其生长特性

参照塔玛亚历山大藻(Alexandrium tamarense)赤潮爆发时的物理条件,以f／2加富的人工海水为培养基,设定了不同的氮、磷水平,研究了在室内批量培养条件下,塔玛亚历山大藻对无机氮、磷的吸收和无机氮、磷对塔玛亚历山大藻细胞生长的影响．结果表明,3种氮浓度条件下,塔玛亚历山大藻的比生长速率几乎没有差异,但低氮(0．0882mmol·L-1)条件下,藻细胞的生物量最低;中氮(0．882mmol·L-1)条件下,藻细胞具有最大的生物量,分别比高氮(2．646mmol·L-1)和低氮下增加44．7％和53．6％．随着培养基中磷浓度的升高,藻细胞生物量也升高,在高磷(0．108mmol·L-1)条件下达到最大值17200cell·ml-1,但在中磷(0．036mmol.L-1)条件下藻细胞具有最大的比生长速率．藻细胞对氮、磷的吸收速率与生长状态有密切关系,氮、磷限制条件下生长的藻细胞对氮、磷有快速的吸收．研究显示,低的N／P比有利于塔玛亚历山大藻的生长分裂,对数生长后期适当补氮则有利于其生物量的积累．     

极地雪藻在不同培养基中生长和虾青素累积的研究

在常温（23℃）和低温（10℃）条件下,用BBM、Bold 1NV、TAP和MCM四种培养基对极地雪藻进行培养。通过对生长速率、细胞数、A535值及虾青素累积量的测定,比较不同培养基、不同培养条件对极地雪藻的生长与虾青素累积的影响。结果表明,低温有利于极地雪藻的生长和虾青素的累积,BBM培养基比其它培养基更适合极地雪藻的生长,10℃时条件下其生长速率最高,培养14d细胞数可达到3．53×10^6／mL;在高光强条件下培养15d后用BBM培养基培养的极地雪藻细胞的虾青素累积为其它培养基的2．21-3．59倍。     

不同接种浓度绿球藻对水产养殖废水净化的影响

通过设置绿球藻(Chlorococcum sphacosum GD)的起始接种浓度(25—400 mg/L),研究其对水产养殖废水的处理效果及藻细胞的生长特性。研究结果表明,起始接种浓度为100 mg/L的绿球藻藻液,其生长特性最佳,比生长速率最大,倍增时间最短。随着起始接种浓度的增加,生长速率逐渐降低,倍增时间逐渐增加。在起始接种浓度为100 mg/L的条件下,在5d的培养周期内,绿球藻能够去除水产养殖废水中96.92%的COD、98.08%的氨氮、98.67%的亚硝氮、91.42%的硝氮及98.36%的总磷。低起始接种浓度(尤其是100 mg/L)有利于绿球藻的生长和污染物降解。研究初步探明了微藻起始接种浓度对水产养殖废水处理效果的影响。通过控制微藻接种浓度有望在提高污染物去除率的同时缩短培养周期并提高容积负荷,为今后微藻用于大规模水产养殖废水的处理提供了一定的理论支持。     

