城市自然水体微生物种群分析及溶藻蛋白酶初步研究

采用PCR-DGGE技术,研究了城市自然水体中微生物菌群结构及投加不同浓度的铜绿微囊藻对水体微生物种群结构变化的影响,同时探讨了藻类诱导水体中微生物产生溶藻蛋白酶的作用;结果表明自然水体中微生物多样性十分丰富,加藻冲击后水体微生物种群结构没有明显变化,个别菌种的优势发生演替;微生物溶藻蛋白酶被诱导,通过片段序列分析,可以基本确定为微生物Clostridium botulinum体内溶藻酶.     

流速对不同浮游藻类的生长影响研究

为了研究流速对不同浮游藻类生长的影响, 于 2015 年 3 月采集东江流域广东惠州河段原水, 在环形有机玻璃水槽中分别培养铜绿微囊藻、斜生栅藻和小环藻, 通过调整水体流速, 研究不同流速对不同藻类的细胞密度、叶绿素 a 浓度、最大比增长率和叶绿素荧光参数 Fv/Fm 的影响。结果表明, 在不同流速条件下, 不同浮游藻类的生理生化特征有所差异; 铜绿微囊藻表现为在不同流速条件下生长状况都较弱; 斜生栅藻和小环藻在低流速(<0.075 m·s–1)条件下繁殖速度较快, 且随着水体流速的增加, 对藻类生长有促进作用, 而在较高流速(>0.075 m·s–1)条件下随着流速的增加, 藻类的生长受到抑制。可见, 不同持续的流动条件是影响浮游藻类数量和生理指标变化的重要原因。该研究为东江水源的流速流量调节控制富营养化和水华防治提供技术支撑。     

海藻抗菌活性物质研究进展（综述）

综述近年来在海洋藻类中发现并已分离鉴定出抗奥林投菌活性物质的化合物,同时对海藻抗菌活性的研究前景进行展望.     

溶藻微生物净化富营养化水体的作用

湖泊富营养化导致的水华藻类频繁暴发已成为当今世界性的环境问题,溶藻微生物作为生物法防治有害藻类水华具有广泛的研究前景,通过查阅文献对微生物控制有害藻类水华进行概述,并探讨进一步的研究趋势和应用前景,以期对微生物溶藻方面的研究及开发应用有一定的参考价值。     

不同外源营养负荷对浮游藻类群落结构特征的影响

为研究不同外源营养负荷对水体浮游藻类群落结构特征的影响, 于2010年12月至2012年6月在亚热带长江流域的4个池塘中开展了氮磷营养添加实验。实验设置4个处理, 即加氮加磷(+N+P)、只加磷(?N+P)、只加氮(+N?P)和氮、磷都不加(?N?P)(对照)。从种类来看, 各种处理对浮游藻类种类数的影响不大, 各处理中种类数相差不多, ?N+P、+N+P、+N?P和?N?P处理中浮游藻类种类数分别为75种、79种、75种和75种。各处理均是绿藻门种类最多, 其次是蓝藻门。从功能群来看, ?N+P处理的中、富营养型藻类占比和+N+P处理的相差不多, 二者均高于2个未加磷处理(+N?P和?N?P处理)的。+N?P处理的贫营养型藻类占比比+N+P处理的高, 甚至高于?N?P处理的。研究结果表明减氮不能控制藻类群落的中、富营养型藻类数量, 只控磷能够推动浮游藻类群落从中-富营养型向贫营养型演替。这一结论有望为制定富营养化治理的氮管理策略提供一定的理论依据。     

溶藻细菌

利用溶藻细菌防治水华和赤潮,作为富营养化水体藻类生物防治的方法已经受到广泛关注.多项研究表明,许多溶藻细菌能分泌胞外活性物质,对宿主藻类的生长起抑制作用.因此,分离筛选环保、高效、专一的溶藻活性代谢产物,最终开发安全、高效的生物杀藻剂已经日渐成为治理藻类水华和赤潮问题的方法之一.近年来,国内外相关人员和机构对溶藻细菌的溶藻机理以及溶藻活性物质的分离、提纯和鉴定进行了较为深入的基础性研究.     

