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1.
从浙江沿海地区赤潮多发区分离获得一株对东海原甲藻(Prorocentrum donghaiense)具有高效溶藻作用的细菌DH-e,研究该菌的溶藻作用方式和对东海原甲藻的生理功能与细胞结构的影响.结果发现其溶藻作用方式为间接溶藻,溶藻效应呈现出作用浓度和时间依赖性,作用浓度0.5%~2.0%,时间为32 h时,溶藻率均达80%以上,具有短期高效的溶藻效应;溶藻活性物质分子量小于2 k Da,具有耐低高温、强酸碱的特性;代谢产物对叶绿素a造成严重的破坏和分解,并改变胞内总糖含量,影响生理代谢活性;SEM与AO/EB双染检测发现溶藻活性物质能够破坏藻细胞膜完整性,显著改变藻细胞内部结构,造成内容物大量释放. 相似文献
2.
溶藻细菌MS7的分类鉴定及其溶藻活性的初步研究 总被引：1，自引：0，他引：1
采用形态学、生理生化指标和16SrRNA基因序列同源性分析的方法,对菌株MS7进行鉴定,并通过溶藻试验测定该菌株对铜绿微囊藻(Microcystis aeruginosa)的溶藻活性和溶藻方式。结果表明,MS7菌株为苏云金芽孢杆菌(Bacillus thuringiensis),对铜绿微囊藻具有高效溶藻效果,当菌浓度为108cells/mL,初始藻液叶绿素a浓度为0.7mg/L时,48h溶藻率达到91%。主要通过分泌胞外物质的间接方式溶藻,溶藻物质属于具有很强的热稳定性的非蛋白质类物质。 相似文献
3.
有效氯对波吉卵囊藻生理活性的影响 总被引：2，自引：0，他引：2
波吉卵囊藻Oocystis borgei是集约化对虾养殖系统中常见的一种优良微藻，能改善养殖水质，增强对虾的抗病能力。本文通过累积培养方法，研究了对虾养殖中常用含氯消毒剂对波吉卵囊藻的种群生长和代谢的影响。结果表明：含氯消毒剂对微藻种群生长有显著影响。有效氯浓度为0．5mg/L时，波吉卵囊藻的生理活性轻微下降：有效氯浓度为2．5mg/L时，引起波吉卵囊藻死亡，其叶绿素含量、藻体干重、光合作用和呼吸作用分别下降了64．72％，13．69％，38．95％和10．38％。且随浓度增加，毒性越大。用浓度小于0．5mg/L的有效氯来防治对虾疾病，不会破环以波吉卵囊为优势种群的微藻生态环境。 相似文献
4.
为研究溶藻菌对赤潮甲藻的作用机制,本文从胶州湾沉积物中分离得到的一株耐盐菌株Zobellella sp. B307,并研究了该菌株对太平洋亚历山大藻(Alexandrium pacificum)的抑制效果,从细胞结构、生理水平和分子水平探究了该菌株的抑藻途径及作用机制。结果表明,该菌株的抑藻途径为分泌胞外活性物质的间接溶藻,72 h的溶藻率高达91%。溶藻过程中藻细胞壁破损,叶绿素a和总蛋白含量显著下降,藻细胞的活性氧(ROS)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性显著高于对照组,这表明溶藻物质对藻细胞造成的强烈氧化损伤是导致其死亡的直接原因。热休克蛋白基因(HSP)表达量显著上调,说明溶藻物质激发藻细胞产生的ROS在激活抗氧化系统的同时诱导产生HSP70,二者联合清除ROS以减缓藻细胞受应激损伤的程度;A.pacificum的网格蛋白基因(Clathrin)表达量显著上调,表示由网格蛋白介导的胞吞作用明显增强,进而说明为减轻光合营养功能受损造成的影响,藻细胞的异养功能增强。本研究结果有助于诠释菌藻关系,更为探究赤潮治理的生物方法提供重要的理论支持和实践指导。 相似文献
5.