白色LED复合光谱对4种淡水微藻的影响

利用光效高、耗能小的LED光谱作为光源培养微藻能够降低微藻培养的成本,促进微藻培养实现工业化。比较了6种已市场化的,具有不同光强、不同光谱组成的白色LED复合光谱(1号,光强2 162 lx;2号,光强2 227lx;3号,光强2 794 lx;4号,光强4 587 lx;5号,光强5 356 lx;6号,光强6 244 lx)对4种淡水微藻生长情况和叶绿素含量的影响。结果发现:四尾栅藻在5号光源下,有最大生物质质量浓度和比生长速率,分别为2.89 g/L和0.32g/(L·d)(以细胞干质量计);钝顶螺旋藻在4号光源下,有最大生物质质量浓度和比生长速率,分别为5.05 g/L和0.33 g/(L·d);布朗葡萄藻在6号光源下,有最大生物质质量浓度和比生长速率,分别为1.22 g/L和0.25g/(L·d);而集胞藻在光强较小的光源下生长较好,当光强为2 162 lx时,生物质质量浓度和比生长速率分别为3.05 g/L和0.22 g/(L·d)。在光强较低的情况下,光质的红蓝比对四尾栅藻和布朗葡萄藻的生长没有显著影响(p0.05);与蓝光相比,红光更利于集胞藻和钝顶螺旋藻的生长,分别在红蓝比(R/B)为11.7的1号光源和4号光源下有最大藻细胞密度3.05和5.05 g/L。四尾栅藻、钝顶螺旋藻和布朗葡萄藻的单位水体内叶绿素含量与比生长速率成正比,而单位质量干藻细胞内的叶绿素含量随光强的增大而有所降低。     

一种快速检测分离溶藻细菌方法的初探

传统的细菌培养基对铜绿微囊藻具有毒性作用。会大大影响溶藻细菌的筛选效率和准确性。通过基本培养基各成分对铜绿微囊藻DS的作用研究发现,培养基中的葡萄糖成分对藻有抑制作用,并且这种抑制作用与培养基中的葡萄糖浓度密切相关,当培养基中葡萄糖的浓度在0．1～0．4g/L时,藻细胞生长受到抑制,当用柠檬酸三钠取代葡萄糖后,铜绿微囊藻在改良后的培养基中生长正常,与对照组相比无显著性差异(P＜0．05)。用改良的培养基富集水样中的溶藻微生物,并用此培养液直接感染宿主藻,一周内即可初步快速检测是否含有溶藻细菌。此种方法既排除了培养基的干扰因素,又迅速增加了溶藻细菌的生物量,并可大量收集细菌分泌的胞外物质,为溶藻细菌尤其以分泌物质溶藻的细菌的初步筛选提供了一条快捷、有效的途径。     

几种固沙荒漠藻的温度适应性

蓝藻结皮在干旱和半干旱区广泛分布,它们在环境状态的维持和改良过程中发挥着重要的作用。在荒漠藻固沙技术的应用过程中,温度不仅影响藻类在培养池中的培养,还影响接种后藻类的生长。因此,摸清优势固沙藻类的温度生长特征及对不同温度的生长适应性,对于接种蓝藻固沙技术的应用具有积极的意义。实验分3部分:研究了室温培养条件下3种荒漠优势蓝藻-具鞘微鞘藻(Microcoleus vaginatus)、爪哇伪枝藻(Scytonema javanicum)、纤细席藻(Phormidium tenue)的生长曲线,在不同温度(2、5、10、15、25、35℃)、开放式载体培养状态下3种蓝藻的生长状况及形态观察,以及爪哇伪枝藻在不同温度(10、15、20、25、30℃)培养条件下的光合活性、光合色素含量和伪枝藻素含量的变化。实验结果表明:(1)在液体培养基中,纤细席藻生长速率最快,高于具鞘微鞘藻和爪哇伪枝藻;(2)开放式载体培养条件下,藻株的生长速率低于液体培养,因此荒漠优势藻类的培养优先选择液体培养,具鞘微鞘藻和爪哇伪枝藻不易被细菌污染,纤细席藻容易受到细菌污染,在培养该藻株时要考虑添加抗生素类药物抑制细菌过度繁殖;(3)爪哇伪枝藻短期培养(18d)宜选择相对较高的培养温度(25-30℃),而长期培养(30d)宜选择相对较低的培养温度(15-20℃)。       

粗枝软骨藻Chondria crassicaulis组织培养初探

在固体培养基上研究了粗枝软骨藻(Chondria crassicaulis)再生的极性,并利用三种不同的培养液和不同的温度对粗枝软骨藻进行切段培养,探索了部分外界因素对粗枝软骨藻生长的影响.发现软骨藻在人工培养条件下的再生出芽过程并无明显极性.在10℃、15℃和22℃三个温度梯度和PES、改良的ASP1和改良的ES三种培养液中,15℃改良的ES培养液中较有利于再生芽的出现.同时我们还观察了粗枝软骨藻四分孢子的发育过程,发现软骨藻具有十字型和四面锥型两种不同的四分孢子囊,软骨藻在四分孢子萌发过程中可形成四种不同的孢子苗.     

