植物酶抑制技术用于检测蔬菜中有机磷及氨基甲酸酯类农药残留

应用植物酶抑制技术检测蔬菜中的有机磷及氨基甲酸酯类农药。用小柱对样品进行预处理，可去除叶绿素的干扰、提高检测灵敏度。提出了抑制率阈值（15％）。应用本方法对市售蔬菜的农药残留进行了调查，检出率约为10％。     

荧光假单胞菌(Pseudomonas fluorescens)工程菌株田间残留和扩散的追踪检测

分别在北京和江苏省连云港市对携带Btcry基因的荧光假单胞菌工程菌进行了田间残留与扩散的追踪检测 .对越冬前后的试验地和保护地土壤样品进行抗生素抗性平板分离 ,能检测到极少量的具有与出发菌株相同抗性的荧光假单胞菌菌落 ,但没有发现工程菌株的残留与扩散 .对江苏试验地样品还进行了工程菌株质粒卡那霉素和壮观霉素抗性标记基因的抗性菌落分离 ,绝大多数样品中都能分离到包括荧光假单胞菌在内的抗性菌落 ,土样中菌密度n(cfu) =10 4 ～ 10 5g-1,但进行Btcry基因PCR -RFLP检测时没有从样品中得到特异扩增产物 .研究结果表明 :工程菌株抗性标记基因在自然界广泛存在 ,工程菌在株环境中没有残留和扩散 ,具有良好的生物安全性 .表 4参 8     

粮食与饲料中七种单端孢霉烯族真菌毒素的测定

本文提出了一种同时检测粮食和饲料中七种主要单端孢霉烯族真菌毒素的电子捕获气相色谱分析方法.粮食样品经醋酸乙酯、氯仿、乙醇提取后,减压浓缩.浓缩液用活性炭-中性氧化铝(2:1,W/W)柱净化,84％乙腈水溶液洗脱.洗脱液减压浓缩至于,残渣用N-七氟正丁酰咪唑衍生化.电子捕获气相色谱的分析结果表明,活性炭-中性氧化铝柱能有效地除去粮食中的干扰物,有很好的分离效果.T-2毒素、HT-2毒素、二乙酰藨草镰刀菌烯醇、新茄病镰刀菌烯醇、脱氧雪腐镰刀菌烯醇、雪腐镰刀菌烯醇、镰刀菌烯酮-X等七种毒素在小麦、大麦、玉米及大米中的回收率在浓度范围为50ng/g—500ng/g的范围内均为80％以上.     

型煤燃烧固硫的钠离子效应

本文用脉冲二氧化硫荧光分析仪连续测试了煤样中二氧化硫的浓度，并用Ｘ荧光、Ｘ衍射和电子扫描电镜等方法，分析了添加钠离子样品的含硫率、物相及表面形貌。实验结果表明，钠离子添加剂改变了二氧化硫释放过程，抑制了硫酸钙的分解。灰样成分中既有稳定的三元化合物３ＣａＯ．３Ａｌ２Ｏ３．ＣａＳＯ４，也有不稳定的化合物硫酸钙存在，说明钠离子添加剂对提高固硫率有促进作用。     

光合细菌PCR检测技术的建立与应用

针对光合细菌传统的菌种鉴定方法和MPN定量方法存在费时、费力和准确性筹的问题,本研究建立了光合细菌特异PCR鉴定技术和实时荧光PCR定量的检测技术.以微生物肥料产品常用的光合细菌沼泽红假单胞菌和类球红细菌作为研究对象,分别依据16S rDNA序列和gyrB序列设计出具有种水平特异性的引物,优化并确定了PCR反应条件,其灵敏度达到100 pg/μL,对6个光合细菌产品鉴定的符合率为100%,结果表明建立的PCR鉴定技术具有特异性、灵敏性和实用性.再根据16S rDNA的保守序列设计了常用光合细菌通用引物,用其对系列稀释的已知菌含量样品的DNA模板进行荧光定量PCR,制作标准曲线.对10个光合细菌样品进行荧光定量PCR法测定,根据与标准曲线比较得出样品中的光合细菌含量,其结果与MPN法的相关系数为0.98,两者具有良好的相天性,结果表明建立的荧光定量PCR法可用于光合细菌的定量检测,并具有高特异性和快速等优点.     

