有机碳源对循环水养殖系统生物滤池净化作用的研究进展

有机碳源作为循环水养殖系统生物膜上微生物的重要营养物质,其在水中的存在形式及含量大小不仅影响生物膜的结构,而且影响主要功能菌的代谢活动,进而影响生物滤池的净水效果。为了进一步了解有机碳源如何影响生物滤池的整个净化过程,探讨其作用机理,总结了近年来循环水养殖系统内不同存在形式的有机碳对生物膜构建、生物膜结构,以及生物膜净化效果(有机物去除、硝化作用、反硝化作用)的研究进展,并针对研究过程中存在的问题进行了分析,以期为相关研究或养殖企业解决生物滤器碳源问题提供参考。     

养殖尾水处理系统填料生物膜氮循环微生物功能特征

养殖尾水污染已成为制约水产养殖业发展的重要因素。填料生物膜养殖尾水处理系统是近年来开发的一种经济、高效去除养殖废水污染物的尾水处理设施。然而关于填料生物膜在氮素迁移转化中微生物生态效应及其功能知之甚少。为此,本研究利用宏基因组学方法剖析填料生物膜微生物群落氮循环过程及其潜在驱动机制。研究发现,填料生物膜微生物主要参与氮代谢活动。与水体相比,填料生物膜的碳代谢活动能力较强(P<0.05)；填料生物膜上硝化作用羟胺还原酶、反硝化作用氧化亚氮还原酶和一氧化氮还原酶及其编码功能基因nosZ和norB、异化硝酸盐还原作用亚硝酸盐还原酶及其功能基因napA、nrfA和nirB、以及固氮酶及功能基因nif HDK丰度相对较高(P<0.05),说明填料生物膜具有比周围水环境更强的氮周转能力。在属水平上,Pseudomonas菌、Spirochaeta菌、Opitutus菌和Syntrophus菌是填料生物膜氮素转化关键过程的重要功能微生物类群。上述研究结果表明,养殖尾水处理系统内复合填料生物膜主要通过关键功能物种介导的固氮和反硝化作用实现养殖尾水氮素的转化和迁移。本研究结果作为野外实验证据可为今后复合填料生物膜系统在水产养殖尾水治理实践提供理论依据。     

养殖污水中主要分解氨氮微生物的分离鉴定

为研究养殖循环水系统中分解氨氮能力较强的相关微生物,从生物滤料载体上收集正常运行条件下自然生长的生物膜。通过富集培养、分离提纯、DNA提取、PCR扩增、16SrRNA测序等步骤,得到一株具有分解氨氮能力的荧光假单胞菌Pseudomonas fluorescens SS101,菌落为淡黄色。结果显示,广泛存在能够分解养殖污水中氨氮并用于自身生长的微生物,除了常见的硝化细菌,一些特异性微生物也具有此功能。这项研究为进一步探索养殖污水微生物群落、优化生物滤池的污水处理性能提供了新思路。     

循环水养鳗系统生物过滤器中微生物群落的代谢特性

为了研究鳗鱼循环水养殖系统不同水处理单元的微生物群落碳代谢特征,实验采用Biolog Eco技术,分析了流化床两个槽和滴流式生物过滤器上、中、下三层的生物膜微生物群落功能多样性。结果显示,流化床两个槽和滴流式生物过滤器中、下层微生物多样性指数（Shannon-Wiener指数、Simpson指数和Pielou指数）无显著差异（P>0.05）,但均显著高于滴流式生物过滤器上层（P<0.05）。平均色度变化（AWCD）与主成分分析（PCA）均证明滴流式生物过滤器上层与其它采样点微生物代谢差异较大。各采样点微生物未对ECO板某一大类碳源表现出偏好,但对衣康酸、D-半乳糖醛酸、L-精氨酸、L-天门冬酰胺、L-丝氨酸、D-甘露醇、D-木糖、N-乙酰-D-葡萄糖氨、吐温40、吐温80、苯乙胺等单一碳源利用较好;而对γ-羟丁酸和α-丁酮酸以及D,L-α-磷酸甘油和1-磷酸葡萄糖利用较差。某些碳源种类如D-葡糖胺酸、α-D-乳糖、2-羟基苯甲酸仅能被部分采样点的微生物利用。本实验利用Biolog EcoPlateTM技术研究中试规模循环水处理单元微生物群落代谢特征,研究结果为生物过滤器的调控提供了一种新的思路即可以通过碳源调节,来促进生物膜微生物群落结构的改变以此提高水处理效率。     

微生物生态制剂的概念及种类

1 微生物生态学及微生物生态制剂的定义 生态学(ecology)是生命科学的一个分支.从范畴来讲,生态学有以下6种不同划分的分类:(1)按生物类型划分:动物生态学、植物生态学、昆虫生态学、微生物生态学;     

