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1.
三种碳源对乌梁素海好氧不产氧光合细菌群落结构的影响 总被引：3，自引：1，他引：2
好氧不产氧光合细菌(AAPB)营光合异养,在水体碳循环中起着重要作用.但是,碳源对AAPB群落结构的影响尚不明确.本文基于16S rDNA和光合反应中心合成中的关键基因——pufM基因,运用变性梯度凝胶电泳(DGGE)技术,比较分析了在微生物分离培养中常用的3种碳源(葡萄糖、丙酮酸钠、酵母提取物)对乌梁素海水体总细菌及AAPB群落结构的影响.结果表明,不同碳源诱导7~21 d后,水体总细菌群落丰富度及多样性指数均有不同程度的提升,AAPB群落则呈现先升后降的趋势.3种碳源中,丙酮酸钠添加后对总细菌及AAPB菌群的丰富度和多样性的提升效果最好.测序及系统发育结果表明,乌梁素海水体经诱导后新检测到了一些原环境中未发现的菌属,一些具有特殊碳代谢能力的菌属丰度得到了提升.本研究为充分认识和理解AAPB的生态学作用和意义,及其富集、分离和培养提供了基础依据. 相似文献
2.
悬浮物在自然水体（池塘、河流、湖泊等）中普遍存在，相较于上覆水，是微生物更为倾向的附着载体。相较于沉积物，更易获取硝酸盐，是水体反硝化发生的热点微区。悬浮物在水体中经历一系列碰撞、絮凝、溶解、离子交换、吸附解吸等物理化学过程，从而会引起颗粒物粒径、营养盐浓度等发生变化；悬浮物的沉降和再悬浮过程也会引起上覆水和沉积物之间的物质交换，并在好氧缺氧过渡过程中对氮转化造成影响，从而直接或者间接影响水体反硝化速率。本文概括了国内外关于悬浮物影响水体反硝化的研究进展和热点，总结了不同浓度、粒径、组成和种类的悬浮物对反硝化作用的影响，从溶解氧、功能微生物、无机氮、有机碳等环境因素重点归纳了悬浮物影响反硝化的过程，比较和分析了悬浮物反硝化的测定方法。结合当前悬浮物反硝化研究现状，建议未来可以从新兴污染物悬浮物、机理模型、测定方法等方面展开深入研究。 相似文献
3.
极端降水是影响水环境质量的重要气象因素之一,随着全球气候变暖,极端降水事件的频率和量级呈显著上升的趋势,对湖泊水化学和水环境产生了深刻的影响.白洋淀是华北地区重要的湖泊型湿地和生态功能区,为查明极端降水条件下白洋淀主淀区的水化学和水质特征,本研究利用Piper三线图、Gibbs图和多元统计方法阐明了白洋淀极端降雨后的水化学特征、氢氧稳定同位素特征和水质空间变化,揭示了极端降水条件对白洋淀主淀区水化学和水质的影响.结果表明：（1）在极端降水条件下,白洋淀主淀区湖水呈弱碱性,水化学类型主要为Ca-HCO3·SO4型,极端降水减弱了蒸发结晶作用和人类活动等因素对白洋淀主淀区湖水水化学组成的影响.极端降水是导致白洋淀主淀区pH、电导率和总溶解性固体发生大幅度变化的原因之一.（2）极端降水条件下白洋淀主淀区湖水的δ2H和δ18O值的范围分别为-60.86‰~-35.01‰和-8.84‰~-3.45‰,其值均与水深呈显著负相关.极端降水使得白洋淀主淀区湖水的氢、氧稳定同位素贫化,但对其空间分布的影响不大,湖水氢、氧同位素关系受降水本身氢、氧同位素关系的影响更为强烈.强降水引起白洋淀的水深突然增加,导致湖水受到的蒸发分馏作用影响减弱.（3）极端降水增加了面源污染扩散的速度,导致白洋淀主淀区湖水中的氨氮、硝态氮和总磷等营养物质浓度升高,白洋淀大气降水中的氨氮也可能导致极端降水条件下主淀区湖水中氨氮浓度升高,而上游水库为了应对强降雨事件进行的调蓄放水使得白洋淀东北部水质有所改善.该研究为白洋淀的生态修复治理和雄安新区的生态系统管理提供了科学依据. 相似文献
4.
