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1.
从枸杞岛海藻场和对照点贻贝场分别采取表层及底层水样,利用细菌通用引物,提取样品总DNA进行聚合酶链式反应(PCR)扩增,采用16SrDNA文库技术,对其细菌群落进行鉴定和分析。结果表明,海藻场表层和底层细菌群落分为5和6个门,贻贝场表层和底层细菌群落分为3和4个门,海藻场中细菌分类门数多于贻贝场内,优势菌均为变形细菌门,分别占克隆文库的比例为40.7%、50%、59.1%和48.1%。γ-变形菌纲为变形细菌门的优势亚群,各个文库中均含有许多未确定其分类的序列,即含有许多未被认知的微生物类群。变形菌门、厚壁菌门和放线菌门为所有水样共有,但在水层垂直分布及不同地理位置间存在较大差异。不同功能类群可能与其特殊生境密切相关。  相似文献   

2.
微表层是海洋环境与大气对流层之间的一层生物膜,具有独特的海洋生态系统和物理化学、微生物组成。本研究采用传统的培养和流式细胞计数方法,比较了微表层和次表层(0.50米深)的细菌丰度,并对筛选的53株菌进行了测序,分析了可培养细菌的群落结构。此外,直接从微表层和相应次表层海水中提取DNA,通过变性梯度凝胶电泳(DGGE)方法分析了总细菌的群落结构。结果表明,海洋微表层存在一个特殊的生态群,其微生物群落结构明显不同于其相应次水层。本研究采用生态学分子技术全面阐述了中国北黄海微表层海水中的漂浮细菌群落结构。  相似文献   

3.
长江口及邻近海域表层海水细菌多样性及群落结构   总被引:4,自引:0,他引:4  
从长江口及邻近海域10 个站点采集表层海水, 通过DAPI 染色计数和克隆文库构建的方法, 对细菌的多样性及群落结构进行初步研究。DAPI 染色计数结果显示长江口及邻近海域表层海水中 细菌丰度总体较高, 生物量变化较大, 从1.16×105(A04 站点)到 1.48×106 cells/mL (B03 站点); 总体 趋势从长江口向外海增加。细菌克隆文库的系统发育分析表明: 细菌序列以变形菌门为主(占总文库 的60.61%), 其中α-变形菌纲是绝对优势类群(50.62%); 其次是拟杆菌门(15.18%)、放线菌门(14.79%) 和蓝细菌门(4.61%), 还有少量厚壁菌门、绿弯菌门、酸杆菌门、浮霉菌门、纤维杆菌门、疣微菌门 等; 另外柔膜菌门和SAR 类群也有发现。文库多样性分析结果显示长江口及邻近海域部分站点表层 海水中细菌多样性显著, 与研究区海域水产养殖活动有关, 并受到区域洋流和海洋化学环境(如低氧 带)的影响。  相似文献   

4.
通过荧光染色、稀释培养、生理生化和16SrRNA基因鉴定等方法,研究了北极黄河站附近海域海水中浮游细菌的丰度、可培养浮游细菌形态学特征及多样性;采用高通量测序技术研究了黄河站附近采样站点(BJ2)的不可培养浮游细菌群落结构。可培养研究结果表明:(1)9个站点(BJ1-BJ9)水样平均含菌数为2.88×108个/L;(2)21株可培养浮游细菌中,仅AB08、AB09和AB17三株细菌为革兰氏阳性菌;(3)细菌主要包括放线菌纲(Actinobacteria),黄杆菌纲(Flavobacteriia)和γ-变形菌纲(Gammaproteobacteria),其中假单胞菌属(Pseudomonas)为优势菌(占71%)。高通量测序结果显示:在得到的1 467个不可培养浮游细菌OTU中,变形菌门(Proteobacteria)和拟杆菌门(Bacteroidetes)为优势菌群,所占比例分别为49.71%和41.61%,还有少量的浮霉菌门(Planctomycetes)和疣微菌门(Verrucomicrobia);其中变形菌门中以α-变形菌纲(α-Proteobacteria)为主要类群。  相似文献   

