溶藻细菌L8的溶藻活性代谢产物对水华鱼腥藻光合特性的影响研究

从广州城区某富营养化池塘筛选出1株溶藻细菌L8(简称L8菌),研究了L8菌的溶藻活性代谢产物(简称L8菌溶藻产物)对水华鱼腥藻(Anabaena flos-aquae)光合特性的影响。结果表明,L8菌溶藻产物能够使水华鱼腥藻中的类胡萝卜素、藻蓝蛋白和别藻蓝蛋白的含量显著升高,经L8菌溶藻产物作用7d后,3者分别升高了35.7%、63.2%和185.7%,而叶绿素a含量下降了51.3%;经L8菌溶藻产物作用7d后,水华鱼腥藻的光系统Ⅱ(PSⅡ)的光化学效率、潜在活性以及光合电子产量均明显降低。低温(77K)荧光发射光谱的变化表明,光合色素相对含量的变化导致光能在水华鱼腥藻2个光系统之间的分配发生了变化,影响了光能在光系统Ⅰ(PSⅠ)、PSⅡ中的分配,进而影响了水华鱼腥藻的光合作用效率。     

嗜盐杆菌HSQAY1对中肋骨条藻的溶藻物质特性

研究嗜盐杆菌菌株(Halobacillus sp.HSQAY1)发酵液在不同p H、温度和反复冻融条件下对中肋骨条藻(Skeletonema costatum)溶藻活性的环境稳定性;并采用乙醇沉淀、硫酸铵沉淀、超滤和聚丙烯酰胺凝胶电泳(SDS-PAGE)等方法对溶藻物质的理化特性进行了初步探讨和分析。结果表明,该菌株产生的溶藻物质在强酸性条件下(p H=3)丧失活性,p H5~11时的溶藻率在83.4%~98.4%之间;30~110℃时溶藻率在71.7%~94.5%之间,表现出一定的酸碱稳定性和热稳定性,且不受反复冻融(-20℃)影响。溶藻活性物质具有被乙醇和硫酸铵沉淀的特性,其活性组分是多种分子质量10k Da的蛋白类物质,溶藻活性蛋白粗提物的SDS-PAGE电泳显示,在15~50 k Da间有3条明显的特异蛋白条带。     

一株铜绿微囊藻溶藻真菌的分离鉴定及溶藻特性

从富营养化水体和土壤中分离筛选出一株溶藻真菌菌株JHQ3,通过ITS序列分析对溶藻真菌JHQ3进行鉴定,并研究了该菌株对铜绿微囊藻的溶藻方式和溶藻特性。结果表明：菌株JHQ3的ITS序列与萨氏曲霉属(Aspergillus sydowii)同源性达100%,菌株JHQ3属于萨氏曲霉属(GenBank登录号为OP363844);溶藻真菌JHQ3对铜绿微囊藻的作用方式以直接溶藻作用为主,间接溶藻作用为辅;在30℃时菌液溶藻效果最好,溶藻率高达94.06%;在pH为7时,溶藻率最高,为83.39%;菌液浓度大于10^-3(即稀释10³倍)时,其溶藻效果随菌液浓度的增加而增强;光暗比为12 h∶12 h时,溶藻效果较好,具有较好的工程应用价值;添加表面活性剂乙二胺四乙酸和Tween-80会抑制溶藻效果。溶藻菌株JHQ3能有效抑制铜绿微囊藻繁殖,在富营养化治理方面具有较好的应用前景。     

DSF型群体感应系统的缺失导致嗜根寡养单胞菌溶藻作用的增强

水环境中的微藻与藻际微生物之间关系复杂多变,而微生物的群体感应(QS)作用会影响并调控菌藻的共生关系。以嗜根寡养单胞菌(Stenotrophomonas rhizophila)野生株(WT)和QS扩散信号因子(DSF)合成酶基因-rpfF基因敲除株(△rpfF)为实验菌株,阐明DSF型群体感应是否调控嗜根寡养单胞菌对铜绿微囊藻的溶藻效果。结果表明：嗜根寡养单胞菌野生株和rpfF基因敲除株的溶藻特性相似,均具有针对铜绿微囊藻的溶藻特异性,主要通过分泌溶藻物质间接作用于藻细胞;野生株和敲除株培养48 h后的无菌滤液均有显著的溶藻作用,在投加体积分数10%无菌滤液的条件下,野生株和敲除株7 d溶藻率分别为53%和78%。此外,实验菌株分泌的溶藻活性物质具有热稳定性和酸碱耐受性,且不容易被乙醇沉淀;三维荧光光谱、紫外可见光光谱、傅里叶变换红外光光谱分析表明菌株胞外滤液中主要以类腐殖酸物质为主,芳香化程度较高;通过比较荧光强度和吸光度可知DSF合成酶基因缺失的嗜根寡养单胞菌的无菌滤液中类腐殖酸物质含量显著高于野生株。结果表明,DSF-QS缺失的嗜根寡养单胞菌生物量增多,能分泌更多的溶藻物质,增强...     