分子世界里的海洋微生物生态学——未来的发展趋势

过去几十年中,遗传学和免疫学方法的进步改变了医学和生物制药学的研究.人类和几种模式生物的基因组已全部完成测序,这一遗传学信息财富的初步开发已经开始引起对这几种生物的研究及由此产生的应用的革命.得益于生物医学领域的技术进步带来的巨大便利,对微生物(包括海洋微生物)生态学的理解也紧随其后.通过这些新方法、新技术的应用,海洋微生物生态学已经从20世纪50、60年代海洋生物学和生物海洋学的小脚注变成了我们对海洋的兴趣焦点.在过去的半个世纪中,我们学到了大量关于海洋中微生物的丰度、分布和活性的知识.由于认识到海洋微生物异常丰富的多样性、它们在全球生物地球化学过程中所起的主导作用以及天然和工程微生物产品给人类带来益处的潜力,它们已成为科研和公众关注的中心,而且人们对这些海洋中微小生物的迷恋也不会迅速消退.最新的研究表明,我们对海洋生态系中微生物多样性广度的了解相当有限,而且,自然界中许多、或者说大多数海洋微生物的优势种还没有被引入实验室培养.因此,我们对这些物种的生化、生理和行为能力的认识还是懵懂的,并且,在可预见的未来,海洋微生物研究还将是海洋科学研究的主要焦点.随着很多领域的研究者转向这项工作,我们可以期待海洋微生物群落组成和功能方面将会有更多的新发现和范例出现.     

生物膜在我国淡水水产养殖生产中的研究进展

综述了生物膜的材料结构、生物膜的形成过程、如何高效率地附着微生物、生物膜对水环境调控的效果、生物膜在水产养殖上的一些应用等,并对生物膜的应用前景进行了展望,重点探讨了生物膜如何高效率地附着微生物,生物膜在水环境治理上的调控效果及其在淡水水产养殖生产上的一些应用。     

微生态学（Microecology）基本定义

本刊讯：微生态学（Microecology）是一门新兴的边缘边科，1985年Volker Rusch对微生态学提出了一个基本定义：“微生态学是细胞水平或分子水平的生态学，它是研究人类、动物、植物正常微生物群与其宿主相互关系的生命科学”。因此，一些专家认为，微生态学是研究微生物菌群的结构和功能，以及微生物与其宿主相互依赖、相互制约关系的科学。最近几年来，根据微生态学合理研制的一些微生态制剂（Microecologics）具有投入小、收益大、无残留、无抗药性、不污染环境等优点，     

相生相克理论在控制水体富营养化中的应用

综述了生态学原理中的相生相克理论在治理水体富营养化中的原理和应用方法,分析了微生物、植物、动物等水生生物在水体环境修复中所起的重要作用,对利用生态学理论修复水域环境提出建议,以期为富营养化水体控制提供有益参考.     

利用人工基质构建微生物膜对养殖水体原位修复效果的评价

<正>有关研究报道通过微生态技术、种植水生植物等对青虾养殖池塘水质具有一定改善的效果。然而采用外源性生物或微生物的技术手段对水体的净化效果往往不太稳定,但运用将人工基质引入池塘固化微生物的办法可在一定程度上有效解决上述问题。本研究在青虾养殖池塘内设置人工基质,固化水中微生物形成生物膜,通过对基质上及水体中微生物数量和水质指     

Bacterial diversity studied by next‐generation sequencing in a mature phototrophic Navicula sp‐based biofilm promoted into a shrimp culture system

The bacterial diversity of a phototrophic biofilm used as nutrient‐recycler into a shrimp aquaculture system and as direct food‐source for shrimp was studied by next‐generation sequencing, considering the 16S rDNA and metagenomics sequence classification using exact alignments. Biofilm was promoted by the modification of cabon:nitrogen ratio and by the addition of the diatom Navicula sp. as promoter. Results revealed a wide diversity of bacteria thriving into the biofilm; most of the bacteria detected in the biofilm belonged to the Proteobacteria (47%), Chlamydiae/Verrucomicrobia (11%), Bacteriodetes (8%), Planctomycetes (5%) Phylum. Species involved in the decomposition of organic matter, nitrogenous‐ and sulfurous metabolites were detected; moreover, filamentous species known as biomass‐bulking enhancers and producers of adhesin‐like compounds were also detected. Surprising results were also obtained by detecting both, strictly anaerobic and aerobic bacteria involved into the metabolism of nitrogenous compounds. Other species not belonging to the marine environment were also detected, but their role is unclear. Finally, the detection of most of these species may constitute a first case report for a phototrophic biofilm. The results suggest an important role of bacteria in this type of biofilm and a complex microbial‐interaction network.     