一株溶藻细菌（Pseudoalteromonas sp．）的分离鉴定及溶藻活性初探 总被引：1，自引：0，他引：1
从海南洋浦港沉积物中分离到一株具有较强溶藻活性的细菌(编号Z3).通过对该菌株进行形态和生理测试以及16SrDNA序列分析,初步鉴定此菌为交替假单胞菌(Pseudoalteromonas sp.).该菌对链状亚历山大藻(Alexan-drium catenella)和塔马亚历山大藻(Alexandrium tamarense)有溶藻活性,对锥状斯氏藻(Scrippsiella trochoidea)和中肋骨条藻(Skeletonema costatum)的生长无影响,表明菌株Z3溶藻活性具有种属特异性.通过该菌的菌体悬浮液和除去菌体滤液对链状亚历山大藻实验表明,此菌株具既有直接溶藻作用又有间接溶藻活性. 相似文献
6.
为探明解淀粉芽孢杆菌及其代谢物对海水养殖环境中微藻的化感作用,本文以实验生态学方法研究了解淀粉芽孢杆菌对球等鞭金藻生长的生态作用。实验设计了不同剂量(100mL、500mL、1000mL)的解淀粉芽孢杆菌纯菌液、解淀粉芽孢杆菌代谢产物、解淀粉芽孢杆菌及代谢产物混合液三种组合研究其对球等鞭金藻的培养影响。结果显示,添加纯菌液组金藻在第1~2 d增长缓慢,藻细胞数无显著差异,但均低于对照组,其中第3~4 d显著低于对照组(P<0.05);添加菌代谢产物组第1 d金藻细胞数与对照组相比无显著差异,2~4 d显著低于对照组(P<0.05);添加菌液及代谢产物混合液组中100mL组金藻生长较缓慢,500μL和1000μL组藻细胞数呈下降趋势,藻细胞数显著低于对照组(P<0.05),1000μL组金藻第2 d已全部死亡。各剂量组藻细胞数均呈现解淀粉芽孢杆纯菌液、解淀粉芽孢杆菌代谢产物、解淀粉芽孢杆菌及代谢产物混合液依次下降,另外,除菌代谢物1000μL剂量组藻细胞数大于500μL剂量组外,其余各组添加量越大藻细胞数越少,呈现剂量效应关系。解淀粉芽孢杆纯菌液、解淀粉芽孢杆菌代谢产物、解淀粉芽孢杆菌及代谢产物混合液抑制率最高分别为35.84%、69.75%、100%,表明解淀粉芽孢杆菌对球等鞭金藻的作用为化感抑制,且抑制效果具有剂量效应。本研究为解淀粉芽孢杆菌在水产养殖中应用效果评价提供了科学依据,同时为赤潮藻类治理提供新思路。 相似文献
7.
研究了有毒赤潮藻塔玛亚历山大藻Alexandrium tamarense对甲壳动物卤虫的干重及能值的影响.实验表明,经过18h的染毒实验,7 500尾卤虫Artemia parthenogenetica在水体中有塔玛亚历山大藻细胞或过滤液(细胞密度均为200cells·ml-1)存在的情况下,其总干重及总能值的增加明显受到抑制.卤虫总干重,对照组增加0.010 4g,而滤液组和藻细胞组均增加了0.002 2g,仅为对照组的21.1%;卤虫总能值,对照组增加0.143 5kJ,而滤液组和藻细胞组则分别增加0.018 0kJ和0.056 8kJ,分别为对照组的39.5%和12.5%.经SAS软件分析,塔玛亚历山大藻细胞对卤虫总干重的影响与对照组比较有显著性差异(p=0.037 0),而对其总能值增加则无显著差异(p=0.1251);而塔玛亚历山大藻过滤液对卤虫的总干重、总能值的增加与对照组都有显著性差异(p分别为0.021 5和0.013 5).另外,无论是藻细胞或是过滤液对卤虫的比能值均无影响.有毒塔玛亚历山大藻使卤虫总干重减少可影响其他相关海洋动物的食物供给,而对卤虫能值的影响则表明毒藻可改变食物链中能量的传递效率,从而影响处于较高营养层的生物.研究还显示该藻的不利影响可出现在赤潮发生期及消退期,这为全面了解赤潮危害提供新的视角. 相似文献
8.
