溶藻类细菌的研究现状

随着全球水体富营养化的加剧,有害藻类水华和赤潮的爆发日趋频繁,所造成的环境和经济问题日益引起人们的重视.溶藻细菌作为水生生态系统生物种群结构和功能的重要组成部分,对维持藻的生物量平衡具有非常重要的作用.目前在物理、化学和其它生物方法治理水华和赤潮都不够理想的情况下,利用溶藻细菌治理水华,可保持水环境生态平衡,从而达到防止水华的目的.而且随着溶藻细菌的生物学活性不断被发现,以茵治藻将作为水华和赤潮生物防治的一个新对策,具有广泛的研究前景.本文通过查阅近年来国内外有关水生生态系统中溶藻细菌研究的最新研究成果并对溶藻细菌防治有害藻类的种类、分离方法、作用方式及可能的作用机理、作用效应、研究前景和存在问题做一阐述,以期对于细菌溶藻方面的研究及开发应用具有一定的参考价值.     

溶藻细菌的生态学作用及其生物量检测方法

有害藻类水华已成为当今世界水体普遍存在的环境问题,溶藻细菌作为水华和赤潮防治的可能生物,引起了众多科研人员的关注。介绍了溶藻细菌的研究概况,重点对溶藻细菌的生态学作用及其生物量的检测方法进行了综述。     

溶藻细菌杀藻物质的研究进展*

溶藻细菌作为防治有害藻类水华的一种可能微生物,已引起了众多科研人员的关注。大多数溶藻细菌分泌的生物活性杀藻物质对宿主藻类具有强烈的杀灭作用。首先讨论了细菌活性杀藻物质的生态作用,重点阐述了目前已经报道的细菌杀藻物质的种类及其提取和分离方法,最后对细菌杀藻物质的进一步研究提出几点看法。     

短小芽孢杆菌溶藻效应研究

随着全球水体富营养化的加剧,有害藻类水华的暴发日趋频繁,其造成的环境和经济问题日益引起人们的重视,寻求有效的水华和赤潮防治途径势在必行。溶藻细菌作为水生生态系统中生物种群结构和功能的重要组成部分,对维持浮游植物生物量平衡具有非常重要的作用。不少研究认为水华和赤潮的突然消亡可能与溶藻细菌的感染有关。有些溶藻细菌能够分泌细胞外物质,对宿     

溶藻微生物的研究进展

溶藻微生物在防治有害藻类水华中的作用和潜力,已受到学者的广泛关注.综述溶藻微生物(主要是溶藻细菌和噬藻体)的溶藻作用机制,量效关系及分子生物学.阐述溶藻微生物对蓝藻水华治理存在的问题,并对溶藻微生物作为潜在的控藻因子进行展望.     

溶藻细菌

利用溶藻细菌防治水华和赤潮,作为富营养化水体藻类生物防治的方法已经受到广泛关注.多项研究表明,许多溶藻细菌能分泌胞外活性物质,对宿主藻类的生长起抑制作用.因此,分离筛选环保、高效、专一的溶藻活性代谢产物,最终开发安全、高效的生物杀藻剂已经日渐成为治理藻类水华和赤潮问题的方法之一.近年来,国内外相关人员和机构对溶藻细菌的溶藻机理以及溶藻活性物质的分离、提纯和鉴定进行了较为深入的基础性研究.     

细菌溶藻技术的研究

近年来水体富营养化而导致的藻类水华爆发事件,对人类健康及水生生态系统产生了严重危害。在利用物理、化学等防治方法都不甚理想的情况下,利用微生物处理作为水华治理的潜在手段已得到学界的广泛关注。通过实验经验和查阅大量文献,对一些细菌溶藻技术进行综述。     