Effects of biological water purification grid on microbial community of culture environment and intestine of the shrimp Litopenaeus vannamei

Biological water purification grid (BWPG), a type of biofilm, could increase aquaculture production by improving the growth of shrimp and culture environment. In this study, the microbial community composition and diversity of water, sediment and shrimp intestine were analysed using the Illumina Miseq high‐throughput sequencing technique. Installation of BWPG did not only increase the dissolved oxygen, pH and decreased inorganic nutrients, but also increased shrimp body length by 5.39% and weight by 16.35%. Furthermore, it was found that the microbial community diversity of water and shrimp intestine in test pond with BWPG was higher than that of control pond without BWPG. Cyanobacteria, Bacillus and Lactococcus were enriched in the test pond with BWPG. However, Rhodobacter was mainly identified in the test pond. It thus seems to suggest that the application of BWPG in shrimp culture pond enhanced the microbial species richness, types of species and proportion of beneficial bacteria in culture environment as well as shrimp intestine. The results from this study will therefore provide some scientific basis for the improvement and development of shrimp aquaculture.     

Biofilm development within a larval rearing tank of the tropical rock lobster, Panulirus ornatus

The role of bacterial biofilms in disease processes is becoming increasingly recognised in both clinical and environmental settings. Biofilm development within a rearing tank of the tropical rock lobster Panulirus ornatus was studied to evaluate if the biofilm is a reservoir for potentially pathogenic bacteria that cause mass larval mortalities. Within a 5000 L larval rearing tank, fiberglass microscope slides were systematically distributed during a standard rearing attempt to assess biofilm development. Culture-based counts for two media types, TCBS and Marine Agar (MA), demonstrated increased bacterial densities until days 11 and 13 respectively. For both media types, a drop in the plate counts was followed by a subsequent increase towards the end of the experiment. Scanning electron microscopy (SEM) confirmed that cell densities decreased between days 13 and 17, most likely due to sloughing of the biofilm into the water column. SEM images revealed distinct changes in dominant morphologies reflecting a succession of bacterial populations. A dynamic succession of microbial species during biofilm development was also demonstrated using denaturing gradient gel electrophoresis (DGGE) profiling of bacterial 16S rRNA genes in combination with statistical ordination analysis. Prominent changes in the DGGE profiles coincided with the decrease in bacterial numbers observed by SEM and plating on MA between days 13 and 17. Fluorescence in situ hybridization (FISH) identified -Proteobacteria as being numerically abundant in the biofilm. This was supported by results from DGGE analysis, which retrieved only sequences affiliated with - and γ-Proteobacteria. DGGE bands affiliated with Vibrio became dominant towards the end of the larval run (days 21 to 24). A Vibrio harveyi strain isolated from the biofilm late in the larval rearing trial (day 24) demonstrated increased larval mortality in small scale phyllosoma survival studies. The detection of Vibrionaceae at the end of the larval trial coincided with mass phyllosoma mortality and show that the biofilm is a reservoir for potentially pathogenic bacteria.     

Comparative study of the culturable microbiota present in two different rearing systems,flow‐through system (FTS) and recirculation system (RAS), in a great scallop hatchery

A comparison of the culturable microbiota present in the different compartments of a great scallop (Pecten maximus) hatchery with two experimental production systems, FTS and RAS, throughout a cycle of larval rearing was carried out. All isolates obtained from broodstock gonads, larvae, tank water, biofilm, microalgae, UV‐treated water and biofilter in both systems at three sampling times were characterized by biochemical tests and identified by sequencing of the 16S rRNA gene. Some of the genera were found to be exclusive of broodstock gonads, such as Sinobacterium, Kordia or Microbulbifer, and differences between gonad microbiota before and after spawning were detected. The number of morphotypes obtained in water, larvae and biofilm was similar in both systems, as well as the behaviour of the microbial populations in almost all hatchery compartments, in which Vibrio, Neptuniibacter, Pseudoalteromonas and Shewanella were the most common genera. The diversity obtained was analysed using the principal component analysis (PCA) and Fisher's exact test, showing that the microbial communities present in the common compartments between FTS and RAS did not significantly differ. These results suggest that, at least from a microbiological point of view, the recirculation system could be a good alternative for the production of scallop larvae.     

