Structure analysis of shallow water ecosystems: Interaction of microbiological,chemical and physical characteristics measured in the overlying waters of sandy beach sediments     

Manfred Bölter  Lutz-Arend Meyer-Reil 《Estuarine, Coastal and Shelf Science》1981,13(5):579-589

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Bacterial production and carbon conversion based on saltmarsh plant debris     

R.C. Newell  E.A.S. Linley  M.I. Lucas 《Estuarine, Coastal and Shelf Science》1983,17(4):405-419

There is a well-defined succession of micro-organisms which colonize powdered leaf debris from Spartina alterniflora and Juncus roemerianus, and aged natural detrital material when these were incubated in estuarine water at temperatures near to those recorded in the habitat at the time of collection. The natural assemblage of free-living bacteria in estuarine water rapidly enters logarithmic growth, subsequently declining with the increase in numbers of bactivorous microflagellates. These are then replaced by a mixed population of ciliates, choanoflagellates, amoeboid forms and attached bacteria which form part of a complex microbial community associated with particulate debris. The rate of increase of bacterial cells (μ), in both spring and summer experiments ranged from 0·010–0·108 h^?1 whilst estimates of bacterial carbon production ranged from 1·5 to 10·1 μg C 1^?1 h^?1, values which conform well with estimates obtained from natural assemblages of marine bacteria in coastal and estuarine waters elsewhere. Although both the ease of degradation of the detrital substrate and incubation temperature are of importance, enrichment of both powdered Spartina leaf debris and aged natural detritus with inorganic nutrients evidently enhances bacterial production under experimental conditions. In addition, the amount of carbon utilized to sustain bacterial carbon production shows a significant reduction following enrichment with NH₄, NO₃ or combinations of NO₃ + PO₄. The bacterial carbon conversion efficiency (μg C incorporated into bacterial production per μg C consumed) × 100, based on powdered Spartina leaves, and aged natural detritus, is thus increased from 9–14%, to as much as 38% in nutrient enriched media. Since NH₄, NO₃ and PO₄ values are generally low in the water column, it seems likely that bacteria achieve a carbon conversion of only 9–14% on natural suspended detrital material, with the possibility of an enhanced conversion of up to 38% occurring at the sediment-water interface where ammonia regeration occurs. This suggests that suspended bacteria which characterize estuarine waters of salt marsh areas may be responsible for the oxidation of 86–91% of the carbon which enters water column microheterotroph food chains, and are probably implicated in the large CO₂ fluxes recently recorded from coastal wetland habitats.  相似文献   

The relationship between fatty acid distributions and bacterial respiratory types in contemporary marine sediments     

R.J. Parkes  J. Taylor 《Estuarine, Coastal and Shelf Science》1983,16(2):173-189

Bacterial communities of different respiratory types were isolated from a marine sediment in a multiple chemostat system in an attempt to obtain bacterial cultures representative of the sediment. The fatty acid distribution of a mixed culture of sulphate-reducing bacteria isolated from this system showed a good correlation with the lipid distribution of the zone of maximum sulphate-reduction activity within the sediment. Both distributions had significant concentrations of C14 : 0, iso and anteiso C15 : 0, C16 : 0, C16 : 1ω7 and C18 : 1ω7. This was in contrast to the lipid profile of Desulfovibrio desulfuricans obtained by batch enrichment, which was dominated by iso C17 : 1ω7 fatty acids and correlated poorly with the sediment. The bacterial community cultured from the sediment was further differentiated according to respiratory types (aerobic, facultative aerobic and facultative anaerobic) by growth in a chemostat under defined conditions. The fatty acid distributions of these communities were sufficiently different to enable the various respiratory types to be recognized by their particular fatty acid composition. Cyclopropyl fatty acids (?17 and ?19) were present in significant levels only in the aerobic bacteria, while the facultative aerobes had significantly higher C18 : 1ω7 than the other cultures and the facultative anaerobic community was the only culture to have significant amounts of C12 : 0. The fatty acid distribution of Loch Eil sediment over the range C12-19 seemed to be predominantly of bacterial origin and were relatively abundant to a depth of 6 cm. The concentration of cyclopropyl fatty acids was highest in the oxidized surface sediments and decreased with depth as anaerobic conditions began to dominate, indicating that these fatty acids may only be indicative of aerobic sedimentary bacteria. In contrast to the fatty acids characteristic of bacteria, those fatty acids in the range C20-30 attributed to a terrestrial input were found in relatively constant concentrations over the whole 0–12 cm depth profile.  相似文献   

