饮用水水源与自来水中病毒和指示细菌存在水平的比较研究

自来水中人肠道病毒的存在已引起人们极大的关切和忧虑。本文报道了武汉东湖水和以东湖为水源的自来水中病毒和指示细菌的存在水平。水源水经过预加氯消毒、絮凝沉淀、砂滤和最后加氯消毒处理而成的自来水中细菌总数检测范围是41—500/升,总大肠菌是2—13/升、粪大肠菌为0—4/升、大肠菌噬菌体是0—13.6PFU/升,平均2.48PFU/升,肠道病毒为0—78PFU/升,平均为6.7PFU/升。水源水经制水工艺处理去除指示细菌、大肠菌噬菌体和肠道病毒的效率分别为97.95—99.99％,90.63％和53.18％。这种结果说明自来水制水工艺能有效地降低指示细菌,大肠菌噬菌体,而去除肠道病毒效率较低,揭示肠道病毒对环境压专的耐受性明显地比指示细菌强。     

毛乌素沙地南缘沙丘生物结皮中微生物分布特征

为探明半干旱沙区生物结皮中微生物分布特征,对毛乌素沙地南缘沙丘生物结皮中微生物数量进行了测定。结果表明:微生物总数从丘顶到丘间地呈递增趋势,除丘顶与迎风坡、迎风坡与背风坡结皮层微生物总数差异不显著外,其他各地貌部位结皮层微生物数量之间差异显著。同一地貌部位结皮层、0～5和5～10cm土层微生物垂直分布有变化,其变化规律为:除迎风坡放线菌数量呈先增加后递减、迎风坡微生物总数、细菌、真菌和丘顶真菌数量随剖面的加深呈递减外,其他各地貌部位微生物数量均呈先降低,后增加的趋势。微生物类群的组成表现为细菌最多,放线菌次之,真菌最少。在丘间地细菌所占微生物总数的比例与丘顶相比有所增加,而放线菌和真菌的比例有所减少。结皮下0～5和5～10cm土层微生物分布与土壤含水量的变化同步,说明土壤水分可能是影响微生物垂直分布的重要因子。     

武汉东湖不同湖区底泥总磷含量及变化的研究

以武汉东湖为对象,研究了1998.03—1999.02期间不同营养水平湖区底泥中(0—5cm,5—10cm)总磷的含量及季节动态。6个站平均总磷含量为1.15mg/g,同80年代初相比,Ⅰ、Ⅱ站底泥中总磷含量分别增高1.42倍和1.03倍。受污水排放影响较重的0站磷含量高达2.78mg/g,而受污水排放影响较小的Ⅳ、Ⅴ站仅分别为0.52mg/g和0.50mg/g。东湖底泥中磷年平均含量与湖水中磷年平均浓度相关系数极高(r=0.997,n=5,p＜0.02)。通过对不同湖泊的底泥磷含量、水柱磷含量和外源负荷的比较和相关分析可以看出,水柱中磷含量较高,磷负荷较大的湖泊底泥中磷含量也高。可以预测,即使东湖的外源负荷得以控制,巨大的底泥磷内源负荷将会继续对东湖水质构成威胁。     

东湖围隔（栏）中的植被恢复对水中氮的影响

利用大型围隔研究自然水体的某些生态过程具有真实准确、易于控制等优点 ,2 0世纪 80年代以来 ,国内陆续开展了一些研究[1～ 4 ] 。水体富营养化是目前我国湖泊存在的普遍问题 ,恢复水生植被可有效改善水质 ,减轻富营养化程度。武汉东湖(Ｅ114°2 3’ ,Ｎ30°33’)是一个典型的浅水城郊湖泊 ,已严重富营养化 ,为重建其水生植被 ,恢复其良性生态系统 ,在东湖建立了两个大型围隔和一个围栏 ,对其中的水生植被恢复及水质变化等方面进行了定位研究 ,旨在为重建和优化东湖水生植被 ,改善其水质提供借鉴。1　研究方法实验区位于东湖的汤林湖区。设…     

