具促生功能拟蕈状芽孢杆菌(Bacillus paramycoides) SH-1464发酵条件优化及其活性

【背景】植物根际促生菌在促进植物生长、提高植物系统抗性及改善土壤养分状况等方面具有极大的应用潜力。【目的】为微生物菌肥的开发利用提供高效微生物资源。【方法】采用稀释涂布平板法分离烟草根际土壤可培养细菌,利用PVK培养基筛选具强溶无机磷活性的菌株,结合钼锑抗比色法测定菌株溶磷活性;利用Salkowski’s比色液检测菌株产吲哚乙酸(indole acetic acid, IAA)活性;以菌株溶磷量和IAA产量为指标,采用单因素试验设计进行发酵条件优化,以得到菌株溶磷活性和产IAA的最佳发酵方案;基于种子促发芽及幼苗促生长试验验证菌株的促生效果;结合形态学、生理生化和16S rRNA基因序列对菌株进行分类学鉴定。【结果】于烟草根际土壤分离得到127个不同分类的菌株,10个菌株具溶无机磷的能力,其中菌株SH-1464溶磷活性最强,溶磷圈直径为16.11 mm,溶磷量为119.22 mg/L;Salkowski’s比色结果表明,菌株具有极强的产IAA活性,为39.88μg/mL。单因素试验结果表明,菌株SH-1464溶磷的最佳碳源为10 g/L葡萄糖,最佳氮源为0.5 g/L蛋白胨,最佳无机磷源及其添加量为2.5 g/L磷酸三钙,最佳初始pH值为7.5,温度30 ℃,转速200 r/min;菌株SH-1464产IAA最佳培养条件为：麦芽糖10 g/L,酵母粉5 g/L,NH₄NO₃ 10 g/L,氯化钾2.5 g/L,l-色氨酸0.1g/L,pH 6.5,温度30 ℃,转速180 r/min。基于单因素试验结果进行优化前后菌株溶磷量及IAA产量对比试验可知,优化后菌株的溶磷量为225.9 mg/L,提升84.5%;IAA产量为75.3μg/mL,提升88.8%。促生试验结果表明：菌株SH-1464处理下番茄种子的发芽率提高84.5%,株高提高55.1%,茎围提高32.5%,根长、根重分别提高16.4%和149%,地上部分鲜重和干重分别提高172.2%和203.6%。结合形态学和分子生物学鉴定菌株SH-1464为拟蕈状芽孢杆菌(Bacillus paramycoides,Genbank登录号为ON417365,保藏号为CCTCCM 2022924);此外,菌株还具有产蛋白酶、产纤维素酶、固氮、分泌铁载体的能力。【结论】菌株SH-1464具有强溶无机磷、固氮、分泌IAA、产蛋白酶、产纤维素酶及分泌铁载体等能力,可显著提高番茄种子的发芽率,对番茄幼苗株高、茎围、根长、根重、地上部分鲜重和干重等农艺性状具有显著促进作用,可作为高效微生物资源在微生物菌剂的开发利用等方面展现广泛应用前景。     

4株茶树根际促生菌菌株的鉴定及促生作用

【背景】根际促生菌可以促进植物生长、提高植物抗性。茶树根际具有特殊的根土微生物生境,可以获得具促生作用的有益微生物。【目的】探究4株茶树根际促生菌菌株的分类地位及促生作用,筛选优良的根际促生菌菌株。【方法】通过形态、生理生化特征、16S rRNA基因序列同源性比对鉴定4株茶树根际促生菌,采用钼锑抗比色法测定溶磷量,通过比色法测定ACC脱氨酶活性、CAS法测定产铁载体能力、Salkowski法测定产IAA (Indoleacetic acid)的能力进行促生作用研究,通过盆栽实验测试白菜、空心菜、苋菜及水稻的株高及鲜重以分析促生效应。【结果】鉴定KKS-6-N1为放射型土壤杆菌(Agrobacteriumradiobacter), KKS-7-N7为铜绿假单胞菌(Pseudomonas aeruginosa),GD3为Pseudomonashunanensis,GD12为弯曲芽孢杆菌(Bacillusflexus)。固氮菌株KKS-6-N1可产铁载体;固氮菌株KKS-7-N7具有解磷及产铁载体能力,分泌的IAA含量高达101.29mg/L;解钾菌株GD3具溶磷能力,分泌的ACC脱氨酶酶活为8.09μmol/(mg·h),相对铁载体含量为0.31;具固氮解钾性能的菌株GD12分泌的ACC脱氨酶活性为14.46μmol/(mg·h)。盆栽试验表明,4个菌株对白菜、空心菜、苋菜的株高和鲜重均有明显促进作用,尤以GD3效果更甚。【结论】茶树根际促生菌菌株Pseudomonas hunanensis GD3促生作用显著,具有开发成微生物菌肥的潜力。     

