不同质量浓度黄莒蒲和狭叶香蒲对铜绿微囊藻的化感作用

分别采用黄菖蒲（IrispseudacorusL．）、狭叶香蒲（TyphaangustifoliaL．）和铜绿微囊藻（Microcystisaeruginosa）共生培养的实验方法研究了不同质量浓度黄菖蒲、狭叶香蒲对铜绿微囊藻的化感作用。结果表明,黄菖蒲在质量浓度大于10g／L时对初始密度为1．0×10^7ind／mL的铜绿微囊藻具有较好的抑制作用,表现为黄菖蒲质量浓度为10、20和40g／L时,第15天对铜绿微囊藻的抑制率分别为30．1％、51．8％和84．0％;狭叶香蒲在质量浓度大于20g／L时对铜绿微囊藻有明显的抑制作用,表现为狭叶香蒲质量浓度为20g／L和40g／L时,第15天对铜绿微囊藻的抑制率分别为34．2％和77．7％,实验过程中,铜绿微囊藻叶绿素a含量逐渐减少,而藻密度、SOD活性及MDA含量先增加后逐渐降低,表明经过一段时间持续地化感胁迫,黄菖蒲和狭叶香蒲可以诱导铜绿微囊藻产生氧化胁迫,导致细胞结构严重损伤和叶绿素大量分解,从而强烈抑制铜绿微囊藻的生长。     

不同质量浓度黄菖蒲和狭叶香蒲对铜绿微囊藻的化感作用简

分别采用黄菖蒲（Iris pseudacorus L.）、狭叶香蒲（Typha angustifolia L.）和铜绿微囊藻（Microcystis aeruginosa）共生培养的实验方法研究了不同质量浓度黄菖蒲、狭叶香蒲对铜绿微囊藻的化感作用。结果表明,黄菖蒲在质量浓度大于10 g/L时对初始密度为1.0×10⁷ ind/mL的铜绿微囊藻具有较好的抑制作用,表现为黄菖蒲质量浓度为10、20和40 g/L时,第15天对铜绿微囊藻的抑制率分别为30.1%、51.8%和84.0%;狭叶香蒲在质量浓度大于20 g/L时对铜绿微囊藻有明显的抑制作用,表现为狭叶香蒲质量浓度为20 g/L和40 g/L时,第15天对铜绿微囊藻的抑制率分别为34.2%和77.7%,实验过程中,铜绿微囊藻叶绿素a含量逐渐减少,而藻密度、SOD活性及MDA含量先增加后逐渐降低,表明经过一段时间持续地化感胁迫,黄菖蒲和狭叶香蒲可以诱导铜绿微囊藻产生氧化胁迫,导致细胞结构严重损伤和叶绿素大量分解,从而强烈抑制铜绿微囊藻的生长。     

广玉兰、龙爪槐和黄杨化感物质对铜绿微囊藻生长的抑制

针对水华的主要物种——铜绿微囊藻,初步测定了60种植物的浸提液对其细胞增殖的抑制率。结果表明,8种植物的浸提液对铜绿微囊藻生长的抑制率达到90%以上。其中,广玉兰、龙爪槐和黄杨叶片浸提液对铜绿微囊藻生长的抑制率分别达到97.4%、95.6%和91.2%。通过计算得到培养7d后广玉兰、龙爪槐和黄杨的50%抑制效应质量浓度(EC50)分别为0.52、1.04、5.87g/L,而90%抑制效应质量浓度(EC90)分别为3.79、6.45、9.09g/L。首次发现此3种植物浸提液中富含能抑制铜绿微囊藻细胞增殖的化学物质,可以作为抑藻化感物质的一个重要来源。根据EC50和EC90对培养时间的拟合方程判断,广玉兰和龙爪槐浸提液对铜绿微囊藻的抑制效果较黄杨浸提液更为长效,且由于其抑制效果优于农作物秸秆,具有进一步研究的价值。     

香蒲中挥发油对铜绿微囊藻的化感抑制作用

湖泊富营养化问题已日益成为全球性的水环境污染问题之一.开发一种有效、安全控制有害藻类暴发的新方法是非常必要的.香蒲(Typha latifola)为多年生宿根性沼泽草本挺水植物,在中国分布广泛,其对受污染河水中COD、氨氮及TP均具有较好的去除效果.为了探讨香蒲对铜绿微囊藻(Microcystin aeruginosa...     

