雨生红球藻在不同培养基的生长比较

研究了雨生红球藻(Haematococcuspluvialis)3个不同品系CH-1、UTEX-16和CS-321分别在3种不同培养基BBM、BG-11、JM中的生长情况。结果表明:在3种培养基中,CH-1的最高细胞密度、生物量和虾青素含量都要高于另外2株雨生红球藻,其中以BBM培养的CH-1生长情况最好,其最终营养细胞密度可达到59.8×104cell?mL-1,干重为0.527g?L-1,细胞密度最高时虾青素含量为3.55mg?L-1。     

雨生红球藻营养细胞的虾青素累积

接种于缺氮培养基的雨生红球藻。当置于光强为10—12klx,温度25℃±1.5℃条件下培养时,营养细胞迅速由绿色变成红色。接种4d时,运动细胞占细胞总数的90%,细胞内的虾青素含量(33.0pg/cell)占最终色素累积量的(60.0pg/cell)的55%。接种6d时,虾青素含量已占最终累积量的75%。电镜观察显示,红色的运动细胞除细胞质的大部分区域充满色素颗粒外,细胞的形态结构与绿色细胞基本一致。实验还表明,当接种物置于低光(0.5—1.0klx)下培养时,营养细胞仍有色素沉积,但累积缓慢。当只有高光胁迫(10—12klx,完全培养基培养)时,营养细胞转变成厚壁孢子后(5d后),才大量积累色素。     

极地雪衣藻的研究进展

综述了富含类胡萝卜素(虾青素)的极地雪衣藻(Chlamydomonas nivalis)研究的最新进展,并对其研究前景作了分析。     

营养胁迫对雨生红球藻虾青素累积的影响

通过改变营养条件可诱导雨生红球藻积累虾青素.氮限制实验表明,色素的累积速率与原初氮浓度成反比,也与细胞分裂速率负相关,当BBM培养基中的NaNO3浓度减半时(0.13g@L-1),对细胞增殖及色素累积相对都有利.在高光强下,进一步进行氮、磷饥饿,红球藻细胞分裂明显受抑,但色素的累积作用增强,培养9d,细胞内次生类胡萝卜素的含量分别比对照组提高141.0%和60.5%,色素的累积高峰也比对照组提前2-4d.提高NaCl浓度至0.8%时的盐胁迫,不能诱导虾青素的形成.实验结果还表明,色素的累积与厚壁孢子的形成并不完全相关,游动细胞也能大量积累红色色素.     

活性氧对雨生红球藻生长及虾青素含量的影响

在雨生红球藻培养液中分别添加活性氧1O2、H2O2和·OH的诱生剂,通过测定细胞密度、叶绿素a含量、虾青素含量,研究了这三种活性氧诱生处理对雨生红球藻生长和虾青素含量的影响,初步探索了利用活性氧诱生剂提高雨生红球藻虾青素含量的可行性。实验结果表明,适当浓度的MB能够促进虾青素含量增加,当MB浓度为10-7mol·L-1时,虾青素含量达到5.27μg·mL-1,比对照显著提高。活性氧诱生剂对雨生红球藻生长有抑制作用,但MB的抑制作用小于H2O2和·OH诱生剂。     

雨生红球藻培养基的改良

近年来,雨生红球藻（ＨａｅｍａｔｏｃｏｃｃｕｓｐｌｕｖｉａｌｉｓＦｌｏｔｅｔＷｉｌｌ）作为一种获取天然虾青素的资源被广泛重视ｌ‘,‘１。目前,有关而生红球藻的研究主要集中于虾青素的积累机制、合成调控及其生物学功能‘）。关于雨生红球资生长调控方面的工作报道较少,还没有一个很理想的红球藻培养基【’］,从而在很大程度上阻碍了对雨生红球藻的深人研究与开发利用。雨生红球藻尤其是它的绿色游动细胞对环境ｐＨ值的改变较敏感,其生长状况与培养液的ｐＨ稳定性关系密切［‘”］,而目前较多采用的ＭＣＭ、ＢＢＭ和Ｂｔｈｌ…     

雨生红球藻虾青素合成研究进展

虾青素是一种重要的次级类胡萝卜素,具有高活性的抗氧化功能,广泛应用于食品保健、医药、水产养殖等领域。雨生红球藻是一种在胁迫条件下能够大量积累虾青素的微藻。文中回顾了雨生红球藻虾青素的生物合成研究的进展,包括虾青素生物合成的诱导与调控、虾青素合成与光合作用及脂类代谢的关系等研究现状。     

