硫酸铜对海洋微藻生长的影响

初步研究了硫酸铜对海洋微藻扁藻、角刺藻、小球藻和角毛藻生长的影响。结果表明,硫酸铜抑制不同微藻生长的最低浓度具有种类特异性,在生产实际中可以利用铜的抑制作用来提高微藻的分离效果。     

盐度、温度、光照强度对耐高温角毛藻藻株生长的影响

<正>盐度、温度和光照对藻类生长具有显著的影响,盐度影响微藻的渗透压、营养盐吸收和悬浮性,温度影响微藻酶的活性和细胞分裂周期等,光照影响微藻光合作用等。本文主要研究盐度、温度、光照不同组合对耐高温角毛藻藻株生长的影响,以期找出最佳的环境条件组合,为耐高温角毛藻藻株生产性培养提供依据。一、材料与方法1.藻种来源实验藻株来自于威海市微藻种质资源开发工     

管角螺代谢物对浮游植物增殖的影响

采集管角螺的粪便,烘干处理后测定其营养成分组成;并在实验室条件下,研究了管角螺(Hemifusus tuba)代谢物对湛江等鞭金藻(Isochrysis zhanjiangensis)、牟氏角毛藻(Chaetoceros muelleri)和亚心型扁藻(Platymonas subcordiformis)生长的影响。结果表明:管角螺粪便中含有粗蛋白质(9.8%)、磷(0.38%)等微藻生长所需的营养物质;管角螺的代谢物对三种单胞藻的生长有明显的促进作用(P0.05),三种微藻的生长与代谢物的添加量呈正比相关;管角螺代谢物对不同微藻的生长作用随种类的不同而具有明显的差异,对湛江等鞭金藻和牟氏角毛藻的增殖作用明显高于亚心型扁藻(P0.05)。     

海产饵用微藻固定化保种技术↑（*）

１２种海产饵料微藻固定化保种培养试验的结果表明,除了隐藻门的波海红胞藻固定化后未见生长,蓝藻门的聚球藻红色品系生长缓慢,存活时间低于３个月外,其他象等鞭金藻３０１１、旋鞭巴夫藻、牟氏角刺藻、绿色杜氏藻和盐泽螺旋藻等存活时间均在１年以上。将固定化的藻种存放在４℃左右的冰箱中,微型小球藻、朱氏四片藻、浅色紫球藻、三角褐指藻和双点舟形藻等的存活时间可达２年左右。微藻固定化后的生长和存活时间受多种因素的影响。     

条斑紫菜提取物对4种赤潮微藻生长的抑制作用

研究条斑紫菜水溶性抽提液对前沟藻、中肋骨条藻、米氏凯伦藻和塔玛亚历山大藻等4种赤潮微藻生长的影响,在此基础上,利用甲醇、丙酮、乙酸乙酯、氯仿和石油醚等有机溶剂浸泡条斑紫菜干粉,经抑藻圈方法检测条斑紫菜水溶性抽提液的抑藻活性。通过测定藻细胞密度和细胞体积,观察藻细胞形态,分析藻细胞内叶绿素、蛋白质和多糖等生理生化指标的变化,对抑藻活性最大的提取物对前沟藻、米氏凯伦藻、中肋骨条藻和塔玛亚历山大藻赤潮微藻生长的抑制作用进行分析,并依次以石油醚、乙酸乙酯和正丁醇为提取溶剂,采用液液分离法对此提取物做了进一步分离。结果表明,当条斑紫菜水溶性抽提液浓度超过16g/L时能显著抑制4种赤潮微藻的生长,尤其是对前沟藻和米氏凯伦藻具有很强的抑制作用。在5种有机溶剂提取物中,甲醇提取物的抑制作用最为明显。进一步研究发现此提取物对4种赤潮微藻的生长抑制显著且具有浓度效应,在16g/L时,此提取物对前沟藻、米氏凯伦藻、中肋骨条藻和塔玛亚历山大藻的生长抑制率分别为70.5%、79.9%、67.1%和65.1%。同时,致使米氏凯伦藻、中肋骨条藻和塔玛亚历山大藻等3种赤潮微藻体积变小,运动能力下降,藻细胞出现空洞、细胞破碎和色素减褪等现象;...     