鄂尔多斯盆地三叠系延长组疑源类的荧光特征

在鄂尔多斯盆地三叠纪湖相沉积的延长组中,发现保存很好的藻类化石,荧光显微镜下显示很好的荧光;我们发现同层位产出的不同藻类化石具有不同的荧光强度,对这些藻类荧光强度的观察,符合以往国外学者提出的化石荧光与化石类别相关的结论。这也是我国首次用化石藻类荧光与生物属性关系进行研究的尝试,为今后利用荧光进行化石藻类分选和超微结构研究作了有益的探索。     

沿岸海域富营养化与赤潮发生的关系

综述了赤潮的发生与沿岸海域富营养化的关系。近几十年来,人类活动使得天然水体的富营养化进程大大加速。营养负荷的增加与高生物量水华的增多相联系。控制营养输入后,浮游植物生物量或有害藻类水华事件也相应减少。营养的组成与浮游植物的种类组成及水华的形成有密切联系。有机营养对有害藻类水华的促进作用受到关注。营养输入时机影响浮游植物种间竞争的结果,因而对浮游植物的群落演替具有深远影响。由于浮游植物存在生理差异,因而对营养加富的反应因种而异。营养在调控某些有毒藻类的毒素产量方面也发挥着重要作用。此外,营养输入与藻类水华之间存在复杂的间接联系。当然,营养状况并非浮游植物群落演替的唯一决定因素。研究结果提示,控制营养输入、减缓水域富营养化是减少有害藻类水华发生的有效途径,而深入研究典型有害藻类的营养生理对策则为防治并最终消除有害藻类水华提供了理论基础。     

污水处理厂化学除磷影响因素的研究

实验模拟同步沉析工艺,以PAC为除磷药剂,研究了搅拌时间、DO、pH、MLSS、PAC投加量几个因素对化学除磷的影响,明确了不同因素的最佳运行参数,并得出了影响化学除磷效果的四个因素的主次顺序为pH投加浓度MLSS搅拌时间。     

Fe(Ⅲ)对藻类生长及光谱特征的影响

利用室内培养实验,研究不同Fe(Ⅲ)浓度处理下太湖藻类叶绿素含量、藻类反射光谱随时间的变化规律。通过导数光谱技术、"红边"光学参数(红边位置)对藻类光谱信息进行定量提取,并与藻类叶绿素含量、藻体Fe(Ⅲ)含量进行相关分析,建立了培养液Fe(Ⅲ)浓度-藻类叶绿素含量-藻类光谱的定量关系。结果表明:适宜的Fe(Ⅲ)浓度(18μmol·L-1)有利于藻类生长及叶绿素合成,过高Fe(Ⅲ)浓度(30μmol·L-1)在培养前期能促进藻类叶绿素的合成,但在培养后期会抑制藻类叶绿素的合成,缺铁(0μmol·L-1)使叶绿素的合成受到显著的抑制;不同Fe(Ⅲ)浓度下藻类光谱植被指数(SR705、ND705)、红边位置与藻类叶绿素含量的相关性显著(P0.05)。     

Settlement behavior of cyphonautes larvae of the bryozoan Membranipora membranacea in response to two algal substrata

Abstract. Settlement is an important process in the biphasic life histories of many marine invertebrates. Little is known regarding the fine-scale behavioral mechanisms for finding and attaching to a suitable substratum, particularly under conditions that may impose a potential challenge, such as flow. In this study, we examined the settlement behavior of cyphonautes larvae of the bryozoan, Membranipora membranacea, in response to two different algal substrata. Larvae showed a strong preference for settling on the kelp Nereocystis luetkeana over the red alga Mazzaella splendens. We then tested whether the behavioral mechanisms used by larvae to attach to these algae differed when presented with the challenge of flowing water during settlement. We found that larvae exhibited different behaviors on the two species of algae in flowing water. Larvae were more often observed in direct contact with the preferred alga (N. luetkeana) exhibiting fine-scale active search behaviors. On the less preferred alga (M. splendens), larvae were less frequently observed in direct contact with the alga, and appeared to be exhibiting broad-scale passive search behaviors along the surface of the blade. Our results suggest that cyphonautes larvae alter their behavior in response to their preferred settlement habitat.     