海洋红酵母产虾青素培养基优化的初步研究

为了提高海洋红酵母发酵虾青素的产量水平,对海洋红酵母的培养基成分进行了初步研究。试验结果表明,海洋红酵母能利用葡萄糖、淀粉水解糖、糖蜜等多种碳源,用淀粉水解糖为碳源培养海洋红酵母所获得的虾青素体积产率最大;用牛肉膏为氮源有利于提高海洋红酵母的生物量,以(NH4)2SO4、NH4Cl和蛋白胨为氮源有利于提高海洋红酵母的虾青素体积产率,用KNO3、草酸铵、蛋白胨、尿素有利于提高海洋红酵母的虾青素细胞产率;在海洋红酵母的培养基中添加Mn2 、Cd2 、Zn2 、Fe2 能增加生物量,添加Zn2 、Fe3 、Mn2 能增加海洋红酵母的虾青素体积产率,添加Fe3 能提高海洋红酵母的虾青素细胞产率。     

雨生红球藻中虾青素的研究与应用

雨生红球藻是单细胞微藻,其中的虾青素具有抗氧化、抗肿瘤、预防心脑血管疾病等多种生物活性,在食品、医药、保健品、化妆品及养殖业有诸多用途。概述了雨生红球藻虾青素含量影响因素,雨生红球藻培养方法、虾青素的提取方法及其应用领域等最新研究成果,为虾青素的开发利用提供帮助。     

Effects of Various Light-Emitting Diode (LEd) Wavelengths on the Growth of Scenedesmus Obliquus Fachb-12 and Accumulation of Astaxanthin

Given the central role of light in the algal photosynthesis, respiration, cell division, growth and the accumulation of value products, the effects of light-emitting diodes (LEDs) light wavelengths (blue, white, red and green) were studied in Scenedesmus obliquus. Biomass, residual nutrient amount, soluble protein, astaxanthin and reactive oxygen species, superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activity were analyzed to determine the effects of different monochromatic light wavelengths via biochemical methods. The results showed that blue light wavelength is the optimal light wavelength for phosphorus removal efficiency and the accumulation of biomass and astaxanthin in S. obliquus. Meanwhile, high reactive oxygen species content under the blue light might induce the accumulation of astaxanthin. The high activity of SOD, CAT and POD might participate in clearing the reactive oxygen species to facilitate the growth of microalgae. Furthermore, we found mixed blue/green lights treatment is the most appropriate mixture for the nitrogen removal. Under the blue light treatment, high light intensity and 18L:6D light cycle is the best condition for biomass and astaxanthin accumulation. Optimal nitrogen/phosphorus removal efficiency was observed under a 24L:0D light cycle. These results might provide a foundational data for the optimizing the productivity of high-value metabolites and treatment of wastewater.     

Seasonal and diel changes in photosynthetic activity of the snow alga Chlamydomonas nivalis (Chlorophyceae) from Svalbard determined by pulse amplitude modulation fluorometry

The seasonal and diel dynamics of the physiological state and photosynthetic activity of the snow alga Chlamydomonas nivalis were investigated in a snowfield in Svalbard. The snow surface represents an environment with very high irradiation intensities along with stable low temperatures close to freezing point. Photosynthetic activity was measured using pulse amplitude modulation fluorometry. Three types of cell (green biflagellate vegetative cells, orange spores clustered by means of mucilaginous sheaths, and purple spores with thick cell walls) were found, all of them photosynthetically active. The pH of snow ranged between 5.0 and 7.5, and the conductivity ranged between 5 and 75 microS cm(-1). The temperature of snow was stable (-0.1 to +0.1 degrees C), and the incident radiation values ranged from 11 to 1500 micromol photons m(-2) s(-1). The photosynthetic activity had seasonal and diel dynamics. The Fv/Fm values ranged between 0.4 and 0.7, and generally declined over the course of the season. A dynamic response of Fv/Fm to the irradiance was recorded. According to the saturating photon fluence values Ek, the algae may have obtained saturating light as deep as 3 cm in the snow when there were higher-light conditions, whereas they were undersaturated at prevalent low light even if on the surface.     