东湖浮游生物群落DNA指纹结构及其与环境理化因子的关系

对武汉东湖5个不同湖区的浮游生物群落DNA进行了RAPD指纹分析,并探讨了DNA指纹结构与环境理化因子的关系．结果表明：所筛选的9条随机引物共扩增210条大小为150～2000bp的谱带,多态率为93．3％．各站点平均有42条谱带,其中Ⅳ站最多（53条）,Ⅴ站最少（35条）．Ⅰ站的PO4^3--P、TP含量最高,Ⅴ站的NH4^＋-N、TN、NO2^--N含量最高,Ⅳ站各理化因子含量均低于其他站点,站点间COD、碱度、硬度、钙含量差异不大．相似性聚类分析表明,基于RAPD标记的浮游生物群落指纹将5个站点划分为两类：Ⅰ、Ⅱ、Ⅲ站聚为一枝,Ⅳ、Ⅴ站聚为另一枝．这与湖区主要理化因子的聚类结果一致．说明东湖不同湖区浮游生物群落DNA指纹与其环境理化因子密切相关．     

原核增强子样序列的研究

本文采用启动子检测载体和增强子检测载体发现来自大肠杆菌JMl03 DNA的一个1．0kb左右的片段能在痘苗病毒启动子上游增强细菌CAT和β－半乳糖苷酶基因在大肠杆菌中的表达,这种增强效应无明显的方向性,一般可使基因表达水平提高3～6倍,此原核增强子样序列同时也具有启动子功能。此外还测定了增强片段的部分DNA序列。     

Ce积累对黄褐土中土壤微生物区系的影响

在黄褐土中模拟长期使用稀土微肥产生的Ce积累以研究稀土对土壤微生物的生态效应 .不同类群微生物对Ce的敏感性依序为细菌 >放线菌 >真菌 .1 0 %吸附容量以上的Ce对细菌总数都产生抑制作用 .1 0 %吸附容量以下的Ce对放线菌总数产生刺激作用 .5～ 50 %吸附容量的Ce对真菌总数产生刺激作用 .5%吸附容量以上的Ce对好气性纤维素分解细菌和氨化细菌都产生抑制作用 .5～ 1 0 %吸附容量和 5～ 50 %吸附容量的Ce分别对分解纤维素真菌、分解蛋白质的真菌产生刺激作用 .在高积累Ce的胁迫下放线菌、真菌、分解纤维素真菌和氨化微生物的种群结构发生了不同程度的改变 .     

东湖原生动物群落结构变化与水质差异的相关研究

东湖自 60年代以来 ,富营养化程度不断加剧 ,由于各湖区接纳污水的程度不同 ,使不同水域的水质状况呈现明显的差别。本研究对东湖污染程度不同的水域设立 6个采样站 ,进行原生动物的采集及鉴定 ,目的是研究水污染造成的原生动物群落结构的变化 ,同时也是对各种结构和功能参数在水生态系统污染的监测和评价中的作用进行比较。1　方法1 .1　采样及镜检在东湖共设 6个采样站 (图 1 ) ,采用ＰＦＵ法[1]收集原生动物。于 1 995年 1月1 5日在各站挂上空白ＰＦＵ ,2月 1 5日取回。用ＰＦＵ挤出液进行活体定性观察 ,在高 ( 4 0× )、中 ( 2 0× )、…     

土壤线虫三种分离方法效率比较

比较了蔗糖离心浮选法、改进的贝尔曼漏斗法和浅盘法对土壤线虫的分离效率。蔗糖离心浮选法分离得到的线虫总数分别为贝尔曼漏斗法的 6 1倍和浅盘法的 11 4倍。而且离心浮选法分离得到的虫体大于 5 3μm(>30 0目 )和 5 3～ 4 0 μm(30 0～ 4 0 0目 )的线虫数显著高于贝尔曼漏斗法和浅盘法。离心浮选法对所有功能类群线虫 (包括食细菌、食真菌、植食和杂食线虫 )的分离效率也均显著高于其他 2种方法。贝尔曼漏斗法的分离效率高于浅盘法 ,主要反映在食细菌线虫和虫体在 4 0～ 32 μm(4 0 0～ 5 0 0 )的线虫数。但在达到相同分离效率时 ,浅盘法比贝尔曼漏斗法需要的时间短     

武汉东湖渔业增产试验效果及水体生物生产力

东湖位于武汉市武昌东郊,由郭郑湖、汤林湖、庙湖、牛巢湖等多个湖区组成,总面积为4万7千多亩。郭郑湖、汤林湖为东湖渔场经营的湖区,按生产计算为2万2千亩。由于有生活污水流入,湖水中营养元素丰富,总氮为     

