过硫酸氢钾复合物粉对4种常见水产病原微生物的杀灭效果

为验证过硫酸氢钾复合物粉在水产养殖中消毒的有效性,评价了其对草鱼(Ctenopharyngodon idella)呼肠孤病毒(Grass carp reovirus, GCRV)、斑点叉尾(鱼回)(Ictalurus punctatus)病毒(Channel catfish virus, CCV)、嗜水气单胞菌(Aeromonas hydrophila)和无乳链球菌(Streptococcus agalactiae) 4种水产常见致病病原的杀灭效果,和有机物、温度、pH3种因素对杀菌效果的影响,并在此基础上开展了过硫酸氢钾复合物粉对池塘养殖水体中目标菌的杀灭试验,和对患嗜水气单胞菌的病鲫(Carassius auratus)的药效试验。结果显示,过硫酸氢钾复合物粉对4种致病微生物均具有显著的杀灭效果。降低菌悬液中有机物浓度、适当提高作用温度或适当降低消毒液pH,均能促进过硫酸氢钾复合物粉消毒液的杀菌效果。通过目标菌的杀灭试验和药效试验,进一步确定了该消毒剂在实际使用中对目标菌杀灭的有效性和对鲫感染嗜水气单胞菌后的显著治疗效果。研究表明,过硫酸氢钾复合物粉是潜在的水产用消毒剂。     

黄连素对3种水产动物致病菌的抑制作用研究

文章研究了黄连素对副溶血弧菌（Vibrio parahaemolyticus）、溶藻弧菌（V.alginolyticus）和嗜水气单胞菌（Aeromonas hydrophila）等3种致病菌的最小抑菌浓度（MIC）和最小杀菌浓度（MBC）,检测了黄连素对病原菌菌体形态和生长曲线的影响,并以此解析黄连素对这3种致病菌的抑制特点和抑菌机制.结果显示,黄连素对副溶血弧菌、溶藻弧菌、嗜水气单胞菌的MIC和MBC分别为0.391 mg·mL^-1和0.391 mg·mL^-1、0.391 mg·mL^-1和0.781 mg·mL^-1、0.781 mg·mL^-1和1.563 mg·mL^-1,说明黄连素对3种致病菌均有明显的抑制作用,其中对副溶血弧菌的抑制效果最佳.同步结果显示,1.00 mg·mL^-1黄连素不仅会严重破坏致病菌的菌体形态,而且使致病菌的迟缓期延长2～7h,这暗示黄连素可能通过影响致病菌的细胞结构和生长繁殖来达到抑菌的效果.由此可见,黄连素在防治水产类细菌性疾病上有很好的应用潜力.     

中草药对中华鳖主要致病菌的抑菌作用

随着养鳖业集约化程度的提高,多种传染性鳖病日益严重,带来很大损失。目前主要的防治药物是各种抗生素,结果导致耐药性的出现,防治效果不稳定,进而造成滥用药的现象。为此,我们根据《新编中药大辞典》选择了５３种对革兰氏阴性菌有较好抑菌作用的中草药对中华鳖主要...     

复合过硫酸氢钾系列产品在水处理和水产养殖中的应用

1过硫酸氢钾复合盐及其应用简介1.1过硫酸氢钾复合盐的物理化学特性1.1.1产品分子式、分子量、结构式由两分子的过硫酸氢钾（KHSO5）,一分子的硫酸氢钾（KHSO4）和一分子硫酸钾（K2SO4）组成的独特的三倍体盐,是一种高效、安全、绿色的酸式过氧化物氧化剂。简称：PMPS或KMPS。     

