光照胁迫对雨生红球藻虾青素积累和抗氧化活性的影响

本文研究了不同光强(120~270μmol/m2·s)和光周期(光/暗:0/24~24/0 h)的光照胁迫对雨生红球藻(Haematococcus pluvialis)虾青素积累、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性、总抗氧化能力(T-AOC)和超氧阴离子自由基(O2-?)清除能力的影响。结果表明,在绿色、褐色和红色细胞期,光强越高,藻细胞虾青素的含量、T-AOC和O2-?清除能力也越高;抗氧化酶(SOD和CAT)活性在绿色细胞期随光强的增加而增加,在红色细胞期则随光强的增加而下降;藻细胞虾青素的含量、T-AOC和O2-?清除能力在红色细胞期最高,而抗氧化酶活性在褐色细胞期最高;藻细胞在不同光周期的270μmol/m2·s的光照下生长10 d时,虾青素的含量、T-AOC和O2-?清除能力随每日光照时间的延长而增高,抗氧化酶活性则先升高后下降。总之,雨生红球藻在270μmol/m2·s的光强下连续光照10 d时虾青素的含量和抗氧化能力最高,这为虾青素作为天然的抗氧化功能食品添加剂的生产和应用提供了新的参考条件。     

利用高效液相色谱法测定雨生红球藻中虾青素含量

利用高效液相色谱法对雨生红球藻中的虾青素含量进行了测定。色谱柱为KromasilC18柱(250×4.6mm),流动相为二氯甲烷∶甲醇∶乙腈∶水=5∶85∶5∶5,流速1mL/min,检测波长480nm,柱温25℃。虾青素在1.896～18.96μg/mL范围内线性关系良好,r=0.9999,RSD=1.12%(n=6),回收率为99.69%～102.6%。本方法简便快速,定量准确,重现性好。     

混合培养对雨生血球藻虾青素产量的影响

研究了不同光照强度及添加不同葡萄糖量进行混合培养对雨生血球藻虾青素产量的影响.研究表明,单位体积培养液虾青素产量因光照强度和葡萄糖添加量不同而不同,在光照强度为2500lx以及葡萄糖添加量为3g/L时,虾青素产量最高.光照强度和葡萄糖添加浓度对虾青素产量具有交互影响.通过中心组合试验,确定混合培养条件下达到最高虾青素产量所需要的葡萄糖添加量及光照强度分别为3.1616g/L和2605.66lx.此时的虾青素产量为41.06mg/L,是自养培养时的2.02倍.     

Highly efficient preparation of free all-trans-astaxanthin from Haematococcus pluvialis extract by a rapid biocatalytic method based on crude extracellular enzyme extract

A highly efficient, rapid, green and safe procedure for the preparation of free all-trans-astaxanthin from Haematococcus pluvialis algal extract, by a crude extracellular enzyme extract, was reported. The free all-trans-astaxanthin obtained by the biocatalysed method had fewer side products compared to the saponification procedure. Through single-factor experiments and a Box–Behnken design, it was possible to find the optimal biocatalytic conditions for the hydrolysis of 2 mg of H. pluvialis oil with 14.7 mg (protein content) of lyophilised crude extracellular enzyme extract obtained from Pseudomonas aeruginosa. The reaction was carried out in 30 min at pH 9.16 and 36 °C, in 5.5 mL total reaction volume, under nitrogen atmosphere and dark conditions. The hydrolysis ratio of the astaxanthin esters was 98.72%, and the production of free all-trans-astaxanthin was 82.83 μg per mg of H. pluvialis oil. The method herein reported was simpler than other enzymatic methods previously described and allowed saving of time and costs.     

