Sabella spallanzanii filter-feeding on bacterial community: ecological implications and applications

The filtration process of Sabella spallanzanii Gmelin on bacterial community was studied in a coastal area of the Northern Ionian Sea (Mediterranean Sea) at three sites, S. Vito, Lido Gandoli and Lido Silvana, where some specimens of S. spallanzanii were transplanted. Analyses were performed both on water and worm samples. A total of six microbial groups were examined: culturable heterotrophic bacteria, total culturable bacteria at 37 degrees C, culturable vibrios, total and fecal coliforms and fecal streptococci. The bacterial densities were usually orders of magnitude higher in the worm homogenates than in the corresponding seawater and the highest values were observed in August. The ability of S. spallanzanii to accumulate the microbial pollution indicators suggests this species can be employed as a bioindicator for monitoring water quality. Moreover, the accumulation capability of S. spallanzanii for specific micro-organisms provides a potential role in sewage bioremediation.     

Microbial pollution indicators and culturable heterotrophic bacteria in a Mediterranean area (Southern Adriatic Sea Italian coasts)

In the present study we evaluated the degree of microbial water pollution along the coast line between Brindisi and Santa Maria di Leuca (Southern Adriatic Sea) as well as the culturable heterotrophic bacteria abundances and biodiversity in relation to the microbiological quality of the water. A total of 3773 colonies were isolated, subcultured and identified by several morphological, cultural and biochemical methods including the standardized API 20 E and API 20 NE tests. Along the examined coastal tract the microbial pollution indicators were always below the tolerance limits for bathing waters defined by the CEE directive, suggesting a good sanitary quality. Concerning culturable heterotrophic bacteria, different temporal density trends were observed in the four sites in relation to their geographical position. A positive relationship between the bacterial abundances and the temperature was observed in S. Cataldo and Otranto. The culturable bacterial community was mainly composed of the genera Aeromonas, Pseudomonas, Photobacterium and Flavobacterium. The Enterobacteriaceae family represented a conspicuous component of the bacterial community too. Bacilli were predominant among the Gram-positive bacteria. Of interest is the isolation of yeasts (2% at the surface and 1% at the bottom) taking into account their capability of biodegradation of various materials. Because of the low level of microbial pollution recorded, our results are indicative of the natural variation and diversity of the culturable bacterial community in such an oligotrophic ecosystem and could represent a good point of comparison with other ecosystems as well as a baseline for long term studies aimed to evaluate the effects of environmental fluctuations and human impacts on this aspect of biodiversity in coastal areas.     

基于多种培养基和不同培养温度的马里亚纳海沟异养细菌多样性分析

马里亚纳海沟具有低温、高压、永久黑暗以及营养匮乏等深海环境特征,其中的细菌多样性对深海环境具有极为重要的作用。为研究马里亚纳海沟海水中异养细菌的物种多样性,采用多种培养基、不同培养温度同步筛选,单菌落16S rRNA基因序列鉴定,邻近法系统发育树构建分析等方法,对25个海水样品进行异养细菌多样性分析。共获得细菌531株,对其中371株进行16S rRNA基因鉴定,共分布41属,97种。经系统进化分析,异养菌株分布于4门:厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)、放线菌门(Actinobacteria)和拟杆菌门(Bacteroidetes)。优势菌群为Proteobacteria,占鉴定菌株数量的58%,其中γ-Proteobacteria占总菌数的52%。此外,还发现4株潜在新物种。     

海南红树林根系土壤中可培养细菌的多样性分析

为研究海南红树林根系土壤细菌多样性,充分发掘中国红树林特有微生物资源,作者于2012年12月份从10份采集于海南北港岛红树林根系淤泥样品中分离可培养海洋细菌,并基于16S rRNA基因序列分析的方法对样品中的细菌多样性进行研究。共分离得到122株海洋细菌,经并菌后选取其中的70株代表性菌株测序,结果发现它们分为4个类群:变形菌门(主要为γ-变形菌纲)(Proteobacteria)、拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)和放线菌门(Actinobacteria),分别占66%,19%,11%和4%。共代表30个属47个种,其中有9个潜在新种和2个潜在新属。本研究结果表明,北港岛红树林中存在着丰富的细菌多样性,很多类群可能是红树林特有细菌物种。     