碳源对铜绿微囊藻生理特性及微囊藻毒素产率的影响

为研究水体中不同碳源对铜绿微囊藻生理特性的影响,以Na2CO3与葡萄糖分别作为铜绿微囊藻生长的无机碳源与有机碳源,将铜绿微囊藻于光照下进行培养,并对其一系列的生理特性与微囊藻毒素产率进行检测。实验结果表明,同等碳浓度下,有机碳源更能促进铜绿微囊藻的生长,经过30 d的培养,铜绿微囊藻在有机碳源中的产量为187.55 g,比其在无机碳源中的产量提高了6.06%;微囊藻毒素在有机碳源中的产量为969.00μg/g,而在无机碳源中的产量却升高至1 193.60μg/g。参与藻毒素合成的3种氨基酸在无机碳源中的浓度要比有机碳源中的浓度高,但是其余几种氨基酸的含量与之情况相反。而有机碳源培养的铜绿微囊藻总可溶性蛋白含量为387.00μg/g,比无机碳源培养的铜绿微囊藻的蛋白含量提高了93.60%。     

美人蕉有机酸组分对铜绿微囊藻的化感作用

对美人蕉叶片水浸提液进行液液萃取得到美人蕉有机酸组分,研究了美人蕉有机酸组分对铜绿微囊藻化感抑制作用,实验结果表明,美人蕉有机酸组分对铜绿微囊藻生长具有低促高抑作用,13.3 g/L和20.0 g/L处理组6 d 后抑制率分别达到98.57%和99.37%,铜绿微囊藻在高浓度美人蕉有机酸组分下,叶绿素含量逐渐降低,总超氧化物歧化酶(T-SOD)和过氧化氢酶(CAT)活性出现先增大后减小,说明美人蕉有机酸组分可能通过对铜绿微囊藻抗氧化酶系统逐渐损伤,最终藻类死亡.通过气相色谱-质谱(GC-MS)分析,鉴定出美人蕉有机酸组分共含有32种有机酸成分,其中饱和脂肪酸18种、不饱和脂肪酸7种、芳香酸5种以及酚酸2种.     

不同浓度Mn2+对铜绿微囊藻的生长及其生物可利用性的影响

利用MA培养液进行藻类增长潜力(AGP)试验,考察了不同浓度Mn2 对铜绿微囊藻生长及其生物可利用性的影响.结果表明,Mn2 为0 mg/L时,铜绿微囊藻生长受到很大抑制,叶绿素a含量较低;Mn2 为0.7～6.0 mg/L时,铜绿微囊藻生长较快,叶绿素a含量都较高,并且相互差异不明显;Mn2 为12.0 mg/L时,可能对铜绿微囊藻生长产生了毒性,生长受到抑制,且叶绿素a含量较低;Mn2 在藻类正常生长所需浓度范围内,其生物可利用性与溶液中Mn2 浓度呈正相关.     

水罗兰对不同密度铜绿微囊藻抑制作用的研究

通过水罗兰与铜绿微囊藻共培养12 d,研究了水罗兰对低密度、高密度的铜绿微囊藻的抑制作用.结果表明,铜绿微囊藻初始光密度(OD680)分别为0.026、0.257时,水罗兰可显著抑制铜绿微囊藻的生长,使其OD680降低.水质检测结果显示,培养过程中共培养液营养盐浓度一直处于较高水平,铜绿微囊藻OD680降低及生长停滞并非因营养不足所引起.通过实验证实了水罗兰可作为铜绿微囊藻水华控制的生态修复物种.     

稻秆对铜绿微囊藻抑制作用的研究

研究了稻秆浸出液对铜绿微囊藻生长的抑制作用.研究表明,稻秆浸出液中含有的化学物质抑制了铜绿微囊藻的生长繁殖.稻秆浸泡时间的延长,有利于提高浸出液的抑藻效果,但浸泡时间过长则无益于抑藻效果提高,浸泡时间为15 d时,抑制率能高达75.99%.稻秆浸出液投加量达7.5%以上具有显著的抑藻效果.不同部位的水稻秸秆浸出液对铜绿...     