根际微生物耦合降解系统的构建及其对蒽污染土壤的修复

摘要将增强型绿色荧光蛋白(EGFP)标记的黄麻土生根际优势菌Tu-1B分别与葸高效降解菌An-2和生物表面活性剂产生菌P7-50进行原生质体电融合，得到两株具有荧光标记的融合子Tu-An和Tu-P．将二融合子接种于植物根际土壤，构建根际微生物耦合降解系统，：在40d时该系统的最大降解率为96％．对根际土壤中的Tu-An融合子进行了检测，结果表明融合子在根际能稳定旺盛生长．图3表4参18     

检测致畸物的gfp基因工程菌的构建

RecA与UvrA是细胞SOS系统中重要的修复蛋白，在细胞DNA损伤后诱导表达．将报告基因绿色荧光蛋白基因（gfpmut3a）分别置于recA和uvrA启动子调控下，构建成质粒pRecAgfp和pUvrAgfp，并转化E．coli DH5α，构建成检测菌株ERS101和EUS101．试验发现，菌株ERS101和EUS101在致畸物吖啶橙处理后，GFP的表达量增高，菌悬液经507nm的蓝光激发后产生的绿色荧光明显增强，且与吖啶橙的浓度具有一定的相关性，即使在0．5μg mL^-1的吖啶橙诱导下也能检测到荧光增强效应．对硝基酚等多种致畸物处理后的检测菌株均有荧光增强效应．图4表1参9     

南海莺琼盆地沉积环境中厌氧纤维素分解菌的分布与作用

在严格厌氧条件下，研究了驾琼盆地东方１－１－１井垂直剖面不同沉积层地质样品中的厌氧纤维素分解菌．结果表明：厌氧纤维素分解菌在各样品中都存在，但其分布有很大随机性，与样品埋藏深度无相关性，与样品中一些有机物含量，如纤维素、半纤维素也无相关性，厌氧纤维素分解菌数量高的样品，其在生物模拟产甲烷实验中的单位有机质产气量也较高，有显著的相关性．菌体形态主要为杆菌和球菌．     

荧光光谱法快速检测土壤中荧光烃类污染物

探讨了正己烷、石油醚及二氯甲烷∶正己烷(1∶2,体积比)混和液三种溶剂浸泡或超声波萃取与荧光光谱相结合测定土壤中荧光烃类污染物的方法,并为了验证方法有效性,对典型煤矿区93个土壤样品中的荧光烃类进行了快速检测。结果表明,采用二氯甲烷∶正己烷(1∶2,体积比)混和液超声波萃取土壤中荧光烃类,耗时短,萃取能力较强。对于具有大量土壤样品的研究区域,超声波萃取与荧光光谱法相结合可大大缩短土壤样品中总荧光烃类污染物的检测时间,进而可快速获知某一研究区内土壤环境中荧光烃类污染物的空间分异规律及相对污染程度,具有一定的应用价值。     

固相萃取净化气相以谱法快速测定土壤中的氯氰菊酯残留

本文介绍了一种氯氰菊酯在土壤中残留量分析方法，选用交微量柱固相萃取和气相色谱电子捕获检测器定量分析，该方法简便，能够在较短时间内处理大量样品，最低检出度为００３７５ｍｇ．ｋｇ＾－１，上率在８２．９１％以上。     

Using a common commensal bacterium in endangered Takahe as a model to explore pathogen dynamics in isolated wildlife populations

Predicting and preventing outbreaks of infectious disease in endangered wildlife is problematic without an understanding of the biotic and abiotic factors that influence pathogen transmission and the genetic variation of microorganisms within and between these highly modified host communities. We used a common commensal bacterium, Campylobacter spp., in endangered Takahe (Porphyrio hochstetteri) populations to develop a model with which to study pathogen dynamics in isolated wildlife populations connected through ongoing translocations. Takahe are endemic to New Zealand, where their total population is approximately 230 individuals. Takahe were translocated from a single remnant wild population to multiple offshore and mainland reserves. Several fragmented subpopulations are maintained and connected through regular translocations. We tested 118 Takahe from 8 locations for fecal Campylobacter spp. via culture and DNA extraction and used PCR for species assignment. Factors relating to population connectivity and host life history were explored using multivariate analytical methods to determine associations between host variables and bacterial prevalence. The apparent prevalence of Campylobacter spp. in Takahe was 99%, one of the highest reported in avian populations. Variation in prevalence was evident among Campylobacter species identified. C. sp. nova 1 (90%) colonized the majority of Takahe tested. Prevalence of C. jejuni (38%) and C. coli (24%) was different between Takahe subpopulations, and this difference was associated with factors related to population management, captivity, rearing environment, and the presence of agricultural practices in the location in which birds were sampled. Modeling results of Campylobacter spp. in Takahe metapopulations suggest that anthropogenic management of endangered species within altered environments may have unforeseen effects on microbial exposure, carriage, and disease risk. Translocation of wildlife between locations could have unpredictable consequences including the spread of novel microbes between isolated populations.     

