电转化法转化钝顶螺旋藻转化条件的研究

确定了电转化法转化钝项螺旋藻S6-4的转化条件。无论受体是藻丝还是单细胞／藻丝段，钝项螺旋藻S6-4在对数生长期内，半致死电场强度无显著差别。实验表明以对数中期的螺旋藻用于转化为宜。当脉冲时间是5．0ms时，藻丝受体和单细胞／藻丝段受体的半致死电场强度分别是3．75—5．0kV／cm和3．1—4．4kV／cm，而电击缓冲液分别是1．0mmol／L HEPES(pH7．5)缓冲液和含有0．5mol／L蔗糖的1．0mmol／L HEP—ES(pH7．5)缓冲液。本文的研究结果为螺旋藻转化及外源基因表达提供了实验基础。     

螺旋藻泡载分离法采收的实验室研究

在一种斜臂泡沫分离装置上，较为详细地研究了泡沫塔构造、起泡剂Tween 20浓度、载气流率、pH值和乙醇浓度等因素对螺旋藻泡载采收性能的影响. 结果表明，斜臂泡沫塔可明显改善藻细胞的泡载性能, 当Tween 20浓度为100 mg/L、载气流率为30 L/h及pH=11、乙醇浓度为1%(j)时，泡载采收过程的分离因子R和浓缩倍数a可分别达到5.04~6.52和2.74~4.31.     

螺旋藻基因工程研究(I)--几种抗生素对钝顶螺旋藻的抑制效应

了建立螺旋藻外源基因表达体系，首先必须选择螺旋藻抗性基因。本实验选用三种抗生素进行敏感性研究，实验结果表明：螺旋藻对这三种抗生素的敏感性有明显差异，它们对螺旋藻生长的抑制作用依次为：氯雷素＞链霉素＞氨苄青霉素。氯霉素对螺旋藻生长的抑制作用与氯霉素的浓度和作用时间呈正相关。600mg/L氯霉素处理48h就对螺旋藻有明显的致死作用，致死率分别为：48h为17。51％、144h为68．67％；400mg/L的氯霉素：48h至死率为1．96％、144h为49．76％；200mg/L以下低浓度的氯霉素对螺旋藻的抑制作用需要较长时间，144h才具有明显的致死作用，致死率为19．24％。     

含亚甲基兰的印染废水培养螺旋藻的研究

在含 2 5mg·L- 1 的亚甲基兰的正常和无氮培养液中培养盐泽螺旋藻 ,观测盐泽螺旋藻的生长、叶绿素含量、藻胆素含量及其对亚甲基兰的脱色率。结果表明 ,盐泽螺旋藻可由染料亚甲基兰提供唯一氮源 ,但不能提供唯一碳源。在培养 8d后 ,无氮培养液中的螺旋藻液吸光度达到 0 2 1 0 ;在正常培养液下螺旋藻液吸光度为 0 32 1。盐泽螺旋藻对染料的脱色效果也比较好 ,在培养 8d后 ,无氮培养液下亚甲基兰脱色率为 85 %;正常培养液下亚甲基兰脱色率为 86%。     

Effect of dietary supplementation of Spirulina (Arthrospira platensis) and Thyme (Thymus vulgaris) on rabbit meat appearance,oxidative stability and fatty acid profile during retail display

The objective of this study was to evaluate the effect of Spirulina and Thyme supplementation on rabbit meat during retail display. At weaning 294 rabbits were allocated to 7 different treatments (42 rabbits/treatment). Rabbits of the control group (C) received a diet without any supplementation throughout the experiment (5–11 weeks of age). The other groups were fed diets containing 5% Spirulina (S), 3% Thyme (T) or both supplements (ST) for the whole trial (5–11 weeks; treatments S, T and ST), or for a part of the growing period (8–11 weeks; treatments C–S, C–T and C–ST). Colour parameters, pH, water holding capacity and drip loss were determined on fresh and stored Longissimus dorsi muscle of 5 rabbits/treatment. Spirulina- and Thyme-supplemented diets had a significant effect on redness and yellowness of Longissimus dorsi. Drip loss was significantly reduced in C–T and T groups that also showed the highest content of α-tocopherol and n − 3 fatty acids content and the lower lipid oxidation.     

Assessment of antioxidant activity and phycocyanin release of Spirulina loaded poly(ε-caprolactone) electrospun nanofibers

PCL with biodegradable property and Spirulina with various biological activities offer good alternative ingredients for the fabrication of functional nanofibers in tissue engineering. The aim of the study is to obtain PCL/Spirulina nanofibers with low diameters and to determine their wettability, antioxidant activity, and phycocyanin release to evaluate their potential as bioactive scaffolds in different applications. PCL/acetic acid/pyridine solutions with three different Spirulina concentrations were electrospun and the obtained nanofibers were investigated. The thinnest PCL/Spirulina nanofibers (117.20 nm) were obtained at 1.5% Spirulina concentration. Although PCL nanofibers with 6% Spirulina concentration showed the highest antioxidant activity and amount of phycocyanin released, PCL nanofibers with 3% Spirulina concentration having similar in vitro results showed superiority when considering the diameter and uniformity of the nanofibers and the cost of the material. The PCL/Spirulina nanofibers with small diameters and antioxidant activity could be regarded as potential extracellular matrix material for tissue engineering.     

螺旋藻两种氮源的比较研究

文章以尿素和硝酸钠作为氮源培养螺旋藻,探讨两种氮源对螺旋藻生长的影响.     

天然食用色素藻蓝蛋白的稳定性研究

采用冻融结合溶胀的方法从钝顶螺旋藻突变株(SP-Dz)中分离得到藻蓝蛋白(Phycocyanion,PC),研究了不同因素对藻蓝蛋白稳定性的影响。实验结果表明:在低温、pH5、NaCl浓度为0.15mol/L条件下藻蓝蛋白稳定性好,适于保存或应用。多因素分析表明,对藻蓝蛋白稳定性影响最大的因素是温度,其次为保存时间,影响最小的是光强。     

钝顶螺旋藻藻蓝蛋白的稳定性试验研究

用冻融的方法制备钝顶螺旋藻(Spirulina platensis)藻蓝蛋白并对纯化后的藻蓝蛋白稳定性进行了初步研究。提取后的粗提液经羟基磷灰石柱层析纯化后其纯度(A621／A280)达3.1温度、酸碱度、乙醇对藻蓝蛋白稳定性有较大影响；NaCl、苯甲酸钠、柠檬酸等食品添加剂对其稳定性影响较小。