Investigation of some physical,chemical, and bacteriological parameters of water quality in some dams in Albaha region,Saudi Arabia

This study was conducted to evaluate the quality of water in selected dams in Albaha region, Kingdom of Saudi Arabia. Water samples from eight dams were subjected to physical, chemical, and bacteriological assessment using standardized procedures of conductivity, total dissolved solids, ions, acidity & alkalinity, and EC blue 100® coliform detection. About three fourth (75%) of dams’ water samples exceeded the permissible levels of pH, total dissolved solids, turbidity, Mn and NO₃ set by Saudi standards. Average levels of total dissolved solids, Fe, Mn, SO₄, NO₃, and NO₂ were 3065.00, 0.10, 0.89, 68.25, 17.91 and 0.016 mg/L, respectively. However, the average pH of water samples was 7.95 ± 0.66 which still within the accepted range set by national and global standards. Moreover, total dissolved solids also exceeded regular standards of Food and Agriculture Organization for irrigation water quality. Coliform bacteria were detected in 37.5% of dams without any significant spatial differences between dams and sites as groups. Correlations were found between pH & NO₃, SO₄ & NO₃, coliform bacteria & turbidity, coliform bacteria & NO₂ levels. Increased concentrations of assessed parameters in dams may be attributed to agricultural activities as well as animal and human wastes deposited into dams via rainfalls and flash floods. Proper treatment of dams needs to be taken into account before consumption and irrigation.     

Membrane filter technique for the quantification of stressed fecal coliforms in the aquatic environment.

A two-layer membrane filtration (MF) medium (injury-mitigating MF [IM-MF]) and a procedure for the enumeration of injured fecal coliforms are described. These procedures included the addition of glycerol and acetate plus reducing agents to both layers of a two-layer medium and rinsing of the filter with a rich resuscitation medium. Some changes in incubation time and temperatures were used. This method was compared with the multiple-tube fermentation most-probable-number procedure and the one-step M-FC agar-membrane filter method (direct M-FC) in terms of fecal coliform recovery from various aquatic environments that cause bacterial injury. With chlorinated sewage effluents, results of the IM-MF technique were equal to or greater than the most probable number in 9 of 18 trials and were 1.3 to 19 times greater than the M-FC method. When sewage samples were chlorinated in the laboratory, fecal coliform counts with IM-MF equaled or exceeded the most probable number in 7 of 15 trials and always exceeded the M-FC. M-FC was exceeded by IM-MF in 30 of 33 trials with clean mountain stream water. Fecal coliform bacteria that were exposed to low levels of an iodophore in the laboratory produced IM-MF counts 3 to 10 times greater than those with M-FC. A biochemical rationale for the formation of the IM-MF medium is discussed.     

Membrane Filter Technique for the Quantification of Stressed Fecal Coliforms in the Aquatic Environment

A two-layer membrane filtration (MF) medium (injury-mitigating MF [IM-MF]) and a procedure for the enumeration of injured fecal coliforms are described. These procedures included the addition of glycerol and acetate plus reducing agents to both layers of a two-layer medium and rinsing of the filter with a rich resuscitation medium. Some changes in incubation time and temperatures were used. This method was compared with the multiple-tube fermentation most-probable-number procedure and the one-step M-FC agar-membrane filter method (direct M-FC) in terms of fecal coliform recovery from various aquatic environments that cause bacterial injury. With chlorinated sewage effluents, results of the IM-MF technique were equal to or greater than the most probable number in 9 of 18 trials and were 1.3 to 19 times greater than the M-FC method. When sewage samples were chlorinated in the laboratory, fecal coliform counts with IM-MF equaled or exceeded the most probable number in 7 of 15 trials and always exceeded the M-FC. M-FC was exceeded by IM-MF in 30 of 33 trials with clean mountain stream water. Fecal coliform bacteria that were exposed to low levels of an iodophore in the laboratory produced IM-MF counts 3 to 10 times greater than those with M-FC. A biochemical rationale for the formation of the IM-MF medium is discussed.     

Full-scale studies of factors related to coliform regrowth in drinking water.

