大连海域海洋放线菌多样性及分类鉴定初探

海洋孕育着丰富的微生物资源,其中海洋放线菌能够产生各种次级代谢产物及生理活性物质,对海洋放线菌的研究具有重要的实际意义。实验对筛选自大连海域的30株放线菌进行了形态及生理生化鉴定、16S rDNA序列的分析及系统发育树构建,结果表明分离到的海洋放线菌中13株分属于放线菌目链霉菌不同种或亚种,说明大连海域的海洋放线菌具有一定的多样性。     

海洋放线菌资源、研究方法与生物活性研究进展

海洋放线菌生活的环境如养分、光照、氧气浓度、压力、盐度和温度等与陆地环境存在极大差异,因此海洋放线菌形成了独特的生物化学代谢和生理能力。近年来,海洋放线菌成为生物资源开发和研究的热点。海洋放线菌分布广泛,种类多样。海洋放线菌活性代谢产物具有极强的医药应用潜力,其代谢产物的功能研究及重要代谢产物的开发成为海洋放线菌研究的重要方向。此外,海洋放线菌在环境保护以及生产应用等方面展现出的潜能,引起研究人员极大的兴趣。本文结合近年来海洋放线菌的分离种类与生境、海洋放线菌的研究策略与手段以及代谢产物功能多样性进行了归纳总结,以期对海洋放线菌的认识更全面、系统。     

智利海洋沉积物中放线菌多样性

【目的】认识智利海洋沉积物中放线菌的多样性。【方法】分别采用选择性分离培养和非培养的基于16SrRNA基因序列系统发育分析方法,对来自智利南部海域海洋沉积物中放线菌多样性进行研究。采用6种选择性分离培养基分离放线菌;利用放线菌特异性引物对样品总DNA进行16SrRNA基因序列扩增并构建了16SrRNA基因克隆文库。分别挑选不同培养特征的22株放线菌和59个基因克隆进行16SrRNA基因序列的系统进化分析;测定分离的放线菌对海水的依赖性及产生抗菌活性化合物的能力。【结果】共分离到328株放线菌;挑选的22株放线菌分别属于小单孢菌属、多形孢菌属、链霉菌属、迪茨氏菌属、气微菌属和短状杆菌属;挑取的59个克隆属于40个分类单元,其中60%分类单元属于放线菌门放线菌亚纲、酸微菌亚纲和红色杆菌亚纲,另外40%的分类单元在放线菌内形成几个独立的进化分支,有可能代表放线菌新类群。22株放线菌有19株具有抗菌活性,50%的生长依赖海水的放线菌也具有抗菌活性。【结论】智利海域沉积物存在丰富的放线菌系统发育多样性并能产生活性次级代谢产物,而且还蕴藏丰富的新类型的放线菌资源。     

海洋微生物抗肿瘤天然产物研究进展

近年来,海洋微生物已成为抗肿瘤天然产物研究的热点,目前从海洋微生物中发现了大量新的抗肿瘤天然产物。文章综述了近几年从海洋微生物(海洋放线菌、真菌和细菌)中分离得到的抗肿瘤活性天然产物的研究进展。     

海洋放线菌的研究现状及未来展望

【背景】放线菌具有丰富的遗传和功能多样性,其次级代谢产物活性广泛,在临床医疗、农业生产和污染防治等领域都发挥着重要的作用。海洋放线菌由于其特殊的代谢途径,能产生独特的活性天然产物而受到广泛关注。【目的】探究国内外海洋放线菌领域研究的热点和趋势,为后续研究提供参考。【方法】以“marine actinomycetes or marine actinobacteria”为关键词,在Web of Science中检索海洋放线菌领域的文章进行计量分析,使用VOSviewer软件对其关键词、国家、机构、作者、发表时间进行可视化分析。【结果】海洋放线菌领域的文章发表数量总体呈逐年上升趋势,主要集中在微生物学及药学领域,中美两国在论文数量和引用频次上远超其他国家,海洋放线菌领域的研究集中在菌株的分离鉴定、活性天然产物挖掘以及生物信息学等方面。【结论】海洋放线菌在全球范围内愈发受到重视,国内外机构应当加强合作,运用生物信息学技术进一步挖掘活性次级代谢产物,推动海洋放线菌领域进一步发展。     