北黄海微表层细菌丰度与可培养细菌群落结构分析

为分析海洋微表层这一特殊生境中的细菌类群,于2010—2011年4个航次对北黄海微表层和次表层海水中的总菌丰度、可培养细菌丰度和群落结构进行了分析。采用流式细胞仪测定总菌丰度,平板计数法测定可培养细菌丰度,PCR-16SrDNA分析可培养细菌的群落结构。结果表明,调查海域微表层海水总菌均值为1.76×106 cell/mL,次表层海水总菌均值为1.07×106 cell/mL。可培养细菌丰度范围是1.00×102~1.70×106 CFU/mL,微表层和次表层可培养细菌所占总菌数量的百分比分别为13.05%和0.45%。微表层对总菌的富集因子(EF)均值为2.02,可培养细菌的EF均值为74.16。PCR-16SrDNA序列分析结果表明,该海域可培养细菌分属变形菌门(Proteobacteria)(94.34%)、厚壁菌门(Firmicutes)(1.89%)、拟杆菌门(Bacteroidetes)(1.89%)和放线菌门(Actinobacteria)(1.89%)4个类群。本研究初步发现,微表层对细菌具有较强的聚集作用,尤其对可培养细菌聚集作用更为明显。微表层中可培养细菌的群落结构与次表层有所不同,其种类丰富,来源和功能多样。由此可见,微表层独特的生境成就了其独特的微生物类群,其生态功能有待于进一步研究。     

Bacterial accumulation by Branchiomma luctuosum (Annelida: Polychaeta): a tool for biomonitoring marine systems and restoring polluted waters

In this study, we examined the bacterial accumulation in the filter feeder polychaete Branchiomma luctuosumGrube (Sabellidae). Analyses were performed on worm homogenates from 'unstarved' and 'starved' individuals, and seawater from the same sampling site (Gulf of Taranto, Western Mediterranean, Italy). Densities of culturable heterotrophic bacteria (22 degrees C), total culturable bacteria at 37 degrees C and halophilic vibrios at 22 and 35 degrees C were measured on Marine Agar 2216, Plate Count Agar and thiosulphate-citrate-bile-salt-agar (TCBS) plus 2% NaCl, respectively. Total and faecal coliforms as well as faecal streptococci were determined by the Most Probable Number method. Results showed that B. luctuosum is able to accumulate all the considered six microbiological groups with a higher efficiency for autochthonous bacteria. The analysis also indicated that bacterial groups differ in their resistance to digestion by B. luctuosum. Our data suggest the potential role of B. luctuosum as an useful bioindicator to assess low levels of microbiological water pollution as well as bioremediator of microbial polluted waters.     

Heterotrophic bacteria in the northern Adriatic Sea: seasonal changes and ectoenzyme profile

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.     

俄罗斯库页岛潮间带沉积物可培养细菌的系统发育多样性

采用2216E、R2A、M1培养基,首次从俄罗斯库页岛潮间带沉积物样品中分离到82株可培养海洋细菌,经查重并菌后选取其中45株具有代表性的菌株进行了16S r RNA基因序列分析和多样性研究。结果发现,它们共分布于变形细菌门(Proteobacteria)、放线菌门(Actinobacteria)、拟杆菌门(Bacteroidetes)和厚壁菌门(Firmicutes)4个类群(分别占45株代表菌株的42.2%、20.0%、20.0%和17.8%),代表着6个纲、27个属、44个种;同时发现其中有8个潜在新种和1个潜在新属。本研究结果表明,俄罗斯库页岛潮间带沉积物可培养细菌的系统发育多样性非常高,大部分菌株与分离自日本和韩国近海的细菌物种在系统发育关系上高度同源,但也存在不少潜在的新物种。     