沿岸海域富营养化与赤潮发生的关系

综述了赤潮的发生与沿岸海域富营养化的关系。近几十年来,人类活动使得天然水体的富营养化进程大大加速。营养负荷的增加与高生物量水华的增多相联系。控制营养输入后,浮游植物生物量或有害藻类水华事件也相应减少。营养的组成与浮游植物的种类组成及水华的形成有密切联系。有机营养对有害藻类水华的促进作用受到关注。营养输入时机影响浮游植物种间竞争的结果,因而对浮游植物的群落演替具有深远影响。由于浮游植物存在生理差异,因而对营养加富的反应因种而异。营养在调控某些有毒藻类的毒素产量方面也发挥着重要作用。此外,营养输入与藻类水华之间存在复杂的间接联系。当然,营养状况并非浮游植物群落演替的唯一决定因素。研究结果提示,控制营养输入、减缓水域富营养化是减少有害藻类水华发生的有效途径,而深入研究典型有害藻类的营养生理对策则为防治并最终消除有害藻类水华提供了理论基础。     

粘细菌的生物活性物质及其应用前景研究进展

粘细菌是一类具有复杂的多细胞群体行为, 属 peoteobacteria 的δ 分支, 能够产生丰富的生物活性物质, 为第二类药源微生物新类群。由于粘细菌的捕食性, 及产生的活性物质结构新、种类多、作用机制新颖多样, 使得粘细菌作为重要的药源开发菌具有潜在的应用前景。粘细菌的活性物质主要在抗肿瘤、抗病毒、抗寄生虫等药研的应用, 特别是抗肿瘤活性甚至高于紫杉醇, 为肿瘤患者带来福音; 利用溶藻粘细菌可以缓解形成水华的有害藻类危害; 农业上可开发除草剂、杀虫剂、粘细菌菌肥, 有利于发展生态有机农业, 生产无公害绿色产品; 粘细菌做为纤维素生物燃料可以缓解燃料危机, 促进可持续发展具有重大意义。     

水华杀藻微生物的分离与分子生物学鉴定

正除藻方法一般分为工程物理方法、化学药剂法和生物方法三大类。作为庞大的富营养化湖泊的藻类控制技术,利用工程物理方法和化学药剂法显然是行不通的,对环境友好的生物控藻技术受到越来越多的关注,国内外许多富营养化湖泊水华的控藻技术的研究热点转向生物控藻技术。在利用生物控藻上,目前主要有三个方面,一是以鱼类控制藻类的生长;二是以水生高等植物控制水体富营养盐及藻类; 三是以微生物来控制藻类的生长。其中由于微生物易于繁殖的特点,使得微生物控藻是生物控藻里最有前途的一种控藻方式。这些杀藻微生物主要包括细菌(溶藻细菌)、病毒 (噬藻体)、原生动物、真菌和放线菌等五类。国内外对杀藻微生物的分离和鉴定有一些报道,但都不够系统和全面, 本文以本实验室的工作为基础,较全面、系统地介绍前三类水华杀藻微生物的分离与纯化及其分子生物学鉴定方法。       

近海海洋生态系统与有害赤潮的发生综述

海洋生态系统是地球生物圈的重要组成部分。目前,人类活动已经严重破坏了海洋生态系统,导致了海洋生态系统的失衡。赤潮的发生正是这种不平衡的具体体现。文章讨论了人类活动对海洋生态系统的负面影响以及对近海海域赤潮发生的推波助澜作用;主要综述了影响赤潮发生和消亡的生态条件及环境影响因子。最后,强调了学科交叉研究在管理和防范赤潮的发生,维护近海海洋生态系统健康服务功能的必要性,并提出了一些相应的对策和措施。     

有害微藻抑藻细菌多样性及抑藻机制研究进展

有害藻暴发能够破坏水生生态系统,对水环境、人类健康及各国经济构成严重威胁。寻找能够有效防治有害藻华或赤潮的方法是现阶段水生生态保护与修复领域的重要研究内容之一。其中,微生物因其分布广、种类多和易繁殖等特点,在有害藻华或赤潮防治方面表现出巨大潜力,正逐渐得到广泛关注。本文从抑藻细菌分布、物种多样性及抑藻机制(抑藻方式、细胞形态、光合作用和氧化损伤)等角度对当前有害微藻抑藻细菌研究进展进行梳理总结,为微生物控藻提供理论参考。     

Recombinase-aided amplification combined with lateral flow dipstick for the rapid detection of Amphidinium carterae

Journal of Applied Phycology - In the context of global climate change, the frequency and duration of harmful algal blooms (HABs) due to eutrophic coastal waters have increased. HABs can cause...     

