硝酸钠浓度对雨生红球藻生长及虾青素积累的影响

研究了0.15、0.30、0.75、1.50 g/L 4种不同硝酸钠营养浓度条件对雨生红球藻生长状况的影响,同时探究了该试验条件对雨生红球藻中虾青素起始积累期和后期积累量的影响,以寻找既能使雨生红球藻在氮源用尽后细胞密度达到或接近最大,同时又能最快直接进入虾青素积累阶段的硝酸钠营养添加浓度。试验结果表明,硝酸钠浓度为0.15 g/L时雨生红球藻细胞生长状况最好,细胞浓度最高可以达到5.19×105个/ml。此条件下细胞尚未停止生长即已有细胞开始积累虾青素,变红(培养的第23天)。使用有机溶剂萃取法以丙酮提取虾青素,硝酸钠浓度为0.15 g/L时,最终虾青素浓度达到19.136 mg/L,是其他硝酸钠浓度下的虾青素含量最大值。     

Astaxanthin from Haematococcus pluvialis Prevents Oxidative Stress on Human Endothelial Cells without Toxicity

Astaxanthin, a powerful antioxidant, is a good candidate for the prevention of intracellular oxidative stress. The aim of the study was to compare the antioxidant activity of astaxanthin present in two natural extracts from Haematococcus pluvialis, a microalgae strain, with that of synthetic astaxanthin. Natural extracts were obtained either by solvent or supercritical extraction methods. UV, HPLC-DAD and (HPLC-(atmospheric pressure chemical ionization (APCI)+)/ion trap-MS) characterizations of both natural extracts showed similar compositions of carotenoids, but different percentages in free astaxanthin and its ester derivatives. The Trolox equivalent antioxidant capacity (TEAC) assay showed that natural extracts containing esters displayed stronger antioxidant activities than free astaxanthin. Their antioxidant capacities to inhibit intracellular oxidative stress were then evaluated on HUVEC cells. The intracellular antioxidant activity in natural extracts was approximately 90-times higher than synthetic astaxanthin (5 µM). No modification, neither in the morphology nor in the viability, of vascular human cells was observed by in vitro biocompatibility study up to 10 µM astaxanthin concentrations. Therefore, these results revealed the therapeutic potential of the natural extracts in vascular human cell protection against oxidative stress without toxicity, which could be exploited in prevention and/or treatment of cardiovascular diseases.     

Dietary carotenoids and skin melanin content influence the coloration of farmed red porgy (Pagrus pagrus)

The present study investigates the effects of dietary carotenoid sources on the coloration of the red porgy, Pagrus pagrus. Red porgies (131.9 ± 16.2 g; mean ± SD) were fed for 12 weeks on five different diets supplemented with red carotenoids (mainly astaxanthin esters) supplied from Haematococcus pluvialis algae and yellow carotenoids (mainly β‐carotene, lutein, and zeaxanthin) supplied from Alfalfa, Medicago sativa L. and Spirulina, Spirulina pacifica. The carotenoid‐supplemented diets did not have any marked effect on the growth rate, the feed conversion ratio, the daily feeding rate, or the hepatosomatic index of red porgy. The biochemical indices measured in plasma including cholesterol, total proteins, glucose, lactate, phospholipids, non‐esterified fatty acids, triglycerides, and thyroid hormones did not differ significantly among groups. Diet did not affect significantly the melanophore‐area coverage, the melanin skin concentration and skin lightness. Carotenoid‐supplemented diets affected significantly the carotenoid deposition in the skin, the presence and distribution of erythorphores and xanthophores, and skin hue and chroma. Overall, data have shown the efficacy of Haematococcus algae in promoting a reddish coloration in red porgy.     

雨生红球藻规模化培养工艺的构建与应用

针对雨生红球藻规模化培养中的工艺流程、生物污染、温度控制、溶氧解析和pH值稳定等问题,于2003年到2005年,在山东省潍坊地区,开展了雨生红球藻中试规模的论证研究。建立了可用于雨生红球藻规模化生产的3种不同类型的光生物反应器(柱式、管道、生物幕)和人工调节太阳能的温控车间,并构建了一套二步规模化培养工艺流程。结果表明,研究构建的培养模式降低了培养过程中的潜在风险,并大大提高了雨生红球藻虾青素含量。与传统培养方式相比,年培养天数大约提高了3倍。在每个批次培养中,细胞生长培养效率提高了至少1.75倍,虾青素累积培养所需时间缩短了40%,虾青素含量提高了4倍。总体来看,研究构建的新工艺比传统开放模式的生产效率有很大提高,全年共计提高了35倍。     