海洋经济微藻混合培养与单独培养下的生长比较

海洋微藻可以广泛应用在水产养殖、食品加工、医药保健、环境保护和生物制能等各种行业,具有非常好的开发利用前景.目前,如何突破海洋微藻培养过程中细胞生物量低下等瓶颈,提高微藻的细胞密度,以低成本、高效率开发利用海洋微藻资源成为了国内外学者关注的焦点.论文以三角褐指藻、亚心型扁藻和杜氏盐藻3 种典型经济海洋微藻为研究材料,在实验室条件下研究了它们两两混合培养与各自单独培养条件下的细胞生长情况,探讨海洋微藻混合培养在促进微藻整体细胞生长方面的可能性.结果显示,三角褐指藻和杜氏盐藻混合培养在生长前9 天的OD680 高于三角褐指藻或杜氏盐藻分别单独培养的OD680 ,而随着试验时间的延长,混合培养条件下的OD680 与单独培养三角褐指藻的OD680 相似;就三角褐指藻和亚心型扁藻混合培养的OD680而言,在整个生长时期均高于单独培养亚心型扁藻的OD680 ,但低于单独培养三角褐指藻的OD680 ;不同的是,杜氏盐藻和亚心型扁藻混合培养下的OD680 在生长第6 天后高于单独培养杜氏盐藻或单独培养亚心型扁藻的OD680 .研究结果表明,混合培养三角褐指藻和杜氏盐藻或混合培养杜氏盐藻和亚心型扁藻具有一定程度促进微藻细胞生长的潜力.研究结果将为经济海洋微藻的高密度培养及其高附加价值活性物质的开发利用提供一个崭新的研究方向.     

不同培养基中MDCK细胞生长及代谢动力学研究

[目的]为筛选适应于MDCK细胞大规模培养的最佳培养基并揭示其代谢动力学规律。[方法]选取商业化的培养基DMEM(试验组A)、EMEM(试验组B)、MEM(试验组C)、M199(试验组D)、DMEM/F12(试验组E)及DMEM:EMEM复合培养基(试验组F)用于MDCK细胞传代培养,研究不同培养基对MDCK细胞生长特性的影响,分析MDCK细胞生长过程中葡萄糖(Gluc)、乳酸(Lac)、谷氨酰胺(Gln)和氨(NH4+)的代谢情况,并进一步进行细胞工厂的培养验证。[结果]结果表明MDCK细胞均能在试验组A、B、E、F四种培养基中生长,其最大增殖浓度E A F B,差异显著(P 0. 05);倍增时间B F A E,差异显著(P 0. 05);细胞比生长速率E A F B,差异不显著(P 0. 05)。不同培养基培养MDCK细胞对数生长期平均葡萄糖比消耗速率、谷氨酰胺比消耗速率及氨比生成速率差异均不显著(P 0. 05),乳酸比生成速率差异显著(P 0. 05)。在试验组A和E培养基中细胞能实现高密度增殖,再将其进行细胞工厂扩大培养验证,发现两种培养基在培养48 h时均能达到单层致密,且细胞密度均达到8. 0×10~8/cells以上,差异不显著(P 0. 05)。[结论]综合研究结果及规模化生产成本因素,采用DMEM培养基(试验组A)培养MDCK细胞,其最大增殖浓度达到6. 4×10~5/m L,倍增时间为22. 835 h,比生长速率为0. 558,可进行大规模培养,为工业化生产提供依据。     