山口红树林根际土壤可培养细菌多样性及其活性筛选

为探讨广西山口红树林土壤可培养细菌的多样性，采用纯培养分离技术对采集的25个红树林样品进行可培养细菌多样性分析，挑选117株菌株进行16S rRNA基因测序并构建系统发育树分析。结果表明117株菌株分别属于9个纲20个目27个科35个属，9个纲包括α-变形菌纲（21.37%）、β-变形菌纲（1.71%）、γ-变形菌纲（12.82%）、δ-变形菌纲（0.85%）、噬纤维菌纲（0.85%）、鞘脂杆菌纲（0.85%）、黄杆菌纲（2.56%）、放线菌纲（27.35%）、芽孢杆菌纲（31.62%）。优势属为芽孢杆菌属，占所有菌株的28.20%，此外α-变形菌纲、γ-变形菌纲、黄杆菌纲和放线菌纲中发现了7株潜在的新物种。分离菌株的产酶活性检测表明，山口红树林根际土壤蕴含丰富的产淀粉酶、蛋白酶、葡聚糖、纤维素酶和几丁质酶等生物活性酶的菌株，其中芽孢杆菌纲的产酶菌株数最为丰富。初步研究结果表明广西山口红树林土壤可培养细菌资源丰富，新物种资源多样，是农业微生物开发应用的重要资源库。     

印度洋深海沉积物样品纯培养细菌的分离鉴定

为探索印度洋深海沉积物中纯培养细菌的多样性,本文对采自印度洋12个沉积物样品进行细菌纯培养分离,共获得343株细菌.所有细菌采用16S?rRNA基因进行比对分析,鉴定为4个门:厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)、放线菌门(Actinobacteria)和拟杆菌门(Bacteroi...     

仿刺参(Apostichopus japonicus)肠道菌群的地域性差异与共性研究

作为高附加值水产养殖物种,仿刺参(Apostichopusjaponicus)的病害和病原微生物研究受到人们关注,但对其共生菌群组成、地域性差异及与水体环境间交流等方面的研究仍十分有限。本研究收集了来自中国、日本和韩国共786例仿刺参肠道、水体和沉积物的16SrRNA基因高通量测序数据,比较细菌群落组成以探寻仿刺参肠道微生物与环境和地域之间的关系。分析结果显示,尽管仿刺参肠道、水体和沉积物中各细菌组分的比例不同,但共有菌属甚多,表明仿刺参可以从外界环境大量获取微生物。与水体和沉积物的样本类型相比,仿刺参肠道微生物多样性最低且所含菌属的种类最少,进一步提示仿刺参肠道对外界来源的微生物进行了富集和筛选,其中变形细菌门(Proteobacteria)、假单胞菌属(Pseudomonas)、嗜冷杆菌属(Psychrobacter)和利斯顿氏菌属(Listonella)的富集尤为明显。中国、日本和韩国来源的仿刺参肠道微生物Alpha多样性无显著差异,但主坐标分析将它们聚为不同的簇,且各自拥有独特的细菌门类。比较中国渤海和黄海两个海区的仿刺参肠道菌群获得了相似的结果,体现出广泛的地域性差异。基于细菌分类的功能预测发现三个国家仿刺参肠道微生物均具有发酵、化能异养和需氧化能异养功能,表明共生菌群在功能上存在共性,并可能对宿主生理产生相同的作用。本研究揭示了仿刺参肠道微生物在不同地域之间存在明显差异,并且与水体环境之间存在着密切的联系,能够为仿刺参共生微生物及其与宿主健康的相关性研究提供基础性资料,并可能在自然循环过程和渔业资源保护过程中发挥作用。     