An 18-month survey of 31 water systems in North America was conducted to determine the factors that contribute to the occurrence of coliform bacteria in drinking water. The survey included analysis of assimilable organic carbon (AOC), coliforms, disinfectant residuals, and operational parameters. Coliform bacteria were detected in 27.8% of the 2-week sampling periods and were associated with the following factors: filtration, temperature, disinfectant type and disinfectant level, AOC level, corrosion control, and operational characteristics. Four systems in the study that used unfiltered surface water accounted for 26.6% of the total number of bacterial samples collected but 64.3% (1,013 of 1,576) of the positive coliform samples. The occurrence of coliform bacteria was significantly higher when water temperatures were > 15 degrees C. For filtered systems that used free chlorine, 0.97% of 33,196 samples contained coliform bacteria, while 0.51% of 35,159 samples from chloraminated systems contained coliform bacteria. The average density of coliform bacteria was 35 times higher in free-chlorinated systems than in chloraminated water (0.60 CFU/100 ml for free-chlorinated water compared with 0.017 CFU/100 ml for chloraminated water). Systems that maintained dead-end free chlorine levels of < 0.2 mg/liter or monochloramine levels of < 0.5 mg/liter had substantially more coliform occurrences than systems that maintained higher disinfectant residuals. Free-chlorinated systems with AOC levels greater than 100 micrograms/liter had 82% more coliform-positive samples and 19 times higher coliform levels than free-chlorinated systems with average AOC levels less than 99 micrograms/liter. Systems that maintained a phosphate-based corrosion inhibitor and limited the amount of unlined cast iron pipe had fewer coliform bacteria. Several operational characteristics of the treatment process or the distribution system were also associated with increased rates of coliform occurrence. The study concludes that the occurrence of coliform bacteria within a distribution system is dependent upon a complex interaction of chemical, physical, operational, and engineering parameters. No one factor could account for all of the coliform occurrences, and one must consider all of the parameters described above in devising a solution to the regrowth problem.     

用污染指示菌评价城市水体污染的研究

选择湖南省常德市江北城区水体为代表开展本项研究。结果表明,水体中污染指示菌,总大肠菌群（ＴＣ）和粪大肠菌群（ＦＣ）密度同ＢＯＤ＿５负荷以及综合污染指数Ｐ呈高度正相关。所以,污染指示菌指标,特别是粪大肠菌群指标足综合评价城市污水,尤其是生活污水污染的一个必不可少的重要参数。对该城区水体细菌污染的评价结果是,生活污水排放愈集中的地区,细菌污染愈严重。其中护城河水的ＴＣ密度超出我国地面水Ⅲ级标准４个数量级;ＦＣ密度超过ＷＨＯ娱乐用水标准３个数量级。护城河是细菌污染最严重水体。包括滨湖公园内湖在内的接纳生活污水多或较多的水体,细菌污好也相当严重。只是远离城区的柳叮湖受污染程度较轻。     

Gas Chromatographic Presumptive Test for Coliform Bacteria in Water

A gas chromatographic procedure which shows promise as a presumptive test for coliform bacteria in water is described. Total coliform bacteria concentrations were determined from the incubation times at 37 C required for ethanol to be produced. Fecal coliform densities were determined in a similar manner at 44.5 C. The culture medium was filter sterilized M-9 salts supplemented with 1% lactose, 0.1% Casamino Acids, and 0.1% yeast extract. Best results were obtained when the initial total coliform concentrations were 5 per ml or higher and when fecal coliform concentrations were 50 per ml or higher. Minimum detection times at these concentrations were 9 and 12 h, respectively.     

Prediction model of PSO-BP neural network on coliform amount in special food

Special food safety supervision by means of intelligent models and methods is of great significance for the health of local people and tourists. Models like BP neural network have the problems of low accuracy and poor robustness in food safety prediction. So, firstly, the principal component analysis was used to extract the key factors that influenced the amount of coliform communities, which was applied to reduce the dimension of this model as the input variable of BP neural network. Secondly, both the particle swarm optimization (PSO) and BP neural network were implemented to optimize initial weights and threshold to obtain the optimal parameter, and a model was constructed to predict the amount of coliform bacteria in Dai Special Snacks, Sa pie, based on PSO-BP neural network model. Finally, the predicted value of the model is verified. The results show that MSE is 0.0097, MAPE is 0.3198 and MAE is 0.0079, respectively. It was clear that PSO-BP model was better accuracy and robustness. That means, this model can effectively predict the amount of coliform. The research has important guiding significance for the quality and the production of Sa pie.     