植物源杀菌剂对水产养殖常见病原菌的抑菌作用研究

植物源杀菌剂因其成分复杂、无污染、属性天然等特点,为水产养殖防治病原菌提供了新思路。本文以虎杖、千里光、黄柏、黄岑、苦参等为原材料,研制开发植物源杀菌剂,研究结果表明其对12种水产养殖常见病原菌均有较好的抑菌效果,对大肠杆菌、荧光假单胞菌的的最低抑菌浓度（MIC）为33μL／L,对金黄色葡萄球菌、痢疾志贺氏菌、温和气单胞菌的MIC为25μL／L,对肠炎沙门氏菌、单增李斯特氏菌的MIC为50μL／L,对拟态弧菌的MIC为100μL／L,对溶藻弧菌的MIC为250μL／L,对弗尼斯弧菌、副溶血弧菌的MIC为500μL／L,对创伤弧菌的MIC为1000μL／L。     

烟酸诺氟沙星对3株水产致病菌的抗生素后效应

采用微量接种菌落计数法，测定了烟酸诺氟沙(norfloxacin nicotinate，NN)对副溶血弧菌、嗜水气单胞菌及溶藻弧菌等3种水产致病菌的抗生素后效应(post—antibiotic effects，PAE)。结果表明，诺氟沙星对3种水产致病菌具有明显的抗生素后效应。不同MIC倍数浓度的NN对细菌的PAE各不相同，4MIC的PAE最高，对3q7T-4、SS—18和3q8T-2三种致病菌的PAE分别为3．1h,2．5h和3．7h，而低浓度的药物则PAE较低，0．5MIC的PAE分别为0．4h,0．6h和0．7h。     

水产致病菌对氟甲砜霉素敏感性及耐药性研究

研究了氟甲砜霉素对7种水产致病菌的最小抑菌浓度(MIC)和最小杀菌浓度(MBC),进行了氟甲砜霉素及其它24种抗菌药物对7种水产致病菌的药敏试验,并测定了7种水产致病菌对氟甲砜霉素的耐药性.结果表明,氟甲砜霉素对水产致病菌有较好的抑菌效果,测试的7种菌中有5种菌对氟甲砜霉素高度敏感,1种菌中度敏感,1种菌产生耐药性,而且测试菌对氟甲砜霉素的耐药性获得速率也较慢.     

6种中草药对4种淡水鱼致病菌体外抑菌作用的研究

研究了6种中草药对4种淡水鱼致病菌温和气单胞菌（Aerom onas sobria）、嗜水气单胞菌（A.hydrophila）、生物Ⅰ-荧光假单胞菌（Pseudom onas fluorescentb iotypeⅠ）和柱状黄杆菌（Flavobacterium columnaris）的体外抑菌作用。以黄连（Coptis chinensis）、大黄（Rhem officinale）、连翘（Forsythia suspensa）、鱼腥草（Houttuynia corda-ta）、厚朴（Magnolia officinalis）和大青叶（Folium isatidis）6种中草药的水提物为研究对象,采用滤纸片法检测其对4种致病菌的抑制活性,并分别测定了这6种植物提取物对供试菌的最小抑菌浓度（M IC）。结果表明,黄连水提物对4种淡水鱼致病菌的抑菌效果最好,大黄和连翘水提物次之,而鱼腥草、厚朴和大青叶水提物的抑菌效果不明显。     

中草药对海水动物致病菌体外抑制作用的初步研究

以扩散法和稀释法研究了31种中草药对6株海水养殖致病菌的体外抑制作用。结果表明,稀释法比扩散法更适用于中草药体外抑菌研究,扩散法由于受培养基等影响,误差较大,故实验以稀释法结果为主进行分析。同种中草药对不同致病菌抑制作用差异大,其中番石榴（Psidium guajava）、苍术（Atractylodes lancea）、黄芩（Scutellaria）和丁香（Eugenia caryophyllata）对美人鱼发光杆菌杀鱼亚种（Photobacterium damselae subsp．piscicida）,肉桂（Cinnamomum cassia）和火炭母（Polygonum chinense）对副溶血弧菌（Vibrio parahemolyticus）均有强杀灭作用;其次板蓝根（Lsatis tinctoria）、女贞子（Ligustrum lucidum）和白术（Atractylodes macrocephala）的抑菌效果较好,其余中草药抑菌效果差（仅在高浓度下才轻微抑菌）甚至完全无效;同菌株对不同种类中草药的敏感性差异也很明显,且抑菌药物种类少,可见药物筛选试验对针对性用药具有重要意义。稀释法结果显示,相同浓度下同种中草药的药粉比水提取物抑菌效果更好。     