乳山湾的污染与异养微生物的调查分析

于1985年5—10月定期采取了乳山湾内和岸边养虾池的水样及底泥进行了异养微生物的分析。菌数的平均值池内高于湾内,其最高值和水中COD的最高值同时出现在养虾旺季的8月份。在湾泥和池泥中的硫酸盐还原菌数均高达10~6个/克以上,与同期内硫化物的最高含量(326mgS/kg)相一致。并发现病原性弧菌也广泛存生。异养菌种群的组成,假单胞杆菌占有最大的比值,反映出该水域为污染类型。上述结果表明该湾的水质条件已远超出国家渔业水质标准,呈现高度的有机物污染状态,其污染源与湾边周围开展大面积的养虾有关。     

Isolation and diversity analysis of heterotrophic bacteria associated with sea anemones

A study was undertaken to investigate the heterotrophic bacterial flora associated with the sea anemones. Samples of the sea anemones Anthopleura midori were collected from the coast of Weihai and bacteria were isolated from these samples. Additionally, high numbers of viable bacteria were obtained from the celom wall and surface of anemone, the community of cultivable bacteria was very diverse. As a result of this isolation, 60 strains were obtained, 56 of them were selected for identification and characterization by 16S rRNA gene sequence analysis and limited phenotypic testing. Among these isolates, 16 strains were phylogenetically related to members of the genus Pseudoalteromonas and neighboring taxa. Other isolates included members of the genera Colwellia, Vibrio, Acinetobacter, Pseudomonas, Endozoicomonas, Roseovarius, Paracoccus, Loktanella, Leisingera, Sulfitobacter, Bacillus, Staphylococcus, Plantibacter, Microbacterium, Micrococcus, Joostella, Psychroserpens, Cellulophaga, Krokinobacter, Polaribacter and Psychrobacter. Seven potential novel species were found. Among 60 strains, 17 of them can produce proteolytic exoenzyme, 20 can produce lipolytic exoenzyme. Strain NQ8 has strong antagonistic effects on some Vibrio strains. This study demonstrates that the culturable fraction of bacteria from the sea anemones Anthopleura midori is diverse and appears to possess much potential as a source for the discovery of novel bioactive materials.     

南极菲尔德斯半岛可培养土壤微生物多样性及理化性质鉴定

为了探索南极可培养土壤微生物的多样性,本研究对中国第31次南极科学考察采集自南极菲尔德斯半岛的5份土壤样品进行了细菌、真菌的分离培养。选择形态差异较大的细菌和真菌进行了16S rDNA和ITS鉴定及系统发育分析。最终共鉴定得到20个属的33株细菌和6个属的8株真菌,其中8株细菌,10株真菌序列相似性较低,可能是新种。该结果表明南极菲尔德斯半岛地区具有丰富的微生物多样性,其中假单胞菌属的细菌居多。对分离得到的细菌和真菌分别进行理化性质和胞外酶活性鉴定,实验结果显示,分离获得的细菌和真菌绝大多数可产生水解酶类并同化多种碳源。初步认定这些微生物在参与南极物质代谢、适应南极极端环境方面发挥作用。本研究丰富了对南极菲尔德斯半岛可培养土壤微生物多样性的认识,并筛选获得了一些产低温酶特性的菌株,这为极地微生物资源的利用研究奠定了基础。     

THE HETEROTROPHIC MICROBES IN DRY VALLEYS VICTORIA LAND AND ROSS ISLAND, ANTARCTICA

During the expedition from Dec. 1981 to Feb. 1982, Dry Valley, Victoria and Ross Island Beach in Antarctica were visited. From ten stations samples of water, soil, snows and seawater were collected, from which heterotrophic microbes (including bacteria, yeast and fungi) were isolated and identified. Results show that there are ten genera of bacteria, nine genera of yeast and nine genera of fungi. Most of the strains grow at the temperatures of 20℃ and 5℃, while a few grow only below 5℃. More bacterial genera were isolated from the beach and nearby lakes than those from the inland Dry Valley, indicating the relations between the strain composition and geographical location and environmental conditions of the polar zone.     

Heterotrophic bacteria of the Dapeng Bay in the South China Sea: community structure, abundance, and the relationships of culturablity with environmental factors

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.     