Extracellular release of small and large molecules by phytoplankton in the Southern Bight of the North Sea     

Christiane Lancelot 《Estuarine, Coastal and Shelf Science》1984,18(1):65-77

Extracellular release by phytoplankton of small and large metabolites (molecular weight 〈and〉 500 d) is determined kinetically in various marine ecosystems including the eutrophic Scheldt estuary, the Belgian coastal zone and the oligotrophic English Channel. Kinetic curves show that while small metabolites are immediately released in the external medium, a lag phase is always observed in the release of large metabolites. Results indicate that 9–48% of the total excreted amount ends up in the small metabolites pool with no dependence on light intensity or nutritive conditions. Relative rates of heterotrophic uptake of the phytoplankton extracellular metabolites are calculated from the time dependent distribution of ¹⁴C labelled extracellular products. The data indicate that small molecules with high turnover rates (up to 25% h^?1) may occasionally be excreted by phytoplankton cells. The turnover time of high molecular weight excreted compounds is much longer. A correlation is found between the rate of production of these large extracellular metabolites and the exoenzymatic activity of the bacterial populations.  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     

L.L.Barton 《中国科学D辑(英文版)》2005,(3)

A lot of fossil bacteria and algae, which were re-placed by uraninite ( pitchblende), were first found inthe ores when the authors studied the sandstone-hostedinterlayer oxidation-zone type uranium deposits innorthwest China[1,2]. It is known that a powerful radia-tion from the uranium ores is harmful and, evendeadly to any life, including microorganism. Whatmechanism does this inconceivable fact result from?Up to the present time in China, there has been no ex-perimental investigation on red…  相似文献   

Vertical quantitative and dominant population distribution of the bacteria isolated from the Muztagata ice core   总被引：6，自引：0，他引：6  

XIANG Shurong  YAO Tandong    AN Lizhe    WU Guangjian  XU Baiqing  MA Xiaojun  LI Zhen  WANG Junxia & YU Wusheng . Key Laboratory of Ice Core  Cold Regions Environment  Cold  Arid Regions Environmental  Engineering Research Institute  Chinese Academy of Sciences  Lanzhou  China  . Institute of Tibetan Plateau Research  Chinese Academy of Sciences  Beijing  China  . College of Life Science  Lanzhou University  Lanzhou  China 《中国科学D辑(英文版)》2005,48(10)

With rapid development of microbiology on ex-treme environment, many microorganisms have been found on glacial surface and in deep glacier around the world. The extensive 16S rRNA sequence analysis of bacteria isolated from glacial samples indicates that the bacteria in ice are highly similar to those from ocean, lake, terrestrial sediment and agricultural soil on the earth[1,2]. This suggests a close relationship be-tween the microorganisms in glacial region and those in other environments s…  相似文献   

污水人工快速渗滤系统中氨氧化菌16S rDNA的DGGE分析     

马鸣超  姜昕  刘菲  李俊 《高校地质学报》2007,13(4):688-693

为了研究污水人工快速渗滤系统(CRI)中氨氧化菌的空间分布规律以及NH4-N在CRI中的迁移转化机理,从深圳运行中的CRI系统砂层填料中以5~10cm间隔垂直取12个样品,对其氨氧化菌的16SrDNA进行DGGE分析。结果表明,CRI系统中氨氧化菌菌群随着深度的增加先增多后减少,在表层至10cm处氨氧化菌约有4~5种组成,主要由某些以有机氮为降解底物的微生物和进水中被砂粒介质截流吸附的微生物组成;在20~90cm范围内氨氧化菌增加至9种左右,多样性最为丰富,是亚硝化作用发生的主要区域;而在100cm以下的范围,由于NH4-N浓度的降低或系统复氧不足,氨氧化菌迅速减少至5~6种。该研究结果证明了氨氧化菌在快渗池内分布范围的变化对NH4-N去除率的影响,即氨氧化菌在快渗池内分布的越接近中上层,对NH4-N的去除效果越好。关于CRI系统中氨氧化菌的空间分布规律及其与NH4-N去除率关系的认识,为工艺改进和效果提高提供了理论基础。  相似文献   