蓝藻对太湖底泥反硝化过程的影响和机理分析 总被引：3，自引：1，他引：2
通过模拟实验,研究了因自然或人工沉降的太湖蓝藻在厌氧条件下作为碳源对底泥微生物反硝化脱氮的促进作用.通过对底泥总氮、化合态氮素、挥发性脂肪酸(VFAs)、COD、电位和pH等指标的监测,发现藻体中大量的生物可降解碳素在厌氧消解后产生挥发性脂肪酸等一些可供反硝化菌直接利用的小分子物质,2×藻组VFAs含量可达2232.96μl/L,1×藻组可达1263.36μl/L,最高可达42.1%,为对照组(无添加蓝藻)的2.43倍,从而促进了硝态氮和亚硝态氮还原成N2和N2O的过程,提高氮素的去除率.但底泥中沉降蓝藻需要一定的降解时间,前4天添加冷冻干蓝藻粉的处理组COD降解率较低,电位处于正值,体系中产生硝态氮,随后COD持续降低,添加2×藻组COD最大去除率为42.08%,1×藻组为32.93%,对照组仅为14.46%,表明藻细胞中的碳素已开始被利用.本研究表明沉降蓝藻细胞能够为底泥中的反硝化过程提供可利用碳源,并深入揭示了沉降蓝藻作为碳源促进底泥反硝化过程的机理和对底泥中C、N的影响,为在湖泊治理中降低氮素的内源污染提供了新的科学依据. 相似文献
5.
水库近岸湿地(消落带)土壤N2O释放和反硝化作用是消落带氮的生物地球化学过程的重要组成部分.以三峡水库支流澎溪河高阳平湖库湾消落带为研究对象,于2013年落干初期,采用C2H2抑制-原状土柱培养法研究该处自然植被恢复区、农耕区和对照组等不同土地类型土壤的N2O释放速率和反硝化速率,并测定了土壤p H值、氧化还原电位、温度、有机质、总氮、铵态氮、硝态氮和土壤孔隙含水量等环境指标.结果表明,自然植被恢复区土壤N2O释放速率为9.88±6.49 g N/(hm2·d),反硝化速率为58.94±52.84 g N/(hm2·d);农耕区土壤N2O释放速率和反硝化速率分别为7.71±4.44和30.70±25.68 g N/(hm2·d).不同土地类型间N2O释放速率差异显著,落干初期土壤氧含量、含水量及氮含量对不同土地类型N2O释放和反硝化作用影响明显.土壤氧含量的升高促进了自然植被恢复区的N2O释放,并在一定程度上抑制了该区域反硝化作用.农耕区土壤含水量高于自然植被恢复区,可能致使N2O释放速率低于自然植被恢复区,而反硝化速率高于自然植被恢复区.消落带土壤氮含量降低同反硝化速率降低有一定联系. 相似文献
6.