Short-term bacterial reactivity of nitrogen-enriched seawater of a eutrophic lagoon

We carried out, in September, a 24 h experiment to determine the potential reactivity of bacterial communities found in the sea water in Arcachon Basin (France). To create eutrophic systems, batches of seawater were enriched with 30 mgl^?1 of either ammonium chloride or amino acids. Samples were taken every 3 h. Quantitative measurements were made of direct counts (AODC), biomass and ATP content. The heterotrophic bacterial communities were defined in terms of their catabolic potentialities and ‘specific’ diversity. Bacterial heterotrophic activity was established by measuring heterotrophic uptake and the mineralization percentage of labelled glucose or amino acids. From these data, ratios of AMP/ATP and P/B were calculated where P is the uptake of labelled substrate and B is the biomass.After the nitrogen enrichment an increase of the respiration was seen at first. After 6 h, a biomass peak appeared associated with a continuous increase in the number of cells. Bacterial growth was concurrent with a qualitative modification of the community: UAI increased, and diversity dropped. A less diversified community resulted suggesting an immature ecological state (zymogenous bacterial). Low values of respiration percentage (20%) characterized high growth yields.     

北极海洋沉积物中可培养细菌及其多样性分析

利用Zobell 2216E培养基和涂布平板法对北极海洋沉积物中可培养细菌进行分离纯化,并利用16SrRNA基因进行分子鉴定与系统发育分析。根据菌落形态学特征,从59个站点的沉积物样品中共分离纯化获得570株细菌;基于16SrRNA基因的分子鉴定与系统发育分析表明,分离到的可培养细菌分别属于细菌域的4个门,5个纲,12个目,23个科,47个属,102个种,其中γ-Proteobactria占绝大多数;有14株菌株与模式菌株的16SrRNA基因序列相似性小于97%,为6个潜在的新种。北极海域的海洋沉积物中存在着丰富的微生物种质资源,为开发新型生物活性物质和特殊功能基因打下了基础。     

青岛多种天气下生物气溶胶中细菌群落特征

为探究雾、霾、沙尘等多种天气下生物气溶胶中细菌群落结构特征,于2017年12月—2018年4月采集了青岛晴天和多种特殊天气下的大气生物气溶胶样品,运用16S rRNA高通量测序方法分析了样品中细菌群落结构。结果表明,在雾、霾、沙尘天均检测到对人体健康存在潜在危害的条件致病菌,其中变形菌门(Proteobacteria)均是优势细菌门,不受天气条件变化影响;霾天时其相对丰度最大。除此以外,沙尘和霾发生时,细菌群落结构显著变化,丰富度和多样性高于晴天,但随霾污染程度的加剧,群落丰富度和多样性下降;雾天多样性下降,丰富度变化不显著。在霾天,不同气团来源中细菌群落结构也存在显著差异。属水平上,霾天不动杆菌(Acinetobacter)和鞘氨醇单胞菌(Sphingomonas)占主导地位;雾天微球菌(Micrococcus)、副球菌(Paracoccus)和假单胞菌(Pseudomonas)占主导地位;沙尘天的优势菌为芽孢杆菌(Bacillus)。RDA分析显示O₃是影响菌群的主要环境因子。     

南极罗斯海区域可培养微生物分离鉴定及产低温酶能力初步筛选

为了利用南极微生物资源、探索南极罗斯海区域可培养微生物多样性，利用传统平板培养法对中国第33次南极科学考察采自南极罗斯海6个站位的海洋沉积物样品进行了细菌、真菌的分离培养。经细菌16S rRNA、真菌ITS基因序列检测及系统发育分析，共获得5个属的36株细菌和6个属的29株真菌。其中嗜冷杆菌属为优势细菌类群，枝孢属为优势真菌类群。该结果表明南极罗斯海区域具有丰富的微生物多样性。细菌API 20 NE生理生化及真菌产胞外酶活性实验显示，分离得到的细菌和真菌绝大多数都有低温酶活性。研究结果为南极罗斯海区域可培养微生物的多样性认识和低温酶产生菌资源获取与开发利用提供了支撑。