5.
秦皇岛作为中国北方重要水产养殖基地,年年爆发褐潮,对当地生态环境造成巨大影响。针对微微型真核浮游生物、浮游病毒和浮游细菌三大类群,进行了褐潮前中2个时期丰度和群落结构及其主要影响因素的分析。本研究利用流式细胞仪技术对褐潮前期和褐潮中期秦皇岛近岸海域微微型真核浮游生物、浮游细菌和浮游病毒的丰度分布特征进行了研究;利用病毒宏基因组技术、18SrDNA V9区和16SrDNA V4~V5高通量测序技术对超微型浮游生物各个类群进行多样性研究。研究发现,褐潮中期微微型真核浮游生物丰度平均值为27.50×103个/mL,浮游细菌丰度平均值为1.97×105个/mL,浮游病毒丰度平均值为9.65×105 VLP/mL。褐潮中期藻类DNA病毒含量提高(20.30%);不等鞭毛虫门为微微型真核浮游植物主要优势类群;变形菌门为浮游细菌主要优势类群。海水生态系统中超微型浮游生物的多样性及丰度对褐潮的发生具有较高敏感性,未来,针对海洋超微型浮游生物的研究,对进一步了解褐潮机制和寻求褐潮消解方法提供了新的角度和思路。  相似文献   

6.
模拟了厦门沿岸海区病毒裂解产物对于自然细菌群落的影响.实验过程中基于不同过滤方式收集的细菌、病毒种群和病毒裂解产物,通过室内模拟培养方式,结合流式细胞计数和总有机碳分析仪分析病毒、细菌丰度和有机碳含量等技术,研究浮游细菌在病毒裂解产物添加下的生长变化.实验结果显示,去除原生生物捕食者的浮游细菌丰度在整个培养过程中持续增加,特别是病毒裂解产物添加组中的细菌类群的增长程度明显,其丰度在5 d的培养时间内从2.76×105cells/cm3上升至1.90×106cells/cm3;而在无病毒裂解产物添加组中其丰度仅仅从3.0×105cells/cm3上升至1.39×106cells/cm3;相对于无病毒裂解产物添加组,培养周期内细菌丰度均值在病毒裂解产物添加组中的绝对增量约为3.64×105cells/cm3,这表明此研究海区的病毒裂解产物在模拟原位环境的培养体系中可快速地被环境中的其他细菌类群吸收、利用,并且在丰度上产生显著影响(p0.05).结合病毒丰度变化以及细菌细胞裂解释放量、细胞碳含量的关系估算了收集来的病毒裂解产物在培养体系中释放的碳量大约为2.12~7.67μg/(dm3·d);它被浮游细菌用于丰度增长方面的贡献大约22.47%~81.25%.此外,在培养过程中,溶解有机碳的浓度在病毒裂解产物添加组中的变化相对于无病毒裂解产物添加组缓慢,但总体上两者随时间变化逐渐减少,它们间的均值差值约为1.04μmol/dm3;结合对应的细菌丰度增量,估算出培养体系中浮游细菌碳含量大约为34.29fg/cell.上述结果揭示了厦门沿岸海域内病毒裂解产物在维持细菌群落多样性和生长繁殖方面的重要生态作用.  相似文献   

7.
细菌群落在海洋生物地球化学过程中起着至关重要的作用。分析判别地理距离和环境条件等因素对细菌群落的影响,有助于理解环境变化如何驱动微生物多样性和功能的机制。通过细菌16SrDNA高通量测序的方法,对南海北部水层及沉积表层细菌群落多样性及空间分布进行比较分析,并检验环境因素、地理限制及海底深度等因素对微生物群落的影响。结果表明,约95%的细菌16SrDNA序列归属于γ-变形菌纲、厚壁菌门、蓝细菌门、α-变形菌纲等优势类群。沉积样本中的优势细菌类群主要与粒度、氮(N)等环境参数相关,而水体样本的优势细菌类群与取样深度密切相关。相关性检验结果显示,沉积样本的α-多样性指数与C有着显著的相关关系,而水体样本的α-多样性指数和β-多样性矩阵则显示与取样深度的显著相关;此外,地理距离和海底深度对β-多样性的影响并不显著,这可能与取样空间尺度有关。  相似文献   