几种矿物粉尘对硅酸盐细菌S35生长的影响     

代群威  董发勤  邓建军 《矿物学报》2006,26(1):33-37

通过对6种矿物粉尘主要化学成分的分析,以及它们与硅酸盐细菌S35的相互作用后各培养液pH值、葡萄糖(GLU)、电解质以及Mn、Si、Fe等的变化的测试,比较矿物粉尘的化学成分和物理性状对试验目标菌生长的影响。利用SEM分析对粉尘与细菌的作用过程中细菌形态和界面作用情况进行了研究。结果表明,所选各种矿物粉尘对细菌生长情况的影响存在差异,矿物粉尘对硅酸盐细菌生长的影响可能与粉尘的化学成分有关。  相似文献   

预处理／复合水解酸化／复合好氧氧化工艺处理综合制药废水   总被引：2，自引：1，他引：1  

张兰英  刘峰  刘娜 《吉林大学学报(地球科学版)》2008,38(6)

针对传统水解酸化和好氧氧化处理工艺存在的问题,对水解酸化工艺及好氧氧化处理工艺进行了改进;并针对东北制药集团制药废水水质特征,设计开发了预处理 复合水解酸化 复合好氧氧化的生物处理技术。工程设计规模为30000 m3/d,两年的运行结果表明,此工艺运行稳定,耐冲击负荷能力强。当平均进水浓度COD为3600 mg/L、BOD5为1000 mg/L、SS为450 mg/L时,平均出水浓度COD≤300mg/L、BOD5≤100 mg/L、SS≤50 mg/L,达到了国家城市排水三级标准医药企业污水排放标准(COD300mg/L)。  相似文献   

Bacterial and algal hydrocarbons in sediments from a saline Antarctic lake, Ace Lake     

John K. Volkman  David I. Allen  Philip L. Stevenson  H.R. Burton 《Organic Geochemistry》1986,10(4-6)

Capillary gas chromatography-mass spectrometry (C-GC-MS) and Iatroscan thin layer chromatography-flame ionisation detection (TLC-FID) were used to study hydrocarbon distributions in a sediment core from Ace Lake, a saline, meromictic lake in the Vestfold Hills of Antarctica. Hydrocarbons were abundant in most core sections (up to 125/μg/g dry wt), particularly in near-surface samples, and the distributions were very complex. Major constituents were identified as phytane, 2,6,10,15,19-pentamethyleicosane, tetrahydrosqualene, a mixture of phytenes, cholesta-3,5-diene and fern-7-ene. Smaller amounts of sterenes and hopenes were also present. The predominance of the first 3 acyclic isoprenoids in sediments buried less than 30 cm is consistent with high populations of methanogenic bacteria known to be present.Phytenes were abundant in all core sections, and there was no relationship between their abundance and that of phytane which suggests that they were not derived from methanogenic bacteria. Phytadienes were minor constituents at all depths studied. An unusual feature of some distributions was the high concentrations of fern-7-ene which was the major hydrocarbon in the 20–25 cm core section. This alkene was only abundant in sediments which contained high concentrations of methanogen markers suggesting that it may also be indicative of anoxic depositional environments. A possible source might be from purple non-sulphur bacteria. High concentrations of straight-chain C₂₉ and C₃₄ alkenes were also found in these sediments but their origin has not been determined. Major changes in the hydrocarbon distributions with depth indicate that the depositional environment in the lake has altered dramatically since the lake was formed less than 8000 years ago. The present condition of permanent anoxic bottom waters probably developed only in the last 1000 years.  相似文献