4种单胞藻对卤虫生长和生殖影响的比较研究

以亚心形扁藻、小球藻、湛江等鞭金藻、绿色巴夫藻为饵料,卤虫为投喂对象,建立五个实验组分别进行研究,观察不同饵料对卤虫生长和生殖的影响,结果表明:投喂亚心形扁藻的卤虫生长最快,成活率高,生殖量也最多,其次为绿色巴夫藻组,湛江等鞭金藻的饵料效果最差.混合4种单胞藻投喂的效果也较好.     

湛江等鞭金藻培养基和培养方法的优化

在室内采用正交试验的方法,对湛江等鞭金藻(Isochrysis zhanjiangensis)氮、磷、铁、碳、维生素B1、维生素B12等主要营养成分进行了优化,获得了以天然海水为基础的优化培养基:NaNO3 60mg/L,KH2PO4 4mg/L,FeC6H5O7 0.5mg/L,NaHCO3 1.0g/L,维生素B1 150μg/L,维生素B12 200 ng/L.试验结果表明,使用优化培养基培养湛江等鞭金藻具有生长速度快、产量高、成本低的优势.应用微生物流加技术培养湛江等鞭金藻可取得较好效果.     

单胞藻超滤浓缩技术的研究

采用超滤技术对球等鞭金藻进行浓缩,比较不同操作压力对浓缩机滤水率及单胞藻活性的影响。操作压力分别为0.02、0.06、0.10、0.16、0.20 MPa对单胞藻进行浓缩,并对不同浓缩时间的浓缩藻进行再培养。结果表明,浓缩机的滤水率随着压力的增大而增大;当压力为0.16 MPa时,滤水率最高,浓缩密度最大,且不影响浓缩藻的细胞活性。     

缘管浒苔对球等鞭金藻生长的克生作用

研究了缘管浒苔新鲜组织、干粉末、培养水过滤液和水溶液抽提液对球等鞭金藻生长的克生作用。结果表明,缘管浒苔新鲜组织、干粉末和水溶性抽提液对球等鞭金藻的生长具有强烈的克生作用。当培养液中缘管浒苔新鲜组织、干粉末和水溶性抽提液的浓度为5.0 gwet/L、1.2 gdry/L和1.0 g/L时,球等鞭金藻不能够维持正常的生长或全部死亡。在缘管浒苔培养水过滤液培养实验中,一次性添加缘管浒苔培养滤液,不能持久地抑制球等鞭金藻增殖,而半连续添加缘管浒苔培养滤液,其克生作用较强,说明克生物质的连续分泌是有效抑制球等鞭金藻生长的关键。经高温高压处理后的缘管浒苔培养滤液对球等鞭金藻无显著的抑制作用,说明缘管浒苔所分泌的克生物质在高温高压下不稳定和易分解。     

单胞藻的生产性培养技术

单胞藻类具有营养丰富,生长繁殖迅速,对环境适应性强和易培养的特点,是水产动物特别是贝类、甲壳类幼体的优质适口饵料。但由于天津地区海水透明度低,有机质含量、浮游动物、浮游植物丰富,进行藻类生产性培养困难很大,为此,2004年笔者以球等鞭金藻(Isochrysis galbana)、小球藻( Chlorellasp.)、牟氏角毛藻( Chaetoceros miiellerilemmermann)、湛江叉鞭金藻(Dicrateria zhanjiangensis)、亚心形扁藻(Platymonas subcordiformis)为试验藻种,研究了海水单胞藻类一级培养(保种)、二级培养(中继培养)、三级培养(生产性培养)的操作规程。探讨…     

温度对等鞭金藻塔溪堤品系细胞密度和叶绿素荧光参数的影响

以等鞭金藻塔溪堤品系Isochrysis galbana（Tahitian strain）为试验材料,采用Water-PAM叶绿素荧光仪测定了该藻一次性培养过程中,不同温度（5～40℃）对其细胞密度、叶绿素相对含量以及叶绿素荧光参数（PSⅡ最大光能转化效率Fv/Fm、光化学淬灭qP）的影响。结果表明：温度对等鞭金藻塔溪堤品系的叶绿素相对含量和细胞密度均有显著影响（P〈0.05）;在本试验条件下,等鞭金藻塔溪堤品系在5、10℃和40℃下不能生长繁殖,该藻生长的适温为15～35℃,最适温度为20～30℃,各处理组的相对生长率从高到低依次为25℃〉20℃〉30℃〉35℃〉15℃;温度对等鞭金藻塔溪堤品系各叶绿素荧光参数也有显著影响（P〈0.05）,从接种后第1天到试验结束,5、10℃和40℃处理组藻类的主要荧光参数（Fv/Fm、qP）均显著低于其它处理组（P〈0.05）,其中25℃和30℃处理组藻类的主要荧光参数总体上低于15℃、20℃和35℃处理组,但高于其它处理组;试验结束时将5、10℃和40℃处理组的藻细胞重新置于25℃下继续培养6 d,5℃和40℃处理组藻类的主要荧光参数不能恢复,而10℃处理组藻类的主要荧光参数可恢复正常。相关性分析结果表明：荧光参数、叶绿素相对含量以及细胞密度与温度的相关性随着培养时间的变化而变化,叶绿素相对含量与细胞密度呈显著的正相关关系（P〈0.05）。     

