安徽升金湖越冬白头鹤（Grus monacha）肠道菌群组成的时间变化

肠道微生物对于维持动物消化道内环境的稳定具有重要意义,而肠道微生物菌群结构也受寄主食物成份等外界环境因素的影响.研究动物肠道微生物菌群结构可以更好地了解动物生活状况.以升金湖越冬白头鹤的粪便作为研究对象,以微生物16S rRNA的V3~V4区作为标记基因,进行高通量测序,分析升金湖越冬不同时期白头鹤肠道菌群结构的差异性.研究结果表明:升金湖越冬期不同时期白头鹤粪便样品中微生物多样性指数如香农威纳多样性指数和辛普森指数无显著性差异.但是越冬期不同阶段的粪便样品中菌群组成存在差异,主要包括:在门分类水平,越冬前期拟杆菌门含量较高,厚壁菌门含量较中后期低;越冬中期放线菌门含量较高;越冬后期变形菌门含量较高.在属分类水平,相对于其他两个时期,越冬前期普氏菌属(Prevotella)含量较高,越冬中期杆菌属(Lysinibacillus)含量较高,越冬后期梭菌属(Clostridium)含量较高,并且普氏菌属含量从越冬前期到中期、再到后期有明显的下降趋势,而梭菌属含量从越冬前期到中期、再到后期有明显的升高趋势.这些结果表明不同越冬时期白头鹤肠道菌群组成不同,越冬期不同阶段的食物变化可能作为一个影响因素.     

黑鲷(Acanthopagrus schlegelii)肠道细菌群落对饲料中添加不同羽毛粉的响应

羽毛粉是一种潜在的饲料蛋白源。在水产动物饲料中添加适量的羽毛粉,不仅可以降低饲料成本,而且有助于禽类废弃物的再利用。在动物消化、降解、吸收羽毛粉过程中,动物肠道中的微生物可能发挥着重要作用;添加羽毛粉的饲料对鱼类肠道微生物多样性与群落结构的影响目前还不清楚。基于细菌16SrRNA基因高通量测序,作者对比研究了以添加羽毛粉(包括水解、酸解、膨化处理或生羽毛粉实验组,添加量为5%)和不添加羽毛粉的饲料(即对照组,包括鱼粉和商业饲料两组)喂养黑鲷12周后,黑鲷肠道细菌多样性与群落结构的变化情况。统计分析结果表明:添加羽毛粉的实验组中肠道细菌的丰富度、辛普森指数和香农指数显著低于对照组(P0.05);不含酸解羽毛粉组的实验组,其细菌群落结构与对照组差异显著(P0.05)。总体来看,黑鲷肠道细菌主要由厚壁菌门(57.3%)和变形菌门(36.3%)组成;实验组细菌群落中拟杆菌纲、梭菌纲、δ-变形菌纲、草酸杆菌科和青枯菌属的相对丰度显著低于对照组。不同的羽毛粉处理组之间也呈现出群落结构上的差异:与水解羽毛粉组相比,生羽毛粉组的变形菌门、γ-变形菌门、海洋螺菌目、盐单胞菌科和盐单胞菌属的相对丰度显著下降;与鱼粉组相比,生羽毛粉组中芽孢杆菌目在群落中的占比显著上升,而拟杆菌门、草酸杆菌科和青枯菌属的占比则显著下降,而且生羽毛粉组中厚壁菌门与变形菌门相对丰度的比值(7.42)明显高于鱼粉组(0.97)和水解羽毛粉组(0.74)且均接近显著(P=0.057)。与鱼粉组相比,水解羽毛粉组中紫单胞菌科和回线属的相对丰度显著下降,而盐单胞菌属的相对丰度显著上升。     

Molecular analyses of bacterioplankton communities with highly abundant Vibrio clades: a case study in Bohai Sea coastal waters