几种海洋溶藻菌溶藻效果研究 总被引：1，自引：0，他引：1
选择海南三亚红沙港易发赤潮--塔马亚历山大藻(Alexandriumtamarense)和中肋骨条藻(Skeletonemacostatum)做为实验藻类,从三亚红沙港海域筛选的海洋细菌中分离出一株溶藻细菌,编号为B7和已发现具有抑藻作用的:恶臭假单胞菌、铜绿假单胞菌、巨大芽孢杆菌作为实验材料与两种藻共同培养表现的牛态关系的差异性.结果表明:在实验室条件下,分别在藻细胞生长的延滞期和指数期加入细菌过滤液,发现4种海洋细菌的过滤液对两种藻生长有不同的抑制作用效果.同时文中对海洋细菌抑藻作用机理、赤潮的生物防治可能性进行了讨论. 相似文献
9.
本文研究了0.25~3 mmol/L浓度的NaHSO3对紫球藻(Porphyridium violaceum)和0.06~0.96 mmol/L浓度的NaHSO3对蓝隐藻(Chroomonas placoidea)的叶绿素荧光参数(PSII最大光能转化效率Fv/Fm、相对电子传递速率rETR、光化学淬灭qP、非光化学淬灭NPQ)、细胞密度、干重、胞外多糖和藻胆蛋白含量的影响。研究表明,较低浓度的NaHSO3对紫球藻和蓝隐藻的生长及活性物质积累有促进作用,2种微藻进行生长和活性物质积累的最适NaHSO3浓度分别为0.5和0.12 mmol/L,此条件下,实验结束时,2种微藻的Fv/Fm、rETR、qP、细胞密度、干重、胞外多糖和藻胆蛋白含量均达到最大值,显著高于对照组。其中,紫球藻的最终细胞密度、干重、胞外多糖和藻胆蛋白含量分别比对照组增加了36.0%、19.1%、71.8%和69.0%。蓝隐藻的上述参数在NaHSO3浓度为0.12 mmol/L时则比对照组增加了60.8%、45.4%、60.0%和53.1%。另一方面,NaHSO3浓度为2~3 mmol/L时显著抑制紫球藻生长及活性物质积累,NaHSO3浓度为0.48~0.96 mmol/L则不利于蓝隐藻生长及活性物质积累。研究结果表明,适合紫球藻和蓝隐藻生长及胞外多糖和藻胆蛋白积累的最佳NaHSO3浓度分别为0.5和0.12 mmol/L,该研究为2种微藻的开发利用提供了理论依据。 相似文献
10.
近年来,有害藻华频繁发生给海洋生态系统甚至人类健康带来严重影响。伊姆裸甲藻（Gymnodinium impudicum）是一种典型有害藻华原因种,开展其溶藻菌筛选工作,将有利于该种藻华的防控研究。本研究从伊姆裸甲藻藻华发生海域,分离一株针对藻华原因种的溶藻菌LD B3,16S rDNA序列分析表明,该菌株属于假交替单胞菌属（Pseudoalteromonas）。菌藻共培养结果显示,2.0%终浓度LD B3菌液添加72 h后,伊姆裸甲藻溶藻率达81.06%,且溶藻效应呈现浓度和时间依赖性。显微观察和生理参数测定结果表明,菌株LD B3可导致伊姆裸甲藻细胞链断裂,最大光合效率（Fv/Fm）下降。溶藻方式研究发现,菌株LD B3主要通过分泌胞外物质实现溶藻,且这类物质对温度较为敏感,初步推断其可能为蛋白类物质。本研究结果表明菌株LD B3在伊姆裸甲藻溶藻剂开发方面有一定应用前景。 相似文献
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12.