氮含量对等鞭金藻生长及生化组分的影响

[目的]为了确定利于等鞭金藻生长及不同生化组分积累的优化氮含量.[方法]采用流加培养方式和单因素考察,研究5种硝酸钠浓度时等鞭金藻生物量及细胞内生化组分含量随培养时间的变化趋势.[结果]在在流加培养方式下,适合等鞭金藻生长和细胞内蛋白质积累的硝酸钠含量为150 mg/L培养液;在含37.5 mg/L硝酸钠的培养液中,等鞭金藻细胞内的总脂含量在培养中期达到最高值;而在含75 mg/L硝酸钠的培养液中可溶性总糖和淀粉含量分别在培养的中后期和后期达到最大值.[结论]培养液中的氮含量对等鞭金藻细胞生长及细胞内生化组分的含量有重要影响.这可能由不同氮浓度下等鞭金藻的代谢途径发生变化所致.从等鞭金藻作为生物能源资源的角度考虑并兼顾生物量,应选择含75 mg/L硝酸钠的培养液培养等鞭金藻.     

Effect of algal addition on stability of fatty acids and some water‐soluble vitamins in juvenile Artemia franciscana

A minor stabilization effect was found for the content of total lipids, total fatty acids and docosahexaenoic acid (DHA) when Artemia franciscana was maintained at high concentrations of Isochrysis galbana for 72 h at 12 °C, both in 3‐ and 4‐day‐old individuals. The eicosapentaenoic (EPA) level was only stabilized at higher algal concentrations in the 4‐day‐old A. franciscana. In the 3‐day‐old A. franciscana, the EPA content increased at all algal concentrations during the first 24 h of post enrichment, presumably as an effect of DHA catabolism. Apparently, the 4‐day‐old A. franciscana metabolized DHA, and other lipids, faster than the 3‐day‐old A. franciscana did. During the 72 h incubation with I. galbana, the content of ascorbic acid (AA) in A. franciscana increased approximately to 1000–1200 μg g^–1 dry weight (DW) at algal concentrations above 3 mg C L^–1, close to AA content of the algae. The vitamin B₆ content in A. franciscana decreased from approximately 20 to 4–11 μg g^–1 DW, with highest loss rates at the higher algal concentrations. The thiamin content of A. franciscana was independent of algal concentration and remained at 20–30 μg g^–1 DW. The nutritional effects of the algal incubation on the 3‐ and 4‐day‐old A. franciscana at algal concentrations which can be used during the cultivation of Atlantic‐halibut larvae (<2 mg C L^–1) was insignificant, except for the small enrichment effect of AA already at 1 mg C L^–1. Other beneficial effects of the algae should not be ruled out, like possible effects on the microflora of A. franciscana even at algal concentrations less than 2 mg C L^–1.     

2株微藻对养殖废水中氮磷去除率的影响

采用2株分离自海南海域的微藻——双眉藻(Amphora sp.BQW)和等鞭金藻(Isochrysis sp.HN)分别处理幼虾养殖废水。结果表明,双眉藻和等鞭金藻均能在幼虾养殖废水中生长,相对生长速率分别是0.168和0.05。培养8 d后,等鞭金藻和双眉藻对幼虾养殖废水总磷的去除率分别达到30.9%和70.9%,总氮的去除率分别为1.0%和28.7%,硝酸盐氮的去除率分别达到了72.0%和85.7%,亚硝酸盐氮无显著差异,而氨氮含量则显著升高。     

Protein, carbohydrate, lipid and chlorophyll a content in Isochrysis aff. galbana (clone T-Iso) cultured with a low cost alternative to the f/2 medium

Growth, proximate composition and chlorophyll a content was estimated in static cultures of Isochrysis aff. galbana (clone T-Iso) to compare the quality and quantity of the biomass produced with an agricultural fertilizer medium versus f/2 medium. Culture of microalgae was done with controlled temperature, air flux of 4.5 l min⁻¹, salinity of 33‰ and an irradiance of 110±3 μmol m⁻² s⁻¹. Daily samples from the cultures were taken to estimate cellular density, proximate composition and chlorophyll a content during 7 days. Mean cellular density from samples with f/2 medium and with agricultural fertilizer were similar (no significance at P≤0.05), and mean growth rates of 0.62 and 0.61 doubling per day, respectively. Maximum similar values of protein content of 7.3 and 7.6 pg per cell were estimated on the 5th day in f/2 and agricultural fertilizer medium, respectively. Carbohydrate and lipid content decreased during the first 5 days corresponding to the exponential growth in both experiments. Higher content of carbohydrate (no significance at P≤0.05) was found in both media during the first 2 days, after 4 days the carbohydrates reduced three times theirs concentrations. Generally lipid contents in the cultures with agricultural fertilizer were significantly higher (P≤0.05) than f/2 medium. The chlorophyll a content increased exponentially during the culture, and its concentration was similar in both experiments. In conclusion, the cellular density and the biochemical constituents were similar when using either media. This fertilizer can be used in the production of I. galbana (T-Iso) employed in aquaculture.