We investigated the bacterioplankton abundance, community composition and the associated Vibrio clades of natural seawater in Bohai Sea coastal waters. Seawater samples (10 L in triplicate) were collected at 0.5, 3, and 5 m depths near the coastal aquaculture zone of the Bohai Sea on May 12, 2016. Real-time PCR and 16S rRNA gene amplicon high-throughput sequencing methods were employed by which 485 operational taxonomic units (OTUs) at a 97% sequence similarity level were generated. Gammaproteobacteria, Alphaproteobacteria, and Bacteroidetes were the most abundant groups, accounting for 49.5%, 23.5%, and 18.9% of the total assemblage, respectively. Obvious variations in Pseudoalteromonas, Vibrio, and Octadecabacter , which were the most abundant genera, could be observed among diff erent samples. Notably, the results of Vibrio -specifi c real-time PCR indicated that Vibrio had extremely high 16S rRNA gene copy numbers. The 16S rRNA gene sequencing results across all the samples also indicated that they occupied a large proportion of the total assemblage. Both the alpha diversity and major bacterioplankton group Pseudoalteromonas had significant correlations with the concentration of PO4^3-. Overall, studies on bacterioplankton communities with highly abundant Vibrio clades can provide interesting insight into the microbial function and health assessment of the Bohai Sea coastal ecosystem.     

南海三沙永乐龙洞古菌群落结构与多样性特征

海洋蓝洞作为一种独特的海洋地貌单元,洞内的生物群落结构与生态系统特征一直是国内外同行学者关注的热点问题之一。南海三沙永乐龙洞是世界上最深的海洋蓝洞(300m),其独特的生态特征更为引入瞩目。本研究以古菌16S rRNA基因序列为目标,采用Illumina高通量测序技术对西沙永乐龙洞内水体与沉积物中的古菌群落结构进行了研究。结果表明,本研究所获得的古菌类群可归为4门、21纲、29目、42科、45属,广古菌和奇古菌是丰度最高的两种古菌。龙洞内表层水体中古菌群落多样性与洞外水体相差不大,但随深度增加,洞内古菌群落多样性显著降低,深水层古菌群落结构与浅水层差异显著。龙洞内沉积物中的古菌生存环境与水体差异巨大,为大量特殊物种提供了生存空间。侧壁沉积物中的古菌群落多样性随深度增加显著降低,而150m平台处古菌群落多样性则远高于侧壁沉积物。水温对龙洞内水体中的古菌群落结构具有显著影响(P0.01)。研究结果显示永乐龙洞古菌群落有很高的多样性,其垂向分布与洞内环境多要素的变化密切相关。本研究对认识三沙永乐龙洞内的生态系统特征有显著意义。     

基于MOD16的山西省地表蒸散发时空变化特征分析

基于MOD16全球蒸散发产品和气象站点实测数据,运用变异系数法、Sen趋势法等研究了山西省2000—2014年地表蒸散发ET、潜在蒸散发PET的空间分布特征、变化趋势及影响因素。结果表明：① MOD16蒸散产品与气象站点实测蒸散发之间具有良好的时空相关性(R ²=0.90),其产品精度可以满足山西省蒸散发时空分布研究的要求;②山西省多年平均ET、PET分别为816.77、1608.46 mm,年内变化表现为先增高后下降的“单峰”型分布,二者差值在5月、6月最大,此时山西省最为干旱;③ 全省年平均ET呈现西北低、东南高的分布特征,PET呈西南高、东北低的分布特征,二者差值整体上较大,表现为全省地表水分比较缺乏,其中忻州、吕梁西部最为严重;④ 全省近15 a来ET和PET的年际变化都比较小,整体上全省PET在增加,ET在相对减少,意味着近15 a来干旱情况在加剧;⑤ ET、PET的时空变化与诸多气象因子相关,在空间尺度上与降水、相对湿度密切相关,在时间尺度上与气温、降水关系最为密切。     

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.     