水产养殖动物致病菌耐药性普查的意义(三)

其四,由于缺乏致病菌对抗生素敏感性变化的普查与系统研究,致使我国新渔药的开发缺少了方向,长期以来没有水产专用药或者特效药应市、在水产养殖中科学用药成了空话、盲目用药的现象在水产养殖业中成了不得已的必然。正是有这些问题的存在,我     

两株光合细菌的分离鉴定及其水质净化效果研究

为了筛选能够高效净化水质的光合细菌菌株,采用半固体试管法和双层平板法,从市售光合菌菌液中分离得到2株光合细菌,分别命名为GHJ-1、GHJ-2,对菌株进行了形态学观察、生理生化及16S rDNA鉴定,比较了这2株光合细菌对青鱼(Mylopharyngodon piceus)养殖污水的净化效果。结果表明:经鉴定这两株光合细菌为Rhodovulum sp菌株。菌株GHJ-1、GHJ-2对污水进行15 d的净化处理后,硝酸盐去除率分别为91.4%和96.3%;亚硝酸盐的去除率分别为68.9%和82.7%;氨氮去除率分别为56.8%和67.5%;COD Mn的去除率分别为61.7%和42.4%。     

海洋光合细菌筛选及其对养殖水体修复效果的测定

集约化投饵型养殖会导致养殖区域底部环境持续恶化,限制了水产养殖的可持续发展。对采自威海金海滩排污口附近污泥中的海洋光合细菌进行了富集、分离和初步鉴定,模拟自然养殖环境,选取优势菌株进行池塘底泥处理试验(上层水体,下层底泥),分析比较两株菌对底泥的改良效果;试验共获得两株优势光合细菌PSB1和PSB2,分属于红假单胞菌属(Rhodopseudomonas)和小红卵菌属(Rhodovulum)。底泥处理试验结果显示:PSB1和PSB2都可以稳定水体pH,降解水中的硫化物、氨氮和化学耗氧量(COD Mn)。PSB1处理底泥最佳效果为:添加1‰的PSB1,水体中pH在6.98~7.33,底泥中COD Mn 、硫化物、氨氮和NO - 2-N降解率分别为92.91%、79.61%、97.00%和73.56%。研究表明,光合细菌可以促进改善水质、维持下层水体的良好水质,在水产养殖中具有良好的应用前景。     

生物强化移动床生物膜反应器处理水产养殖循环水初步研究

利用自制的硝化细菌菌剂促进移动床生物膜反应器(Moving bed biofilm reactor,MBBR)的挂膜启动,分析不同载体氨氮负荷、碳氮比条件下反应器运行状况,并进一步进行了实验室模拟循环水养殖草金鱼实验。结果显示,利用自制硝化菌剂能够完成整个移动床反应器的启动过程,在接种15 d后使循环出水氨氮稳定在1 mg/L以下。单位体积载体氨氮负荷实验表明,MBBR能够在100 mg TAN/(L填料·d)条件下,使出水满足一般水产养殖水质要求(氨氮0.5 mg/L,亚硝氮0.1 mg/L)。进水碳氮比在1以内时MBBR能够稳定高效运行。在实验室模拟循环水养殖过程中,经菌剂强化的MBBR能维持循环出水氨氮低于0.5 mg/L,亚硝氮低于0.05 mg/L。     

In vitro and in vivo antibacterial activity of shrimp chitosan against some intestinal bacteria

