UV-B辐射对雨生红球藻生长和类胡萝卜素含量的影响

以BG11培养基,对雨生红球藻进行了室内培养,研究了增强UV-B辐射对雨生红球藻生长速率和虾青素含量的影响.室内培养的条件是UV-B辐射强度为0.1J·m-2·S-1,0.2J·m-2·S-1, 0.3J·m-2·S-1, 光照强度为60 μmoL·m-2·S-1(昼夜比为12 h:12 h),温度为20～26℃.测定了培养液细胞数目、叶绿素a、类胡萝卜素的含鼍,并对雨生红球藻进行了显微结构观察.结果显示在室内培养雨生红球藻增加UV-B辐射,能够提高其细胞内虾青素的含量,其显微结构显示类胡萝卜素颗粒明显增加的现象.本研究目的是在室内培养雨生红球藻提高虾青素产量的方法.     

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。     

营养盐对雨生红球藻光合作用影响的研究

以单细胞雨生红球藻为实验材料,利用ＭＣＭ改良配方制作基本培养液,通过测溶解氧的方法,试验氮,磷,碳和盐度等对细胞生长的影响。结果表明;雨生红球藻的光合作用与上述营养浓度有直接的关系,５、０．５、５×１０＾－３Ｍｏｌ／Ｌ的ＫＮＯ３,ＫＨＯ２ＰＯ４,ＮａＨＣＯ３是该藻光合作用的适宜浓度,并对ＭＣＭ改良配方再次修正２,初步建立起养殖该藻的营养模式,为大规模模养殖打下了基础。     

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…     

不同激光对雨生红球藻的刺激效应

本文研究了Ｈｅ－Ｎｅ激光和半导体激光对生产虾青素的雨生红球藻（Ｈａｅｍａｔｏｃｏｃｃｕｓ ｐｌｕｖｉａｌｉｓ）的生理刺激作用。对两种激光不同辐照剂量的生长刺激作用,叶绿素含量及虾青素累积速率的变化进行了比较。实验结果表明,低功率的红色激光对红球藻营养细胞的增殖具有明显的促进作用。     

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。     

超临界C02萃取雨生红球藻中虾青素工艺的研究

本工艺以雨生红球藻粉为原料,采用超临界COz萃取技术,萃取雨生红球藻浸膏,可有效地将雨生红球藻颗粒中的虾青素萃取出来,使萃余物（残渣）中总虾青素含量的平均值为0．224％;提取物得率（以油浸膏的总量计）可达28．5％;虾青素的提取率可达66．69％;雨生红球藻油浸膏中虾青素含量为5．710％。     

雨生红球藻对环境胁迫的分子防御机制

虾青素是一种具有极强的生物抗氧化性的类胡萝卜素,在医药,食品等方面均有广阔的应用.雨生红球藻在逆境下能够大量积累虾青素,已成为目前研究的热点.从雨生红球藻生存的角度来看,虾青素的积累是细胞对逆境防御的方法之一.除此之外,雨生红球藻还通过调整相关酶的表达类来使细胞度过难关.主要综述了雨生红球藻对环境胁迫防御的两种分子机制,即早期机制和长期机制.     

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。     

超临界CO2萃取雨生红球藻中虾青素工艺的研究

本工艺以雨生红球藻粉为原料,采用超临界CO2萃取技术,萃取雨生红球藻浸膏,可有效地将雨生红球藻颗粒中的虾青素萃取出来,使萃余物(残渣)中总虾青素含量的平均值为0.224%;提取物得率(以油浸膏的总量计)可达28.5%;虾青素的提取率可达66.69%;雨生红球藻油浸膏中虾青素含量为5.710%.     

沉默lycB基因对雨生红球藻类胡萝卜素合成代谢的影响

雨生红球藻是一种淡水浮游单细胞绿藻, 逆境条件下可积累大量的类胡萝卜素。番茄红素是类胡萝卜素中的一种, 是类胡萝卜素合成代谢中的一个重要中间产物。番茄红素β-环化酶(LycB)是催化番茄红素形成β-胡萝卜素的关键酶。文章以杜氏盐藻lycB基因为干扰序列, 构建了含卡那霉素与阿特拉津双抗性的RNAi载体p1301-BS-RNAi。将其电转化进雨生红球藻细胞, 经抗性筛选、基因组PCR及RT-PCR筛选, 获得了16个独立的干扰株系。选取生长良好的7个进行高光诱导, 发现其番茄红素含量增加了99.4%, β-胡萝卜素含量减少了48.4%, 即通过异源的lycB-RNAi基因沉默可抑制番茄红素向β-胡萝卜素的转化。对比分析发现, 番茄红素增加量仅是β-胡萝卜素减少量的5%, 表明因lycB-RNAi抑制而产生的番茄红素的95%又被其他通路转换成了其他代谢产物, 因此要实现雨生红球藻番茄红素含量的大幅增长, 需协同调控其他代谢通路。     

Time- and media-dependent secondary carotenoid accumulation in Haematococcus pluvialis