《Marine Chemistry》2005,93(1):1-19
To examine microbially mediated degradation of algal fatty acids in marine environments, we conducted a series of microcosm experiments by incubating Emiliania huxleyi cells in simulated oxic/anoxic sediment–water interface systems. Variations in concentration of fatty acids, lipid-degrading enzyme (lipase) activity, and bacterial abundance over 2-month incubations were followed to determine degradation rate constants of major algal fatty acids and responses of bacteria. In the cell-spiked experiments, fatty acids bound in the membrane and intracellular components were separated to examine effects of structural association of fatty acids on their degradation. Experimental results showed that algal fatty acids generally degraded faster (2–4×) under oxic than under anoxic conditions. Most membrane fatty acids seemed to more readily degrade than intracellular ones under anoxic conditions but the two classes degraded at similar rates under oxic conditions. Ratios of oxic to anoxic degradation rate constants were generally higher for intracellular fatty acids than for membrane fatty acids, implying that oxygen might play a more critical role in intracellular fatty acid degradation. Most algal fatty acids degraded almost completely under oxic conditions while a significant fraction (10–40%) of initially added algal fatty acids remained after 2 months under anoxic conditions. By contrast, variations in bacterial abundance during incubations were apparently greater under anoxic conditions compared to oxic conditions, suggesting that the function and relative effectiveness of aerobic vs. anaerobic bacteria rather than total bacterial abundance control biochemical degradation of algal fatty acids. Variations in potential lipase activity followed the same pattern as bacterial abundance in oxic and anoxic systems, indicating that bacteria might be a major source for lipase in these experimental systems. Bacteria-specific fatty acids varied differently during incubations and were not directly linked to bacterial abundance. 相似文献
13.
Phytoplankton and bacteria diversity were studied before, during and after red tide phenomena during spring season 2015 in the Eastern Harbour (E.H.) of Alexandria, Egypt. Fifty five species of phytoplankton were identified and represented different distinct classes “Bacillariophyceae; Dinophyceae, Chlorophyceae, Cyanophyceae and Eugelenophyceae”. Also, Diatom formed the most dominant group. The average number of the phytoplankton density varied from 4.8 × 104 to 1.1 × 106 cell l-1 during the study period and Skeletonema costatum was the agent causing the red tide. The existence percentages of bacteria ranged from 2.6 to 17.9% on all media tested. The bacterial isolates on the nutrient agar medium represented the highest existence with a total percentage of 43.6%, followed by MSA medium (25.7%), while the lowest percentage was for the AA medium at 7.8%. However, twelve isolates were selected as representative for bacterial community during study interval. Based on the morphological, biochemical, physiological and enzymatic characteristics, the bacterial strains were described. Depending on the 16S rDNA gene sequence, three common antagonists were aligned as: Vibrio toranzoniae strain Vb 10.8, Ruegeria pelagia strain NBRC 102038 and Psychrobacter adeliensis strain DSM 15333. The interaction between these bacteria and S. costatum was studied. The growth of S. costatum was significantly lower whenever each bacterium was present as compared to axenic culture. More specifically, 30% (v/v) of the all tested bacteria showed the strongest algicidal activities, as all S. costatum cells were killed after two days. 10% of R. pelagia and P. adeliensis also showed significant algicidal activities within six days. 相似文献
14.
发展机载激光荧光雷达系统测量叶绿素a的浓度,模拟了采用三倍频355 nm波长激光作为激发光,机载海洋激光荧光雷达在不同飞行高度和测量不同深度水层的情况下,测量海表叶绿素a浓度的相对误差。依据模拟的参数建立机载激光荧光雷达系统并进行初步机载实验,获得了同经验数据较为一致的测量结果。 相似文献
15.
An algal bloom is defined as a relatively rapid increase in the biomass of phytoplankton in an aquatic system. During 30 March to 24 April 2007, a cruise was conducted in the central Southern Huanghai Sea to investigate the spring bloom processes. The spatial and temporal variations of phytoplankton are discussed based on the in-situ observations and simultaneous remote sensing data. The explosive algal blooming varied quickly in temporal and spatial scales, due to the highly patchy distribution. Data obtained at the 2 anchor stations (BM1 and BM2) were analyzed in the present study. Horizontal advection is speculated to be responsible for the abrupt decrease in the concentration of chlorophyll-a at stations BM1 and BM2. At station BM2, the intermediate high chlorophyll-a concentration, coinciding with the low temperature, was found to be advected from the inshore colder water mass located to the east of the site. 相似文献
16.