8.
通过提取山东半岛北岸不同类型潮间带海水样品的总DNA,构建16S r DNA文库,利用群落相似性分析(ANOSIM)和非度量多维尺度转换排序(NMDS),探究潮间带类型对浮游细菌群落结构的影响,并对比了与近海浮游细菌群落结构的差异。分析结果显示,浮游细菌的丰度及多样性受到潮间带类型的影响,烟台养马岛泥滩、石滩、辛安河沙滩、黄河三角洲碱蓬区和天鹅湖海草区以变形菌门占优势,而黄河三角洲米草区以拟杆菌门为优势菌,其中,天鹅湖海草区浮游细菌的丰富度和多样性最高。潮间带海水中浮游细菌的组成与近海存在显著差异,潮间带浮游细菌的丰度及多样性均显著高于近海。推测季节因素、植被类型、有机质来源可能是造成潮间带不同生境与近海浮游细菌多样性差异的重要因素。  相似文献   

9.
研究海水环境中Q235碳钢锈层中微生物群落的多样性。应用16SrDNA基因文库技术,分别对实海全浸一年的Q235碳钢内外锈层中的微生物进行基因文库的构建和分析。通过克隆测序构建了含有64个OTUs的细菌16SrRNA基因文库,结果表明锈层中微生物种类丰富,主要分布于13个已知的菌门,包括变形菌门;拟杆菌门;硅藻门;酸杆菌门;浮霉菌门;硝化螺旋菌门;厚壁菌门;绿弯菌门;疣微菌门;绿菌门;放线菌门;红藻门以及螺旋体门。内外锈层的优势菌均为变形细菌门,分别占文库序列的46%和53%,其中α-变形菌纲又为门中优势类群,但在内外锈层中还存在明显的系统发育学分歧。  相似文献   

10.
为查明海水池塘跑道养殖系统(IPRS)的不同生境中细菌群落特征以及不同群落间的相互作用关系,本研究采用16S rRNA基因高通量测序技术对IPRS中鱼类肠道、水体和沉积物的细菌群落组成和结构进行了研究。研究表明,鱼类肠道、水体和沉积物的细菌群落在结构和多样性上均存在显著差异。不同生境中细菌群落的优势组成不同,花鲈(Lateolabrax maculatus)肠道内相对丰度最高的菌门为厚壁菌门(Firmicutes, 57.92%),河鲀(Takifugu rubripes)肠道内为弯曲杆菌门(Campylobacterota, 41.17%),水体和沉积物中均为变形菌门(Proteobacteria),其相对丰度分别达到91.03%和48.06%。LEfSe分析表明,栖粪杆菌属(Faecalibacterium)、拟杆菌属(Bacteroides)和罗氏菌属(Roseburia)等20个菌属在花鲈肠道内显著富集;unclassified_Arcobacteraceae、普雷沃菌属(Prevotellaa)和罗尔斯顿菌属(Ralstonia)等12个菌属在河鲀肠道内显著富集;伍斯菌属(W...  相似文献   

11.
The community composition,abundance and culturablity of heterotrophic bacterioplankton in the Dapeng Bay of the South China Sea were investigated by morphological method,bacterial cultivation and biochemical methods over an annual cycle.Aeromonas and Pseudomonas were the predominant genera among the Gram-negative bacteria.The bacterioplankton abundance fluctuated from 2.07×10 8 to 2.44×10 9 cells/dm 3 ,and culturable bacteria abundance ranged between 0.1×10 6 and 16.07×10 6 CFU/dm 3 .The Culturablity of heterotrophic bacteria ranged between 0.01% and 1.31%.The relationship between bacterial culturablity and the environmental factors was also studied in different sites of the Dapeng Bay.Throughout the bay,a significantly positive relationship was evidenced between bacterial culturability and temperature,meanswhile bacterial culturability was significantly inversely related with salinity.The positive relationship was shown at the central bay while a negative relationship was observed at the bay mouth and there was no significant correlation at top bay between bacterial culturablity and chlorophyll a of sea water.A positive relationship was found between culturability and DIN all the bay,but DIP showed a significantly negative relationship with bacterial culturability only at the mouth of the bay.  相似文献   