花生根际微生物的分离及高效功能菌株筛选

【背景】花生根际分布着丰富的微生物类群，分离筛选多种功能的高效微生物是研发高效复合菌肥的基础。【目的】从花生根际土壤及根表分离微生物，分析可培养微生物的多样性，筛选高效解有机磷和无机磷、产吲哚乙酸(indole-3-acetic acid, IAA)和铁载体功能的菌株，为研发花生微生物菌肥打下基础。【方法】利用稀释涂布法，从采自山东省栖霞市、平度市、烟台市莱山区 3个样点的花生根际土、根表样品中分离微生物，基于16S rRNA基因序列对其进行系统发育分析，并通过初筛和复筛筛选高效解磷、产IAA和铁载体的菌株。【结果】共分离、纯化、保藏147株菌，其中75株分离自根际土壤，72株分离自根表样品。系统发育分析表明所有的菌分布于放线菌门(Actinomycetota)、芽孢杆菌门(Bacillota)、拟杆菌门(Bacteroidota)和假单胞菌门(Pseudomonadota)这4个门的40个属，优势属为链霉菌属(Streptomyces, 21.77%)、芽孢杆菌属(Bacillus, 16.33%)；根表样品微生物的多样性高于根际样品；共筛选到解有机磷菌株62株，短波单胞菌(Brevundimonas) YTU21021解有机磷能力最强为1.12 mg/L；解无机磷菌株31株，不动杆菌(Acinetobacter) YTU21009解无机磷能力最强为7.04 mg/L；产IAA的菌株63株，肠杆菌(Enterobacter) YTU21054产IAA量最高，达184.19 mg/L；产铁载体细菌7株，伯克氏菌(Burkholderia) YTU21051产铁载体能力最强，A_s/A_r为0.90。【结论】花生根际和根表样品中可培养微生物多样性较为丰富，本研究筛选到的高效功能菌丰富了花生根际功能微生物资源，为后续与高效根瘤菌联合研发花生复合微生物菌肥奠定了基础。     

巨菌草根部促生菌的筛选及其促生效应

为进一步开发植物促生菌,该研究以巨菌草根部为主要材料进行巨菌草促生菌的筛选,采用解磷、固氮和产IAA等筛选标准对初筛菌株分别进行多项促生能力的测定。通过形态观察、生理生化特性和 16S rDNA序列同源性分析对促生效果最好的菌株YB-07进行分类和鉴定,分别测定其促生能力后从中筛选出促生效应强的11个菌株进行盆栽试验,并通过对这些菌株单独回接和多菌混接的小麦盆栽试验测定其对小麦的促生效应。结果表明:从巨菌草根部分离得到了101株促生菌株,分类鉴定结果显示菌株YB-07归属于根瘤菌属(Rhizobium),其溶磷量为20.1 mg·L^-1、产IAA量为23.7 mg·L^-1,同时具有产氨能力。盆栽试验测定结果显示,多菌混合接种对小麦的促生效应在株高、干重、鲜重和叶绿素含量上,分别较对照组增加了24.49%、31.84%、28.06%和34.14%。单菌接种对小麦的促生表现在株高、干重、鲜重和叶绿素含量上,分别较对照组增加了13.54%、20.45%、16.84%和35.19%。所筛选到的菌株具有良好的促生长作用,能为进一步构建巨菌草促生菌菌群提供良好的种质资源。     

