紫球藻多糖浓度增加对其他逆境适应性的改变

紫球藻 (Porphyridiumsp .)是一种海水单细胞红藻 ,是多种天然产物的来源。在其培养繁殖过程中 ,能够合成藻胆蛋白、高不饱和脂肪酸、硫酸酯多糖等生物活性物质 ,具有广阔的应用前景。盐胁迫会导致紫球藻的结合态多糖浓度的增加 ,由此可能产生相应的耐盐性的提高 ,并有利于对其他逆境的适应。该项研究采用外加紫球藻多糖或采用盐逆境诱导紫球藻多糖的积累 ,然后解除盐逆境的胁迫的方法获得多糖含量有显著提高的紫球藻试材 ,再给与其他的逆境 :如光抑制 ,低温处理 ,并测定主要的生理生化参数。试验结果表明 ,外加 0 .0 5 %紫球藻多糖的藻细胞光合效率 ,在光抑制条件下 ,低于不加多糖的对照 ,但在低温 ( 4℃ )时 ,高于对照。外加多糖对PSⅡ没有显著影响。紫球藻在去盐后的 48h恢复培养时间内 ,多糖的含量以及光抑制和低温条件下的光合效率都逐渐恢复到对照的水平。但是 ,去盐恢复培养的紫球藻PSⅡ效率在光抑制条件下却高于加盐及未加盐的两种对照 ,显示盐诱导的紫球藻多糖可能增加了PSⅡ对光抑制的忍耐程度。     

通入CO2和补加氮源对紫球藻生长和代谢物质积累的影响

论文研究了柱状光生物反应器中CO2浓度和氮源添加模式等培养条件对紫球藻(Porphyridium sp.UTEX 637)生长和主要代谢产物积累的影响。结果表明,通入CO2能显著促进紫球藻的生长及胞外多糖、水溶性蛋白和总脂等生物活性物质的积累,其中1%的CO2浓度对紫球藻的生长及活性物质积累最有利,该条件下紫球藻的最高干重可达到8.14 g/L,是对照组的4.93倍;胞外多糖产量明显高于对照组,最高可达到238.8 mg/L;补加氮源KNO3对紫球藻生长及胞外多糖、水溶性蛋白含量均有明显的促进作用,最高干重、胞外多糖含量可分别达到对照组的1.5倍和1.25倍,但不利于总脂的积累。     

红藻糖苷对超低温冻存微藻的保护作用

为研究红藻糖苷对超低温冻存微藻细胞的保护作用,研究将3种不同的微藻置于含10% DMSO和不同浓度红藻糖苷的冻存液中,冻存并解冻后,以流式细胞仪检测细胞存活率,测定复养后藻株的生长曲线及相关生理参数。结果显示,由于冷冻损伤,冻存后各种藻细胞的生长速率、细胞密度及生理指标都显著性下降,而红藻糖苷协同DMSO能够显著增加细胞的存活率,尤其15%红藻糖苷能将紫球藻存活率提升20%（P0.05）;生长曲线得到明显改善;且对PSII最大光能转化效率也有显著性提高（P0.05）。总体结果来看,红藻糖苷对超低温冻存微藻,特别是紫球藻具有明显的保护作用,且效果强于蔗糖。     

三种紫球藻亲缘关系RAPD分析

利用RAPD技术对铜绿紫球藻（Porphyridium aerugineum 755）,淡色紫球藻（Porphyridium purpureum 806）和紫球藻（Porphyridium cruentum）的亲缘关系进行分析。从50个随机引物中筛选出25个种间多态性较强,重复性较好的引物。检测到233个位点。在233个条带中有186个多态性位点。多态位点比率为79．73％,平均每个引物扩增9个条带,多态性条带7个。聚类分析结果表明：铜绿紫球藻、淡色紫球藻和紫球藻之间的平均遗传距离为0．455,其中铜绿紫球藻和淡色紫球藻之间的遗传距离为0．413,铜绿紫球藻和紫球藻之间的遗传距离为0．556,淡色紫球藻和紫球藻之间的遗传距离最小为0．396。所以由RAPD试验的分析结果可以得出：三种紫球藻为独立的种,其中淡色紫球藻和紫球藻是亲缘关系较近的两个不同种。紫球藻属种间个体DNA多态性比较丰富,因此利用RAPD技术可以从DNA水平上检测紫球藻属种间差异。     

三种紫球藻亲缘关系RAPD分析

利用RAPD技术对铜绿紫球藻（Porphyridium aerugineum 755）,淡色紫球藻（Porphyridium purpureum 806）和紫球藻（Porphyridium cruentum）的亲缘关系进行分析。从50个随机引物中筛选出25个种间多态性较强,重复性较好的引物。检测到233个位点。在233个条带中有186个多态性位点。多态位点比率为79.73%,平均每个引物扩增9个条带,多态性条带7个。聚类分析结果表明：铜绿紫球藻、淡色紫球藻和紫球藻之间的平均遗传距离为0.455,其中铜绿紫球藻和淡色紫球藻之间的遗传距离为0.413,铜绿紫球藻和紫球藻之间的遗传距离为0.556,淡色紫球藻和紫球藻之间的遗传距离最小为0.396。所以由RAPD试验的分析结果可以得出:三种紫球藻为独立的种, 其中淡色紫球藻和紫球藻是亲缘关系较近的两个不同种。紫球藻属种间个体DNA多态性比较丰富,因此利用RAPD技术可以从DNA水平上检测紫球藻属种间差异。     