太湖梅梁湾水土界面反硝化和厌氧氨氧化 总被引：18，自引：3，他引：15
运用无扰动芯样实验室内流动培养、稳定同位素示踪、同位紊气态产物测定及同位素配对技术,对太湖梅梁湾北部到南部的4个梯度样点的水土界面反硝化和厌氧氨氧化速率进行研究.结果表明,梅梁湾内及湾外开敞湖区4个样点的水土界面反硝化脱氮速率为(46.36±13.26)-(16.34±22,74)μmol/(m~2·h),厌氧氨氧化脱氮速率为(7.50±2.21)-(2.05±2.90)～mol/(m~2.b).梅梁湾北部河口区水土界面总脱氮能力明显高于梅梁湾南部及开敞湖区.通过对脱氮过程的进一步研究发现.北部脱氮过程主要以上覆水硝酸盐为底物的非耦合反硝化过程(D_w)为优势过程,而梅梁湾外开敞湖区则以沉积物硝化过程耦合控制的反硝化(D_n)为主.影响D_n、D_w在反硝化中比重的主要因素是沉积物溶氧侵蚀深度和上覆水NO_3~-.浓度的差异;梅梁湾厌氧氨氧化脱氮比例占总脱氮比例为12%-14%,湾外开敞湖区则占11%,影响其比例差异的主要因子是反硝化强度的大小及其反硝化中间产物--亚硝酸盐含量的差异. 相似文献
7.
湖泊底泥疏浚环境效应:Ⅲ.对沉积物反硝化作用的影响 总被引：8，自引：1，他引：7
通过为期一年的疏浚模拟试验,在试验室培养疏浚与对照柱样,研究了底泥疏浚对沉积物反硝化过程的影响.沉积物反硝化速率的测定采用经典的乙炔抑制法.研究结果表明,在一年的试验周期内,疏浚和对照柱沉积物的反硝化速率分别为6.9-26.9nmol/(g·h)和21.6-102.7nmol/(g·h),除2006年的2月外的其他月份,疏浚沉积物的反硝化速率显著(P<0.05)低于未疏浚对照沉积物,同时还研究了环境因子对沉积物反硝化速率的影响,结果表明,疏浚和对照沉积物的反硝化速率都受温度的控制.硝态氟浓度是疏浚和对照沉积物反硝化速率的主要限制因子,有机碳对疏浚沉积物的反硝化速率有影响,但对未疏浚对照沉积物的反硝化速率没有影响.疏浚后短期内沉积物反硝化速率低于未疏浚对照沉积物,可看作是底泥疏浚在富营养华水体脱氮方面的一个负效应. 相似文献
8.
超微真核藻个体微小、比表面积大,具有高效的碳吸收速率,对水体初级生产力具有重要的贡献.目前对淡水超微真核藻的认知还非常有限.于2017年5月对白洋淀进行采样调查,结合流式细胞术和高通量测序技术探究了白洋淀超微真核藻群落结构的空间分布特征及关键环境影响因子.结果表明,白洋淀超微真核藻的平均丰度为7.59×104cells/ml,且随着营养水平的升高呈现先增加后降低的变化趋势.回归分析表明,超微真核藻丰度在中营养水平水域主要受溶解性总磷和TN/TP影响,在富营养水域主要与盐度有关.测序比对结果表明在纲水平上白洋淀超微真核藻主要以绿藻纲Chlorophyceae、硅藻纲Bacillariophyceae、中心硅藻纲Coscinodiscophyceae、金藻纲Chrysophyceae为主,不同区域差异不大.但在操作分类单元(Operation Taxonomy Units,OTU)水平上,超微真核藻群落结构在白洋淀不同营养状态湖区存在显著差异,中营养水域主要类群为栅列藻科Scenedesmaceae,近囊胞藻属Paraphysomona sp.,定鞭藻纲Haptophyceae和甲藻纲Dinophyceae为主,而富营养水域主要类群为红球藻科Haematococcaceae,金藻纲的Chromulinale sp.和Chrysophycea sp..Bioenv分析表明,对超微真核藻群落组成影响最大的环境因子是溶解性总氮、溶解性总磷、TN/TP、硝态氮、溶解氧.本研究表明超微真核藻的群落结构存在较明显的环境异质性,对白洋淀水体富营养化状态有很好的指示. 相似文献
9.