The green microalgae Haematococcus pluvialis synthesizes secondary carotenoids after exposure to environmental stress, a process that is used for the biotechnological production of astaxanthin (Ax). This study reports, for the first time, the medium-dependent changes in the carotenoid pattern throughout the cultivation process as well as the exact composition of carotenoids and their fatty acid mono- and diesters using LC-MS. Secondary carotenoid formation started immediately upon exposure to nutrient depletion and high light conditions. Ax and its corresponding mono- and diesters were detected simultaneously. After 15 days of cultivation, no significant changes were detected in carotenoid composition; however, the ratio between carotenoid mono- and diesters still varied. Main carotenoids were identified as Ax linolenate and Ax oleate, but also five adonirubin and one lutein monoester were detected. The influence of three different autotroph media was studied on carotenoid content, which reached a maximum 16.1 mg/g dry weight. The results indicate that media composition has an influence on the ratio of Ax mono- to diester but not on the qualitative composition of secondary carotenoids in H. pluvialis. Beside the pathway via echinenone, canthaxanthin and adonirubin the results indicate that Ax biosynthesis takes place via another route: from beta-carotene via beta-cryptoxanthin, zeaxanthin and adonixanthin.     

Abscisic acid-dependent algal morphogenesis in the unicellular green alga Haematococcus pluvialis

To study the physiological role of abscisic acid (ABA) in the unicellular green alga Haematococcus pluvialis, we investigated the effect of ABA on both algal morphogenesis and carotenogenesis in liquid and plate cultures. When ABA was added to vegetative cells of H. pluvialis, red mature cyst cells with enhanced carotenogenesis rapidly appeared on agar plates in Petri dishes. We considered these conditions as drought stress. In plate culture, the morphological change from vegetative to cyst cells was prevented by the inhibitor of chloroplastic protein synthesis, chloramphenicol (CP), resulting in algal death. Exogenous ABA caused recovery of algal encystment even in the presence of CP. The relationship between ABA concentration and morphogenesis in H. pluvialis showed that a decrease in ABA coincided with cyst formation. In contrast, immature cyst cells underwent maturation accompanied by enhanced carotenogenesis in either the presence of CP or the absence of ABA. Therefore, ABA might regulate algal morphogenesis from vegetative to cyst cells, but not carotenogenesis in cyst cells of H. pluvialis. Furthermore, endogenous active oxygen species generated under drought stress were involved in all algal events, including ABA biosynthesis, encystment, and enhanced carotenogenesis. These results indicate that ABA, induced by oxidative stress, could function as a stress hormone in algal morphogenesis in H. pluvialis under drought stress.     

Optimization of culture medium for growth of Haematococcus pluvialis

A central composite rotatable design was used to examine the effects of five components of the medium on the growth of Haematococcus pluvialis in batch culture. The medium components considered were: sodium acetate,potassium nitrate, major elements, trace elements and vitamins. Within the range of the concentrations tested, a moderate concentration of the major elements significantly enhanced algal growth, both in terms of specific growth rate and cell dry weight, whereas the vitamins had no significant effect. Based on the response surface contour plots and the results of numerical analyses, the optimal nutrient concentrations for growth in terms of specific growth rate were 0.51 g L^-1 sodium acetate, 0.25 g L^-1 potassium nitrate, 0.63 mL L^-1 of the major element stock solution and 0.2 mL L^-1 of the trace element stock solution. The optimal nutrient concentrations for biomass production were 1.64 g L^-1 sodium acetate, 0.37 g L^-1potassium nitrate, 2.52 mL L^-1 of the major element stock solution and 0.03 mL L^-1 of the trace element stock solution. This revised version was published online in August 2006 with corrections to the Cover Date.     

雨生红球藻混合营养与异养培养研究

研究雨生红球藻混合营养生长与异养生长对碳源及碳源浓度的需求,并对两种生长型进行比较。结果表明,乙酸钠较葡萄糖等碳源更能维持红球藻进行混合营养民异养生长。红球藻混合营养型生长与异养型生长的适宜乙酸钠浓度范围分别是０．５￣１．０ｇ／Ｌ和１￣１．５ｇ／Ｌ。混合营养型及异养型的平均速率分别是０．７２ｄ＾－１和０．５３ｄ＾－１,培养８ｄ的细胞干重分别是０．６５ｇ／Ｌ和０．３２ｇ／Ｌ。与光养型（对照）相比,混     

氮、磷营养对雨生血球藻绿色细胞生长的影响

采用BBM培养基,以雨生血球藻(Haematococcus pluvialis CG-11)为研究材料,通过测定细胞生长速率、叶绿素和类胡萝卜素含量、生物量和虾青素含量,探讨氮、磷营养对雨生血球藻营养细胞生长的影响.结果显示:H.pluvialis CG-11生长的适宜氮源形式是NaNO₃和NH₄NO₃;适宜H.pluvialis CG-11生长的氮浓度为41.2mg·L^-1,磷浓度为5.3～53.3mg·L^-1.