ABSTRACT:   The effects of shrimp chitosan with deacetylation degrees (DD) of 50%, 70% and 95% (DD50, DD70, DD95) on the growth of the intestinal bacteria were investigated in vitro in the laboratory media, and in vivo by an oral feeding test using hamsters as the animal model. The antibacterial activities of these chitosan products against one strain of pathogenic Clostridium perfringens and 13 strains of probiotics, including seven strains of Lactobacillus , and six strains of Bifidobacterium were evaluated. In vitro , the antibacterial activities of DD95 and DD70 were much higher than that of DD50. The strains of probiotics were more resistant to chitosan than the pathogen of C .  perfringens . The minimal lethal concentration for DD95 against C. perfringens was 250 p.p.m., whereas the survival percentages for most probiotics tested were above 90% for DD95 at 500 p.p.m. The animals were fed on either a control diet, or diets containing powdered chitosan instead of 5% cellulose in the control diet for 4 weeks. The cecal bacterial counts of total aerobes, total anaerobes, lactobacilli, bifidobacteria and clostridia were similar for the control and experimental groups. The reasons for the differences in the antibacterial activity in vitro and in vivo are discussed.     

柠檬酸、Nisin-柠檬酸联合对三种常见水产病原菌的作用

选用嗜水气单胞菌、副溶血弧菌、荧光假单胞菌三种常见水产病原菌,用于测定柠檬酸的抑菌效果及最小抑菌浓度,并研究了柠檬酸抑菌作用的稳定性。三种菌均为革兰氏阴性菌。试验结果表明,柠檬酸对三种菌都有不同程度的抑菌作用,并得到最小抑菌浓度,依次是:0.0011g/mL,0.0008g/mL,0.00125g/mL;在最小浓度下抑菌作用可达6d之久,柠檬酸抑菌效果有一定的稳定性。将Nisin溶于0.00125g/mL,得到复合液的抑菌效果强于柠檬酸单独作用,且稳定性增强。     

柠檬酸、Nisin-檬酸联合对三种常见水产病原菌的作用

选用嗜水气单胞菌、副溶血弧菌、荧光假单胞菌三种常见水产病原菌，用于测定柠檬酸的抑菌效果及最小抑菌浓度，并研究了柠檬酸抑菌作用的稳定性。三种菌均为革兰氏阴性菌。试验结果表明，柠檬酸对三种菌都有不同程度的抑菌作用，并得到最小抑菌浓度，依次是：0．0011g／mL，0．0008g／mL，0．00125g／mL；在最小浓度下抑菌作用可达6d之久，柠檬酸抑菌效果有一定的稳定性。将Nisin溶于0．00125g／mL，得到复合液的抑菌效果强于柠檬裴单独作用，且稳定性增强。     

Abundance of sulphur‐oxidizing bacteria in coastal aquaculture using soxB gene analyses

Molecular techniques based on sequencing of metagenomic clone libraries provide an insight into the diversity of microbial populations. Using nucleic acid‐based methods, the diversity of soxB genes was examined to detect and characterize sulphur‐oxidizing bacteria in Indian coastal aquaculture environments. Gene‐specific degenerate primers were used to amplify various fragments (710, 753, 483–503, 280 and 239 bp) of soxB genes. Metagenomic clone libraries were constructed for 753, 483–503 and 239 bp fragments of soxB genes. The abundance of soxB revealed the presence of sulphur‐oxidizing organisms. Amino acids in parts of the soxB‐encoded proteins were aligned to known conserved amino acid residues. The level of conservation ranged from 23% to 30%. A phylogenetic tree constructed from aligned amino acid sequences of SoxB revealed different clusters associated with the branches of phototrophic α‐ and γ‐proteobacteria. In general, soxB is widespread among the various phylogenetic groups, although this does not necessarily mean that the organism can use sulphur compounds. Our results suggest that the chemolithoautotrophy based on sulphur oxidation in coastal aquaculture is primarily sustained by the presence of sulphur oxidizers, which involve the soxB gene. This study aids identification of the phylogenetic characteristics related to sulphur bioremediation in poorly characterized coastal aquaculture environments.     