Conservation implications of physiological carry‐over effects in bats recovering from white‐nose syndrome

Although it is well documented that infectious diseases can pose threats to biodiversity, the potential long‐term consequences of pathogen exposure on individual fitness and its effects on population viability have rarely been studied. We tested the hypothesis that pathogen exposure causes physiological carry‐over effects with a pathogen that is uniquely suited to this question because the infection period is specific and time limited. The fungus Pseudogymnoascus destructans causes white‐nose syndrome (WNS) in hibernating bats, which either die due to the infection while hibernating or recover following emergence from hibernation. The fungus infects all exposed individuals in an overwintering site simultaneously, and bats that survive infection during hibernation clear the pathogen within a few weeks following emergence. We quantified chronic stress during the active season, when bats are not infected, by measuring cortisol in bat claws. Free‐ranging Myotis lucifugus who survived previous exposure to P. destructans had significantly higher levels of claw cortisol than naïve individuals. Thus, cryptic physiological carry‐over effects of pathogen exposure may persist in asymptomatic, recovered individuals. If these effects result in reduced survival or reproductive success, they could also affect population viability and even act as a third stream in the extinction vortex. For example, significant increases in chronic stress, such as those indicated here, are correlated with reduced reproductive success in a number of species. Future research should directly explore the link between pathogen exposure and the viability of apparently recovered populations to improve understanding of the true impacts of infectious diseases on threatened populations.     

发酵稻草抑藻机理研究

稻草在通气条件下经1个月发酵后,发酵稻草及其发酵液对鱼腥藻和念珠藻的生长具有显著的抑制效果,而对小球藻的抑制效果不明显,这说明发酵稻草的抑藻作用是有特异性的;经过灭菌的发酵稻草、没有经过发酵的稻草则没有抑藻作用,显示抑制藻类的物质是在稻草经过发酵后形成的,且该物质对热敏感。我们从发酵稻草中分离出21株微生物,发现其中一株(B3)具有和发酵稻草相同的抑藻效果,它能强烈地抑制鱼腥藻和念珠藻的生长,但它的发酵滤液没有抑制作用。本实验表明发酵稻草的抑藻作用是由于稻草在发酵过程中富集了某种微生物,这种微生物直接作用于藻类,使藻类的生长受到抑制,甚至死亡。     

叶面喷施铈硅复合溶胶抑制生菜砷积累效应研究

采用水热合成法,利用正硅酸乙酯和硝酸铈分别制备了二氧化硅和二氧化铈溶胶。通过土培盆栽试验,在广东省汕头市莲花山钨矿区砷污染土壤上种植意大利生菜,研究了叶面喷施不同浓度二氧化硅、二氧化铈以及不同掺杂比的铈硅复合溶胶对生菜地上部生物量、叶绿素含量、砷含量以及生菜地上部砷积累量的影响。结果表明：叶面喷施不同浓度铈、硅溶胶及不同掺杂比的铈硅复合溶胶均可以缓解生菜砷毒害,表现为生菜的地上部鲜重升高了9%～58.8%,砷含量降低了23%～48%。叶面喷施低浓度的二氧化铈掺杂5mmol·L-1二氧化硅复合溶胶可以增加生菜叶片叶绿素含量,进一步提高二氧化硅缓解生菜砷毒害效果。其中以叶面喷施5mmol·L-12%铈掺杂二氧化硅复合溶胶生菜地上部鲜重最高为对照的1.6倍;砷含量最低为对照的51.4%。叶面喷施铈、硅复合溶胶不仅可以降低生菜可食用部位砷浓度,而且可以减少生菜地上部吸收积累砷总量,从而降低了砷通过食物链对人体健康的危害。与传统土壤施用硅肥相比,叶面施用硅溶胶具有经济高效的优点,为土壤砷污染控制提供了一种新的选择。     

Trace Metal Voltammetric Determination of Otoliths of Tench Tinca Tinca (L.): Its Possible Uses in Monitoring the Quality of Fresh Waters

New data of heavy metals in otoliths of fresh water teleosts are reported. Differential pulse anodic stripping voltammetry (DPASV) has been used for determining copper, lead, cadmium and zinc in otoliths of tench, Tinca tinca (L.). the analytical procedure followed gives data of good repeatability and with low detection limits, in a simple and inexpensive way. Tench of age ranging from 3 to 8 years were examined. Four year old fish had maximum concentrations of heavy metals, and an otolith weight adequate for experimental determinations in bulked samples. Fresh water teleosts are less mobile than marine ones, and could be used for monitoring the quality of waters suspected for pollution, and eventually verifying the influence of the environmental variations on the metal bioaccumulation.     