Satellite discrimination of Karenia mikimotoi and Phaeocystis harmful algal blooms in European coastal waters: Merged classification of ocean colour data

The detection of dense harmful algal blooms (HABs) by satellite remote sensing is usually based on analysis of chlorophyll-a as a proxy. However, this approach does not provide information about the potential harm of bloom, nor can it identify the dominant species. The developed HAB risk classification method employs a fully automatic data-driven approach to identify key characteristics of water leaving radiances and derived quantities, and to classify pixels into “harmful”, “non-harmful” and “no bloom” categories using Linear Discriminant Analysis (LDA). Discrimination accuracy is increased through the use of spectral ratios of water leaving radiances, absorption and backscattering. To reduce the false alarm rate the data that cannot be reliably classified are automatically labelled as “unknown”. This method can be trained on different HAB species or extended to new sensors and then applied to generate independent HAB risk maps; these can be fused with other sensors to fill gaps or improve spatial or temporal resolution. The HAB discrimination technique has obtained accurate results on MODIS and MERIS data, correctly identifying 89% of Phaeocystis globosa HABs in the southern North Sea and 88% of Karenia mikimotoi blooms in the Western English Channel. A linear transformation of the ocean colour discriminants is used to estimate harmful cell counts, demonstrating greater accuracy than if based on chlorophyll-a; this will facilitate its integration into a HAB early warning system operating in the southern North Sea.     

Applied simulations and integrated modelling for the understanding of toxic and harmful algal blooms (ASIMUTH): Integrated HAB forecast systems for Europe's Atlantic Arc

Reasons for the emergent interest in HABs are abundant, including concerns associated with human health, adverse effects on biological resources, economic losses attributed to recreation, tourism and seafood related industries, and the cost of maintaining public advisory services and monitoring programs for shellfish toxins and water quality. The impact of HABs can potentially be mitigated by early warning of their development. In this regard the project ASIMUTH (Applied Simulations and Integrated Modelling for the Understanding of Toxic and Harmful algal blooms) was borne in order to develop short term HAB alert systems for Atlantic Europe. This was achieved using information on the most current marine conditions (weather, water characteristics, toxicity, harmful algal presence etc.) combined with high resolution local numerical predictions. This integrated, multidisciplinary, trans-boundary approach to the study of HABs developed during ASIMUTH led to a better understanding of the physical, chemical and ecological factors controlling these blooms, as well as their impact on human activities. The outcome was an appropriate alert system for an effective management of areas that are usually associated with HAB events and where these episodes may have a more significant negative impact on human activities. Specifically for the aquaculture industry, the information provided enabled farmers to adapt their working practices in time to prevent mortalities in finfish farms and/or manage their shellfish harvest more effectively. This paper summarises the modelling and alert developments generated by the ASIMUTH project.     

Detection of several harmful algal species by sandwich hybridization integrated with a nuclease protection assay

The frequent occurrence of harmful algal blooms (HABs) is a pressing topic in marine research. An integrated sandwich hybridization and nuclease protection assay was established to qualitatively and quantitatively detect 12 harmful algal species. This method demonstrated good reliability, specificity and accuracy for analyzing samples from individual and mixed cultures, as well as field collection, and cell volumes were positively correlated to the slopes of calibration curves. The lowest quantitative detection limits were those concentrations observed during blooms; thus, this technique provides an efficient alternative to microscopy for rapid identification and quantitation of harmful algal species and could be routinely used to monitor phytoplankton in field surveys.     