印度洋深海热液区可培养细菌的分子鉴定与系统发育分析

采用MMJHS寡营养培养基从印度洋深海热液区沉积物和热液硫化物中分离获得16株细菌,通过16S rDNA序列比对和生理生化分析,对它们进行了鉴定并构建了系统发育树.结果表明,12株细菌属于γ-变型菌(γ-Gammaproteobacteria),其中6株属于盐单胞菌属(Halomonas),4株属于嗜冷杆菌属(Psychrobacter),2株属于食碱菌属(Alcanivorax);其余4株属于芽孢杆菌(Bacillus),其中1株为地衣芽孢杆菌(Bacillus licheniformis).分离获得的16株细菌中,4株为革兰氏阳性细菌,12株为革兰氏阴性细菌;H2S反应、吲哚测定反应、M.R和V-P均呈阴性.本研究为深入认识和开发利用深海热液区微生物资源奠定了基础.     

16S rRNA Gene Phylogenesis of Culturable Predominant Bacteria from Diseased Apostichopus japonicus(Holothuroidea,Echinodermata)

Cultured Apostichopusjaponicus in China suffers from a kind of skin ulceration disease that has caused severe economic loss in recent years. The disease, pathogens of which are supposed to be bacteria by most researchers, is highly infectious and can often cause all individuals in the same culture pool to die in a very short time. The 16S rRNA gene phylogenesis of the culturable bacteria from the lesions of diseased individuals was conducted to study the biodiversity of the bacterial communities in the lesions and to identify probable pathogen(s) associated with this kind of disease. S. japonica samples were selected from a hatchery located in the eastern part of Qingdao, China. Bacterial universal primers GM5F and DS907R were used to amplify the 16S rRNA gene of bacteria colonies, and touchdown PCR was performed to amplify the target sequences. The results suggest that γ- proteobacteria (Alteromonadales and Vibrionales) of CFB group, many strains of which have been also determined as pathogens in other marine species, are the predominant bacterial genera of the diseased Apostichopusjaponicus individuals.     

16S rRNA gene phylogenesis of culturable predominant bacteria from diseased Apostichopus japonicus (Holothuroidea, Echinodermata)

Cultured Apostichopus japonicus in China suffers from a kind of skin ulceration disease that has caused severe economic loss in recent years. The disease, pathogens of which are supposed to be bacteria by most researchers, is highly infectious and can often cause all individuals in the same culture pool to die in a very short time. The 16S rRNA gene phylogenesis of the culturable bacteria from the lesions of diseased individuals was conducted to study the biodiversity of the bacterial communities in the lesions and to identify probable pathogen(s) associated with this kind of disease. S. japonica samples were selected from a hatchery located in the eastern part of Qingdao, China. Bacterial universal primers GM5F and DS907R were used to amplify the 16S rRNA gene of bacteria colonies, and touchdown PCR was performed to amplify the target sequences. The results suggest that γ- proteobacteria (Alteromonadales and Vibrionales) of CFB group, many strains of which have been also determined as pathogens in other marine species, are the predominant bacterial genera of the diseased Apostichopus japonicus individuals.     

一株深海中等嗜热嗜酸菌的分离及鉴定

从太平洋热液区样品中分离纯化到一株中等嗜热嗜酸菌,命名为TPY。文中对该菌株的形态、生理生化特征1、6S rDNA序列以及亚铁和单质硫氧化活性进行了研究。TPY菌株为短杆状,革兰氏阳性菌,大小为(0.3~0.5)μm×(1~3)μm;最适生长温度为50℃,最适生长pH值为1.8;该菌既能利用亚铁盐、单质硫自养生长,也能利用酵母粉、葡萄糖、蛋白胨和甘油等有机物异养生长;TPY菌与Sulfobacillus acidophilus(AB089842)的16S rDNA序列高度相似,其同源性为99%。这些结果表明,TPY菌是一株来自深海的嗜酸硫化芽孢杆菌(Sulfobacillus acidophilus),该菌的成功分离将有助于对太平洋热液区微生物种群结构的全面了解。同时,TPY菌对亚铁和单质硫的良好氧化能力显示出其在生物浸矿中的应用潜力。