大连渤海老虎滩海域沉积物可培养放线菌的多样性

【目的】研究大连渤海老虎滩海域可培养放线菌的多样性。【方法】利用5种不同的培养基分离、培养海洋沉积物中的放线菌,并用16S rRNA基因序列对部分放线菌株进行系统发育分析。【结果】根据菌落表型共分离到1215株放线菌。选择271株具有代表性的菌株进行16S rRNA分析,结果表明,251株(92.26%)属于放线菌门,覆盖11个科,15个属;其余20株属于厚壁门和变形菌门;有7株为潜在的新种。【结论】大连渤海老虎滩海域的沉积物中存在较为丰富的放线菌和新种资源,这些菌株为将来开发新的微生物代谢产物奠定了基础。     

海洋放线菌研究进展

海洋放线菌因其产生独特的次生代谢产物而备受世界的关注。本文以海洋放线菌的研究历史为主线,综述了海洋放线菌研究的发展历程,海洋放线菌的概念、生物资源、多样性及其分布状况、次生代谢产物以及基因组研究等方面,探讨了其生态功能,最后展望了我国海洋放线菌研究存在的问题及未来发展的前景。     

海洋链霉菌Streptomyces sp. SCSIO 1672及其代谢产物水杨酸的分离鉴定

从南海海洋沉积物中分离得到1株海洋放线菌,鉴定为链霉菌Streptomyces sp. SCSIO 1672。通过优化发酵条件,采用海虾生物致死活性和高效液相色谱追踪,利用有机溶剂萃取、正相硅胶、反相硅胶等各种色谱层析方法分离出活性化合物,通过波谱数据解析出海洋放线菌SCSIO 1672次级代谢产物中的该活性化合物为水杨酸。     

印度洋红树林沉积物可培养海洋放线菌多样性及其活性

【目的】本研究旨在了解印度洋红树林沉积物可培养海洋放线菌多样性、抗菌活性及产酶活性。【方法】选用24种碳源为唯一能源培养基,利用稀释平板涂布方法对8个印度洋红树林沉积物样品进行分离,并基于16S rRNA基因系统发育分析的方法研究样品中海洋放线菌多样性;对分离得到的菌株进行抗菌活性和产酶活性检测。【结果】24种唯一碳源分离培养基中,非糖类碳源特别是甘油、丙氨酸分离效果最好,其次是多糖物质,最后是单糖。共分离得到521株海洋放线菌,经并菌后选取其中的139株代表性菌株测序,结果发现它们主要分布在放线菌纲7个亚目10个科的16个属,其中35个为潜在新种。有43.1%、33.3%、26.9%、25.5%、15.7%的实验菌株分别对枯草芽孢杆菌、白色念珠菌、大肠埃希氏菌、金黄色葡萄球菌、黑曲霉具有抑制作用;有36.5%、26.5%、22.4%、15.9%的实验菌株分别具有蛋白酶活性、纤维素酶活、淀粉酶活性、酯酶活性。【结论】印度洋红树林沉积物蕴藏着丰富的海洋放线菌资源,并具有较高生物活性,为后续工作提供良好的实验材料。     

嗜盐放线菌资源及次生代谢产物研究进展

嗜盐放线菌是重要的极端微生物资源,因其独特的生长环境、生理机制而备受关注。本文对嗜盐放线菌的定义、生物多样性及次生代谢产物的研究进展进行综述。结合我国嗜盐放线菌的研究现状,分析尚存在的问题及其发展前景。     