一种快速检测分离溶藻细菌方法的初探

传统的细菌培养基对铜绿微囊藻具有毒性作用。会大大影响溶藻细菌的筛选效率和准确性。通过基本培养基各成分对铜绿微囊藻DS的作用研究发现,培养基中的葡萄糖成分对藻有抑制作用,并且这种抑制作用与培养基中的葡萄糖浓度密切相关,当培养基中葡萄糖的浓度在0．1～0．4g/L时,藻细胞生长受到抑制,当用柠檬酸三钠取代葡萄糖后,铜绿微囊藻在改良后的培养基中生长正常,与对照组相比无显著性差异(P＜0．05)。用改良的培养基富集水样中的溶藻微生物,并用此培养液直接感染宿主藻,一周内即可初步快速检测是否含有溶藻细菌。此种方法既排除了培养基的干扰因素,又迅速增加了溶藻细菌的生物量,并可大量收集细菌分泌的胞外物质,为溶藻细菌尤其以分泌物质溶藻的细菌的初步筛选提供了一条快捷、有效的途径。     

Nutritional Characteristics of the Atypical Mycobacteria

The ability of Mycobacterium kansasii and groups II and III of the atypical mycobacteria to utilize oleic acid, as well as selected carbohydrates and other compounds, as sources of carbon for growth was compared with that of the H37Rv and H37Ra strains of M. tuberculosis. The highest rate of growth of all of the mycobacteria examined occurred in the medium containing oleic acid as the carbon source when single substrates were tested. The H37Ra strain of M. tuberculosis and all of the atypical mycobacteria examined, except the P-8 strain of M. kansasii, displayed a deficiency in ability to utilize glucose for growth. The deficiency was manifested as delayed appearance of growth, suboptimal growth, or complete inability to utilize the sugar. Variant substrains of organisms that possessed an enhanced ability to utilize glucose for growth were isolated from representative strains of M. kansasii and groups II and III atypical mycobacteria inoculated on modified Kirchner glucose-agar and incubated for an extended period of time.     

Effect of titanium (III) citrate as reducing agent on growth of rumen bacteria.

We compared the growth of 10 strains of rumen bacteria in an anaerobic medium reduced with cysteine hydrochloride, dithiothreitol, or titanium (III) citrate. The redox potential of medium reduced with cysteine hydrochloride was -167.8 mV; with dithiothreitol it was -175.8 mV; and with titanium(III) citrate it was -302.4 mV at a concentration of 5 X 10(-4) M titanium and -403.9 mV at 2 X 10(-3) M titanium. Maximum growth of the strains was generally lower with dithiothreitol or titanium(III) citrate than with cysteine hydrochloride, although growth was greater than in medium lacking an added reducing agent. Strains for which cysteine was required or markedly stimulatory grew only poorly with titanium(III) citrate. No strain grew in medium with sodium citrate as the energy source. Titanium(III) citrate could be used to reduce anaerobic media for some rumen bacteria if the exclusion of a sulfur-containing reducing agent is required.     

Evaluation of a modified culture medium for Borrelia burgdorferi sensu lato

The aim of the present study was to assess the possible use of a modified medium, prepared in the laboratory using the constituents of Barbour-Stonner-Kelly (BSK) medium and medium 199 as base, for the culture of Borrelia strains, comparing the growth of individual strains in this medium and in the BSK-H medium, and the protein profile and antigenic characteristics of Borrelia proteins expressed in these media. A qualitative evaluation of growth of Borrelia species was made with acceptable results (morphology and motility), but during a quantitative evaluation using the three main genospecies of Borrelia, the better results were obtained with a B. burgdorferi sensu stricto strain. The modified medium did not enable the growth of a B. afzelii strain. The protein profile and antigenic characteristic of the expressed proteins in the modified medium were studied with satisfactory results. These results suggest the modified medium as an alternative for the cultivation of Borrelia strains, with some limitations, in poorly-resourced laboratories.     