基于植物昼夜释氧变化规律的复合垂直流人工湿地氮形态 总被引：1，自引：1，他引：0
为了研究植物根系释氧规律对人工湿地中硝化与反硝化作用的影响,采用传统连续运行方式及根据释氧规律调节的新型运行方式(白天连续进水、夜间停水),在复合垂直流人工湿地小试系统中进行实验,采用代表性的挺水植物香蒲作为湿地植物,水力负荷为0.71 m3/(m2.d).结果表明:系统内白天以好氧的硝化作用为主,夜间以厌氧、缺氧的反硝化作用为主,且在新型运行方式下,系统内白天亚硝酸盐氮累积量为传统运行方式的5倍,硝酸盐氮累积量为其2倍,夜间亚硝酸盐氮和硝酸盐氮减少量又分别比传统运行方式高64%和26%.这说明在新型运行方式下,人工湿地脱氮效果优于传统运行方式. 相似文献
10.
《湖泊科学》2022,34(2)
湖 泊 科 学（Hupo Kexue）
2022年第34卷第2期3月6日
目次
综述
湖泊蓝藻水华防控方法综述（349）
史小丽,杨瑾晟,陈开宁,张民,阳振,于洋
噬藻体对蓝藻种群密度的调控及其对水体中物质循环的影响（376）
张奕妍,黄兰兰,王夕予,丁士明,刘子鹤,童银栋
研究论文
——富营养化与水华防控
基于Sentinel-3 OLCI影像的巢湖藻蓝素浓度年内动态遥感监测（391）
汪志成,王杰,晏实江,崔玉环,王行行
南亚热带特大型水库浮游植物群落特征及其与环境因子的关系：以新丰江水库为例（404）
张辉,彭宇琼,邹贤妮,张婷婷,巫楚,乔永民,杨洪允
钱塘江干流夏季浮游植物群落结构特征及其对水文气象的响应（418）
张萍,国超旋,俞洁,权秋梅,姚建良,王吉毅,叶小锐,朱梦圆,孙起亮,朱广伟
鄱阳湖流域柘林水库秋季浮游植物群落结构及其构建过程驱动机制（433）
陈康,孟子豪,李学梅,朱挺兵,胡飞飞,刘璐,朱永久,范春林,杨德国
城市中小河道沉水植物盖度和生物量计算方法——基于上海市的调查分析（445）
张群,刘家霖,朱义,张春松,宋晴,崔心红
——生物地球化学与水环境保护
太湖沿岸区浅层底泥重金属污染分析及生态风险评价（455）
陆志华,蔡梅,王元元,钱旭,潘明祥
水库环保疏浚及板框脱水工程中余水水质及变化规律（468）
朱伟,许小格,侯豪,程林,李岳鸿,林小蔚,吴勇
新疆艾比湖流域河湖水质变化（20052020年）（478）
张飞,王维维,辛红云,郝晋新,刘长江,段潘
白洋淀湿地表层土壤主要环境元素分布特征及来源（496）
刘雪松,王雨山,王旭清,尹德超
白洋淀湿地不同植物群落区表层沉积物碳氮磷化学计量特征（506）
尹德超,王雨山,祁晓凡,安永会,王旭清,徐蓉桢
基于SWAT模型的典型农业小流域氮污染时空分布特征及关键源解析（517）
王慧勇,遆超普,王良杰,董磊,夏永秋,颜晓元
鄱阳湖水体溶解无机碳的季节变化、输送及其来源（528）
李艳红,葛刚,胡春华
白洋淀春季沉积物好氧反硝化菌群落结构特征及对溶解性有机物的响应（538）
陈召莹,张甜娜,张紫薇,周石磊,董宛佳,崔建升,罗晓
亚高山湖泊天才湖周边土壤腐殖酸的光降解研究（553）
安世林,罗春燕,陈煜,杜瑛珣
——淡水生态与生物多样性保育
网围拆除后东太湖鱼类功能群时空变化及影响因子（569）
谷先坤,刘燕山,唐晟凯,李大命,张彤晴,曾庆飞,毛志刚,陈辉辉,谷孝鸿
秀丽白虾(Exopalaemon modestus)对亚热带湖库春夏季水体营养水平和浮游生物群落的影响——
基于微宇宙模拟实验（582）
宁晓雨,张磊,陈坤全,韩财安,李启升,李宽意,何虎,赵璧影
基于脂肪酸生物标志物分析南京市及其周边不同营养水平湖库的浮游动物碳源（590）
马静静,李廷真,李宽意,苏雅玲,刘正文
——流域水文与水资源安全
鄱阳湖环湖灌区枯季缺水量分析及对策建议（601）
李振旗,程和琴,李纪人,向诗月,滕立志
三峡水库蓄水前后长江中下游流量频率分布特征及其对洪水造床作用的影响（616）
周炜兴,孙昭华,周坤,李芷晴,陈立
控制反调节水库协同生态调度的优化策略：以三峡葛洲坝梯级水库为例（630）
李游坤,林俊强,秦鑫,刘毅,任玉峰,张晓光
基于频谱分析的水体波浪紊动流速分离方法（643）
段雨新,张占飞,张英豪
半干旱地区洪水模拟效果差异性分析及影响因子响应评估（652）
刘玉环,李致家,刘志雨,罗赟,霍文博
过坝下泄水流中温室气体排放速率的数值模拟（664）
黄菊萍,欧洋铭,李然,冯镜洁,李哲
——湖泊沉积与环境变化
太湖流域长荡湖近百年生态环境演变过程（675）
刘维淦,林琪,张科,沈吉
黑龙江省连环湖孢粉记录揭示的约220年的环境变化与人类活动（684）
王小丽,肖海丰,肖霞云
自然解读
神奇的球状冰（冰球、冰蛋）（695）
解飞,卢鹏,程斌,杨倩,李志军 相似文献
11.
《Advances in water resources》2004,27(4):335-348
Heterotropic bacteria can degrade organic substrates utilizing different terminal electron acceptors. The sequence of electron acceptor utilization depends on the energy yield of the individual reaction pathway, which decreases as the redox potential decreases. Due to these differences in energy yield, and an inhibiting activity of oxygen on some enzymatic processes, the simultaneous utilization of oxygen and nitrate as terminal