共培养条件下黄菖蒲和狭叶香蒲对铜绿微囊藻光合系统的影响

采用共培养的实验方法,通过测定铜绿微囊藻(Microcystis aeruginosa)叶绿素a含量及叶绿素荧光参数,研究了黄菖蒲(Iris pseudacorus L.)和狭叶香蒲(Typha angustifolia L.)对铜绿微囊藻光合系统的影响。结果表明,共培养条件下,黄菖蒲和狭叶香蒲对铜绿微囊藻的光合系统具有明显的化感作用,表现为,处理组中铜绿微囊藻的叶绿素a含量从第4天开始显著(Paried t-test,pFv/Fm(光系统Ⅱ最大量子产量)值也呈现逐渐下降的趋势,说明黄菖蒲和狭叶香蒲对铜绿微囊藻产生了化感抑制,光合效率和光能转化效率下降;而Ik(半饱和光强)和α(光限制斜率)值呈现先增加后逐渐降低的趋势,从第4天开始显著(Paried t-test,p<0.05)低于对照组,表明黄菖蒲和狭叶香蒲的化感作用在短时间内可以激发铜绿微囊藻对光强的耐受能力并能提高藻的光能利用效率,但是随着化感时间的延长,铜绿微囊藻对强光的耐受能力及光能利用效率下降。     

不同水温下鲴鱼对铜绿微囊藻的控制作用及对水质的影响

在室内受控模拟条件下开展实验,研究了在19、23、27、31、35℃5个水温梯度下鲴鱼对铜绿微囊藻和水质的影响。研究结果表明,在不同水温下,鲴鱼对铜绿微囊藻具有较强的控制作用,实验结束时铜绿微囊藻密度减少至初始密度的18%~30%,摄食率和消化率分别为6.83×104~8.32×104cells/(g·d)、93%~98%;叶绿素a的去除率为68%~88%;实验组TP、TN去除率分别为22%~25%、20%~38%,对照组的分别为80%~94%、28%~40%。对照组NH+4-N浓度变化很小(0.071~0.073 mg/L),而实验组氨氮浓度显著增大(2.222~3.645 mg/L),分别为初始值的31、34、42、51和46倍。     

Mechanisms of photosynthetic inactivation on growth suppression of Microcystis aeruginosa under UV-C stress

This study aims to investigate the effects of UV-C irradiation on photosynthetic processes of Microcystis aeruginosa to unravel the mechanism(s) involved in how and in what ways UV-C mediates growth suppression and cellular recovery. Changes in the concentration of photosynthetic pigments, photochemical efficiency, PS II core protein (D1) content, and the coding genes expressions were measured. The results indicate that UV-C doses at 20–200 mJ cm⁻² lead to rapid reduction in gene expression of both psbA (for D1) and cpc (for phycocyanin), but the suppression was short term and recoverable within 3 d of post-UV incubation. Conversely, UV-C doses at ?50 mJ cm⁻² could induce marked decline in photochemical efficiency (represented by the optimal PS II quantum yield, F_V/F_M, and the effective PS II quantum yield, Y) as well as decreases in D1 content and water soluble pigments (phycoerythrins, phycocyanins, allophycocyanins) in M. aeruginosa during the post UV-C incubation period. The results suggest that interruption of both the light energy harvesting apparatus (especially the water soluble pigments) and the photochemical process mainly accounted for the growth suppression effect in UV-C irradiated M. aeruginosa.     

铁改性竹屑生物炭的添加对苦草 (Vallisneria spiralis)水质净化及其生理特性的影响

利用苦草水质净化模拟系统,通过循环批次实验考查在系统基质中添加3%的不同浓度FeCl₃改性竹屑生物炭对系统水质净化效果和苦草生理生化特性的影响。结果表明,栽种苦草提高了系统净化NH₄⁺-N、TN、TP、COD的效率。随着FeCl₃浓度的升高,系统净化NH₄⁺-N的效果增强,TN的效果影响不大,而COD、TP的效果降低。添加3%的0.10 mol·L⁻¹和0.20 mol·L⁻¹ FeCl₃改性竹屑生物炭抑制苦草生长及其光合作用,导致苦草体内过氧化物酶 (POD) 活性增强及丙二醛(MDA)含量升高,诱导了细胞脂质过氧化;添加3%的0.05 mol·L⁻¹ FeCl₃改性竹屑生物炭,促进苦草根系生长,提升苦草根系活力。低浓度(0.05 mol·L⁻¹)FeCl₃改性竹屑生物炭在强化水质净化,促进苦草生长恢复具有一定的应用潜力。     

