盐藻运动特性及其影响因素

为了揭示盐藻的运动特性,在不同条件下观察了玻璃U形管两端盐藻的密度变化。结果表明,盐藻运动受光照、ATP、丙二酸钠和粘度的影响。盐藻具有向光源方向聚集的运动特性;供给ATP时盐藻运动加速,加入丙二酸钠时盐藻运动减慢,盐藻的运动是一个消耗能量的过程;增加介质粘稠度会使其运动速度减慢。     

盐藻醛缩酶的盐适应性及其与物质积累的关系

在不同N aC l质量浓度下培养盐藻,分析盐藻醛缩酶的盐适应性及其与物质积累的关系。试验结果表明,在NaCl质量浓度为40～120 g/L时,盐藻醛缩酶活性与盐度具有正相关性;在NaCl质量浓度为120～200 g/L时,盐藻醛缩酶活性与盐度具有负相关性;在NaCl质量浓度为120 g/L时,盐藻醛缩酶活性最高。盐藻醛缩酶是一种高盐适应酶。盐藻醛缩酶活性与盐藻细胞密度、叶绿素形成和蛋白质积累均呈正相关关系。在盐藻醛缩酶活性最高时,盐藻物质积累量最多。     

盐藻过氧化氢酶对盐的适应性及其与物质积累的关系

将盐藻分别接于NaCl质量浓度为40、80、120、160、200g/L的培养液中,置光照培养箱中培养,分析盐藻过氧化氢酶对盐的适应性及其与物质积累的关系。结果表明,在NaCl质量浓度为40～120g/L和120～200g/L的范围内,盐藻过氧化氢酶活性与NaCl质量浓度分别具有正负相关性;在盐度为120g/L时,盐藻过氧化氢酶活性最高。盐藻过氧化氢酶是一种高盐适应酶,活性与盐藻细胞密度、叶绿素形成和蛋白质积累呈正相关关系。在盐藻过氧化氢酶活性最高时,盐藻物质积累量最多。     

6-BA与盐藻生长的关系

试验结果表明,在6-BA质量浓度较低时,6-BA与盐藻生长正相关;在6-BA质量浓度较高时,6-BA与盐藻生长负相关;培养液中1.5 mg/L的6-BA是盐藻的最佳促生长质量浓度,且6-BA对盐藻生长的促进效果可被萘乙酸(NAA)提高.     

盐胁迫条件下盐藻的生长及特异表达蛋白的研究

采用不同NaC1浓度培养盐藻.通过分光光度法记录其生长状态.试验结果表明,在NaC1浓度为1.0～2.0 mol/L时.盐藻生长状态良好;NaCl浓度为3.0～4.0 mol/L时盐藻生长缓慢;盐藻经不同NaCI浓度培养0.5、5、23 h后抽提蛋白,所获得的粗提蛋白经SDS-聚丙烯酰胺凝胶电泳分离,观察不同NaCI浓度培养液中生长的盐藻可溶性蛋白质SDS-PAGE图谱.发现在低NaC1浓度(1.0～2.0 mol/L)下培养时23、51 kD蛋白略有变化但变化不大;在高NaC1浓度(3.0～4.0 mol/L)下胁迫5、23 h时23 kD蛋白显著增加;高NaC1胁迫23 h时51 KD蛋白含量下降明显.验结果证明51、23 kD蛋白可能与盐藻耐盐机制有关.     

饵料对不同品系卤虫生长和生殖的影响

用盐藻、米糠、螺旋藻粉、酵母、米糠 盐藻这5种饵料类型培养江苏台北盐场、西藏巴里坤湖、山西运城、美国大盐湖等4个品系的卤虫，考察其生长、存活和繁殖特性.结果表明米糠、螺旋藻、米糠 盐藻利于卤虫的生长，盐藻和米糠 盐藻利于卤虫的成活，米糠、螺旋藻、米糠 盐藻可促进卤虫的繁殖；美国大盐湖品系的综合性能最佳，以它作为增养殖对象是较好的选择。     

