Marine magnetotactic bacteria were collected from the intertidal sediments of Yuehu Lake（China）, where their abundance reached 103–104 ind./cm3. Diverse morphotypes of magnetotactic bacteria were observed, includin...Marine magnetotactic bacteria were collected from the intertidal sediments of Yuehu Lake（China）, where their abundance reached 103–104 ind./cm3. Diverse morphotypes of magnetotactic bacteria were observed, including cocci and oval, vibrio-, spirillum-, rod-, elliptical-, handle- and bar-shaped forms. The magnetococci were the most abundant, and had flagella arranged in parallel within a bundle. The majority of magnetosomes were arranged in one, two or multiple chains, although irregular arrangements were also evident. All the results of high-resolution transmission electron microscopy（HRTEM） analysis show that magnetosome crystals were composed of Fe3O4, and their morphology was specific to particular cell morphotypes. By the 16 S r RNA gene sequence analysis, we found fourteen operational taxonomic units（OTUs） which were related to magnetotactic bacteria. Among these, thirteen belonged to the Alphaproteobacteria and one to the Gammaproteobacteria.Compared with known axenic and uncultured marine magnetotactic bacteria, the 16 S r RNA gene sequences of most magnetotactic bacteria collected from the Yuehu Lake exhibited sequence identities ranging from 90.1% to96.2%（〈97%）. The results indicate that microbial communities containing previously unidentified magnetotactic bacteria occur in the Yuehu Lake.展开更多
月湖是山东荣成湾内的一个正在开发水产养殖业与旅游业的小海湾,然而在人为活动干预下,月湖的环境与生态系统发生了剧烈的变化,如水质恶化、水产品产量下降等。1999 年夏季开始对月湖开展了环境化学的调查。结果表明,海水溶解氧的含量正...月湖是山东荣成湾内的一个正在开发水产养殖业与旅游业的小海湾,然而在人为活动干预下,月湖的环境与生态系统发生了剧烈的变化,如水质恶化、水产品产量下降等。1999 年夏季开始对月湖开展了环境化学的调查。结果表明,海水溶解氧的含量正常,在某些站位上溶解氧饱和度超过100% 。生化耗氧量一般小于4 m g/L。化学耗氧量则在3～4 m g/L之间。海水中氮,磷,硅含量均低于国家海水标准,表明月湖缺少陆地水供应来源。展开更多
基金The National Natural Science Foundation of China under contract Nos 41606187 and 41276170the National Natural Science Foundation of China under contract No.41330962+1 种基金the National Natural Science Foundation of China-Shandong Joint Fund for Marine Science Research Centers under contract No.U1406403supported by Laboratoire International Associé de la Bio-Minéralisation et Nano-Structures
文摘Marine magnetotactic bacteria were collected from the intertidal sediments of Yuehu Lake（China）, where their abundance reached 103–104 ind./cm3. Diverse morphotypes of magnetotactic bacteria were observed, including cocci and oval, vibrio-, spirillum-, rod-, elliptical-, handle- and bar-shaped forms. The magnetococci were the most abundant, and had flagella arranged in parallel within a bundle. The majority of magnetosomes were arranged in one, two or multiple chains, although irregular arrangements were also evident. All the results of high-resolution transmission electron microscopy（HRTEM） analysis show that magnetosome crystals were composed of Fe3O4, and their morphology was specific to particular cell morphotypes. By the 16 S r RNA gene sequence analysis, we found fourteen operational taxonomic units（OTUs） which were related to magnetotactic bacteria. Among these, thirteen belonged to the Alphaproteobacteria and one to the Gammaproteobacteria.Compared with known axenic and uncultured marine magnetotactic bacteria, the 16 S r RNA gene sequences of most magnetotactic bacteria collected from the Yuehu Lake exhibited sequence identities ranging from 90.1% to96.2%（〈97%）. The results indicate that microbial communities containing previously unidentified magnetotactic bacteria occur in the Yuehu Lake.
文摘月湖是山东荣成湾内的一个正在开发水产养殖业与旅游业的小海湾,然而在人为活动干预下,月湖的环境与生态系统发生了剧烈的变化,如水质恶化、水产品产量下降等。1999 年夏季开始对月湖开展了环境化学的调查。结果表明,海水溶解氧的含量正常,在某些站位上溶解氧饱和度超过100% 。生化耗氧量一般小于4 m g/L。化学耗氧量则在3～4 m g/L之间。海水中氮,磷,硅含量均低于国家海水标准,表明月湖缺少陆地水供应来源。