Allelopathic effects of several concentrations of fresh tissue,dry powder and dry tissue of three bloom-forming green macroalgae Ulva pertusa,Ulva linza and Enteromopha intestinalis on the red tide microalga Heterosigma akashiwo were evaluated in microcosms systems.The effects of macroalgae culture medium filtrate were investigated on H.akashiwo using initial or semi-continuous filtrate addition.Preliminary studies on the algicidal effects of one aqueous and four organic solvent extracts from the macroalgae on the microalga were carried out to confirm the existence of allelochemicals in the tissue of these macroalgae.The dry powder of U.pertusa was extracted with methanol,and the methanol extracts were partitioned to petroleum ether phase,ethyl acetate phase,butanol phase and distilled phase by liquid-liquid fractionation.The bioassays of the activity of every fraction were carried out on H.akashiwo.The resultant microcosms assay showed that the growth of H.akashiwo was strongly inhibited by using fresh tissues,dry powder or dry tissue of these three macroalgae,while aqueous and methanol extracts of both macroalgae had strong inhibitory effects on the growth of H.akashiwo,and the EC 50 values for methanol extract of U.pertusa,U.linza or E.intestinalis were 0.016,0.028×10-12 or 0.033×10-12,respectively.While the other three organic solvent extracts（acetone,ether and chloroform） had no apparent effect on its growth,this suggests that the allelochemicals from these three macroalgae had relatively high polarities.The activity of petroleum ether phase,ethyl acetate phase,butanol phase and distilled phase of U.pertusa methanol extract was carried out on H.akashiwo indicating that petroleum ether phase and ethyl acetate phase had stronger algicidal effect on H.akashiwo.The inhibition effect of the ethyl acetate phase was not as strong as that of petroleum ether phase,and effective concentration of petroleum ether phase was 17 mg/L for H.akashiwo.However,no significant algicidal effects were observed on the butanol phase and distilled water phase.These three macroalgae＇s culture medium filtrate exhibited no apparent growth inhibitory effect on the microalga under initial filtrate addition whereas the growth of H.akashiwo was significantly inhibited under semi-continuous filtrate addition,which suggests that continuous release of small quantities of rapidly degradable allelochemicals from the fresh tissue of both macroalgae was effective in inhibiting the growth of H.akashiwo. 相似文献
17.
光照和营养盐胁迫对龙须菜生长及生化组成的影响 总被引：9，自引：0，他引：9
以龙须菜(Gracilaria lemaneiformis)为实验材料,分别研究了光照强度、营养盐胁迫对其生长及生化组成的影响。结果表明,在800～3000lx的范围内随光强的升高,龙须菜生长率增加,但藻红素(PE)、叶绿素a、蛋白质和可溶性总糖含量却降低,即低光强更利于龙须菜生化组分的积累。饥饿处理组、饱和处理组及正常对照组的生长率分别为0.9%,5.01%,3.06%。饥饿处理组的总C含量最高,总N及C/N比值高(>15),饱和处理组则相反,C/N比值<10,即存在C高N低、N高C低的现象。表明水体营养状况对龙须菜生长、体内生化组分有显著影响。总C、总N及C/N比都能很好地反映藻体的营养状态。饱和处理组藻体呈现深红色,饥饿处理组藻体色泽为浅黄色,因此也可根据藻体色泽的变化来估计藻体的营养状态。 相似文献
18.
从漳江口红树林区采集的沉积物样品中分离到1株放线菌菌株BS01 Brevibacterium sp.,其胞外活性产物对塔玛亚历山大藻Alexandrium tamarense具有明显的溶藻作用.采用单因素及均匀设计,通过摇瓶培养对BS01产溶藻活性物质的发酵培养基及发酵条件进行优化.结果表明,在可溶性淀粉为碳源、硝酸钠为氮源、装液量为40%、起始pH值为7.5、培养温度为28℃、转速为150r·min-1、振荡培养时间为48h的条件时,BS01发酵产物的杀藻活性最强.通过均匀设计进行最佳发酵培养基及培养条件优化的结果为:可溶性淀粉为20g·L-1,硝酸钠为0.5g·L-1,pH为7.7,温度为27.2℃.研究结果为杀藻活性物质高效提取及杀藻机制研究奠定了基础. 相似文献