Pharmaceutically active secondary metabolites of marine actinobacteria

Marine actinobacteria are one of the most efficient groups of secondary metabolite producers and are very important from an industrial point of view. Many representatives of the order Actinomycetales are prolific producers of thousands of biologically active secondary metabolites. Actinobacteria from terrestrial sources have been studied and screened since the 1950s, for many important antibiotics, anticancer, antitumor and immunosuppressive agents. However, frequent rediscovery of the same compounds from the terrestrial actinobacteria has made them less attractive for screening programs in the recent years. At the same time, actinobacteria isolated from the marine environment have currently received considerable attention due to the structural diversity and unique biological activities of their secondary metabolites. They are efficient producers of new secondary metabolites that show a range of biological activities including antibacterial, antifungal, anticancer, antitumor, cytotoxic, cytostatic, anti-inflammatory, anti-parasitic, anti-malaria, antiviral, antioxidant, anti-angiogenesis, etc. In this review, an evaluation is made on the current status of research on marine actinobacteria yielding pharmaceutically active secondary metabolites. Bioactive compounds from marine actinobacteria possess distinct chemical structures that may form the basis for synthesis of new drugs that could be used to combat resistant pathogens. With the increasing advancement in science and technology, there would be a greater demand for new bioactive compounds synthesized by actinobacteria from various marine sources in future.     

海南西海岸真红树内生放线菌多样性及其延缓衰老活性初筛

为了发掘红树林内生放线菌资源和进行新型海洋药物研究,该文选择海南西海岸14种真红树的根、茎、叶、花、胚轴为研究对象,采用9种不同分离培养基[改良的高氏培养基(AGG)、海藻糖-天冬酰胺培养基(M4)、海藻糖-脯氨酸培养基(M5)、改良ISP5培养基(M7)、精氨酸-天冬酰胺培养基(M9)、改良淀粉-水解酪素培养基(M10)、酪氨酸-天冬酰胺培养基(P7)、燕麦培养基(P3)、棉籽糖-组氨酸培养基(M11)],结合稀释涂布法和三线划线法从真红树组织中分离菌株,基于菌株16S rRNA基因序列信息等分子生物学鉴定方法对获得的海洋放线菌进行多样性分析,并使用模式生物秀丽隐杆线虫对所得内生放线菌的延缓衰老活性进行研究。结果表明:(1)从46份真红树组织中共获得24株放线菌,隶属于7科11属,其中9株菌株为链霉菌属(Streptomyces),且IMDGX 6270、IMDGX 6137和IMDGX 6173为3株疑似潜在新菌株。(2)秀丽隐杆线虫模型筛选发现4株放线菌(IMDGX 6157、IMDGX 6182、IMDGX 6248、IMDGX 6360)具有延缓衰老的活性,与空白组比较,生存时间分别延长17.16%、28.11%、29.05%、27.10%。综上结果说明海南西海岸区域真红树植物中可能含有较丰富的放线菌资源,能够为延缓衰老药物的研发提供新来源。     

Research on marine actinobacteria in India

Marine actinobacteriology is one of the major emerging areas of research in tropics. Marine actinobacteria occur on the sediments and in water and also other biomass (mangrove) and substrates (animal). These organisms are gaining importance not only for their taxonomic and ecological perspectives, but also for their unique metabolites and enzymes. Many earlier studies on these organisms were confined only to the temperate regions. In tropical environment, investigations on them have gained importance only in the last two decades. So far, from the Indian peninsula, 41 species of actinobacteria belonging to 8 genera have been recorded. The genus, Streptomyces of marine origin has been more frequently recorded. Of 9 maritime states of India, only 4 have been extensively covered for the study of marine actinobacteria. Most of the studies conducted pertain to isolation, identification and maintenance of these organisms in different culture media. Further, attention has been focused on studying their antagonistic properties against different pathogens. Their biotechnological potentials are yet to be fully explored.     

Biologically active metabolites of marine actinobacteria

Data on the chemical structures and biologic activities of metabolites of obligate and facultative marine actinobacteria published between 2000 and 2007 are reviewed. The structural features of five groups of metabolites related to macrolides and compounds containing lactone, quinone, and diketopiperazine residues; cyclic peptides; alkaloids; and compounds of combined nature are discussed. The review shows the large chemical diversity of metabolites of actinobacteria isolated from marine ecotopes. In addition to metabolites identical to those previously isolated from terrestrial actinobacteria, marine actinobacteria produce compounds not found in other natural sources, including microorganisms. Probably, the biosynthesis of new chemotypes of bioactive compounds by marine actinobacteria is related to the chemical adaptation of microorganisms to the marine environment. The review emphasizes the importance of chemical studies of metabolites produced by marine actinobacteria. These studies will provide new data on marine microbial producers of biologically active compounds and the chemical structures and biologic activities of new natural lowmolecular-weight bioregulators.     