铜绿假单胞菌NY3所产表面活性剂对原油降解的影响

铜绿假单胞菌NY3是从石油污染土壤中分离出的一株能快速代谢疏水性化合物的菌种。研究了该菌产表面活性剂及对原油降解的作用。实验表明,在敞开体系中,投加82 mg/L NY3菌产的鼠李糖脂,240 h能使NY3对原油的降解率提高50%。投加甘油使NY3产鼠李糖脂与降解原油同步进行,与投加鼠李糖脂对原油降解的促进作用相近。投加9‰甘油使NY3在168 h对原油的降解率提高43%。NY3菌能同时降解原油中的直链烷烃及菲(Pr)和芘(Ph)等多环芳烃。在敞开体系中用少量甘油使产鼠李糖脂和降解原油同步进行,节约处理费用。研究结果为NY3菌株在露天石油污染环境修复中的应用奠定了基础。     

Isolation and identification of an anti-algal compound from Artemisia annua and mechanisms of inhibitory effect on algae

The goals of this work were to isolate and identify an anti-algal compound from extracts of Artemisia annua and study its mode of action on Microcystis aeruginosa. The anti-algal compound was isolated from the extracts using column chromatography and activity-guided fractionation methods. Artemisinin with strong anti-algal activity was identified by gas chromatography-mass spectrometry and ¹H Nuclear Magnetic Resonance. The EC₅₀ of artemisinin on M. aeruginosa was 3.2 mg L⁻¹. Artemisinin decreased the soluble protein content and increased the superoxide dismutase activity and ascorbic acid content of M. aeruginosa, but exerted no effect on soluble sugar content. The results suggested the mode of action of artemisinin on algae may primarily be the increasing level of reactive oxygen species in algae cells. The results of our research could aid in the development of new anti-algal substances and lead to further study of mechanisms of inhibitory effect on algae.     

Effects of sub-lethal glyphosate concentrations on growth and photosynthetic performance of non-target species Bolboschoenus maritimus

Glyphosate use has increased over the last decades for the control of invasive plant species in wetland ecosystems. Although glyphosate has been considered ‘environmentally’ safe, its repeated use could increase the toxicological risk derived from diffuse pollution of surface and groundwater on non-target vegetation. A glasshouse study was designed to determine the effect produced by the addition of different sub-lethal doses of glyphosate herbicides (5–30 mg L⁻¹) to the nutrient solution on the growth and photosynthetic apparatus of Bolboschoenus maritimus. Although B. maritimus plants were able to grow and survive after 20 d of exposure to glyphosate, the presence of this herbicide affected their growth, through a direct interaction with the root system. Particularly, at 30 mg L⁻¹ glyphosate, B. maritimus showed ca. 30% of biomass decrease. The reduction in B. maritimus growth was due to a decrease in net photosynthetic rate (A), which ranged between values ca. 11.5 and 5.5 μmol m⁻² s⁻¹ CO₂ for the control and the highest glyphosate treatment, respectively. The response of A to glyphosate could be largely accounted for by non-stomatal limitations, since stomatal conductance was similar in all glyphosate treatments. Thus, A decrease was prompted by the negative impact of herbicide on photochemical (PSII) apparatus, the reduction in the absorption of essential nutrients, the reduction of photosynthetic pigments and possibly the reduction in Rubisco carboxilation capacity. Moreover, glyphosate excess caused photoinhibitory damage. In conclusion, in this study we have shown that herbicide water pollution could be a source of indirect phytotoxicity for B. maritimus.     

铜绿微囊藻生长条件优化模拟研究

采用Plackett Burman实验设计与响应曲面法(RSM)相结合,研究了环境因子对铜绿微囊藻生长的影响。首先采用Plackett-Burman设计对影响藻细胞生长的环境因子进行筛选,结果表明:温度、NaNO3、K2HPO4、Ferric.Citrate对铜绿微囊藻的生长有重要影响,各因子影响值大小为E温度EK2HPO4ENaNO3EFerric.Citrate。在此基础上,用Box-Behnken设计对铜绿微囊藻的生长条件进一步优化,通过对藻细胞最大现存量与各考察因子之间的输入响应关系进行分析,结果表明:铜绿微囊藻的最佳生长条件是:温度为29℃,NaNO3为1.059 mmol/L,K2HPO4为0.057 mmol/L,Ferric.Citrate为0.024mmol/L,此时藻细胞的最大现存量为10.8293×105cells/mL。