12.
2008年9月~2009年10月,对刺参肠道与养殖环境中异养细菌和弧菌周年变化进行了初步研究。结果表明:刺参肠道与养殖环境中(水体、底泥、附着基)异养细菌数(HPC)、弧菌数(VBC)均呈现出明显的季节变化,肠道中HPC、VBC分别为1.85×105~2.17×109CFU/g、4.1×104~2.2×108CFU/g,水体中HPC、VBC分别为90~4.67×105CFU/mL、0~5.3×103CFU/mL,底泥中HPC、VBC分别为9.80×104~6.72×106CFU/g、1.01×104~5.75×105CFU/g,附着基中HPC、VBC分别为2.78×105~2.57×107CFU/g、4.6×104~1.31×107CFU/g,夏、秋两季细菌总数较高,冬、春低温季节细菌数量显著下降。通过VBC与HPC的比值可以看出,在冬、春季细菌总数较低的季节,弧菌与异养细菌数量比例较高,最高值达到:43.8%、43.2%,通过对优势菌的分离鉴定,冬、春两季灿烂弧菌(Vibrio splendidus)均占优势,这可能是造成冬、春两季刺参发病的诱因之一。本文通过研究刺参肠道与养殖环境中异养细菌和弧菌的变化规律,以期为刺参的健康养殖提供有益参考。  相似文献   

13.
The paper considers the concentrations and functional characteristics of viruses, bacteria, and heterotrophic nanoflagellates determined for the first time in the Laptev Sea in August-September, 2014. The abundance of bacteria, viruses, and heterotrophic nanoflagellates varied from 110.1 × 103 to 828.4 × 103 cells/mL, from 384.2 × 103 to 2932.8 × 103 particles/mL, and from 108 to 651 cells/mL, respectively. The daily bacterioplankton production varied from 4.2 × 103 to 381.7 × 103 cells/mL, with an average of 117.6 × 103 cells/mL. Electron transmission microscopy has for the first time shown that the frequency of visibly infected bacterial cells varied from 0.2 to 2.0% (0.8% on average) of NB. The average virus-induced mortality of bacteria was 6.3% of bacterioplankton production, with variations ranging from 1.4 to 16.9%. Grazing on bacteria by heterotrophic nanoflagellates contributed more to bacteria mortality than virus-induced bacterial lysis. By grazing on bacteria, heterotrophic nanoflagellates consumed large quantities of viruses located on the surface and inside bacterial cells.  相似文献   

14.
研究了深圳海域2008年4月、9月的水体弧菌数量、种类组成及其分布,探讨了弧菌总数及各优势类群的数量分布与环境因子间的相关关系。结果表明:弧菌总数分布具有季节性,东部海域春季(4月)的弧菌数量高于秋季(9月)的,其均值分别为1.50×104 ,8.89×102 CFU/cm3;在西部海域秋季的略高于春季的,其均值分别为5.09×102,2.66×102 CFU/cm3;弧菌数量最高值出现在大亚湾(4.40×104 CFU/cm3)。弧菌的优势类群具有季节性分布特征:春季特有的优势类群有Vibrio gigantis类似种和V. splendidus类似种,秋季特有的优势类群有V. natriegens类似种;V. alginolyticus类似种是两个季节共有的优势类群,其数量春季高于秋季的。弧菌种类、数量与海水温度、盐度及细菌总数、Chl-a等环境因子有一定的相关性,其中盐度为弧菌种类及数量分布的主要影响因子。  相似文献   