基于动力学模型的法夫酵母发酵生产虾青素的补料策略优化

对法夫酵母的不同补料发酵方式进行了研究.基于底物抑制模型,提出了一种优化的两阶段补料策略,用于法夫酵母产虾青素的高密度发酵.在发酵的延迟期和对数生长期早期,糖浓度控制在25 g/L左右,在此条件下,生物量可以达到最大,且时间缩短.在对数生长期后期及稳定期,糖浓度控制在5 g/L,虾青素的合成时间可以有效延长.与传统的补料方式相比,采用此补料策略取得了较好的发酵效果.发酵终点细胞干重达到23.8g/L,虾青素产量达到29.05 mg/L,分别比分批发酵提高了52.8%和109%.     

装液量和接种量对红发夫酵母生长和虾青素积累的影响

在摇瓶中研究了不同接种量和装液量对红发夫酵母PhaffiarhodozymaAs2 .15 5 7生长及虾青素积累的影响。结果表明在 5 0 0ml摇瓶中装液量为 5 0ml时对红发夫酵母生长及虾青素合成有利 ,接种量为 10 %有利于菌体生长和虾青素合成。     

Reaction of Astaxanthin with Peroxynitrite

The in vitro reactivities of astaxanthin toward peroxynitrite were investigated and the reaction products after scavenging with peroxynitrite were analyzed in order to determine the complete mechanism of this reaction. A series of carotenoids, 13-apo-astaxanthinone (1), 12′-apo-15′-nitroastaxanthinal (2), 12′-apo-astaxanthinal (3), 10′-apo-astaxanthinal (4), 9-cis-14′-s-cis-15′-nitroastaxanthin (5), 14′-s-cis-15′-nitroastaxanthin (6), 13-cis-14′-s-cis-15′-nitroastaxanthin (7), 10′-s-cis-11′-cis-11′-nitroastaxanthin (8), 13,15,13′-tri-cis-15′-nitroastaxanthin (9), 9-cis-astaxanthin (10), and 13-cis-astaxanthin (11), were isolated from the reaction products of carotenoids with peroxynitrite. Our previous studies achieved for the first time the isolation of nitro derivatives from the reaction of astaxanthin with peroxynitrite. Here we identify the major remaining reaction products of this reaction and investigate the stabilities of the nitro astaxanthins.     

Mechanisms governing sex-ratio variation in dioecious Rumex nivalis

Sex ratios of flowering individuals in dioecious plant populations are often close to unity, or are male biased owing to gender-specific differences in flowering or mortality. Female-biased sex ratios, although infrequent, are often reported in species with heteromorphic sex chromosomes. Two main hypotheses have been proposed to account for female bias: (1) selective fertilization resulting from differential pollen-tube growth of female- versus male-determining microgametophytes (certation); (2) differences in the performance and viability of the sexes after parental investment. Here we investigate these hypotheses in Rumex nivalis (Polygonaceae), a European alpine herb with female-biased sex ratios in which females possess XX, and males XY1Y2, sex chromosomes. Using field surveys and a glasshouse experiment we investigated the relation between sex ratios and life-history stage in 18 populations from contrasting elevations and snowbed microsites and used a male-specific SCAR-marker to determine the sex of nonflowering individuals. Female bias among flowering individuals was one of the highest reported for populations of a dioecious species (mean female frequency = 0.87), but males increased in frequency at higher elevations and in the center of snowbeds. Female bias was also evident in nonflowering individuals (mean 0.78) and in seeds from open-pollinated flowers (mean 0.59). The female bias in seeds was weakly associated with the frequency of male flowering individuals in populations in the direction predicted when certation occurs. Under glasshouse conditions, females outperformed males at several life-history stages, although male seeds were heavier than female seeds. Poor performance of Y1Y2 gametophytes and male sporophytes in R. nivalis may be a consequence of the accumulation of deleterious mutations on Y-sex chromosomes.     

虾青素抑癌作用机制研究进展

虾青素是一种从虾蟹外壳、牡蛎、鲑鱼及藻类、真菌中发现的橙红色类胡萝卜素,其抗氧化性极强,因而在人体营养与健康领域有着广泛的应用前景。已有许多动物实验模型证实,虾青素能显著抑制肿瘤生长、诱导细胞凋亡、抑制癌细胞转移、调节细胞间隙通讯和增强机体免疫力。其作用机制不仅仅与其抗氧化作用有关,还可能通过活化过氧化物酶体增殖物激活受体γ(PPARγ),抑制NF-κB激活等调控多种信号分子实现其抑癌作用。本文对虾青素抑癌防癌作用机制进行了综述。