有机磷农药对滇池微囊藻生长和摄磷效应的影响

采集滇池水体作为铜绿微囊藻培养基,研究了两种有机磷农药(甲胺磷和辛硫磷)对微囊藻生长和摄磷效应的动力学规律。结果表明,在滇池水体中添加较低浓度的甲胺磷(0.8、1.6、3.2mg/L)和辛硫磷(0.02、0.06、0.1mg/L)均能不同程度地促进微囊藻的生长,且在HGZ培养基中抑制微囊藻生长的浓度在滇池水体中却能促进微囊藻的生长。微囊藻的生长取决于细胞内磷的浓度且对磷的吸收利用存在积累性,在微囊藻生长初期,摄取各形态磷的速率较快;随后微囊藻摄取各形态磷的速率较慢。总溶解磷(TSP)和溶解反应磷(SRP)是微囊藻优先摄取的磷形态,在生长过程中微囊藻利用了大量的溶解有机磷(DOP)作为磷源加速生长。这一特点对于微囊藻成为淡水湖泊富营养化发展过程中的一种重要优势种具有极为重要的作用。     

Photosystem I-Mediated Regulation of Water Splitting in the Red Alga, Porphyra sanjuanensis

The marine red alga, Porphyra sanjuanensis is found mainly in the high intertidal zone and at low tide subject to frequent and extreme water stress, often accompanied by high temperatures and light intensities. Such exposures can lead to severe desiccation which is accompanied by the progressive loss of photosynthetic activity. Even following the loss of more than 90% of the thallus water content the alga recovers rapidly when returned to seawater. This stress-induced, reversible inactivation of photosynthesis is believed to be a protective adaptation which prevents photodamage to the exposed alga. Effects of light, inhibitors of water splitting, and electron donors to PSI on variable fluorescence and water splitting suggest that activity of the oxygen evolving complex is regulated by the PSI-driven reduction of a component of intersystem electron transport.     

The Effect of a Quaternary Amine (Aliquat 336) on Growth and Photosynthesis of the Green Alga Chlorella emersonii, and the Effect on Photosynthesis in Isolated Spinach Chloroplasts

A quaternary amine, Aliquat 336, inhibits the growth of the green alga Chlorella emersonii, ¹⁴C-fixation of the alga is also inhibited. The effect and the site of action of the compound was studied by using isolated spinach chloroplasts. The carbon dioxide dependent oxygen evolution of the chloroplasts is inhibited directly upon the addition of the amine and the oxygen evolution is replaced by an oxygen uptake. By investigating some electron transport reactions in the chloroplasts we were able to show that Aliquat 336 affects the electron transport on the level of photophosphorylation. The results from the in vivo and the in vitro experiments thus show that the quaternary amine affects the photosynthetic process. Aliquat 336 is a solvent extractant used in several industrial processes for extraction of metals from aqueous solutions. Aliquat 336 could be considered a presumptive water pollutant as the compound could enter a recipient water body and thus affect photosynthesis.     

The dominant <Emphasis Type="Italic">Ulva</Emphasis> strain of the 2008 green algal bloom in the Yellow Sea was not detected in the coastal waters of Qingdao in the following winter

The region of Qingdao, China, experienced the world's largest green tide from May to July 2008. More than one million tons of fresh algal biomass of the green alga Ulva prolifera was harvested, while more was suspected to have sunk to the bottom. The original source of this seaweed was suspected to be from the south as revealed by satellite images. The floating biomass drifted with the water current northward and flourished in nearshore waters around Qingdao. However, direct biological evidence for “seed” source is lacking. It is still unclear whether this alga could survive the Qingdao local coastal environment and pose future danger of potential blooming. Systematic and seasonal sampling of waters in the intertidal zone at six collection sites along the Qingdao coast was conducted from December 2008 to April 2009. Forty-eight water samples were analyzed. From these, nine different morphotypes of Ulva were grown in the laboratory under standard temperature and light regimes. Growth of Ulva was observed in all water samples. However, molecular phylogenetic analyses revealed that the dominant U. prolifera strain of the 2008 bloom was absent in all the water-derived cultures during the sampling period. These results provide evidence that the dominant bloom-forming alga was unlikely able to survive the coastal waters (the minimal surface water temperature in February is 2°C) in winter conditions in Qingdao, even though all the sampling locations were heavily covered by this alga in June 2008.     