15.
研究了深圳海域2008年4月、9月的水体弧菌数量、种类组成及其分布,探讨了弧菌总数及各优势类群的数量分布与环境因子间的相关关系。结果表明:弧菌总数分布具有季节性,东部海域春季(4月)的弧菌数量高于秋季(9月)的,其均值分别为1.50×104,8.89×102CFU/cm3;在西部海域秋季的略高于春季的,其均值分别为5.09×102,2.66×102CFU/cm3;弧菌数量最高值出现在大亚湾(4.40×104CFU/cm3)。弧菌的优势类群具有季节性分布特征:春季特有的优势类群有Vibrio gigantis类似种和V.splendidus类似种,秋季特有的优势类群有V.natriegens类似种;V.alginolyticus类似种是两个季节共有的优势类群,其数量春季高于秋季的。弧菌种类、数量与海水温度、盐度及细菌总数、Chl-a等环境因子有一定的相关性,其中盐度为弧菌种类及数量分布的主要影响因子。  相似文献   

16.
Dimethylsulfide enrichment in the surface microlayer of the South China Sea   总被引:5,自引:0,他引:5  
A total of 22 sea surface microlayer samples collected from the Nansha Islands waters of the South China Sea were analyzed for dimethylsulfide (DMS), chlorophyll a and nutrients including nitrate, phosphate and silicate. The DMS concentrations in surface microlayer samples ranged from 82 to 280 ng S/l with a mean of 145 ng S/l. A significant correlation was found between DMS and chlorophyll a data both in the surface microlayer as well as in the subsurface water. However, no correlation was observed between DMS and nutrient concentrations in the surface microlayer. The DMS concentrations were higher in all surface microlayer samples, compared with subsurface samples. The enrichment factor (EF) of DMS in the surface microlayer varied from 1.21 to 3.08 with an average of 1.95. The EF of DMS was significantly correlated with that of chlorophyll a in the microlayer. The enrichment of DMS in the microlayer may be due to two factors, including the in situ production from phytoplankton and the transportation from the underlying seawater. The diel variations in DMS and chlorophyll a concentrations were studied at a fixed station. The highest concentrations of DMS in the surface microlayer and subsurface water were simultaneously observed in the late afternoon (1800 h), while the highest levels of chlorophyll a were simultaneously found at night (0200 h).  相似文献   

17.
The number and lipolytic activity of neustonic and planktonic bacteria inhabiting estuarine Lake Gardno were determined. Lipolytic bacteria were very numerous in investigated layers of water, accounting for 10–88% of the total number of culturable heterotrophic bacteria. Significant differences were found in the decomposition of individual lipid substrates by bacteria. The highest percentage of neustonic and planktonic strains were able to hydrolyse tributyrin and Tween 85. The least numerous bacteria group was microflora hydrolysing Tween 20 and Tween 40. The activity of lipases synthesized by bacteria from the subsurface layer was higher than that of lipases produced by bacteria isolated from the surface layers. A significant effect of salinity on the activity of lipases has been shown.  相似文献   

18.
冬季刺参养殖环境与肠道内细菌菌群的研究   总被引:2,自引:0,他引:2  
运用传统细菌分离培养与分子生物学技术相结合的方法,对2008年11月至2009年1月冬季刺参(Apostichopus japonicus Liao)养殖池塘环境(养殖水、底泥、附着基)及刺参肠道内的细菌菌群进行了分析。应用平板稀释涂布培养计数法测得刺参养殖池塘水体、底泥、附着基和肠道细菌数量分别为0.75×102~1.4×104cfu/mL、8.7×104~8.1×105cfu/g、3.8×105~2.8×106cfu/g、7.1×105~1.5×107cfu/g;根据形态学差异从培养所得的细菌中筛选得到22株菌,用限制性内切酶Rsa I和Msp I对所分离菌株进行ARDRA(Amplified rDNA Restriction Analysis)分析,这22株菌被分为8种不同的分类单元(Operational Taxonomic Unit,OTU),其中OTU2与OTU3所包含的菌株分别占分离菌株种数的30%和20%;此外,作者对不同环境培养所得的优势度最高的细菌进行分子鉴定分析。结果表明:水环境中优势菌为施氏假单胞菌(Pseudomonas stutzeri)、门多萨假单胞菌(Pseudomonas mendocina)及巨大芽孢杆菌(Bacillus megaterium),沉积物中优势菌为巨大芽孢杆菌(B.megaterium)、施氏假单胞菌(P.stutzeri)、苏云金芽孢杆菌(Bacillus thuringiensis),附着基中优势菌为巨大芽孢杆菌(B.megaterium)、苏云金芽孢杆菌(B.thuringiensis),灿烂弧菌(Vibrio splendidus),肠道中优势菌为巨大芽孢杆菌(B.megaterium)、苏云金芽孢杆菌(B.thuringiensis),灿烂弧菌(V.splendidus)、施氏假单胞菌(P.stutzeri)。通过对冬季刺参池塘细菌菌群多样性分析和优势菌鉴定,为筛选低温益生菌和防治刺参疾病提供了有益参考。  相似文献   