两种微藻在无菌和带菌状态下生长特点比较研究

对无菌和带菌的波吉卵囊藻(Oocystis borge)和小球藻(Chlorella sp.)生长特点进行比较研究,并且研究光照和盐度对无菌和带菌的波吉卵囊藻和小球藻生长的影响.结果表明:与带菌藻相比,无菌藻更加稳定,不易老化. 光照和盐度对无菌和带菌的波吉卵囊藻和小球藻的生长均有显著影响(P<0.05),但在相同条件下,无菌和带菌藻的增殖率差异不显著(P>0.05).这说明可以直接利用无菌化微藻代替自然带菌藻进行微藻的生理特征以及微藻与其它生物之间关系的研究.     

四种微藻对氨苄青霉素敏感性的研究

海洋微藻培养中抗生素的大量使用对微藻的生长产生一定的影响。为了研究抗生素在海洋微藻培养过程中对微藻的影响,本文探讨了四种海洋微藻(海链藻、小硅藻、塔胞藻、小球藻)对氨苄青霉素的敏感性,通过培养过程中加入抗生素进行培养并测定其光密度值进行试验。研究表明,氨苄青霉素对海链藻的生长影响较大,对其它的三种微藻影响较小。     

碳、氮、磷营养对7种海洋微藻种群增长的影响研究

文章采用批次培养方式研究双胞旋沟藻(Cochlodinium geminatum)、米氏凯伦藻(Karenia mikimotoi)、中肋骨条藻(Skeletonema costatum)、牟氏角毛藻(Chaetoceros muelleri)、球形棕囊藻(Phaeocystis globosa)、亚心形扁藻(Platymonas subcordiformis)和眼点拟微绿球藻(Nannochloropsis oculata)在不同碳(C)、氮(N)、磷(P)条件下的生长特性,以期为养殖尾水的原位处理筛选优良藻种(株)。结果表明,这7种微藻的比生长速率与C、N、P浓度总体呈正相关。相较对照组,C对旋沟藻、骨条藻和拟微绿球藻比生长速率的促进作用分别为35%、19%和19%,P对比生长速率的最大促进作用介于25.01%~446.60%,硝酸盐为16.54%~77.52%,铵盐为15.79%~88.82%,尿素为25.16%~71.43%。7种微藻的最大比生长速率与细胞体积总体呈负相关,棕囊藻的比生长速率最高,拟微绿球藻和扁藻最大比生长速率与其他藻华种相比无显著差别。微藻的氮磷吸收速率随细胞体积增加呈升高趋势,单位氮磷利用效率随细胞体积增加呈降低趋势。培养液中P吸收速率显著高于N,氮磷比均呈升高趋势。眼点拟微绿球藻和亚心形扁藻可用于养殖尾水氮磷的快速去除。     

大气CO2水平升高对微藻影响的研究进展

大气CO₂浓度升高将干扰水体的碳酸盐缓冲系统,导致水体pH值下降,对水生微藻产生一定的影响。文章从生长状况、光合作用、藻细胞化学元素组成和群落结构4方面分别综述大气CO₂浓度升高对海洋微藻和淡水微藻的影响。在生长方面,大气CO₂浓度升高不仅会影响某些海洋微藻和淡水微藻的生长速率,还会使某些藻细胞的形态发生变化。在光合作用方面,大气CO₂浓度升高可能会减弱微藻对CCM机制的依赖性;对不具有CCM机制的微藻来说,CO₂浓度增加可能会减弱其碳限制程度,有利于微藻光合作用。在藻细胞化学元素组成方面,大气CO₂浓度的升高对微藻细胞化学元素组成的影响与藻类的生长是否受营养盐限制有关,只有当藻类生长受到水体营养盐浓度限制时,CO₂浓度升高才会显著改变其元素组成。在群落结构方面,当微藻个体发生变化时,微藻种群间的竞争优势也会发生改变,体积较小的微藻可能将从全球CO₂水平升高的趋势中受益更多。在间接因素温度导致的水生环境变化的条件下,可能更有利于蓝藻生长,使其拥有更大的竞争优势。微藻群落结构的改变,对整个海洋生态系统和淡水生态系统都可能会造成严重的影响。最后展望了在全球大气CO₂水平升高的背景下微藻响应机制方面研究方向。     