溶藻菌H6对铜绿微囊藻的溶藻特性研究

全球水华现象日益严重，微生物控藻由于具有成本低、高效、环境友好等优点被广泛关注。以筛自河道的一株溶藻菌H6为对象，开展其对铜绿微囊藻(Microcystis aeruginosa)的溶藻特性研究。实验结果表明，H6最佳投加量(体积分数)为5%,最佳投加时机为蓝藻水华暴发初期(680 nm波长处的光密度(OD₆₈₀)为0.3),pH控制在5～11,7 d溶藻率超过70%。H6以间接溶藻为主，直接溶藻为辅，通过分泌耐高温的溶藻物质进行除藻且溶藻产物为腐殖酸类物质。H6属于肠杆菌属(Enterobacteriaceae),在宽pH范围内有较好溶藻效果，丰富了水体蓝藻水华治理方面的菌种资源；分泌的溶藻物质的耐高温特性为后续菌粉制备及生产应用提供了便利。     

溶藻放线菌改性制剂对铜绿微囊藻的控藻能力研究

采用喷雾干燥法制备了一种溶藻放线菌粉剂,此粉剂按1∶10 000的质量比投加4 d后对铜绿微囊藻的溶藻效率可达90%,该粉剂经过壳聚糖改性处理后,在1∶20 000的质量投加比下,0.5 h即可絮凝去除90%的藻细胞,4 d后的溶藻效率仍可达80%。由于既能快速絮凝除藻,又能长效溶藻,使得改性溶藻放线菌粉剂具有更为广阔的应用前景。     

一株具有藻毒素降解和溶藻功能细菌的分离鉴定

从太湖水华腐烂蓝藻中富集筛选出一株编号A-8的细菌。该菌株菌落圆形、灰白色,革兰氏染色阴性,氧化酶阴性,接触酶阳性;分子系统进化树显示为溶血不动杆菌。根据以上结果,将此菌株鉴定为溶血不动杆菌。此外,对这株菌降解微囊藻毒素、不同生长时期的细菌的溶藻效果及溶藻专一性进行了研究。结果显示:该菌在3 d时间里将藻毒素降解了30.4%;细菌通过分泌胞外物质溶藻,细菌在衰退期时胞外分泌物的溶藻效果最好;该菌还对瘤状念珠藻、颤藻等9种蓝藻有溶藻作用。     

溶藻细菌及其溶藻活性物研究进展

利用溶藻细菌及其产生的溶藻活性物控制有害藻华是未来最有发展潜力的生物控制方法之一。对溶藻细菌类群、溶藻活性物、溶藻作用方式及溶藻机制进行综述,并在此基础上对溶藻细菌的研究进行展望。     

溶藻细菌对富营养化水体藻类群落结构的影响

向富营养化水体投放3株溶藻细菌(蜡状芽孢杆菌(Bacillus cereus)L7、L8和短小芽孢杆菌(Bacillus pumilus)L18)的菌液.在试验期内,3株溶藻细菌显示出很好的控藻效果,使叶绿素a(Chl-a)和藻类密度分别比初始值降低87%以上和72%以上;藻类Shannon-Weaver多样性指数维持在2～3,Pielous均匀度指数介于0.60～0.81,其中,溶藻细菌L7效果最明显.而未投加菌液的水体Chl-a未发生明显上升,但藻类密度自9.55×104个/mL上升到2.09×105个/mL,藻类Shannon-Weaver多样性指数由2.17降到1.11,Pielous均匀度由0.60降到0.33.3株溶藻细菌并非简单地杀灭水体中的全部或某些藻类,而是能明显地调节藻类群落结构,使其朝着较为稳定的方向发展,在修复藻型富营养化水体水生生态系统方面有很好的应用前景.     