大型海藻龙须菜与东海原甲藻间的营养竞争

生物方法作为一种新兴的赤潮防治方法,因为其作用的专一性及较少的负效应,越来越受到人们的重视。研究了龙须菜(G racilaria lem aneif orm is)与东海原甲藻(P rorocentrum d ongha iense)之间营养盐NO3-、PO43-竞争的情况。结果显示,两者共培养时,龙须菜对营养盐的快速吸收利用,使得共培养体系中营养盐迅速降低,最终导致东海原甲藻消亡,而东海原甲藻对于龙须菜的生长不构成明显的影响。在营养盐充分的条件下,1g鲜重的龙须菜对NO3-的吸收能力相当于6.0×107个东海原甲藻细胞,对PO43-的吸收相当于2.4×107个东海原甲藻细胞。相对于东海原甲藻,龙须菜对营养盐的吸收利用更具有优势。龙须菜可作为有效吸收营养盐的大型海藻,用以降低近海水域富营养化程度及有害赤潮发生的几率。     

Eutrophication and harmful algal blooms: A scientific consensus

In January 2003, the US Environmental Protection Agency sponsored a “roundtable discussion” to develop a consensus on the relationship between eutrophication and harmful algal blooms (HABs), specifically targeting those relationships for which management actions may be appropriate. Academic, federal, and state agency representatives were in attendance. The following seven statements were unanimously adopted by attendees based on review and analysis of current as well as pertinent previous data:

• (1)Degraded water quality from increased nutrient pollution promotes the development and persistence of many HABs and is one of the reasons for their expansion in the U.S. and other nations;
• (2)The composition–not just the total quantity–of the nutrient pool impacts HABs;
• (3)High-biomass blooms must have exogenous nutrients to be sustained;
• (4)Both chronic and episodic nutrient delivery promote HAB development;
• (5)Recently developed tools and techniques are already improving the detection of some HABs, and emerging technologies are rapidly advancing toward operational status for the prediction of HABs and their toxins;
• (6)Experimental studies are critical to further the understanding about the role of nutrients in HABs expression, and will strengthen prediction and mitigation of HABs; and
• (7)Management of nutrient inputs to the watershed can lead to significant reduction in HABs.

Supporting evidence and pertinent examples for each consensus statement are provided herein.     

The effect of iron on Chilean Alexandrium catenella growth and paralytic shellfish toxin production as related to algal blooms

BioMetals - The dinoflagellate Alexandrium catenella is a well-known paralytic shellfish toxin producer that forms harmful algal blooms (HABs) worldwide. Blooms of this species have repeatedly...     

Harmful dinoflagellate blooms caused by Cochlodinium sp.: Global expansion and ecological strategies facilitating bloom formation

The past two decades have witnessed an expansion in the reported occurrences of harmful algal blooms (HABs) caused by the dinoflagellate Cochlodinium. Prior to 1990, blooms had been primarily reported in Southeast Asia, with South Korea alone reporting more than $100M USD in annual fisheries losses during the 1990s. Since then, time blooms have expanded across Asia, Europe, and North America, with recognition of multiple species and ribotypes that exhibit similar ecophysiological and harmful characteristics. Here, we summarize the current state of knowledge regarding taxonomy, phylogeny, detection, distribution, ecophysiology, life history, food web interactions, and mitigation of blooms formed by Cochlodinium. We review this recent expansion of Cochlodinium blooms and characterize the ecological strategies utilized by Cochlodinium populations to form HABs. Although Cochlodinium is comprised of more than 40 species, we focus primarily on the two HAB-forming species, C. polykrikoides and C. fulvescens, specifically describing their flexible nutrient acquisition strategies, inhibition of grazing by inducing rapid mortality in a diverse set of predators, and allelopathic inhibition of a broad range of competing phytoplankton. Finally, we summarize the available information on prevention, control, and mitigation strategies specific to this genus, and discuss pressing questions regarding this increasingly important HAB organism.