19.
珠江口异养细菌时空分布特征及其调控机制   总被引:2,自引:0,他引:2  
河口是海陆相互作用的重要地带, 往往呈现出独特的生物地球化学过程, 是研究碳循环过程的重要场所。在春季(2015年5月)、夏季(2015年8月)和冬季(2016年1月)分别对珠江口海域异养附生细菌和游离细菌时空分布及其各自高核酸(HNA)、低核酸(LNA)类群的相对贡献进行了调查研究, 并对其调控因子进行了相应探讨。结果表明, 珠江口异养细菌分布具有明显的时空差异。空间分布上, 珠江口异养细菌丰度自河口上游至下游呈递减趋势, 主要与上游污水输入以及珠江径流与高盐外海水在河口内的混合有关; 在雨季, 河口中下游盐度锋面区出现异养细菌丰度和叶绿素a质量浓度的高值区, 锋面区使营养物质停留时间增加, 促进浮游生物生长。垂直方向上, 表层异养细菌丰度略高于底层。时间尺度上, 异养细菌总丰度在春季最高(表层均值为2.94±1.23×109个 •L-1, 底层为2.81±1.50×109个 •L-1), 夏季次之(表层均值为2.32±0.43×109个 •L-1, 底层为1.90±0.50×109个 •L-1), 冬季最低(表层均值为1.06±0.33×109个 •L-1, 底层为9.76± 3.44×108个 •L-1)。珠江口海域异养细菌以附生细菌为主, 占异养细菌总丰度的16.56%~96.19%, 整体分布较稳定, 冬季最高(平均78.65%)、夏季(70.32%)与春季相近(68.17%)。附生细菌以代谢活跃的HNA类群为主, 游离细菌则主要以LNA类群为主, 代谢活性整体相对较低。  相似文献   

20.
A seasonal study of the quantitative and qualitative distribution of heterotrophic bacterial community was carried out in the Adriatic Sea between April 1995 and January 1996, in order to evaluate its spatial and temporal variability and metabolic potential in the degradation processes of organic matter. The culturable bacteria (CFU) ranged between 0.1 and 22% of total bacterioplankton with a maximum percentage in surface samples of coastal zones. Their distribution was generally affected by the prevailing hydrological conditions. At the coastal stations about 44-75% of CFU variance could be explained by river runoff. The changes in the composition of heterotrophic bacterial community showed a seasonal succession of main bacterial groups, with a prevalence of Gram negative, non fermenting bacteria in the cold period (April-January) and an increase of Vibrionaccae and pigmented bacteria in summer. The seasonal variations were more important at the stations influenced by rivers than offshore. The bacterial community showed a greater versatility for organic polymers hydrolysis in the offshore station than in the coastal areas. Over 60% of all isolated heterotrophic bacteria expressed peptidase, lipase and phosphatase ectoenzymes activities, in all seasons and showed an increasing trend in warm period (in July October). The alpha- and beta-glucosidase potentials of bacteria were lower (20% on average) and showed different pattern during the year. These results suggest different role of the bacterial community in the decomposition of organic matter in the Adriatic Sea. Since only 20% of bacterial strains expressed glucosidase activity, carbohydrate-rich polymers such as mucilage might accumulate.  相似文献   

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