Environmental evaluation near a fuel vendor within Parque Nacional Morrocoy, Venezuela. II: Water quality, sediments and biota

This paper is the second part of a base line study carried out in the coastal region near a marine service station located in Morrocoy National Park, Venezuela. Results from a physical and chemical characterization of the water and sediments of four sites located around the service station are presented. The physical and chemical factors measured in water included: temperature, salinity, specific conductance, dissolved oxygen, saturation percentage of dissolved oxygen, pH, total suspended solids, transparency, oil and grease, total residual petroleum hydrocarbon, vanadium and lead, total coliform bacteria, and the presence of coliform bacteria. The factors measured in sediments include: granulometry, organic material, total carbonates, vanadium, lead, oil and grease, and total hydrocarbons. In addition, the amount of vanadium and lead in sample tissue from three species which are abundant and widely distributed in each site was measured in order to evaluate the potential of these species as bio-indicators. The water in the area where this study was conducted is shallow, warm, and thermally homogeneous, with high salinity and normal pH and dissolved oxygen, and supersaturated with oxygen in certain hours in sites adjacent to abundant underwater vegetation. The water is moderately turbid with a tendency towards less dissolved oxygen with increased depth. The estimated values of NMP/100 ml of the coliform fecal organisms is within legal limits even though the total number of water coliforms measured in Site 2 was ten times higher than in Site 1. This increase is associated with the proximity of Site 2 to an outflow of pre-treated sewage. The values of TRPH in the water collected from each site were low and very close to the detection limit (0.8/ml). Vanadium was not found, while lead was detected in 11 of the 12 samples. Compared to the values measured for Site 1, which was the local reference, only one sample had a concentration of three times the maximum baseline. The amount of lead found in all analyzed samples was acceptable, according to the standards set by the State of Washington (maximum value: 292 mg/kg), while the concentration of lead in the sediments around the supply dock were 1.5 to 3.4 times greater than the Dutch norm. It can be concluded that there is no evidence of an accumulation of Va or Pb in the species selected as bioindicators. An observation program is proposed in which variables similar to those measured for this characterization will be studied with some modifications. A more intense sampling of some variables is recommended (lead in water and sediments, total coliform and fecal matter in consecutive samples and in days following a high concentration of visitors) as is the elimination or minimization of other variables.     

耕作与栽培方式对瓜类土壤细菌数量及枯萎病拮抗细菌分布的影响

以新疆、福建和浙江等地采集的132份土壤样品为对象,利用平板计数和Biolog等方法研究了不同耕作与栽培制度下瓜类土壤细菌数量及瓜类枯萎病拮抗细菌的分布与主要类群.结果表明,瓜类耕作土壤中的可培养细菌种群数量平均为非耕作土壤的16.2倍,根际为根围的2.0倍,轮作为连作的3.5倍,未嫁接平均为嫁接的1.5倍;水旱轮作和嫁接处理的瓜类土壤易获得拮抗细菌,其中荧光假单胞菌是主要类群,占总数的80%以上.     

Quantitative determination of total coliforms and Escherichia coli in marine waters with chromogenic and fluorogenic media

This study compared the performance of LMX(R) broth (LMX), Chromocult Coliform(R) agar (CC) and Chromocult Coliform agar plus cefsulodin (10 microg ml-1) (CC-CFS), with standard methods multiple tube fermentation (MTF), for the enumeration of total coliforms and Escherichia coli from marine recreational waters. LMX and CC are two media designed to concurrently detect total coliform (TC) bacteria and E. coli by the specific action of beta-galactosidase (total coliforms) and beta-glucuronidase (E. coli). Overall results for the TC test showed that LMX, CC and MTF recovered 2.63, 1.95 and 1.90 times as many TCs as CC-CFS, respectively. Data from the multiple range test showed significant differences (P < 0.05) between TC counts on CC-CFS and LMX. The traditional MTF was less sensitive for E. coli enumeration. However, there was no statistically significant differences between LMX, CC, CC-CFS and the MTF method for E. coli enumeration. Background interference was reduced on CC-CFS and the counts obtained reflected more accurately the number of TCs. Therefore, the contribution of beta-galactosidase positive, non coliform bacteria (Aeromonas spp. and Vibrio spp.) to TC counts should not be neglected.