烟草根际可培养微生物多样性及防病促生菌的筛选

[背景] 根际微生物在植物根部生态系统中扮演着重要角色,影响着植物的营养吸收和健康生长。[目的] 了解常年不发病烟田烤烟品种K326根际可培养微生物的多样性,筛选具有防病促生功能的菌株,为烟草病害绿色防控提供资源。[方法] 采用传统培养方法对烟草根际土壤中的细菌和真菌进行分离鉴定,评价菌株的促生特性及病原菌拮抗能力,并进一步验证典型菌株对盆栽烟苗的促生效果。[结果] 共获得261株微生物菌株,包括160株细菌和101株真菌。经分子鉴定,细菌中以变形菌门（Proteobacteria）和厚壁菌门（Firmicutes）为主要类群;真菌中以子囊菌门（Ascomycota）和毛霉菌门（Mucoromycota）为主要类群。在属水平上,细菌以假单胞菌属（Pseudomonas）和芽孢杆菌属（Bacillus）为主,真菌以曲霉属（Aspergillus）和青霉属（Penicillium）为主。从不同种水平上进一步选择44株细菌为代表菌株,发现它们均具有不同程度的吲哚-3-乙酸（Indole-3-Acetic Acid,IAA）产生能力,9株能够溶解有机磷,16株能够溶解无机磷,13株产生铁载体,14株产生生1-氨基环丙烷-1-羧酸（1-Aminocyclopropane-1-Carboxylate,ACC）脱氨酶。从160株细菌中筛选得到抑制青枯病菌和黑胫病菌的菌株数目分别为25、26株。经盆栽试验发现韩国假单胞菌（P. koreensis） HCH2-3、浅黄绿假单胞菌（P. lurida） FGD5-2和贝莱斯芽孢杆菌（B. velezensis） EM-1对烟苗呈现不同程度的促生作用,其中3株菌联合施加对烟苗的促生效果最明显。[结论] 烟草根际存在着丰富多样的具有防病促生潜力的微生物,并且合成菌群或功能互补的菌株联合施用是未来微生物菌剂研发的重要方向。     

苎麻促生菌的筛选、鉴定及其促生效应

【目的】以苎麻(Boehmeria nivea L. Gaud)根及根围土壤为研究材料,进行苎麻促生菌的筛选,并初步探索其促生作用机制。【方法】首先,以溶磷和解钾为基本筛选标准,初筛菌株在实验室条件下测定多项促生能力进行复筛;然后通过种子萌发、盆栽试验测定菌株对苎麻的促生效应,最后,通过形态观察、生理生化特性和16S rRNA基因序列同源性分析,对促生菌株进行分类学鉴定。【结果】从苎麻根和根围土壤中分离得到了13株菌同时具备溶磷和解钾能力,其中4株菌(RA-2、RAM-2、RAM-5和RAM-6)具备产铁载体、产IAA和产氨能力。种子萌发和盆栽试验的测定结果显示：4株菌株均能促进苎麻种子的萌发和植株的生长,其中菌株RA-2和RAM-5相比于对照处理能显著提高苎麻种子的萌发率、幼根长、株高和根系干重。分类鉴定结果显示菌株RA-2和RAM-5均属于伯克霍德菌属(Burkholderia)。【结论】从苎麻根围筛选到具有促生能力的菌株,为进一步开发研制苎麻专型促生菌剂或专型微生物有机肥提供资源。     

油樟内生溶磷菌的筛选及其生物学特性

筛选具有溶磷能力的植物内生细菌,并探索该类菌的促生和抗逆性能,有助于扩大溶磷微生物来源、研发微生物肥料、改善土壤磷素营养和提高农业产量。该研究以从油樟组织中分离得到的50株内生细菌为材料,通过溶磷圈法初筛得到24株具有溶磷潜能的菌株,利用钼蓝比色法测定它们的溶磷能力和培养液的pH值,并研究溶磷能力较强菌株产生吲哚乙酸( IAA)、铁载体、1-氨基环丙烷-1-羧酸( ACC)脱氨酶、几丁质酶等促生和抗逆性能。结果表明：24株油樟内生细菌都能从磷酸钙中释放出有效磷(溶磷量为51.26~237.08μg·mL-1),其中,YG60、YG43、YG36、YG25、YG49、YG44株菌的溶磷量较高,均大于150μg·mL-1。接种油樟内生菌后,培养液的pH值均有一定程度的降低,但菌株溶磷量与培养液pH值间不存在显著相关性。6株溶磷量大于150μg · mL-1的菌株大部分具有分泌IAA、产铁载体、ACC脱氨酶活性和几丁质酶活性的能力;其中YG43、YG60和YG25分泌IAA的能力较强(IAA分泌量分别为22.55、18.75和16.41μg·mL-1),YG43和YG60产铁载体的能力较强(As/Ar小于0.6),YG43、YG60和YG25的ACC脱氨酶活性(分别为0.194、0.224、0.208 U·mg-1)较高,YG43和YG60的几丁质酶活性(分别为2.968 U和2.502 U)较高。综合菌株的溶磷、促生和抗逆性能,认为YG43、YG60和YG25菌株在促进植物生长、提高植物抗性及生物防治方面具有较好的应用前景。     

