UV-B辐射对两种海洋微藻生长的影响

研究了两种微藻－－小新月菱形与青岛大扁藻在一范围内（小新月菱形藻０～３．００ｊ／ｍ＾２,青岛大扁藻０～１１．２５Ｊ／ｍ＾２）ＵＶ－Ｂ辐射对其相对增长率（Ｋ）,蛋白质含量、类胡萝卜素含量以及超氧化物歧化酶（Ｓｕｐｅｒｏｘｉｄｅ ｄｉｓｍｕｔａｓｃ,ＳＯＤ）活性的影响。结果表明,（１）随着辐射剂量的升高,两种微藻的相对增长率（Ｋ）逐渐下降,其各自的半数有效抑制浓度４８ｈ,ＥＣ５０分别为,小新月菱形藻１     

微藻空气净化系统

该技术是利用微藻光合作用,将二氧化碳转化为氧气对空气进行净化。本文介绍的是以板式光生物反应器为依托的微藻光合作用系统,该系统制成隔断水晶墙适合室内应用,水晶墙式光生物反应器相当于一面"会呼吸的墙",起到了室内空气净化的效果。     

微藻对海水中重金属离子的净化作用研究

探讨了海洋微藻(塔胞藻)对重金属离子的净化作用.在其培养液中加入含有Pb、Hg、Cr、Cd等离子的化合物,塔胞藻经过一定时间生长后调查培养液内重金属离子的含量.结果表明,液体内藻细胞密度达到104个/mL,对重金属离子的净化作用最明显,而且微藻对不同重金属离子的净化效率也各不相同.     

毛蚶对单胞藻的滤除率、选择性和消化状况

测定了不同水温下毛蚶对5种单胞藻的滤除率、选择性和表观消化状况,结果表明,在16℃~24℃的水温范围内,毛蚶对海洋小球藻的滤除率逐步升高,24℃时的最大滤除率为1.849 4(mL/ind.min),24℃~26℃时的滤除率逐步下降。22℃为毛蚶对微绿球藻、球等鞭金藻3011和三角褐指藻的最佳滤食温度,最大滤除率分别为1.142 4、3.804 5和4.430 4。水温8℃~24℃之间,毛蚶对巴夫藻的滤除率变化不明显,平均滤除率为2.797 2。毛蚶不仅对不同大小、形状的藻类具有选择性,而且对大小、形状相似的藻类也具有明显的选择性。水温22℃下,毛蚶对5种单胞藻的表观消化状况不同。贝类对其滤除率大、消化状况差的藻类在促进贝类净化进程中有良好的应用参考价值。     

光照强度对九孔鲍幼虫及幼鲍生长存活的影响

在自然光周期下，分别在高温长光照和低温短光照的两个节季节，采用控制光照强度的方法进行对九孔鲍幼虫及幼鲍50d左右培育的小型试验。结果表明，光照强度对附着基上摄食微藻的幼虫及幼鲍生长和存活等有重要的影响。对幼虫及幼鲍最适宜的光照强度，在高温长光照下为700－1200lx，在低温短光照下为1300－2000lx。选用适宜的光照强度在高温长光照和低温短光照下先后进行了3次经量育苗试验，获得了与小型试验相同的结果。     

光照对细胞融合藻Tetraselmis sp·－1混合培养的影响

对细胞融合技术获得的1株新型融合微藻(Tetraselmis sp.-1)进行摇瓶混合培养,并分析光照强度对该培养条件下融合微藻的影响.结果表明1) 在培养基中添加葡萄糖对融合微藻的生长有强烈的促进作用,融合微藻生长速率为0. 576 g/(L*d),是自养培养的7.38倍;2)在光照强度为3 000 lx混合培养时,葡萄糖消耗速率达最大值3 g/(L*d);3)在光照强度为2 000 lx混合培养时,藻细胞密度最大,为2.60 g/L,以葡萄糖计算的基质得率随光照强度的增加而显著下降;4)融合微藻叶绿素a含量在混合培养条件下,随光照强度的增大而增加;5) 在混合培养条件下,光照对NH4+的同化为正影响,融合微藻氮含量和CC/CN分别为5.68和6.06,均介于自养培养与异养培养之间.     

