Gel microbead cultivation with a subenrichment procedure can yield better bacterial cultivability from a seawater sample than standard plating method     

Shiqi Ji  Rui Zhao  Qi Yin  Yuan Zhao  Chenguang Liu  Tian Xiao  Xiaohua Zhang 《中国海洋大学学报(英文版)》2012,11(1):45-51

A gel microbead (GMD) cultivation method was employed to cultivate microorganisms from an amphioxus breeding zone in Qingdao, P. R. China. The culture results were compared with those by standard plating method. In the GMD-based method, the microcolony-forming GMDs were sorted by fluorescence-activated cell sorting (FACS). To further get pure cultures, a subsequent enrichment culture and a streaking purification procedure were conducted on marine R2A medium. Eighty bacterial strains isolated by the GMD-based method were randomly selected for sequencing. These isolates belonged to Alphaproteobacteria (33%), Gammaproteobacteria (44%), Bacteroidetes (11%), Actinobacteria (5%), Firmicutes (5%), Epsilonproteobacteria (1%), and Verrucomicrobia (1%), the last two groups being usually difficult to culture. The 16S rRNA gene sequences revealed a diverse community with 91.1%-100% of the bacterial rRNAs similarities. Thirteen strains were sharing 16S rRNA gene sequence which was less than 97% similar to any other rRNA genes currently deposited in TYP16S database. Seventy isolates derived from the standard plating method fell into 4 different taxonomic groups: Alphaproteobacteria (9%), Gammaproteobacteria (81%), Bacteroidetes (7%) and Firmicutes (3%) with a 16S rRNA gene sequence similarities between 95.8%-100%, in which only 3 strains were sharing 16S rRNA gene sequence of less than 97%. The results indicated that the GMD-based method with subenrichment culture yielded more taxonomic groups and more novel microbial strains, including members of previously rarely cultured groups, when compared with the standard plating method, and that this method markedly improved the bacterial cultivability.  相似文献   

现代海底热液场低温弥散流区微生物生态的研究进展          下载免费PDF全文

李季伟  周怀阳  彭晓彤  陈智强  孙治雷  李江涛  陈顺  章力学 《海洋科学进展》2012,30(2):295-304

现代海底低温热液弥散流区微生物生态的发育情况已经成为当前热液系统研究关注的热点之一。大量的分析表明在低温热液弥散流区赋存着丰富的化能自养微生物,以硫、铁等元素的氧化还原反应获取新陈代谢能量,这些微生物的分布与低温热液流体的物理化学条件有着密切的联系。这些发现极大地丰富了我们对低温弥散流区微生物生态、关键地球化学过程与微生物新陈代谢耦合关系的认识。此外,低温热液流体是研究洋壳深部生物圈的窗口,通过这个窗口可以了解地壳内部生命的新陈代谢方式,进而理解地球内部微生物与洋壳内部流体、岩石之间的相互作用机制。  相似文献   

污泥屏障渗透性及重金属阻截效果试验研究   总被引：1，自引：0，他引：1  

张虎元  杨博  高全全  张光伟 《岩土力学》2012,33(10):2910-2916

目前,废弃物处置场渗滤液中的重金属污染物只能依靠极低渗透性的水力屏障来控制,还不存在利用化学场专门拦截重金属污染物的反应型屏障。在有机结合生活污泥的低渗透性与丰富的有机质和厌氧微生物特性的基础上,提出“污泥屏障”的构想。研究利用柔性壁渗透仪测量不同有效应力作用下生活污泥试样的渗透系数,并对渗出液的化学性质进行了监测,验证污泥屏障的可行性。试验结果表明：随着有效应力的增大,污泥试样干密度提高,渗透系数的对数值随孔隙比的减小线性降低。试样内部微生物厌氧呼吸形成的生物膜和无机物沉淀以及黏土颗粒双电层厚度的增大,也是污泥渗透系数降低的原因,污泥渗透系数仅为 数量级。另外,污泥强烈吸附能力及厌氧微生物呼吸作用形成的中-弱碱性还原环境,对渗透液中的Zn和Cd都起到了很好的拦截作用。  相似文献   

Distribution of microbial fatty acids and fatty alcohols in soils from an altitude transect of Mt. Jianfengling in Hainan,China: Implication for paleoaltimetry and paleotemperature reconstruction     