The green macroalga Dictyosphaeria ocellata influences the structure of the bacterioplankton community through differential effects on individual bacterial phylotypes

Marine macroalgae are subjected to large numbers of bacteria in their environment. These bacteria have the potential to affect the health and ecology of algae in a variety of ways and can be both beneficial and harmful to the algae. Therefore, algae have likely evolved mechanisms to differentially regulate the growth of bacterial species. In this study, we examined the effects of the green alga Dictyosphaeria ocellata on the bacterioplankton community in field enclosure experiments and on individual, naturally co-occurring bacterial strains in laboratory co-culture experiments. In field experiments, we compared the bacterioplankton communities of enclosures with and without D. ocellata using denaturing gradient gel electrophoresis and found that the alga significantly changed the bacterial community composition. Seven bacterial phylotypes were eliminated in the presence of the alga and five were found exclusively with the alga. We also examined the effects of algal-treated water on the development of the bacterial community within enclosures and found no change in the community composition. Laboratory co-culture experiments revealed that D. ocellata and D. ocellata extracts affect the growth of individual bacterial strains in a species-specific manner and that the mechanisms responsible for these effects also differed by bacterial species.     

发菜的生态条件及其规律分析

 本文研究了甘肃永登和内蒙阿拉善左旗的发菜生态条件,发现了发菜生长中的水分节律现象。 发菜生于干燥的高原荒漠草原地带,属大陆性气候。其年平均气温为4.5—8℃,≥10℃积温为2231—2800℃·年,年温差大,昼夜温差明显。年平均降水量为201—290mm,集中在6—8月。年平均相对湿度为46—58%,有露水的天气约80天。土壤主要是由第三纪红土母质发育而来的棕钙土,营养贫乏,石灰质沉积明显,呈强碱性反应。年日照时数3000±300小时,辐射强烈。发菜在结构和生理上表现出强烈的旱生生态适应性,包括它的耐旱,耐贫瘠,嗜阳、嗜碱以及对温度变化的适应性强。 发菜生长中具有明显的水分节律现象。在5—10月,在暂短的降雨和露水后,藻体迅速吸取水分而得以生长。尔后,水分又很快被蒸发,藻体变干,生长停滞。发菜在这种湿润⇌干燥的反复节律中得到不断的断续生长和积累,从而完成发菜在干燥条件下的年生长过程。     

The occurrence of Gonyostomum semen (Ehr.) Diesing in Finnish lakes

Since the early nineteen-eighties swimmers have complained of the nuisance effect of Gonyostomum semen in Finnish lakes. This alga causes an unpleasant slimy coating on the skin after swimming. Although it was first identified in Finland in 1894, the first complaints concerning G. semen were reported to the Finnish water authorities in 1978. During the period 1978–1989 a total of 110 water samples were qualitatively microscoped for G. semen. According to the results the alga seems to have spread from the south-eastern part of Finland throughout the southern part of the country and northwards almost to the Arctic circle.139 quantitative samples from monitored lakes were also analysed. The alga seems to prefer dystrophic and eutrophic conditions.     

Larval recruitment of the blue mussel Mytilus edulis: The effect of flow and algae

The mussel Mytilus edulis settlement and distribution was studied on plastic panels with manipulated flow regime (faired, bluff, split and angled) with or without water soluble metabolites of the green alga Cladophora rupestris. The panels were exposed vertically on a device (hydrovane) that ensures their constant orientation in the current during the peak of larval settlement at 1 m depth. In order to investigate larval distribution on the panels, half of them were coated with a silicone vacuum grease that prevents larvae from de-attachment. This grease was not toxic and did not attract or repel larvae. Low densities of larvae on the un-greased plates compared to the greased ones suggested that some of larvae left the substratum. The blue mussel larvae initially settled in regions of reduced shear velocity and then redistribute to the regions of high shear velocity. The presence of the alga increased the density of blue mussel larvae and changed their distribution on the panels. Overall, our results demonstrated that larval recruitment of M. edulis is an active process affected both by boundary-layer hydrodynamics and algal waterborne compounds.     

EFFECT OF WATER POTENTIAL ON A MICROCOLEUS (CYANOPHYCEAE) FROM A DESERT CRUST1

The effect of water potential, on the growth and photosynthesis of a species of Microcoleus forming a desert crust was determined, using both osmotic and matric variations in water potential. The alga was quite sensitive to moisture stress, partial inhibition of growth being observed at -7 bars, and complete inhibition at -18 bars. Photosynthesis was markedly inhibited at -18 bars, and virtually completely at, -28 bars (water potential of seawater) and lower. The alga was more sensitive to matric reduction in water potential than osmotic. By comparisons of these results with those obtained with other algae, it is concluded that this desert crust alga is not especially adapted to grow and photosynthesize at low water potentials, although it shows considerable ability to survive severe drought conditions.