6种微藻生长及脂肪累积对氮含量变化的响应

研究了绿色巴夫藻、米氏凯伦藻、球等鞭金藻、三角褐指藻、海水小球藻、衣藻的生长及脂肪累积对氮含量变化的响应。试验结果表明,6种微藻生长及总脂对不同氮含量均有一定程度的响应。微藻生长,绿色巴夫藻、米氏凯伦藻、球等鞭金藻3种微藻响应明显,绿色巴夫藻以氮含量100%组生长最快,第10d时,比氮含量40%组快512%,比氮含量20%组及60%组分别快62%、61%;米氏凯伦藻氮含量80%组生长最快,第10d达到最高值,超出其他试验组约60%;球等鞭金藻氮含量80%组最快,第10d生长量超过100%试验组67%;三角褐指藻、海水小球藻、衣藻响应程度小于其他微藻。总脂积累,三角褐指藻氮含量80%组总脂含量最高,达细胞干质量的80.77%,是氮含量100%组2.5倍;绿色巴夫藻氮含量60%组最高,达细胞干质量的73.68%,是氮含量100%组3.4倍;其他4种微藻在降低氮含量后,总脂均超过细胞干质量的30%。三角褐指藻在生物柴油制备方向极具开发前景。     

不同饵料对毛蚶幼体发育的影响

在毛蚶人工育苗过程中,使用球等鞭金藻、角毛藻、小球藻、扁藻4种藻类的不同组合投喂毛蚶幼体。结果表明,饵料种类越多,变态率越高,生长速度越快;球等鞭金藻、角毛藻、小球藻、扁藻搭配(体积比1:1:1:1)变态率为30%,出库需(壳长1 mm)27 d;球等鞭金藻、角毛藻、小球藻搭配(体积比1:1:1)变态率为29%,出库需29 d;球等鞭金藻、小球藻搭配(体积比1:1)变态率为24%,出库需31 d;角毛藻、小球藻搭配(体积比1:1)变态率为19%,出库需33 d;单一投喂小球藻,变态率为3%,出库需44 d。说明不同饵料间的营养可以互补,多种饵料搭配能为幼体发育提供更全面的营养,饵料多样性是影响幼体培养效果的重要因素。     

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。     

Evaluation of Five Microalgae Diets for Juvenile Pen Shells Atrina maura

–Juvenile pen shells Atrina maura were fed for 21 d with equal daily rations, equivalent to 6.5% of their live weight, of monoalgal cultures of Tetraselmis suecica, Isochrysis galbana, Chaetoceros muelleri, Chaetoceros calcitrans , and Thalassiosira pseudonana. Pen shell survival was 100% in all cases. All microalgae diets produced shell growth, and live and ash-free dry weight increases. However, the two Chaetoceros strains gave significantly better results, with shell height increases of 4.7 to 2.9 mm, live weight gains of 0.5 to 0.3 g, and final ash-free dry weights of 0.16 to 0.14 g after 3 wk. These results are not related to the algae gross biochemical composition, suggesting that other factors are involved in their nutritional value for this mollusc species.     

硫酸铜、生石灰对微囊藻生长的影响

微囊藻对水产养殖是有害的,生产上多采用硫酸铜或铜、铁合剂杀灭,为了确切了解硫酸铜对微囊藻的致毒效果和生石灰对微囊藻生长的影响,我们分别用不同浓度的硫酸铜、生石灰检验了对微囊藻生长的影响。结果表明:生石灰对微囊藻的生长有促进作用,硫酸铜对微囊藻的生长有抑制甚至杀灭作用,0.6×10~(-6)以上作用显著。     

The Efficacy of Copper Sulfate in Controlling Infection of Saprolegnia parasitica

Saprolegnia parasitica is a severe fish pathogen that causes important economic losses worldwide. Copper is an important additive in the aquaculture industry for control of algal growth, ectoparasites, and fungal disease. However, at present no data is available on the specific interaction of copper sulfate with oomycete. In our study, the efficacy of copper sulfate on the mycelium and zoospore of S. parasitica was assessed in vitro, and S. parasitica infection experiment was conducted to assess its performance in vivo. The results indicated that copper sulfate at ≥0.5 mg/L inhibited the growth of mycelium, no primary zoospores were released at ≥1.0 mg/L. Additionally, 0.5 mg/L copper sulfate could reduce the infection rate of S. parasitica in the grass carp, Ctenopharyngodon idellus. This study demonstrates the good efficacy of copper sulfate on the control of S. parasitica infection in grass carps, and suggests that copper sulfate could be used as a drug additive to control the S. parasitica infection in the aquaculture industry.     