electron acceptors may not occur for many degradation processes, unless the oxygen concentration falls below a given threshold level (about 0.2 mg/l).Two sand column experiments were conducted, with toluene as the carbon source, and showed an apparent simultaneous utilization of oxygen and nitrate as electron acceptors in regions where the oxygen concentration was significantly higher (⩾1.1 mg/l) than the above mentioned threshold concentration. Results from aerobic and anaerobic plate-count analyses showed growth of both aerobes and denitrifiers in the zone of the column where simultaneous utilization of oxygen and nitrate was observed. From these observations, it was postulated that the porous media contained oxygen-free microlocations where the denitrifiers were able to degrade the toluene.To simulate the observed dynamics, a dual biofilm model was implemented. This model formulation assumes that the biofilm is composed of two distinct layers, where the outer layer is colonized by aerobic bacteria and the inner layer by denitrifying bacteria. The thickness of the aerobic layer is such that oxygen is depleted at the boundary of these two layers, resulting in oxygen-free microlocations that allows denitrification to proceed, even though oxygen is still present in the bulk fluid phase. The model simulations compared well to the experimental profiles. Model analyses indicated that changes in physical, chemical, and hydrologic parameters could change the length and location of the zone where at the macroscopic level, oxygen and nitrate are utilized simultaneously. Comparisons of the proposed model to macroscopic modeling approaches showed that a dual biofilm model is able to describe the simultaneous utilization of oxygen and nitrate more accurately. 相似文献
12.
Increased construction of coastal canal communities had led to a deterioration of the water quality in the canals. In addition to being used for recreational activities, the canals serve as a dumping place for domestic sewage from these communities. This study was conducted to determine the prevalence of transferable drug-resistant (R+) bacteria in six coastal canals. A significantly higher number of R+ bacteria (both pathogenic and nonpathogenic) occurred in the bottom sediments than in the overlaying water. These sediments can be resuspended following rain, dredging, storms, boating, and diving, thus releasing their bacterial populations into the overlaying water. 相似文献
13.