维生素C碳点对水产养殖主要病原菌的抗菌性能及其生物相容性

为了验证维生素C碳点对水生动物病原菌的抑制效率,实验采用3倍梯度稀释法检测了维生素C碳点对嗜水气单胞菌、副溶血性弧菌、灿烂弧菌、诺卡氏菌等12种常见水产病原菌的最小抑菌浓度(MIC)和最小杀菌浓度(MBC),在此基础上,测定了其对这12种水产病原菌的抑菌动力学曲线。此外,基于纳米材料可能存在的生物相容性等问题,实验采用MTT法检测了维生素C碳点对草鱼肾细胞的细胞毒性,并以斑马鱼胚胎为测试对象,测定其经维生素C碳点暴露后的胚胎毒性。结果显示,维生素C碳点对所监测的12种水产病原菌均有显著的抑制作用,MIC为20.6～61.7μg/mL,基本达到与抗生素氟苯尼考同等的抗菌作用。维生素C碳点在MIC范围内胚胎和细胞存活率可接近100%,与对照组无差异。研究表明,维生素C碳点对水产主要病原菌有良好的杀菌和抗菌效果,具有较好的生物相容性,在水产养殖细菌性病害防治上具有潜在的开发应用前景。     

Variability of the nitrifying bacteria in the biofilm and water column of a recirculating aquaculture system for tilapia (Oreochromis niloticus) production

The aim of this study was to evaluate variability of nitrifying bacterial community in the biofilm and in the water of a recirculating aquaculture systems (RAS) in a tilapia farming in order to determine if nitrification process is dependent, or not, of nitrifying bacteria abundance. Biofilm and water samples were collected periodically for 30 days and analysed with the fluorescent in situ hybridization (FISH) technique, used to quantify ammonia‐oxidizing bacteria (AOB) and nitrite‐oxidizing bacteria (NOB). Ammonia presented the peak in the first week, while the nitrite's maximum was recorded in the second week. Nitrate increased steadily, indicating nitrification activity. Total bacterial abundance in biofilm increased continuously, while in water, it did not change significantly. In the biofilm, number of AOB was high at beginning, decreased after few days and increased again following augment of ammonia. Number of NOB also showed an increase in abundance in biofilm following the increment of nitrite and nitrate. In water, AOB and NOB did not show major variability. Relative abundance of nitrifying bacteria represented more than 30% of total bacteria in biofilm at beginning of the experiment. Their contribution decreased to >3% in last days. It indicates that nitrifying bacteria are biofilm colonizers, and that their activity seems to be directly related to the concentration of nitrogen compounds. However, contribution of nitrifying bacteria did not vary much along the time. We may conclude that the biofilm‐nitrifying bacteria plays major role in nitrification process in RAS and that the activity of these organisms is dependent of their abundance in response to the concentration of nitrogen compounds.     

In vitro antibacterial effect of berberine hydrochloride and enrofloxacin to fish pathogenic bacteria

Berberine the main antibacterial substance in the rhizome of Coptis chinensis Franch, is used as an antimicrobial agent for a long time. This study was carried out to investigate the potential of berberine alone or in combination with enrofloxacin against six common fish pathogens for use in fish disease management in aquaculture. The minimum inhibitory concentrations (MICs) of berberine hydrochloride against Aeromonas hydrophila, Pseudomonas fluorescens, Vibrio vulnificus, Edwardsiella ictaluri, Escherichia coli and Streptococcus agalactiae were determined and to be >500, >500, >500, 300, 400 and 100 μg mL^?1 respectively. The minimal bactericidal concentrations (MBCs) of berberine hydrochloride to E. coli, E. ictaluri and S. agalactiae were 300–500 μg mL^?1. In combination with enrofloxacin, the MICs and MBCs of berberine hydrochloride significantly decreased against E. coli and E. ictaluri but not against Streptococcus dysgalactiae. These results demonstrated that the berberine hydrochloride enhanced the bactericidal effect of enrofloxacin and vice versa. The synergistic bactericidal effect of berberine hydrochloride and enrofloxacin suggest its potential use in fish disease management in aquaculture. This is the first study on the inhibitory effect of berberine hydrochloride against fish pathogenic bacteria.