Antibiotics modulate biofilm formation in fish pathogenic isolates of atypical Aeromonas salmonicida

Atypical Aeromonas salmonicida causes furunculosis infections of non-salmonid fish, which requires antibiotic therapy. However, antibiotics may induce biofilm in some bacteria, which protects them against hostile conditions while allowing them to persist on surfaces, thus forming a reservoir for infection. The aim of this study was to determine whether atypical isolates of A. salmonicida increased biofilm in the presence of two antibiotics, florfenicol and oxytetracycline. A microtitre plate assay was used to quantify biofilm in the presence and absence of each antibiotic. Fifteen of 28 isolates formed biofilms under control conditions, while 23 of 28 isolates increased biofilm formation in the presence of at least one concentration of at least one antibiotic. For oxytetracycline, the most effective concentration causing biofilm to increase was one-quarter of that preventing visible bacterial growth, whereas for florfenicol it was one-half of this value. This is the first study to demonstrate that a bacterial pathogen of fish increases biofilm in response to antibiotics. Biofilm formation may increase the risk of re-infection in culture systems and this lifestyle favours the transmission of genetic material, which has implications for the dissemination of antibiotic-resistance genes and demonstrates the need for enhanced disease prevention measures against atypical A. salmonicida.     

一种自行研制的养殖水原位净化装置的应用效果试验

基于硝化细菌、聚磷菌等微生物种群分布于自然水体中,且喜欢吸附在固体表面形成生物膜,吸收水中氨氮、亚硝酸盐氮、磷等营养成分进行繁殖和生长的生物学原理,研制了一个由支架浮力系统、微生物附着基、上升流系统、锁磷区和光伏发电系统5部分组成的圆柱形(半径75 cm、高100 cm)养殖水原位净化装置。试验结果显示:生物膜建成后,装置在1 mg/L、3 mg/L和5 mg/L氨氮质量浓度组的淡水(水温22~25℃)和海水(水温27~31℃)中,日消减氨氮量分别为304.587 g、283.748 g、314.753 g和247.274 g、261.756 g、282.721 g,日消减淡水和海水中总磷量分别为0.485 g、0.427 g、0.462 g和0.566 g、0.595 g、0.493 g,显示出较强的氨氮和总磷的消减能力。日氨氮消减量差异性,淡水3个质量浓度组间不显著(P>0.05),海水3个质量浓度组间显著(P<0.05)。日总磷消减量差异性,淡水3个质量浓度组间、海水3个质量浓度组间均不显著(P>0.05)。该装置具有较强的氨氮和磷的消减能力和使用方法简单、运行成本低等特点,可在水产养殖尾水净化处理中推广使用。     

细薄星芒海绵体内微生物分布特点的透射电子显微镜观察与分析

采用透射电子显微镜对我国南海细薄星芒海绵体内微生物的分布进行了观察研究，同时结合海绵的结构特点与摄取营养的方式对分布特点进行了分析讨论。研究证明：在细薄星芒海绵体内除骨骼外的细胞间中质层、细胞内、海绵内腔等部位均分布着形态多样的微生物，其中海绵中质层是共(寄)生微生物最为丰富的地方。海绵微生物的分布特点与海绵腔状多孔的结构以及依靠过滤海水获取营养的方式有关，这对于将来揭示微生物在海绵体内的聚集机制及其与环境的关系具有重要价值。     

细菌群体感应淬灭的几种调控机制及其潜在应用

群体感应（quorum sensing,QS）作为一种调控机制,细菌通过感知细胞外环境中的信号分子浓度变化调控调节着生物发光、质粒转移、抗生素合成、生物膜形成及毒力因子表达等多种重要的生物学功能,协调细菌群体行为以适应环境变化。文章简要综述细菌细胞之间的群体感应功能及其几种主要淬灭调控机制,为促进基于Qs为靶标的生态防控病害新技术构建提供参考,为Qs相关研究及具有潜在应用价值的Qs抑制剂开发提供思路。     

东湖生物膜的建群过程及其生理特性研究

为探讨天然水体中生物膜的建群过程及生理特性,本研究将人工基质大理石投放到东湖沿岸带浅水区域,分析了生物膜在人工基质上从开始建群直至发育为成熟群落,并最终衰退的整个过程。结果表明,建群过程中,生物膜的生物量(叶绿素a、蛋白质、干重、无灰干重)、营养物质含量(总氮、总磷)均呈现先上升后下降的趋势,各指标之间具有显著相关性。低温会减缓生物膜的生长,弱光会加剧生物膜的衰退,生物膜的生长发育会影响周围水体氮、磷元素浓度。生物膜中碱性磷酸酶活性与自身生物量呈显著正相关性。水体中氮/磷的比值决定生物膜中氮/磷的比值。刚毛藻属是东湖生物膜的优势物种。对生物膜建群过程及生理特性的研究,有助于更好地将生物膜应用于污染水体的净化和修复。