14.
In a previous study we demonstrated the progressive disappearance of Escherichia coli populations upon contact with marine environment (Bianchi & Mircea, 1976). We have used the same experimental device to study the behaviour of other bacteria of enteric or terrigenous origin (Vibrio cholerae, Streptococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa) when rejected into the sea. 相似文献
15.
Magnetotactic bacteria and their magnetofossils in sediments 总被引：1，自引：0，他引：1
Living magnetotactic bacteria from freshwater environments show, under natural and laboratory conditions, a great variety of morphological appearances. Their magnetosomes vary in number, shape, and size. One species of bacteria yields up to 1000 magnetosomes per cell. Individual particles reach a size of up to 200 nm. As a rule, they form elongated chains. In bacteria which are held under laboratory conditions, loop-shaped arrangements and nearly unordered clusters are also found. During the laboratory experiments, different species of bacteria periodically dominated. Freshwater samples always exhibited a great variety of different magnetosomes. On the other hand, samples from marine environment clearly showed the preponderance of one type of particle. These observations may reflect specific properties of the physico-chemical milieu in which the bacteria grew. At the end of our experiments north- and south-seeking bacteria co-existed in roughly equal quantities.Quaternary unconsolidated sediments from the Ammersee (Bavaria) and the Antarctic, Quaternary to Tertiary deep-sea sediments from the Atlantic and Pacific, and Jurassic limestones from the Sonnwendgebirge (Tyrol, Austria) were analyzed for fossil magnetosomes. We found that fossil magnetosomes were morphologically similar to those from living bacteria, but seemed to be corroded in some cases.The observed differences in quantity, size and shape of magnetosomes from various sediments may be influenced by variations in bacterial viability and particle stability at different sites, but are not determined by geographical latitude. 相似文献
16.
Sulfur cycling in the biosphere is tightly interwoven with the cycling of carbon and nitrogen, through various biological and geochemical processes. Marine microorganisms, due to their high abundance, diverse metabolic activities, and tremendous adaptation potential, play an essential role in the functioning of global biogeochemical cycles and linking sulfur transformation to the cycling of carbon and nitrogen. Currently many coastal regions are severely stressed by hypoxic or anoxic conditions, leading to the accumulation of toxic sulfide. A number of recent studies have demonstrated that dissimilatory sulfur oxidation by heterotrophic bacteria can protect marine ecosystems from sulfide toxicity. Sulfur-oxidizing bacteria have evolved diverse phylogenetic and metabolic characteristics to fill an array of ecological niches in various marine habitats. Here, we review the recent findings on the microbial communities that are involved in the oxidation of inorganic sulfur compounds and address how the two elements of sulfur and carbon are interlinked and influence the ecology and biogeochemistry in the ocean. Delineating the metabolic enzymes and pathways of sulfur-oxidizing bacteria not only provides an insight into the microbial sulfur metabolism, but also helps us understand the effects of changing environmental conditions on marine sulfur cycling and reinforces the close connection between sulfur and carbon cycling in the ocean. 相似文献
17.