YANG Huan  DING WeiHua  XIE ShuCheng 《中国科学:地球科学(英文版)》2014,57(5):999-1012

The temperature gradient along the altitude transect of Mt.Jianfengling provides a good opportunity to establish and evaluate the microbial lipid-based environmental proxies.The soils collected from 14 different altitudes of Mt.Jianfengling contain abundant microbial fatty acids and fatty alcohols,including iso/anteiso fatty acids(i/aC12:0–i/aC19:0),10-Me-C16:0 fatty acid,iso/anteiso fatty alcohols(i/aC13–iC26),10-Me-C16:0 fatty alcohol and unsaturated fatty alcohols,which can indicate a strong microbial activity in the Jianfengling soils.The branched and unsaturated fatty alcohols can be only detected when saponification is performed,implying that these lipids are present as the constituents of bacterial wax esters in the soils.The ratio of aC15/iC15 fatty acids is positively correlated with altitude,suggesting that the decrease in temperature can induce the increase in the relative abundance of anteiso C15 fatty acid.In contrast,the ratio of aC15/iC15 fatty alcohols and of aC15/nC15 fatty alcohols both decrease with increased altitude or decreased temperature.Similarly,the ratio of nC18:1/nC18:0 fatty alcohols also decreases with decreased temperature,which is opposite to the previous observation that unsaturation of fatty acids in microorganism increases in response to decreased temperature.Besides,the average chain length(ACL)of long chain fatty alcohols(C22–C30)from leaf waxes and carbon preference index(CPI)of all n-fatty alcohols are also significantly correlated with altitude or mean annual temperature,demonstrating their potential for paleoclimate reconstruction.The correlation of microbial fatty acids and alcohols as well as ACL and CPI of plant wax-derived fatty alcohols with altitude may provide novel ways to reconstruct paleotemperature and paleoaltimetry.  相似文献   

极地微生物菌种数据库的设计及其功能简述   总被引：1，自引：0，他引：1       下载免费PDF全文

凌晓良  俞勇  朱建钢  陈波  夏明一  程文芳 《极地研究》2009,21(1):69-75

极地微生物菌种数据库,在功能设计上不仅考虑到共享中国极地科学数据库系统的元数据管理、用户权限认证和后台数据管理功能模块与部分数据,而且考虑到新开发的用户管理模块、数据管理与维护模块、数据查询模块,以及文献信息要求等的特殊性。其技术架构采用基于WEB的浏览器/服务器模式。数据库设计中除考虑到管理的主体对象--菌种资源信息外,还考虑用户、资源利用和成效跟踪等相关信息,并通过相关联的用户与权限系统、数据管理与维护系统和数据发布系统,实现用户与操作、资源与利用的一体化管理。该数据库不仅实现多种信息的综合管理与实时发布,而且提供定制式、人性化管理与用户界面以及综合统计和报表等多项功能。  相似文献   

一株菌红素产生菌的鉴定及色素组分分析     

崔恒林  代春华  董英  陆玲  秦怀兰 《海洋科学》2005,29(2):43-48

对分离自腌鱼的高产菌红素(bacterioruberin)的菌株r-fish进行了形态特征、生理生化特性与细胞化学组分的分析以及基于16SrDNA序列的系统发育分析。形态特征、生理生化特性及细胞化学组分的分析结果表明菌株r-fish为球形的嗜盐古菌。基于16SrDNA序列的系统发育结果表明,r-fish与Halobacterium trapanicum NCIMB784菌株的相似性为99．8％,归入Na-trinema属。用TLC法对r-fish的色素进行了分析,r-fish的色素组分包括菌红素(bacteriorubefin)、脱水菌红素(anhydrobacteriorubefin)、双脱水菌红素(bisanhydrobacteriorubeftn)和一未知色素。与Halobacteriumhalobium和Halococcus morrhuae的色素组分相似。  相似文献   

羟基游离基杀死压载水中微生物研究   总被引：9，自引：0，他引：9       下载免费PDF全文

白敏冬  张芝涛  白希尧  周晓见  邓淑芳  王宁 《海洋与湖沼》2003,34(5):484-489

利用介质阻挡强电离放电的方法，将空气中的O2和海水中H2O电离离解成OH等氧化自由基，溶于海水中形成高浓度羟基药剂。羟基致死压载水中入侵的细菌、微藻生物的反应属于游离基反应，具有广谱致死特性，在压载水外排(或输入)过程中就可致死入侵微生物，不存在药剂污染海洋环境等问题。实验室研究结果表明：致死微生物的羟基阚值为O．8mg／L。  相似文献   

三峡消落带土壤—植物—微生物作用下的氮循环关键过程研究进展          下载免费PDF全文

李姗泽  王雨春  张家晖  赵建伟  温洁  包宇飞  陈铭 《湖泊科学》2023,35(2):398-410

流域氮污染问题是世界面临的共同难题,大型水利水电工程极大地改变了流域氮循环过程。三峡水库作为我国重要的优质淡水资源库,却面临着支流水华频繁暴发的水安全问题。如何有效削减氮污染并维持水库消落带生态系统的稳定性,是三峡水库生态安全运行中亟待解决的实际问题。水库消落带作为邻近水体的“生物地球化学循环热区”,在营养元素循环、面源污染截留、温室气体排放等过程中扮演着重要角色。随着生物信息学、分子生物学等新型研究手段在环境研究中广泛应用,氮循环过程与机理得到了更微观的诠释,氮循环功能微生物的多样性和生态位分化等方面的研究也取得了突出成果。本文基于对三峡水库消落带土壤-植物-微生物作用下的氮循环关键过程所开展的最新研究,结合消落带水陆交错的特殊环境条件,综述水库消落带中氮循环的关键过程和机理,分析水库消落带对流域水环境和温室气体排放的潜在影响,并对未来消落带亟待解决的问题做了进一步展望,以期为大型水库消落带生态系统的综合管理提供科学支撑。  相似文献