Colouring ornamental fish (Cyprinus carpio and Carassius auratus) with microalgal biomass

Koi carp and goldfish value increases with intensity of skin colour, which is an important quality criterion. Fish cannot fully synthesize their own carotenoid colourings and these must therefore be included in their diet. Two trials were undertaken to investigate skin colour enhancement in ornamental species (i.e. three chromatic varieties of koi carp (Cyprinus carpio), namely Kawari (red), Showa (black and red) and Bekko (black and white) and goldfish (Carassius auratus)) by feeding a dietary carotenoid supplement of freshwater microalgal biomass [Chlorella vulgaris, Haematococcus pluvialis, and also the cyanobacterium Arthrospira maxima (Spirulina)], using a diet containing synthetic astaxanthin and a control diet with no colouring added for comparison. In the first trial, five homogeneous duplicate groups of 25 juvenile koi carp (C. carpio) (initial mean body weight 24.6 ± 0.7 g) were fed, for 10 weeks, one of the four diets containing 80 mg colouring/kg diet. In the second trial, this procedure was repeated for five homogeneous duplicate groups of 25 goldfish (C. auratus) (initial mean body weight of 0.9 ± 0.1 g). Initial and final samples of skin along the dorsal fin were withdrawn, from five fish per group, for subsequent analysis of total carotenoid content (spectrophotometric analysis), and red hue (colorimetric analysis, CIE (1976) L* a* b* colour system). Growth and feed efficiency were not significantly different between groups administered by the various dietary treatments. In both trials, dietary carotenoid supplementation increased total skin carotenoid content. The more efficient colouring for koi carps was found to be C. vulgaris biomass, providing both maximum total carotenoid deposition and red hue for the three chromatic koi carp varieties studied, and particularly for the kawari variety. For goldfish the best colouring obtained, as ascertained by total carotenoid content, was also achieved using C. vulgaris biomass, and red hue was maximum when using H. pluvialis biomass.     

一株新分离雨生红球藻培养条件的优化

为探究一株新分离雨生红球藻的适宜生长条件,以藻细胞密度为响应值,通过单因子试验方法,获得该株雨生红球藻生长的最佳光照强度、培养温度和接种密度分别为105 μmol/(m²·s)、21 ℃和 7.5×10⁴ cells/mL。然后采用响应曲面法(RSM)耦合Box-Behnken设计,建立了预测雨生红球藻细胞密度的二次多项式方程,培养光照强度、温度和接种密度及其二项式对雨生红球藻细胞培养密度有着显著影响。各因素影响强弱的顺序:接种密度>光照强度>培养温度。响应曲面法获得雨生红球藻的最佳培养条件为光照强度120 μmol/(m²·s),温度20 ℃,接种密度9.25×10⁴ cells/mL,在此组合条件下雨生红球藻细胞密度可达45.08×10⁴ cells/mL,比单因素实验得到的最高藻细胞密度高出6.9%。     

Fe2+,醋酸盐和双氧水对雨生红球藻积累虾青素的影响

研究了亚铁离子、醋酸盐和双氧水三种化学因子对雨生红球藻积累虾青素的交叉影响和虾青素积累过程中藻体总可溶性蛋白的变化.结果表明,在营养盐缺乏的前提下,添加45 mM醋酸盐和450 μM亚铁离子,25 ℃,24 h连续光照,6 000 lx光强下进行逆境胁迫诱导,能够大大缩短雨生红球藻虾青素积累周期,比空白对照提前一个月使藻细胞完全变红（显微观察）.但诱导过程中会造成部分藻细胞白化,自溶或破壁死亡,虾青素产量比空白对照下降了7.4%;在雨生红球藻虾青素积累过程中,藻体总可溶性蛋白含量逐渐降低,说明雨生红球藻中虾青素的积累可能以蛋白质的消耗为基础.     