Comparison of four different culture media for isolation and growth of type II and type I/III Mycobacterium avium subsp. paratuberculosis strains isolated from cattle and goats

Culture is considered the definitive technique for Johne's disease diagnosis, and it is essential for later applications of certain molecular typing techniques. In this study, we have tested four solid media (Herrold's egg yolk medium [HEYM] with sodium pyruvate and mycobactin [HEYMm-SP], HEYM with mycobactin and without sodium pyruvate [HEYMm], Middlebrook 7H11 with mycobactin [Mm], and L?wenstein-Jensen with mycobactin [LJm]) for isolation of Mycobacterium avium subsp. paratuberculosis strains in 319 tissue samples from cattle herds and goat flocks. We have shown that each of the two main groups of M. avium subsp. paratuberculosis (type II and type I/III) has different requirements for growth in the culture media studied. The recommended solid media for isolation of type I/III strains are LJm and Mm, since the combination of both media allowed the recovery of all these strains. The most widespread culture medium, HEYM, is not suitable for the isolation of this group of M. avium subsp. paratuberculosis strains. Regarding the type II strains, HEYMm-SP was the medium where more strains were isolated, but the other three media are also needed in order to recover all type II strains. The incubation period is also related to the strain type. In conclusion, because the type of strain cannot be known in advance of culture, coupled with the fact that cattle and goats can be infected with both groups of strains, we recommend the use of the four solid media and the prolongation of the incubation period to more than 6 months to detect paratuberculous herds/flocks and to determine the true prevalence of the infection.     

An algal medium based on fertilizers and its evaluation in mariculture

Five agricultural fertilizers were tested as potential nutrient enrichments for the mass culture ofTetraselmis suecica. Maximum algal growth was observed for the trade fertilizer Igromurtonik^R (Murphy Ltd, England) adjusted for a nitrate to phosphate ratio of 24:1. The gross biochemical composition ofT. suecica grown in the enriched fertilizer was compared to the composition of the alga grown in control medium. The nutritional value of the algal material was then tested on the rotiferBrachionus plicatilis. The medium based on the fertilizer is as an inexpensive substitute for mass algal culture ofTetraselmis suecica, a food source for the rotiferBrachionus plicatilis.     

Microbial control of the culture of Artemia juveniles through preemptive colonization by selected bacterial strains.

The use of juvenile Artemia as feed in aquaculture and in the pet shop industry has been getting more attention during the last decade. In this study, the use of selected bacterial strains to improve the nutritional value of dry food for Artemia juveniles and to obtain control of the associated microbial community was examined. Nine bacterial strains were selected based on their positive effects on survival and/or growth of Artemia juveniles under monoxenic culture conditions, while other strains caused no significant effect, significantly lower rates of survival and/or growth, or even total mortality of the Artemia. The nine selected strains were used to preemptively colonize the culture water of Artemia juveniles. Xenic culture of Artemia under suboptimal conditions yielded better survival and/or growth rates when they were grown in the preemptively colonized culture medium than when grown in autoclaved seawater. The preemptive colonization of the culture water had a drastic influence on the microbial communities that developed in the culture water or that were associated with the Artemia, as determined with Biolog GN community-level physiological profiles. Chemotaxonomical characterization based on fatty acid methyl ester analysis of bacterial isolates recovered from the culture tanks was performed, and a comparison with the initially introduced strains was made. Finally, several modes of action for the beneficial effect of the bacterial strains are proposed.     

Collection and culture of live foods for aquaculture in Taiwan

Collection and culture of live foods to be used instudies of feeds for rearing finfish and shellfishlarvae in Taiwan began in 1982. Today, 31 species (49strains) of microalgae, three species (nine strains)of rotifers, one cladoceran and one copepod are holdas start culture. Microalgae are collected from localwaters and obtained from foreign collection centers.The most common genera are Chlorella,Nannochloropsis, Tetraselmis, Chaetoceros, Skeletonema, Isochrysis, and Pavlova. Someinteresting genera such as Ellipsoidion,Nannochloris, Synechococcus, and Alexandriumare also included. Three types of rotifers, i.e. L, S,and SS-type, which are classified as Brachionusplicatilis, B. rotundiformis, and Brachionus sp. are found in Taiwan waters. Among therotifers, six strains have been isolated and cultured.Another L-type strain and two SS-type strains wereobtained from foreign sources. The cladoceran Diaphanosoma aspinosum and copepod Apocyclopsroyi are the most common species used in aquaculture.Studies of live foods including their morphology,culture techniques, fatty acid composition andnutritional value as feeds have been undertaken.     