Copper Concentrations in Channel Catfish Ictalurus punctatus Ponds Treated with Copper Sulfate

Copper sulfate (CuSO₄5H₂O) is used to reduce the abundance of blue-green algae and combat off-flavor in channel catfish culture. Copper sulfate usually is applied at a concentration of one-one hundredth of the total alkalinity. A study was performed at the Auburn University Fisheries Research Unit to determine the duration of elevated copper (Cu) concentration following copper sulfate applications. Two alkalinity treatments, 20-40 mg/L and 110-130 mg/L (as CaCO₃), were examined. Copper sulfate was applied biweekly for 14 wk at 03 mg/L for the low alkalinity treatment and 1.2 mg/L for the high alkalinity treatment. Total copper concentrations in pond waters declined to the background level by 48-h post treatment. In addition, total copper concentrations were determined in waters of 38 catfish production ponds located in west central Alabama. The mean and standard deviation were 0.0092 ± 0.0087 mg Cu/L. Copper quickly precipitates from the water or is absorbed by sediments following copper sulfate treatment. Although concentrations of copper in pond waters increase immediately following copper sulfate treatment, they rapidly decrease and seldom exceed the United States Environmental Protection Agency's National Recommended Water Quality Criteria for Priority Toxic Pollutants of 0.013-mg Cu/L. Findings of this study suggest that copper sulfate treatment will not contaminate effluent from catfish ponds because of the short time that applied copper remains in the water column. Furthermore, the most frequent applications of copper sulfate occur in late summer months when rainfall is minimal and pond overflow is rare.     

三种赤潮微藻基因组DNA快速制备方法的研究

采用超声波法、煮沸法和微波法3种方法分别对塔玛亚历山大藻、环状异帽藻和角毛藻进行细胞破碎及快速制备基因组DNA的研究。通过细胞计数和DNA浓度测定的手段对三种方法进行了比较,以选择适合不同藻种的细胞破碎方法。结果表明,塔玛亚历山大藻和环状异帽藻用超声波法破碎效果较好;角毛藻用微波法较好。对用该三种方法制备的基因组DNA做了PCR扩增,电泳检测表明,与CTAB法扩增效果一样。本文建立的微藻DNA快速制备方法有望应用在赤潮藻类的快速分子鉴定方面。     

Nutritional Value of Preserved Microalgae for Subadult Mytilus galloprovincialis

Abstract.— Subadult (4–5 cm) Mytilus galloprovincialis were fed for 31 d with equal daily rations, equivalent to 6% of their body weight on a dry weight basis, of Chaetoceros sp. and Phaeodactylum tricornutum fresh, or preserved by air-drying, freeze-drying, and by freezing. At the end, increases in size, in dry weight, and in condition index with preserved diets were significantly lower than those of the mussels fed with live algae. In general, the frozen diets were better than the air- and freeze-dried ones. Increases with live Chaetoceros sp. were greater than with live P. tricornutum ; however, with preserved diets the latter was better than Chaetoceros sp .     

Hatchery cultivation of Pacific oyster juveniles using algae produced in outdoor bloom-tanks

Algae were bloomed as batch cultures by adding fertilizers to natural seawater in 500 l outdoor tanks, from mid-June to mid-August, over a period of 2 y. In the first year of experiments the bloomed algae were fed to Pacific oyster (Crassostrea gigas Thunberg) juveniles at a range of rations from 0.06 to 1.63 g (organic weight of algae) g–1 (live weight of spat) week–1. At rations of 0.5 g g–1 week–1 or higher, growth rates of juveniles were similar (mean, 97%) to those fed a control diet of intensively cultured algae (Tetraselmis suecica Kylin) Butch and Chaetoceros calcitrans (Paulsen) Takano at a ration of 0.3 g g–1 week–1). In the second year, the bloomed algae were fed at a ration of 0.5 g g–1 week–1 throughout all the experiments, and gave growth rates of 70–98% (mean, 85.6%), compared with the control diet. The proportion (by weight) of the diet consumed by the juveniles was about 70% for the control diet and 78% for the bloomed algae. Total lipid and essential fatty acid content of the bloomed algae were similar and total carbohydrate content was lower, when compared with typical published values for intensively cultured algae food species. © Rapid Science Ltd. 1998