微生物发酵产物中溶藻物质的提取方法

微生物溶藻是藻类水华控制的研究热点,但目前仍缺乏去除微生物发酵产物中营养物质的方法学研究,对野外水体采集的微囊藻的溶藻活性研究也较少见。比较了不同极性溶剂对溶藻物质的固液萃取效率,研究了分子筛层析对溶藻物质的纯化效果,并测定了各提纯步骤的中间产物对野外水体采集的铜绿微囊藻的溶藻效果。结果表明,在溶藻活性基本保持稳定的前提下,固液萃取串联分子筛层析技术对TOC、TN和TP的总去除率平均高达97%,其中,固液萃取的分级去除率平均高达90%,而分子筛层析的分级去除率平均为70%,且分子筛层析后的产物对野外水体采集的铜绿微囊藻的去除率稳定在60%左右。结果说明,固液萃取与分子筛层析技术可以作为溶藻物质工业化提取与实验室纯化的重要方法。     

Phytostabilization of a metal contaminated sandy soil. II: Influence of compost and/or inorganic metal immobilizing soil amendments on metal leaching

A lysimeter approach (under natural climatologic conditions) was used to evaluate the effect of four metal immobilizing soil treatments [compost (C), compost+cyclonic ashes (C+CA), compost+cyclonic ashes+steel shots (C+CA+SS)) and cyclonic ashes+steel shots (CA+SS)] on metal leaching through an industrially contaminated soil. All treatments decreased Zn and Cd leaching. Strongest reductions occurred after CA+SS and C+CA+SS treatments (Zn: -99.0% and -99.2% respectively; Cd: -97.2% and -98.3% respectively). Copper and Pb leaching increased after C (17 and >30 times for Cu and Pb respectively) and C+CA treatment (4.4 and >3.7 times for Cu and Pb respectively). C+CA+SS or CA+SS addition did not increase Cu leaching; the effect on Pb leaching was not completely clear. Our results demonstrate that attention should be paid to Cu and Pb leaching when organic matter additions are considered for phytostabilization of metal contaminated soils.     

Inactivation of antineoplastics in clinical wastewater by electrolysis

Wastewater from clinical institutions contains a considerable amount of toxic substances. Among the toxic substances, antineoplastics may induce carcinogenesis, teratogenesis, and the emergence of mutant microorganisms in the environment. Although the incineration or chemical treatments of disposed antineoplastics are recommended, a high energy during incineration and a careful quality control during chemical treatment are required. In this study, we determined the conditions for the electrolytic treatment of an antineoplastic, epirubicin hydrochloride (EH), using two platinum electrodes with a constant current of 100 mA. We analyzed the cytotoxicity, mutagenicity and antibacterial activity of electrolyzed EH and compared them with those of unelectrolyzed EH. Nearly 100% cytotoxicity, mutagenicity and antibacterial activity were eliminated and HPLC did not detect an EH molecule, in the case of electrolysis for 6 h. We also examined the biological cytotoxicities of electrolyzed irinotecan hydrochloride, vincristine sulfate, mitomycin C, paclitaxel, methotrexate and cisplatin, and found that 72.1-99.999% toxicity was eliminated by electrolysis under the same conditions. The biological toxicity of a mixture of these drugs was determined to be decreased by approximately 99% by electrolysis under the same conditions.     

Does quinone or phenol enrichment of humic substances alter the primary compound from a non-algicidal to an algicidal preparation?