10升气升环流式生物反应器培养紫草细胞

本文采用自行设计研制的10升气升环流式生物反应器培养紫草细胞,培养周期34d．前14d为细胞生长培养,细胞生长呈正常的S型曲线,细胞增长到原细胞接人量的4倍．后20d为紫草色素生产培养,细胞增长到32倍。整个周期每升培养液可生产紫草色素0．6g,在反应器中,培养液pH值的变化与细胞生长呈正相关,与紫草色素的形成呈负相关,pH值变化规律可用于监测紫草细胞在生物反应器的生长和色素形成．     

Comparison of Four Different Culture Media for Isolation and Growth of Type II and Type I/III Mycobacterium avium subsp. paratuberculosis Strains Isolated from Cattle and Goats

Culture is considered the definitive technique for Johne's disease diagnosis, and it is essential for later applications of certain molecular typing techniques. In this study, we have tested four solid media (Herrold's egg yolk medium [HEYM] with sodium pyruvate and mycobactin [HEYMm-SP], HEYM with mycobactin and without sodium pyruvate [HEYMm], Middlebrook 7H11 with mycobactin [Mm], and Löwenstein-Jensen with mycobactin [LJm]) for isolation of Mycobacterium avium subsp. paratuberculosis strains in 319 tissue samples from cattle herds and goat flocks. We have shown that each of the two main groups of M. avium subsp. paratuberculosis (type II and type I/III) has different requirements for growth in the culture media studied. The recommended solid media for isolation of type I/III strains are LJm and Mm, since the combination of both media allowed the recovery of all these strains. The most widespread culture medium, HEYM, is not suitable for the isolation of this group of M. avium subsp. paratuberculosis strains. Regarding the type II strains, HEYMm-SP was the medium where more strains were isolated, but the other three media are also needed in order to recover all type II strains. The incubation period is also related to the strain type. In conclusion, because the type of strain cannot be known in advance of culture, coupled with the fact that cattle and goats can be infected with both groups of strains, we recommend the use of the four solid media and the prolongation of the incubation period to more than 6 months to detect paratuberculous herds/flocks and to determine the true prevalence of the infection.     

Cryopreservation of economically valuable marine micro-algae in the classes Bacillariophyceae, Chlorophyceae, Cyanophyceae, Dinophyceae, Haptophyceae, Prasinophyceae, and Rhodophyceae

The ability to routinely cryopreserve micro-algal species reduces costs associated with maintaining large culture collections and reduces the risks of losing particular strains or species through contamination and genetic drift. Cryopreservation is also a useful adjunct in aquaculture hatcheries for strains of micro-algae where the nutritional status may change as a result of continuous sub-culture. In this study, cryopreservation of isolates from seven micro-algal classes was investigated. Successful candidates included the marine dinoflagellates Amphidinium carterae, Amphidinium trulla, and Gymnodinium simplex, and the haptophytes Chrysochromulina simplex, Prymnesium parvum, Prymnesium parvum f. patelliferum, Isochrysis galbana, and Pavlova lutheri. Also successfully cryopreserved were the planktonic diatoms Chaetoceros calcitrans, Chaetoceros muelleri, Chaetoceros sp., and the benthic Nitzschia ovalis, the chlorophyte Chlamydomonas coccoides, the rhodophyte Porphyridium purpureum, the prasinophytes Tetraselmis chuii, and Tetraselmis suecica, and the cyanophytes Raphidiopsis sp., and Aphanizomenon flos-aquae. All species were successfully cryopreserved using 15% Me2SO.