雨生红球藻虾青素粉对锦鲤组织色素沉积的影响

本试验的目的是探讨锦鲤饵料中雨生红球藻虾青素粉的最适添加量及锦鲤的着色规律。试验将平均体重为10g的420尾锦鲤分成7组,每组3个重复。在基础饵料中分别添加0,0．5,1．5,2．5,3．5,4．5,5．5g／kg雨生红球藻虾青素粉,试验结果表明：在相同饲养条件下饲养60d,锦鲤头和鳍中色素的沉积量各组差异不显著（P〉0．05）。而体组织中色素沉积量各组间差异显著（P〈0．05）,其中,雨生红球藻虾青素粉添加量为3．5g／kg的组着色最显著。     

Effects of dietary supplementation of Haematococcus pluvialis powder on gonadal development,coloration and antioxidant capacity of adult male Chinese mitten crab (Eriocheir sinensis)

The green algae Haematococcus pluvialis is an important source of natural astaxanthin as feed additive. This study was conducted to investigate the effects of dietary supplementation of H. pluvialis powder on gonadal development, coloration and antioxidant capacity of adult male Chinese mitten crab Eriocheir sinensis, and four experimental diets were formulated to contain 0, 0.2%, 0.4% and 0.6% of H. pluvialis powder. There were four treatments (defined as D1~D4) in this study and each treatment had three replicates. Dietary H. pluvialis contents had no significant effects on survival, body weight gain rate and gonadal development of male E. sinensis. For colour parameters, the total carotenoids content in carapace and hepatopancreas as well as hepatopancreatic lightness (L*) and carapace redness (a*) increased significantly with increasing dietary H. pluvialis (p < 0.05). For the antioxidant indices in the serum, D4 had the lowest activities of superoxide dismutase (SOD) and peroxidase (POD), but the highest glutathione peroxidase (GSH‐Px) and lactic dehydrogenase (LDH), while the malondialdehyde (MDA) in serum and hepatopancreas decreased significantly with the rising content of dietary H. pluvialis (p < 0.05); D1 had the highest levels of SOD, POD and GSH‐Px in hepatopancreas. For the non‐specific immune indices, the highest activities of acid phosphatase (ACP) and γ‐glutamyl transpeptidase (γ‐GT) were found on the serum of D3 and D4 (p < 0.05). D1 had the highest levels of ACP and alkaline phosphatase (ALP) in hepatopancreas, while D2 and D3 had the lowest levels of ALP and ACP respectively. These results suggested the optimal dietary natural astaxanthin level was around 40 mg/kg diets.     

盐胁迫对雨生红球藻虾青素累积、虾青素合成相关酶基因表达和抗氧化指标的影响

为探讨盐胁迫对雨生红球藻(Haematococcus pluvialis)虾青素合成的影响与机理,以及雨生红球藻各抗氧化机制之间的关系,本研究采用生化和分子生物学方法研究了不同浓度(0.04 mol/L、0.08 mol/L、0.12 mol/L和0.16 mol/L)和不同时间(3 d、6 d和9 d)的盐(Na Cl)胁迫对雨生红球藻生长、虾青素积累、番茄红素β-环化酶(Lcy)、β-胡萝卜素羟化酶(Crt R-B)和β-胡萝卜素酮化酶(Bkt)基因表达、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-Px)的活性以及丙二醛(MDA)含量的影响。结果表明,各胁迫时间的雨生红球藻的密度均随着盐胁迫浓度的增加而不断下降,在盐胁迫的第9天,雨生红球藻的死亡率和孢子比例均随着盐胁迫浓度的增加而不断升高;雨生红球藻虾青素含量、Lcy、Crt R-B和Bkt基因表达量均随着盐胁迫浓度和时间的增加而不断提高;雨生红球藻SOD、CAT和GSH-Px活性以及MDA含量在不同浓度和不同时间的盐胁迫下与对照组(0.00 mol/L Na Cl)相比均升高,且在不同时间的0.12 mol/L Na Cl胁迫下与对照组相比均显著升高(P0.05);雨生红球藻虾青素含量、Lcy、Crt R-B和Bkt基因表达量在盐胁迫的早期(第3天)和中期(第6天)阶段较低,在盐胁迫的后期(第9天)阶段较高,而SOD、CAT和GSH-Px活性以及MDA含量在盐胁迫的早期和中期阶段较高,在盐胁迫的后期阶段较低。实验结果说明了适当浓度和时间的盐胁迫能促进雨生红球藻累积虾青素,雨生红球藻在盐胁迫下主要是通过提高虾青素合成相关酶基因的转录水平来促进虾青素的合成,其虾青素和抗氧化酶的抗氧化活性可能互为补充,共同保护雨生红球藻免受盐胁迫的氧化损伤。