北极海冰细菌产胞外酶及主要环境因子的初步研究   总被引：1，自引：3，他引：1       下载免费PDF全文

曾胤新  俞勇  涂雪梅  陈波  何剑锋 《极地研究》2003,15(4):303-309

覆盖在北极海洋上的广阔海冰为其内部生存的微生物群落提供了一个独特的生境。研究表明 ,大量海冰细菌能够分泌产生胞外酶 ,其中产蛋白或脂质水解酶细菌的比例远高于产多糖水解酶的细菌。温度、盐度是直接影响海冰细菌生存与活力的 2个主要环境因子。 76%的产酪蛋白酶海冰细菌为低温菌 ,菌株只能在 <35°C条件下生长 ;而 98%的酪蛋白酶最适作用温度≥ 35°C ,其中 62 %的酶最适作用温度≥ 45°C。几乎所有的产酪蛋白酶海冰细菌都耐盐或嗜盐  相似文献   

硅酸盐细菌GY03菌株的絮凝特性   总被引：17，自引：1，他引：17  

连宾  陈烨  袁生  刘丛强 《矿物学报》2003,23(4):303-307

从土壤中筛选分离到一株硅酸盐细菌GY03菌株，对其絮凝特性进行了研究。结果表明，GY03菌株营养要求简单，在生长的同时合成胞外高聚物，具有良好的絮凝性能。GY03菌株所产絮凝物质有88％以上分布在细胞表面，该絮凝剂的絮凝活性随菌体生长量的增加而同步增高，不同金属离子对GY03菌株絮凝活性有影响。实验条件下，1h内GY03菌株所产生的微生物絮凝剂对高岭土悬浮液絮凝率为78％，经放置24h后最高絮凝率可达98％，对制药废水浊度去除率为78．1％～94．7％，COD去除率为48．0％-87．5％，生活污水浊度去除率为85．3％～92．5％，对墨汁溶液的脱色率为53．2％以上。因而认为该菌株是一种很有应用前景的絮凝剂产生菌。  相似文献   

滇池微生物解磷与聚磷作用的实验研究及磷的现代沉积与微生物成矿作用   总被引：4，自引：0，他引：4  

东野脉兴  樊竹青  张灼  夏学惠  田升平  周建民 《吉林大学学报(地球科学版)》2003,33(3):282-289

滇池是世界上磷质来源最丰富的湖泊，是研究磷的现代沉积和微生物对磷循环作用及微生物成矿的天然场所。研究发现，滇池微生物种群和数量繁多，但能对磷溶解、转化、迁移、聚集、沉积的微生物主要有解磷菌和聚磷菌两类。这两类微生物与滇池磷的含量之间有一系列规律的相关性：在底泥磷高含量区域，解磷菌的种群和数量与底泥磷含量成负相关关系，与水体磷含量成正相关关系，而聚磷菌的种群和数量与底泥磷含量成正相关关系，与水体磷含量成负相关关系；在底泥磷低含量区域，上述相关性则相反。滇池中这种活着的微生物在自然环境条件下对磷的溶解、转化、迁移、聚集和沉积的作用，对古磷块岩微生物成矿说提供了可靠的依据，而且对以磷为限制性因子的湖、海、江河环境污染的防治提供了理论资料。  相似文献   

高岭土深加工产品开发     

杨玉枝  赵风 《内蒙古地质》1997,(2)

当前世界上煅烧高岭土产品已瞄准高档化、专用化、精细化和功能化，深加工系列产品已应用于高档汽车、船舶、乳胶、颜料、化工、造纸、涂料等方面。内蒙古自治区有丰富的高岭土资源，我们应依托优势资源，尽快掌握高新技术，开发高岭土系列产品，争取在较短的时间内在国内外激烈的市场竞争中立于不败之地，为自治区的经济繁荣起到积极的推动作用。  相似文献   