《Advances in water resources》2007,30(6-7):1608-1617
Populations of chemotactic bacteria are able to sense and respond to chemical gradients in their surroundings and direct their migration toward increasing concentrations of chemicals that they perceive to be beneficial to their survival. It has been suggested that this phenomenon may facilitate bioremediation processes by bringing bacteria into closer proximity to the chemical contaminants that they degrade. To determine the significance of chemotaxis in these processes it is necessary to quantify the magnitude of the response and compare it to other groundwater processes that affect the fate and transport of bacteria. We present a systematic approach toward quantifying the chemotactic response of bacteria in laboratory scale experiments by starting with simple, well-defined systems and gradually increasing their complexity. Swimming properties of individual cells were assessed from trajectories recorded by a tracking microscope. These properties were used to calculate motility and chemotaxis coefficients of bacterial populations in bulk aqueous media which were compared to experimental results of diffusion studies. Then effective values of motility and chemotaxis coefficients in single pores, pore networks and packed columns were analyzed. These were used to estimate the magnitude of the chemotactic response in porous media and to compare with dispersion coefficients reported in the field. This represents a compilation of many studies over a number of years. While there are certainly limitations with this approach for ultimately quantifying motility and chemotaxis in granular aquifer media, it does provide insight into what order of magnitude responses are possible and which characteristics of the bacteria and media are expected to be important. 相似文献
18.
Sulfate-reducing bacteria (SRB) HSR1, HSR4, and HSR14 isolated from the salt pans of Goa grew best at 90-100/1000 salinity on substrates like formate, acetate, lactate, butyrate, ethanol and benzoate. They were gram negative, non-sporulating, non-motile rods lacking in desulfoviridin and cytochromes. Examination of these isolates for heavy metal tolerance and response studies in terms of growth and sulfate-reducing activity (SRA) were carried out using HgCl2 and Pb(NO3)2 at final concentration of 50, 100, and 200 and 100, 200 and 500 microg ml(-1) respectively. With Hg, HSR1 showed approximately 80% of the control's growth at 100 and 200 microg ml(-1) but SRA reached only 60% of the control values at the end of 14 days. HSR14 could reach >100% of the control's growth at 200 microg ml(-1) but the SRA reached only up to 60% of the control without metal at 100 microg ml(-1). Though the concentration of Pb was double that of Hg, HSR4 could grow and respire better than the control, the growth being stimulated by 160% and respiration by 170% in the presence of 500 microg ml(-1) of Pb(NO3)2. It is probable that some hypersaline SRB are more tolerant to heavy metals than the mesohaline counterparts and could be more effectively used for precipitating these metals in bioremediatory measures. Further examination of their responses to varied concentration of metals under different salinities would indicate their range of applicability. 相似文献
19.
《国际泥沙研究》2020,35(3):227-236
The spatial distribution of bacterial communities inhabiting sediment is heterogeneous at different spatial scales,but mostly unexplored.Here,it is postulated that the heterogeneity of the bacterial community composition varies at the same scale of the heterogeneity of sediment chemical properties.The large spatial scale(km) diversity in sediment from a brackish water lagoon(Chilika Lake,India) is studied,considering the large scale physical and chemical characteristics of land cover,climate,pH,and salinity.Seventy-two samples(24 stations,3 seasons:winter,rainy,and summer) of sediment from Chilika Lake were analyzed by 16 S ribosomal ribonucleic acid(rRNA) gene sequencing,and the relations with land cover and other physico-chemical paramete rs are discussed.Mo re samples were collected after a severe cyclonic storm(Phailin) passed near the lagoon in 2013,to see the impact of the tropical storm on the spatial and tempo ral distribution of bacteria in the sediment.The results demonstrate clear spatial relations between physico-chemical parameters(e.g.,salinity),land surfaces(e.g.,drainage area),and the distribution of sediment microbial communities. 相似文献
20.
M.L. Lizárraga-Partida H. Rodríguez-Santiago J.M. Romero-Jarero 《Marine pollution bulletin》1982,13(2):67-70
Heterotrophic and hydrocarbonoclastic bacteria were enumerated at the water surface and in sediment at 14 stations located in the Ixtoc I area. The distribution of heterotrophic bacteria in water and in sediment seems to be influenced by the river waters and the characteristics of sediments. The concentrations of hydrocarbonoclastic bacteria in sediments are low, and their relative percentage in regard to the heterotrophic bacteria, which are in general less than 1%, lead us to believe that the area studied was not affected by the Ixtoc I blowout. 相似文献