脱落酸对紫球藻（Porphyridiu sp.）生长代谢的影响

为优化培养条件和提高紫球藻(Porphyridiu sp.)生物量及代谢产物产量,研究了7种浓度的脱落酸(ABA)在三种氮素营养水平下对紫球藻生长的影响,结果表明,ABA浓度在0.01～1.0 mg·L-1范围内,外源ABA浓度的升高有利于紫球藻增殖,对紫球藻的干重、叶绿素a含量、蛋白质含量、胞外多糖含量、藻红素含量都有一定的促进作用;但在ABA浓度在10 mg·L-1时,则呈递抑制趋势.其中中氮水平下外源ABA浓度1.0 mg·L-1是紫球藻生长的最佳浓度,最有利于紫球藻生物量及代谢产物的积累,此时紫球藻的生物量为3.463 mg·mL-1,胞外多糖含量最高,占藻体干重的34.31%.在高氦营养水平下还能体现ABA对紫球藻生长所起的作用,而低氮下生长的紫球藻对ABA的作用不敏感.     

紫球藻及其多糖抗菌性能初探

本文报道紫球藻提取液及其多糖溶液抗病原细菌、真菌性能的研究结果。采用管碟法分别测定紫球藻培养分泌物、藻体破碎后的水提物和醇提物、胞外多糖和胞内多糖水溶液等的抗菌能力。结果表明,各样品均有一定抗菌能力,紫球藻水提物和胞外分泌物抗菌性能较强。经比较分析,多糖是抗菌作用的主要组分。紫球藻提取物及其多糖对革兰氏阳性细菌(特别是对金黄色葡萄球菌和八叠球菌)的抑菌作用较为明显,具有一定开发价值。     

硝态氮对紫球藻抗氧化能力及NO产生的影响

以紫球藻为研究对象,探讨了在不同硝酸钠浓度下紫球藻超氧化物歧化酶(SOD)、过氧化氢酶(CAT)的变化及一氧化氮(NO)的产生情况。研究表明紫球藻在12 mmol/L硝酸钠培养时生长良好,8 mmol/L次之,4、16 mmol/L培养时细胞产量略低。在硝酸钠培养过程中,NO的含量呈先上升、后下降、再上升的趋势,但各浓度培养时差异不大。SOD、CAT的含量对16 mmol/L硝酸钠及无氮条件较敏感,但SOD的含量整体上比CAT含量高。     

13种微藻的脂肪酸组成分析

分析了13种微藻(包括7种绿藻,5种杂色藻和1种红藻)的总脂含量和脂肪酸组成,结果表明,不同门类微藻的脂肪酸组成差异较大:绿藻的脂肪酸组成以C16和C18为主;杂色藻类的脂肪酸组成相近,金藻门含有14:0、16:0、18:1、18:4等特征脂肪酸,三角褐指藻主要的脂肪酸为14:0、16:0、16:1、16:3和20:5,而粉核油球藻的脂肪酸以14:0、16:0、20:5为主;紫球藻的脂肪酸组成以16:0、20:4和20:5为主。在测试的13种微藻中,杜氏盐藻的亚麻酸含量最高,占总脂肪酸的60.9%;等鞭金藻的十八碳四烯酸含量最高,占总脂肪酸的19.6%;紫球藻和粉核油球藻中花生四烯酸与二十碳五烯酸(EPA)含量分别占总脂肪酸的17.1%和20.9%。     

铜绿紫球藻(Porphyridium aerugineum)755培养的研究

紫球藻是一种具有潜在应用价值的经济微藻,它的生长速率受各种环境因子的影响.本文研究了不同光强、光周期、盐度、NaHCO3浓度、葡萄糖浓度、培养方式等因子对铜绿紫球藻(Porphyridium aerugineum)755生长的影响,并确定其最佳的培养条件.此外还分析了该藻的吸收光谱,为其培养提供参考数据.     

Induced cultivation pattern enhanced the phycoerythrin production in red alga Porphyridium purpureum

Bioprocess and Biosystems Engineering - Porphyridium purpureum is a rich source for producing phycoerythrin (PE); however, the PE content is greatly affected by culture conditions. Researchers have...     