Experimental study on reduction of U (Ⅵ) by an anaerobic bacterium, Shewanella putrefaciens: Application to sandstone-hosted interlayer oxidation-zone type uranium deposits, China     

MIN Maozhong  XU Huifang  L.L.Barton  PENG Xinjian  Yin Lin  WANG Rucheng 《中国科学D辑(英文版)》2005,48(3)

An experimental study on reduction of U (Ⅵ) by anaerobic bacteria, Shewane//a putrefaciens, is first reported here in China. The experimental conditions were: 35℃ and pH =7.0-7.4, corresponding to a physicochemical environments in which the sandstone-hosted interlayer oxidation-zone type uranium deposit formed in Northwest China's Xinjiang. Bacteria adopted in the present experiment, Shewanella putrefaciens, occur extensively in natural environment. Our study shows that nano-crystal precipitates of uraninite quickly occurred on the surface of the cells within one week. It was found that the pitchblende was characterized by a random arrangement of uraninite nanocrystals (2-4 nm) in it, significantly different from natural pitchblende in which uraninite nanocrystals are arranged in order. Finally, a possible mechanism of uranium biomineralization by microorganisms in the deposits is discussed. Our investigation may supply a technical train of thoughts for bioremediation of nuclear-contaminated water environments and for underground dissolving extraction of the sandstone-hosted uranium ores.  相似文献   

Biomineralization of Uranium: A Simulated Experiment and Its Significance   总被引：5，自引：0，他引：5  

L. L. BARTON  H. WIATROWSKI 《《地质学报》英文版》2005,79(1):134-138

A simulated experimental reduction of U^v1 and the synthesis of uraninite by a sulfate-reducing bacteria,Desulfovibrio desulfuricans DSM 642, are first reported. The simulated physicochemical experimental conditions were:35℃, pH=7.0-7.4, corresponding to the environments of formation of the sandstone-hosted interlayer oxidation-zone type uranium deposits in Xinjiang, NW China. Uraninite was formed on the surface of the host bacteria after a one-week‘s incubation. Therefore, sulfate-reducing bacteria, which existed extensively in Jurassic sandstone-producing environments,might have participated in the biomineralization of this uranium deposit. There is an important difference in the orderdisorder of the crystalline structure between the uraninite produced by Desulfovibrio desulfuricans and naturally occurring uraninite. Long time and slow precipitation and growth of uraninite in the geological environment might have resulted in larger uraninite crystals, with uraninite nanocrystals arranged in order, whereas the experimentally produced uraninite is composed of unordered uraninite nanocrystals which, in contrast, result from the short time span of formation and rapid precipitation and growth of uraninite. The discovery has important implications for understanding genetic significance in mineralogy, and also indicates that in-situ bioremediation of U-contaminated environments and use of biotechnology in the treatment of radioactive liquid waste is being contemplated.  相似文献   

A study of crude oil‐degrading bacteria from mangrove forests in the Persian Gulf     

Iman Fakhrzadegan  Mehdi Hassanshahian  Majid Askari Hesni  Amir Saadatfar 《Marine Ecology》2019,40(2)

Mangroves are coastal ecosystems, found in tropical and subtropical regions around the world. They are found in the transitional zones between land, sea, and rivers. Petroleum hydrocarbons are the most common environmental pollutants, and oil spills pose a great hazard to mangroves forests. This research was focused on the isolation and characterization of crude oil‐degrading bacteria from mangrove ecosystems at the Persian Gulf. Sixty‐one crude oil‐degrading bacteria were isolated from mangrove samples (plant, sediment, and seawater) that enriched in ONR7a medium with crude oil as only carbon source. Some screening tests such as growth at high concentration of crude oil, bioemulsifier production, and surface hydrophobicity were done to select the most efficient strains for crude oil degradation. Molecular identification of strains was carried out by amplification of the 16S rRNA gene by PCR. The results of this study were indicated that the quantity of crude oil‐degrading bacteria was higher in the root of mangrove plants compare to other mangrove samples (sediment and seawater). Also, identification results confirmed that these isolated strains belong to Vibrio sp. strain NW4, Idiomarina sp. strain BW32, Kangiella sp. strain DP40, Marinobacter sp. strain DW44, Halomonas sp. strain BS53, and Vibrio sp. strain DS35. The application of bioremediation strategies with these bacteria can reduce crude oil pollution in this important marine environment.  相似文献   