饲料盐藻水平对卵形鲳鲹体色和生长的影响

以初始体质量为(13.88±0.28)g的卵形鲳鲹为试验对象,研究不同盐藻添加量(0.0%、0.1%、0.2%、0.4%、0.8%、1.6%)饲料对其体色和生长的影响。每组设3个平行,每个平行饲养20尾鱼,每日饱食投喂2次(8:00;17:00),试验周期为56d。结果显示,盐藻添加量为0.1%~1.6%时,随着饲料中盐藻水平的提高,卵形鲳鲹背部和腹部黄色值(b*)呈显著上升趋势(P0.05),饲料中添加盐藻可明显改善卵形鲳鲹体色;与此同时,卵形鲳鲹质量增加率和特定生长率随饲料盐藻水平的上升呈下降趋势(P0.05),未添加盐藻的对照组具有最高蛋白质效率和最低饲料系数,且与盐藻添加量为0.4%的试验组差异显著(P0.05),饲料中添加盐藻对卵形鲳鲹生长性能和饲料利用没有明显的促进作用;此外饲料盐藻水平对卵形鲳鲹体成分也没有显著影响(P0.05)。     

外加CO_2对盐藻生长及碳酸酐酶活性的影响

在光照阶段开始前向盐藻培养体系中通入CO_2至其饱和(pH=6.0),探究外加CO_2对盐藻生长及细胞碳酸酐酶活性的影响。结果显示,未加CO_2的对照组盐藻培养液的pH在8.10~8.20,外加CO_2至饱和时培养液的pH从6.00升至7.04,盐藻生物量、叶绿素含量、细胞内外碳酸酐酶比活性均显著高于未加CO_2的培养体系;未加CO_2和通入CO_2的两种体系中细胞外碳酸酐酶比活性均显著高于细胞内碳酸酐酶比活性,前者分别是后者的1.39、1.71倍。这表明在盐藻培养体系中通入CO_2至饱和时,盐藻通过提高细胞内外的碳酸酐酶活性加快对CO_2的吸收,进而快速生长,提高生物量。此结果为利用盐藻吸收转化工业排放的CO_2并获取盐藻生物量的进一步研究提供了试验依据。     

盐生杜氏藻的生物学特性及其开发利用

盐生杜氏藻(Dunaliella salina),是一种富含β-胡萝卜素的极具经济价值的单细胞藻类,目前对它的研究和利用越来越广。本文介绍了盐藻的生物学特性、开发利用和培养条件。     

锰对盐藻生长与物质积累的调控作用

试验结果表明,培养液中锰质量浓度过高或过低都不利于盐藻细胞的生长与物质积累。培养基中锰质量浓度为4.0 mg/L时,盐藻细胞生长、蛋白质合成与β-胡萝卜素积累最多。当培养液中锰质量浓度较高(8.0 mg/L)或较低(2.0 mg/L)时,单个盐藻细胞中的蛋白质与β-胡萝卜素含量较高。但此时,因培养液中细胞密度较低,盐藻细胞积累的物质总量仍然较少。在锰质量浓度较高或较低的逆境条件下,盐藻可能通过适应性反应形成了逆境蛋白质与胡萝卜素等。     

杜氏盐藻和亚心型扁藻混合培养生长的初步研究

在实验室条件下研究了杜氏盐藻和亚心型扁藻在单独培养和相同接种比例混合培养下的生长情况。结果显示,单独培养盐藻的生长经历了3个明显的阶段,生长曲线呈现"S"型;单独培养扁藻与混合培养藻在18 d内还未到达稳定期,仍保持一定的生长态势。混合培养、单独培养盐藻以及单独培养扁藻的最大光密度值(OD680)分别为0.784、0.702和0.765。混合培养藻的生物量(0.841 mg/ml)也稍高于单独培养盐藻(0.582 mg/ml)和单独培养扁藻的生物量(0.819 mg/ml)。试验结果表明,混合培养盐藻和扁藻具有一定的促进藻生长和提高生物量产出的潜力。     

盐藻超氧化物歧化酶分子类型鉴定

对盐藻细胞反复冻融和超声波破碎获得超氧化物歧化酶粗酶液,再经丙酮沉淀、70℃热处理、DEAE-52柱层析获得纯化超氧化物歧化酶,经SDS-聚丙烯酰胺凝胶电泳,检测出1条超氧化物歧化酶谱带。该纯化超氧化物歧化酶在紫外光区的吸收峰波长259 nm和可见光区的吸收峰波长671 nm与报道的Cu/Zn-SOD基本一致,并且它对H2O2和KCN均敏感,说明盐藻中的超氧化物歧化酶为Cu/Zn-SOD类型。     