虫草的抗菌抗肿瘤活性研究进展

虫草代谢产物丰富,很多具有抗菌和（或）抗肿瘤活性,有关其生物活性物质的研究受到广泛关注。对有抗菌和（或）抗肿瘤活性研究报道的虫草作了系统总结。     

The role of exopolysaccharides in fouling phenomenon during ultrafiltration of microalgae (Chlorella sp. and Porphyridium purpureum): Advantage of a swirling decaying flow

Ultrafiltration of two microalgae species, Chorellasp. and Porphyridium purpureum, has been performed in two filtration units of different configurations: a module generating a classical tangential-plane flow and another one inducing a swirling decaying flow. The swirling motion is generated by a unique tangential inlet at the bottom of an annulus. Permeation flux obtained in each ultrafiltration unit depends on the filtered species, and specific deposits are associated to each species and module. Enhancement in permeation flux in the swirling configuration compared with that obtained in the plane unit can reach 40% during the ultrafiltration of Porphyridium purpureum and is negligible for the suspensions of Chlorella sp. The experimental data revealed the significant role of the soluble compounds in the medium culture in terms of flux limitation. It seems that the soluble products and their interactions with the microalgal cells are strongly involved in the fouling mechanism.     

生物活性材料与牙周组织再生

生物活性材料是一类经由材料表面或界面产生特殊生物或化学反应,从而影响组织和材料间的结合、诱发细胞活性或引导组织再生的生物材料。近年来,生物活性材料已广泛应用于牙周组织再生。本文对不同类型生物活性材料的特点及其在牙周组织再生中的作用进行综述,为推动其在牙周组织再生领域中的应用提供参考。     

Applied modern biotechnology for cultivation of <Emphasis Type="Italic">Ganoderma</Emphasis> and development of their products

A white-rot basidiomycete Ganoderma spp. has long been used as a medicinal mushroom in Asia, and it has an array of pharmacological properties for immunomodulatory activity. There have been many reports about the bioactive components and their pharmacological properties. In order to analyze the current status of Ganoderma products, the detailed process of cultivation of Ganoderma spp. and development of their products are restated in this review article. These include the breeding, cultivating, extracting bioactive component, and processing Ganoderma products, etc. This article will expand people’s common knowledge on Ganoderma, and provide a beneficial reference for research and industrial production.     

Bioactive substances produced by marine isolates of Pseudomonas

Pseudomonas is a genus of non-fermentative gram-negative Gammaproteobacteria found both on land and in the water. Many terrestrial isolates of this genus have been studied extensively. While many produce bioactive substances, enzymes, and biosurfactants, other Pseudomonas isolates are used for biological control of plant diseases and bioremediation. In contrast, only a few marine isolates of this genus have been described that produce novel bioactive substances. The chemical structures of the bioactive substances from marine Pseudomonas are diverse, including pyroles, pseudopeptide pyrrolidinedione, phloroglucinol, phenazine, benzaldehyde, quinoline, quinolone, phenanthren, phthalate, andrimid, moiramides, zafrin and bushrin. Some of these bioactive compounds are antimicrobial agents, and dibutyl phthalate and di-(2-ethylhexyl) phthalate have been reported to be cathepsin B inhibitors. In addition to being heterogeneous in terms of their structures, the antibacterial substances produced by Pseudomonas also have diverse mechanisms of action: some affect the bacterial cell membrane, causing bacterial cell lysis, whereas others act as acetyl-CoA carboxylase and nitrous oxide synthesis inhibitors. Marine Pseudomonas spp. have been isolated from a wide range of marine environments and are a potential untapped source for medically relevant bioactive substances.     

Lipid and unsaturated fatty acid productions from three microalgae using nitrate and light-emitting diodes with complementary LED wavelength in a two-phase culture system

Bioprocess and Biosystems Engineering - In this study, Pavlova lutheri, Chlorella vulgaris, and Porphyridium cruentum were cultured using modified F/2 media in a 1 L flask culture. Various nitrate...     

利用海洋硅藻生产生物活性物质研究进展*

生物活性物质在食品、饵料、化妆品、保健品和医药等行业具有广阔的应用前景,其研究早已受到广泛关注。鉴于海洋硅藻具有生长速度快、生物活性物质含量高、易于规模培养、便于提取等诸多优势,为理想的生物活性物质生产者。尽管国内外已进行了大量利用海洋硅藻生产生物活性物质的研究,但是受限于培养工艺老旧、生产成本过高等缺陷,商业化利用海洋硅藻开发生物活性物质依然停滞不前。阐述海洋硅藻五种常见生物活性物质的应用价值,进一步探讨海洋硅藻高产生物活性物质的策略,就如何低成本、高效开发利用硅藻源生物活性物质提出建议,为海洋硅藻商业化开发利用提供参考。     

Detection of small bioactive peptides from Atlantic herring (Clupea harengus L.)

Recent research has shown that fish residual materials contain a range of components with interesting biological activity. Therefore, there is a great potential in the marine bioprocess industry to utilize these by-products as starting material for generating more valuable products. The aim of the present study was to search for bioactive peptides (in particular small natural bioactive peptides with molecular weight lower than 10 kDa) in Atlantic herring (Clupea harengus L.) by-products such as skin and more general residual materials. By such means a range of peptides with claimed interesting biological activities was found. Herein the activity of the detected bioactive peptides and strategies for isolating peptide fragments containing the bioactive motif is discussed. Identification of bioactive peptides in crude peptide/protein sources (skin and residual materials) was performed directly using a combination of mass spectrometry (Orbitrap), bioinformatics and database search. This method was a good angle of approach in order to map the potential in new species and species that have been very little studied.