天津沿海赤潮发生的基本特征研究     

张琪  孙家伟  冯延竹  李希彬  王鲁宁  崔健 《海洋预报》2020,37(1):62-66

使用《天津市海洋环境状况公报》中的数据,分析天津沿海赤潮发生的特征。通过分析发现2005-2017年天津海域共发生赤潮30次,累计发生面积4 695 km2。天津沿海赤潮发生主要集中在夏季,又以8月最多,占赤潮发生总数的30%。通过赤潮优势种的分析发现近年来天津海域赤潮生物的优势种类有不断增加的趋势。同时本文从水文气象条件诱发赤潮的角度分析得出了天津沿海最易发生赤潮的天气形势,天津沿海25~27℃水温范围内赤潮发生较多,最适宜赤潮发生的风速为3、4级风,风向为东南风、西南风。  相似文献   

南海沉积物细菌胞外蛋白酶在家族水平上的多样性   总被引：2，自引：0，他引：2  

杨金玉  冯阳阳  陈秀兰  解彬彬  张玉忠  石梅  张熙颖 《海洋学报(英文版)》2019,38(12):73-83

海洋产蛋白酶细菌及其分泌的胞外蛋白酶在降解有机氮以推动海洋氮循环进行方面发挥着重要作用，但目前对这二者多样性的认识非常有限。本研究自南海沉积物中筛选得到90株产蛋白酶细菌，并通过N-端氨基酸序列，分析了其胞外蛋白酶在家族水平上的多样性。16S rRNA基因序列分析的结果表明，筛选的产蛋白酶细菌均属于Gammaproteobacteria纲，且大多数属于Alteromonadales目和Vibrionales目的不同属。对其中14株菌株的14个胞外蛋白酶的N-端氨基酸序列分析表明，所有这些蛋白酶属于金属蛋白酶的M4家族或丝氨酸蛋白酶的S8家族。本研究提供了海洋沉积物产蛋白酶细菌在类群及其胞外蛋白酶在类型上的新细节，这将有助于全面了解微生物酶促降解海洋沉积物有机氮的过程和机理。  相似文献   

胶州湾沉积物中石油降解菌的降解能力及多样性研究     

高伟  高祥兴  米铁柱  韩彬  张毅然  李馨子  尹晓斐  孙承君  李倩  崔志松  栾晓  于志刚  郑立 《海洋学报(英文版)》2019,38(6):54-64

2013年青岛输油管道爆炸，大量石油污染了附近海岸。课题组采集了污染的沉积物样品，以原油为唯一碳源和能源，富集了四个石油降解菌群。生物多样性和群落分析表明，Luteibacter、Parvibaculum 和属于食烷菌科的一个属是降解菌群的主要优势菌，都属于变形菌门。从石油降解菌群中分离筛选，获得了9株具有不同16S rRNA基因序列的降解菌，分别属于8个属。重量法测定降解菌的石油降解率，其中5株的石油降解率大于30%。GC-MS分析结果表明，石油降解菌多倾向于降解烷烃，对多环芳烃的降解能力较差，其中5株细菌的烷烃降解率较大，仅1株菌D2对多环芳烃的降解率较大，其降解率在34.9%到77.5%。通过对高通量数据的分析，表明食烷菌属是菌群A和菌群E的主要降解菌群，其中筛选获得的菌株E4可能是菌群E的一株优势降解菌。本研究所筛选菌株证明了其石油降解潜力，为油污染海滩生物修复提供了菌株资源。  相似文献