Dissolved organic matter (DOM) has been shown to affect phytoplankton species directly. These interactions largely depend on the origin and molecular size of DOM and are different in prokaryotes and eukaryotes. In a preceding study, however, two humic substance preparations did not adversely affect coccal green algae or cyanobacterial growth even at high concentrations of dissolved organic carbon (DOC). These results contradicted previous findings, showing a clear, negative response of different phototrophs to much lower DOC concentrations. To test whether or not at least defined building blocks of humic substances (HSs) are effective algicidal structures, we enriched two humic preparations with hydroquinone and p-benzoquinone, respectively, and exposed two different green algae, Pseudokirchneriella subcapitata and Monoraphidium braunii, and two cyanobacterial species, Synechocystis sp. and Microcystis aeruginosa, to the unmodified and enriched HSs. As response variables, growth rates in terms of biomass increase, chlorophyll-a content, and photosynthetic yield were measured. The highest concentration (4.17 mM DOC) of the modified HSs clearly inhibited growth; the cyanobacterial species were much more sensitive than the green algal species. However, realistic ecological concentrations did not adversely affect growth. Aerating the exposure solution for 24 h strongly reduced the inhibitory effect of the modified HSs. The algicidal effect was obviously caused by monomers and not by polymerised high molecular weight HSs themselves. Furthermore, the maximum quantum yield (Φ PSII max) was stimulated in the green algal species by low and medium DOC concentrations, but reduced in the cyanobacterial species upon exposure to higher HS concentrations. The quinone- and phenol-enriched HSs only showed algicidal activity at high concentrations of 4.17 mM DOC and lost their effects over time, presumably by oxidation and subsequent polymerisation. This study confirms that the applied humic substances themselves are not effective algicides even if enriched in effective structures.     

Does cadmium play a physiological role in the hyperaccumulator Thlaspi caerulescens?

The southern French (Ganges) ecotype of Thlaspi caerulescens J & C Presl is able to hyperaccumulate several thousand mg Cd kg(-1) shoot dry weight without suffering from phytotoxicity. We investigated the effect of Cd on growth and the activity of carbonic anhydrase (CA), a typical Zn-requiring enzyme, of T. caerulescens in soil and hydroponic experiments. In one of the hydroponic experiments, T. caerulescens was compared to the non-accumulator Thlaspi ferganense N. Busch. In the soil experiment, additions of Cd at 5-500 mg kg(-1) soil increased the growth of T. caerulescens significantly. In the hydroponic experiments, exposure to Cd at 1-50 microM for three weeks had no significant effect on the growth of T. caerulescens, but decreased the growth of T. ferganense markedly even at the lowest concentration of Cd (1muM). Cadmium exposure significantly increased the CA activity in T. caerulescens, but decreased it in T. ferganense. The CA activity in T. caerulescens correlated positively with the Cd concentration in the shoots up to 6000 mg kg(-1), even though shoot Zn concentration was decreased by the Cd treatments. For comparison, Cd treatments had no consistent effect on the activity of superoxide dismutase in T. caerulescens. The results suggest that Cd may play a physiological role in the Cd-hyperaccumulating ecotype of T. caerulescens by enhancing the activities of some enzymes such as CA. Further research is needed to establish whether a Cd-requiring CA exists in T. caerulescens.     

Evaluation on estrogenicity and oxidative hepatotoxicity of fossil fuel industrial wastewater before and after the powdered activated carbon treatment

There are 10 manufacturers who produce fossil fuel products in the Da-Hse Industrial District, Kaohsiung County, southwestern Taiwan. Before discharging the wastewater into the nearby aquatic environment, the pretreated wastewater from these manufacturers must be processed in a treatment plant which includes four major processing units: equalization, a primary clarifier, an aeration basin, and a final clarifier. In order to estimate the potential environmental risks of industrial wastewater from each manufacturer and the treatment efficiency of the powdered activated carbon treatment (PACT) system used in this wastewater treatment plant, in vitro bioassays for estrogenicity and oxidative hepatotoxicity were carried out using a stably transfected human breast cancer cell line, MVLN, and a human hepatocellular carcinoma cell line, HepG2, respectively. Estrogenic substances occurred in nine of 10 pretreated wastewaters from these manufacturers in which the relative luciferase activity ranged from 18.9% to 98.0% for 1-fold-condensed wastewaters corresponding to the concentration of the original wastewater. The estrogenicity was highest at the influent of the treatment plant and decreased through the treatment process. About 81% estrogenicity clearance was found through all processing units. On the other hand, oxidative hepatotoxic substances existed in seven of 10 pretreated wastewaters from these manufacturers in which relative TBARs activity ranged from 18.5% to 43.0% for 1-fold-condensed wastewater. The TBARs of influent samples apparently decreased through the processing units until the aeration basin, but abruptly rose in the final clarifier, which was a result of the addition of an active charcoal-retrieving agent with the molecular formula of (C(2)H(3))(n)CONHCH(2)N(CH(3))(3)Cl and which had high TBARs activity. No TBARs activity being found in effluent samples could be a consequence of allowing sufficient time for coagulation between the active charcoal and its retrieval agent which decreased the residual active charcoal-retrieving agent. We concluded that the industrial wastewater treatment plant using the PACT system in the Da-Hse Industrial District is suitable for removing estrogenic substances and oxidative hepatotoxic substances discharged from these industrial manufacturers.     