两种培养基间雨生红球藻细胞生长分化差异及磷的作用

基于雨生红球藻游动细胞和不动细胞间Triton X-100敏感性的差异,建立了一种快速监测培养过程中细胞分化的指标,对比了雨生红球藻在BG11和BBM两种培养基中的细胞生长与分化差异. 结果表明,在BBM培养基中培养8 d,雨生红球藻的游动细胞比例始终较高,而在BG11中早期不动孢子囊释放的游动孢子则快速成熟并转变成不动细胞. 这主要是由于BBM中游动细胞通过有丝分裂或孢子囊两种模式维持了其继续分裂与增殖的能力,而BG11中这些繁殖形式缺失的主要原因在于其较低的磷浓度,培养基中适当的高磷含量对保持雨生红球藻培养中期游动细胞的持续繁殖非常关键.     

雨生红球藻高产虾青素的培养条件优化

本研究从5种培养基中筛选出最适于雨生红球藻HP1藻株绿色细胞生长阶段细胞增殖的培养基,并针对筛选出的培养基分别进行有机碳源和无机碳源及其浓度的优化。在此基础上,以光照强度、初始p H值和诱导时间为实验因素,采用单因素试验、中心点复合设计(CCD)响应面法对雨生红球藻虾青素积累阶段的胁迫条件进行优化。结果表明:HP1藻株在配方A及OHM培养基中均能达到较高生物量,有机碳源和无机碳源的最优浓度均为0.5 g/L。HP1虾青素积累的最优胁迫条件为:光照145μmol/m~2·s,初始p H 7.0,诱导时间9 d。在上述条件下,以有机碳源(NaAC)和无机碳源(NaHCO_3)为碳源的培养体系中,虾青素产量最大分别为5.74 mg/L、4.25 mg/L。研究结果将为进一步提高雨生红球藻虾青素产量提供科学依据。     

响应面法优化雨生红球藻中虾青素的提取条件

以雨生红球藻粉为原料,选取乙酸乙酯:乙醇(1:1,v/v)为提取溶剂,以虾青素提取率为评价指标,在单因素实验的基础上,利用响应面法对雨生红球藻中虾青素的提取条件进行了优化。结果表明,影响虾青素提取条件的强弱分别为温度>液固比>时间,通过计算回归方程优化得到的最佳提取条件为:温度50℃,时间100 min,液固比1.5:1。通过与荆州公司提供的提取方法和碱提法对比,应用此方法虾青素提取率分别提高了44.31%和86.80%。     

Optimization of Microwave-Assisted Extraction of Astaxanthin from Haematococcus Pluvialis by Response Surface Methodology and Antioxidant Activities of the Extracts

Abstract

Microwave-assisted extraction (MAE) was applied for the extraction of astaxanthin from Haematococcus pluvialis and response surface methodology (RSM) was used to optimize extraction parameters to the content of astaxanthin. Four independent variables such as microwave power (W), extraction time (sec), solvent volume (mL), and the number of extraction were optimized in this paper. The optimal conditions were determined and tri-dimensional response surfaces were plotted from the mathematical models. The F-test and p-value indicated that microwave power, extraction time, the number of extraction, and their quadratic had a highly significant effect on the response value (p <0.01), then the solvent volume and the interaction effects of microwave power and the number of extraction also displayed significant effect (p <0.05). Considering the extraction efficiency, the optimized conditions of MAE were as follows: microwave power was 141 W, extraction time 83 sec, solvent volume 9.8 mL, the number of extraction four times. About 594 ± 3.02 µg astaxanthin was extracted from Haematococcus pluvialis the dried powders (100 mg) under the optimal conditions, and it close to the predicted contents (592 µg). The antioxidant activities of the extracts obtained under optimal conditions were analyzed, and the results showed that the extracts presented strong ability of inhibiting the peroxidantion of linoleic acid, exhibited strong radical-scavenging properties against the DPPH, as well as strong reducing power.     

雨生红球藻保健酒的研发

本文以雨生红球藻为主要原料,配以其他传统保健食品资源,研制新型保健酒——雨生红球藻保健酒,以感官品评的方式调配出最佳风味,并对保健酒的市场现状及未来展望进行了分析。