浮游微藻生态调控技术在对虾养殖应用中的研究进展

微藻技术是一项有机结合藻类生物学、藻类生态学及水生生态系统学的新兴生物技术,它以水体中的浮游微藻为对象,充分运用微藻的生理、生态特点,进而用以调控和优化水体生态环境。文章就当前在水产养殖领域中的微藻生态调控技术的相关研究进行了系统的综述,并对其在对虾养殖中的应用进行了展望。     

Accumulation of Astaxanthin by a New Haematococcus pluvialis Strain BM1 from the White Sea Coastal Rocks (Russia)

We report on a novel arctic strain BM1 of a carotenogenic chlorophyte from a coastal habitat with harsh environmental conditions (wide variations in solar irradiance, temperature, salinity and nutrient availability) identified as Haematococcus pluvialis Flotow. Increased (25‰) salinity exerted no adverse effect on the growth of the green BM1 cells. Under stressful conditions (high light, nitrogen and phosphorus deprivation), green vegetative cells of H. pluvialis BM1 grown in BG11 medium formed non-motile palmelloid cells and, eventually, hematocysts capable of a massive accumulation of the keto-carotenoid astaxanthin with a high nutraceutical and therapeutic potential. Routinely, astaxanthin was accumulated at the level of 4% of the cell dry weight (DW), reaching, under prolonged stress, 5.5% DW. Astaxanthin was predominantly accumulated in the form of mono- and diesters of fatty acids from C16 and C18 families. The palmelloids and hematocysts were characterized by the formation of red-colored cytoplasmic lipid droplets, increasingly large in size and number. The lipid droplets tended to merge and occupied almost the entire volume of the cell at the advanced stages of stress-induced carotenogenesis. The potential application of the new strain for the production of astaxanthin is discussed in comparison with the H. pluvialis strains currently employed in microalgal biotechnology.     

Heterotrophic Production of Omega-3 Long-Chain Polyunsaturated Fatty Acids by Trophically Converted Marine Diatom Phaeodactylum tricornutum

We have created via metabolic engineering a heterotrophic strain of Phaeodactylum tricornutum that accumulates enhanced levels of the high value omega-3 long chain polyunsaturated fatty acid (LC-PUFAs) docosahexaenoic acid (DHA). This was achieved by generation of transgenic strains in which the Δ5-elongase from Ostreococcus tauri was co-expressed with a glucose transporter from the moss Physcomitrella patens. This double transformant has the capacity to grow in the dark in liquid medium supplemented with glucose and accumulate substantial levels of omega-3 LC-PUFAs. The effects of glucose concentrations on growth and LC-PUFA production of wild type and transformed strains cultivated in the light and dark were studied. The highest omega-3 LC-PUFAs accumulation was observed in cultures grown under mixotrophic conditions in the presence of 1% glucose (up to 32.2% of total fatty acids, TFA). Both DHA and EPA are detected at high levels in the neutral lipids of transgenic cells grown under phototrophic conditions, averaging 36.5% and 23.6% of TFA, respectively. This study demonstrates the potential for P. tricornutum to be developed as a viable commercial strain for both EPA and DHA production under mixo- and heterotrophic conditions.     

利用藻菌共生体系强化养猪废水厌氧消化液培养微藻

利用养猪废水厌氧消化液培养微藻是一项极具潜力的污水资源化技术,如何强化微藻产量是该技术领域的研究热点。本研究在利用养猪废水厌氧消化液培养微藻时,通过投加活性污泥,构成藻菌共生体系,并对关键工艺参数(藻菌比例、微藻接种浓度以及光照周期)进行优化,分析藻菌共生系统培养微藻以及回收氮磷的适宜条件和相关机理。结果表明,在适宜的藻菌比(1∶0.2)条件下,藻菌共生系统有利于提高微藻生长量以及氮磷的回收效率。在优化的接种浓度和光照条件下,进一步运行藻菌共生反应器和微藻纯培养反应器,前者有利于提供微藻生长的碳源,维持体系的酸碱环境,从而提高微藻的生长限值,水力停留时间(HRT)为2 d时,可收获更多的微藻生物质(0.16 g·L~(-1)·d~(-1)),相对于微藻纯培养反应器提高了117%。延长HRT至12 d,微藻呈现二次生长,并且具有较好的污染物去除率。