多孔铁-碳-稀土合金填料对高盐废水中氯离子的去除

高盐废水是目前水处理领域的难点,主要研究了不同因素下多孔铁碳合金填料对氯离子的去除效果,及Cl-的去除机理。在进水pH为2,停留时间为60 min,Cl-浓度20 000 mg/L条件下进行实验,通过静态实验和连续实验确定Cl-主要去除途径为微电解过程引起的填料吸附。这种合金填料对实际高氯废水也有较好的处理效果,针对变性淀粉废水,在最优条件下填料对废水中氯离子有较强的吸附去除能力,同时COD去除率能达到57%,废水的可生化性得以大幅度提高。     

Completely autotrophic nitrogen-removal over nitrite in lab-scale constructed wetlands: evidence from a mass balance study

A mass-balance study was carried out to investigate the transformation of nitrogenous pollutants in vertical flow wetlands. Landfill leachate containing low BOD, but a high concentration of ammonia, was treated in four wetland columns under predominately aerobic conditions. Influent total nitrogen in the leachate consisted mainly of ammonia with less than 1% nitrate and nitrite, and negligible organic nitrogen. There was a substantial loss of total nitrogen (52%) in one column, whereas other columns exhibited zero to minor losses (<12%). Net nitrogen loss under study conditions was unexpected. Correlations between pH, nitrite and nitrate concentrations indicated the removal of nitrogen under study conditions did not follow the conventional, simplistic, chemistry of autotrophic nitrification. Through mass-balance analysis, it was found that CANON (Completely Autotrophic Nitrogen-removal Over Nitrite) was responsible for the transformation of nitrogen into gaseous form, thereby causing the loss of nitrogen mass. The results show that CANON can be native to aerobic engineered wetland systems treating wastewater that contains high ammonia and low BOD.     

Removal characteristics of trace compounds of landfill gas by activated carbon adsorption

The removal characteristics of trace compounds and moisture in raw landfill gas (LFG) were studied. The LFG from the extraction well was saturated with water and moisture was eliminated by physical methods including cyclone-type dehydrator and compressor. The moisture removal efficiency of dehydrator and compressor was above 80%. As the moisture contents of LFG decreased, the toxic compounds like aromatics and chlorinated compounds were effectively removed by using the granular activated carbon. The breakthrough time and adsorption capacity of benzene, toluene, and ethyl benzene decreased rapidly when the relative humidity is over 60%. The effect of moisture was more pronounced at lower adsorbate concentrations tested than at higher concentrations. The breakthrough curves for multi-component mixtures show displacement effects. In the course of competing adsorption, adsorbates with strong interaction force to displace weakly bounded substances. Adsorption by activated carbon is in descending order of xylene, ethylbenzene, toluene, tri or tetrachloroethylene, benzene, carbon tetrachloride and chloroform in LFG, respectively.     

蠕虫捕食对污泥性质的影响

利用一种新型静态序批式蠕虫生物反应器处理剩余污泥,另设一个未加蠕虫的反应器作为对照。通过对比分析2个反应器中污泥的比减量速率、沉降性能、脱水性能和比好氧速率来研究蠕虫捕食对污泥性质的影响。实验结果表明,蠕虫具有良好的污泥减量效果,蠕虫加入后可使污泥比减量速率增加（0．15±0．02）mg／（mg·d）。蠕虫作用后污泥沉降性能明显改善,污泥容积指数（SVI）降低28．9％,胞外聚合物（EPS）含量减少和污泥絮体结构变得更加密实规则是污泥沉降性能得到改善的重要原因。蠕虫捕食后污泥脱水性能变差,污泥标准化毛细吸水时间和比阻分别增大2．45倍和1．16倍,推测主要是由污泥絮体平均粒径减小造成的。另外,蠕虫的存在会降低污泥的微生物活性,异养细菌、氨氧化细菌和亚硝酸盐氧化细菌的比好氧速率分别降低7．09％、7．84％和8．29％。