The “agitator”: an inexpensive device for culturing large numbers of fragile marine invertebrate larvae

The “agitator”, a device designed for culturing lecithotrophic echinoderm larvae, is described. The unit consists of an open system which is easily constructed and is made up of a base which holds the culturing baskets as well as a lid or manifold carrying a tube which transports fresh seawater into each culture, gently stirring it and eliminating any decaying embryos. The device is scalable and water flow can be adjusted for laminar flow or slow dripping. The method has been used to successfully rear large numbers of lecithotrophic larvae of the starfish Solaster stimpsoni. The agitator could be used to culture any fragile planktonic organisms that require an extended rearing time.     

Prevalence of the Crayfish Plague Pathogen Aphanomyces astaci in Invasive American Crayfishes in the Czech Republic

Abstract:  In Central Europe invasive North American crayfishes are carriers of the oomycete Aphanomyces astaci, which causes crayfish plague. This lethal disease currently represents one of the major threats to native European crayfishes. We used molecular methods—species-specific amplification and sequencing of the pathogen DNA—to investigate the prevalence of individuals latently infected with A. astaci in 28 populations of two invasive American crayfish species (6 of the signal crayfish [ Pacifastacus leniusculus ] and 22 of the spiny-cheek crayfish [ Orconectes limosus ]) in the Czech Republic. The pathogen occurred in 17 investigated populations. We recorded a high variation in positive reactions, ranging from 0% to 100%, in populations of O. limosus . In P. leniusculus, however, only one individual out of 124 tested positive for the pathogen. There was a clear relationship between the water body type and pathogen prevalence in O. limosus . Infection ratios in isolated standing waters were usually low, whereas in running waters, pathogen prevalence often exceeded 50%. Other evaluated characteristics of potential plague pathogen carriers (size, sex, and the presence of melanized spots in the cuticle) seemed to be unrelated to infection. Our data suggest that in contrast to other European countries, O. limosus seems to be the primary reservoir of crayfish plague in the Czech Republic. Although all populations of alien American crayfishes may be potential sources of infections and should be managed as such, knowledge on the prevalence of the plague pathogen at various localities may allow managers to focus conservation efforts on the most directly endangered populations of native crayfishes.     

Electrophoretic studies on muscle myogens of some penaeid prawns

The muscle myogen patterns of some penaeid prawns studied by electrophoresis in cellulose acetate membrane are presented. Each pattern was species specific and appears to be independent of sex. The results suggest that muscle myogen patterns could be useful in taxonomic studies of penaeid prawns. Specimens preserved in phenoxyethanol were compared with fresh specimens. Preservation resulted in some losses of protein zones and, in cases where sufficient zones are preserved, the method could be used to advantage for solving taxonomic problems. Mr. Lim unfortunately passed away in November 1969.     

Detecting Cryptosporidium parvum and Giardia lamblia by coagulation concentration and real-time PCR quantification

Rapid and sensitive pathogen detection methods are essential for the effective functioning of the water treatment industry, yet for many pathogens, effective detection and removal methods are still lacking. Cryptosporidium parvum oocysts and Giardia lamblia cysts are two of the most common waterborne pathogens currently infecting the water supply. In this study, a new method was developed for the detection of Cryptosporidium parvum oocysts and Giardia lamblia cysts. The method includes multi-steps as coagulation concentration of (oo)cysts in water, the dissolution of the resulting flocs into a small volume using acid, filtration of the (oo)cysts solution, and DNA extraction, purification, and examination using real-time PCR. The method was tested using spiked tap water and reservoir water as references, and the mean recovery ranged from 19.6% to 97.6% for oocysts, and from 51.4% to 98.7% for cysts. The method is economical and convenient, and is especially suitable for relatively high turbidity surface water.     

Inventory of benthic macroinvertebrates and zooplankton in several European Bonamia ostreae-endemic areas and their possible role in the life cycle of this parasite

Bonamia ostreae is a protozoan parasite of the native oyster, Ostrea edulis. The parasite can be transmitted directly from infected to uninfected oysters. Though direct transmission of the parasite can occur between oysters it is unclear if this represents the complete life cycle of the parasite, and the involvement of a carrier/reservoir cannot be ruled out. A survey of benthic macroinvertebrate and zooplankton survey was carried out in the North Channel, Cork Harbour, Ireland, an area where B. ostreae is endemic and the parasite has been present since the 1980s. This was compared to several European surveys of benthic macroinvertebrate and zooplankton species found in other B. ostreae endemic areas. The objective was to identify any species that were common to these sites and could act as possible carrier/reservoir hosts for the pathogen. Species that were found to be common in two or more sites were included in two comparison tables. These species will be targeted in future studies investigating the possible role of macroinvertebrates and zooplankton in the complete life cycle of B. ostreae.