硝尔库勒湖可培养放线菌多样性及其功能酶和抗细菌活性

【目的】认识和了解硝尔库勒湖可培养放线菌的多样性、功能酶和抗细菌活性特点,为今后的开发和利用奠定基础。【方法】应用可培养技术和基于16S r RNA基因序列的系统发育分析硝尔库勒盐湖沉积物中放线菌的多样性。常规方法检测样品成分因子,并筛选了嗜盐放线菌的蛋白酶、淀粉酶和酯酶活性;抑菌圈法检测放线菌新种的抗细菌活性。【结果】分离获得了51个OTUs,分属于24个不同的属,其中15个OTUs代表了放线菌新种;链霉菌属是优势菌属,占全部分离菌株数量的16.25%。硝尔库勒湖放线菌类群数量一定程度上受样品成分因子的协同影响。代表新种的菌株展示了良好的功能酶活性和抗细菌活性,其中代表链霉菌新种的菌株XHU5011不仅具有多种酶活性,而且具有强大的抗金黄葡萄球菌、耻垢分枝杆菌和荧光假单胞菌的能力,具有很好的开发潜能。【结论】硝尔库勒盐湖中存在丰富的可培养放线菌多样性,潜藏着大量的放线菌新资源,并且具有很好的功能酶和天然产物挖掘潜力。     

微生物遗传多样性的挖掘和代谢工程应用

随着近年来系统生物学研究的深入,微生物的基因组、转录组、蛋白组及代谢组等不同层次的组学信息不断增加。我国具有丰富的微生物多样性,但目前对多样性的研究大多集中在物种多样性及生态多样性方面,对微生物菌株水平遗传多样性的研究还刚刚起步。以酿酒酵母和链霉菌为例,结合本课题组的成果,总结了近年来利用其基因组序列及转录组蛋白质等功能基因组信息,开发利用其遗传多样性的研究进展。在工业酿酒酵母中发现了多个独特的功能基因,包括絮凝基因及与环境胁迫耐性相关的调节蛋白基因,还发现了独特的启动子序列。此外,在海洋放线菌基因组中也发现了独特的调节基因。对微生物遗传多样性的挖掘利用,不仅有助于深入理解微生物不同菌株中独特的调节方式,也为微生物的代谢工程改造提供了大量新的可利用的遗传组件。     

An assessment of actinobacterial diversity in the marine environment

The 16S rRNA gene sequence diversity within the Phylum Actinobacteria was assessed from four sources: PCR-generated V6 sequence tags derived from seawater samples, metagenomic data from the Global Ocean Sampling (GOS) expedition, marine-derived sequences maintained in the Ribosomal Database Project (RDP), and select cultured strains for which sequence data is not yet available in the RDP. This meta-analysis revealed remarkable levels of phylogenetic diversity and confirms the existence of major, deeply rooted, and as of yet uncharacterized lineages within the phylum. A dramatic incongruence among cultured strains and those detected using culture-independent techniques was also revealed. Redundancy among the actinobacteria detected using culture-independent techniques suggests that greater sequence coverage or improved DNA extraction efficiencies may be required to detect the rare phylotypes that can be readily cultured from marine samples. Conversely, new strategies need to be developed for the cultivation of frequently observed but yet to be cultured marine actinobacteria.     

Diversity and biogeography of marine actinobacteria

The actinomycetes, although not all the Actinobacteria, are easy to isolate from the marine environment. However, their ecological role in the marine ecosystem is largely neglected and various assumptions meant there was little incentive to isolate strains for search and discovery of new drugs. However, the marine environment has become a prime resource in search and discovery for novel natural products and biological diversity, and marine actinomycetes turn out to be important contributors. Similarly, striking advances have been made in marine microbial ecology using molecular techniques and metagenomics, and actinobacteria emerge as an often significant, sometimes even dominant, environmental clade. Both approaches - cultivation methods and molecular techniques - are leading to new insights into marine actinobacterial biodiversity and biogeography. Very different views of actinobacterial diversity emerge from these, however, and the true extent and biogeography of this are still not clear. These are important for developing natural product search and discovery strategies, and biogeography is a hot topic for microbial ecologists.