藻类在线分析仪在海洋环境监测中的应用研究

利用藻类在线分析仪测定了3种不同微藻(盐藻、角毛藻、金藻)的荧光值,同时采用经典方法同步测定叶绿素a浓度和细胞密度。分析结果显示,荧光值与叶绿素a浓度、细胞密度具有显著的正相关关系。因此,利用藻类在线分析仪能够反映海水中微生物量的变化,也能够反映海水中叶绿素a浓度的变化。藻类在线分析仪的应用,能够及时掌握海水中生态环境的变化,为海域自然灾害的预警提供有力的科学依据。     

The effect of three carotenoid sources on growth and pigmentation of juvenile freshwater crayfish Cherax quadricarinatus

The effect of adding carotenoids from various sources to feed of juvenile freshwater crayfish Cherax quadricarinatus on pigmentation, growth and survival was examined under laboratory conditions. Juvenile crayfish were fed diets fortified with carotenoids at a level of 100 μg g⁻¹ for a period of either 49 or 55 days. Carotenoid sources were: dried algal cells prepared from Dunaliella salina in which the main carotenoid is β-carotene; a synthetic carotenoid, astaxanthin (Carophyll Pink 8%, manufactured by Hoffman–La Roche) and alfalfa meal. Crayfish receiving feeds fortified with carotenoids exhibited better body colouration than those in the control group, which were fed a diet to which no carotenoids were added. Growth and survival of the crayfish were not affected by the addition of carotenoids to their diet.     

Comparative Studies of β-carotene and Protein Production From Dunaliella salina Isolated From Lake Hoze-soltan,Iran

A novel Dunaliella salina (D. salina) was isolated from Hoze-soltan Lake, Iran. The investigated strain was capable of producing carotenoids and protein, using different NaCl concentrations and pH variations in Hoze-soltan saline water. The experiment was carried out within 42 days. The results indicated that protein production and pigmentation correlated well with growth rate. The optimum amount for growth, carotenogenesis, and protein production was determined in a culture with 10% NaCl and pH 8.5. After 42-days incubation, 14.95 ± 0.6 μg/mL of carotenoids and 186 ± 8.6 μg/mL of protein were obtained in this medium. Further observation revealed that growth was inhibited in all samples with 30% NaCl. The amount of each biosynthesized component by Dunaliella salina was in accordance with growth stage, cell number, and growth pattern of microalgae.     

盐生杜氏藻粉对脊尾白虾存活和生长的影响

本文研究了饲料中添加盐生杜氏藻粉(0％、0．5％、1％、2％和4％)对脊尾白虾(平均初始湿重0．715g)存活和生长的影响。实验周期30 d。结果表明:白虾存活率以1％添加组最高,特定生长率和吸收效率以2％添加组最高,摄食量以4％添加组最高,而饲料系数以1％添加组最低;回归分析表明,脊尾白虾特定生长率达到最大值时的盐生杜氏藻粉添加量为2．76％。     

Effects of diet, stocking density and environmental factors on growth, survival and metamorphosis of clam, Paphia malabarica (Chemnitz) larvae

A series of experiments were conducted to evaluate the effects of diet, stocking density and environmental factors on the growth, survival and metamorphosis of short neck clam Paphia malabarica larvae. These experiments examined the following factors: diet [ Isochrysis galbana , Nannochloropsis salina and a mixture of I. galbana and N. salina (1:1 w/w)], stocking density (1, 3, 5 and 7 larvae mL⁻¹), light intensity (unshaded, partially shaded and fully shaded) and water filtration (unfiltered and sand filtered). Results indicated that N. salina could replace 50% of I. galbana as a food source for the clam larvae with an increase in growth, survival (47.2%), metamorphosis (33.5%) and early settlement. Larval growth decreased significantly with increasing stocking density. A density of 1–3 larvae mL⁻¹ appeared to be optimal for normal growth of clam larvae. Neither diet nor stocking density used in the study had a significant effect on larval survival. Under partially shaded (light intensity=1000–5000 lx) and fully shaded (light intensity <1000 lx) conditions, larval growth was significantly faster than under direct sunlight (unshaded). Larvae grew significantly faster in the unfiltered water than in the filtered water.