玉米根际高效溶磷菌的筛选、鉴定及促生效应研究

为获得玉米根际高效溶磷促生菌(Plant growth-promoting rhizobacteria,PGPR)并明确其促生特性,采用选择培养方法从玉米根际土壤筛选出优良PGPR 菌株,测定其溶磷及分泌吲哚乙酸(IAA)的能力,并对优良菌株进行鉴定;采用盆栽试验研究菌株的促生作用。结果分离到2 株优良PGPR 菌株CH07和FD11,其溶磷量分别为368.5 mg/L和321.5 mg/L,产IAA量分别为30.93 mg/L和15.93 mg/L。形态学特征、生理生化特征和16S rDNA 序列分析结果表明,CH07为芽孢杆菌属(Bacillus aryabhattai),FD11为链霉菌属(Streptomyces maritimus)。最后通过盆栽试验对这2株细菌分离物的促生效果进行比较,结果发现,CH07、FD11,尤其是CH07与FD11的复合物,对苋菜的株高及地上部鲜重有积极作用,可作为研制生物肥料的优良菌株资源。     

辣椒根际促生菌的分离筛选及抗病促生特性研究

获得辣椒根际促生菌(Plant growth promoting rhizobacteria,PGPR)并探究其抗病促生特性。采用固氮、无机磷和有机磷培养基从江苏省徐州市采集的辣椒根际土壤中分离筛选根际促生菌株(PGPR),通过形态特征及16S rDNA序列分析进行菌株鉴定,对菌株的固氮、解磷、分泌3-吲哚乙酸(IAA)能力及对4种辣椒病害病原菌抗病能力进行探究。得到13株辣椒PGPR菌株,经鉴定分别属于Bacillus、Pseudomonas、Lelliottia、Siccibacter、Achromobacter、Microbacterium和Paenibacillus;13株PGPR菌株均有固氮功能;其中7株可解有机磷,分别属于Lelliottia、Bacillus、Siccibacter、Microbacterium、Paenibacillus;5株可解无机磷,分别属于Lelliottia、Bacillus、Siccibacter、Pseudomonas;3株具有分泌IAA能力,分别属于Lelliottia、Siccibacter、Bacillus;5株具有抗病能力,分别属于Bacillus、Lelliottia、Siccibacter。辣椒根际土壤含有在农业生产上具有潜在的应用价值的多功能根际促生菌。     

具有ACC脱氨酶活性的绞股蓝内生细菌的分离鉴定及其抑菌促生作用

采用富集筛选法从绞股蓝根中筛选得到6株具有ACC脱氨活性的细菌,其中菌株JDG-6、JDG-7、JDG-14、JDG-16、JDG-23均具有较强的分泌铁载体能力,但菌株JDG-32没有产铁载体能力。抑菌试验结果显示,菌株JDG-6、JDG-7、JDG-14和JDG16对一种或多种供试菌有抑菌作用,其中菌株JDG-14能抑制大肠埃希菌、藤黄八叠球菌和白色念球菌的生长。促生试验表明,菌株JDG-6、JDG-7和JDG-14均能促进水稻幼苗根的伸长,其中菌株JDG-14的促生作用最为明显,与对照组相比水稻幼苗的根长和根鲜重分别增长了26%和21%。通过形态特征观察、生理生化试验以及16S rDNA序列分析,菌株JDG-6、JDG-7、JDG-16和JDG-23属于假单胞杆菌属（Pseudomonas）,菌株JDG-14为木糖葡萄球菌（Staphylococcus xylosus）,而菌株JDG-32为枯草芽胞杆菌（Bacillus subtilis）。菌株JDG-6、JDG-7和JDG-14均具有ACC脱氨酶活性和抑菌活性的促生菌,具有农业应用潜力。     

Influence of saprophytic microorganisms and Globodera rostochiensis (Wollenweber, 1923) Skarbilovich, 1959 on physiological processes of tomato (Solanum lycopersicum)

Pot experiments were conduced in a greenhouse, as test plants the dwarf tomato. This study concerns the impact of simultaneous occurrence of saprophytic soil microorganisms: Penicillium frequentons, Streptomyces scabies, Trichoderma viride and Globodera rostochiensis, present separately or together, on the growth of tomato (growth, yield, assimilation, transpiration). The saprophyte who particular decreased the negative influence of G. rostochiensis on tomato was P. frequentans. The presence of that organism caused a significant increase of the average yield and the individual fruit weight.     

Degradation of Antibiotics (Tetracycline,Sulfathiazole, Ampicillin) Using Enzymes of Glutathion S-Transferase

Swine wastewater is not easily treated in biological wastewater treatment plants. One reason is that some antibiotics are not easily degradable in a normal treatment system and inhibit the biological organisms in the treatment system. Specifically, tetracycline, sulfathiazole, and ampicillin are representative antibiotics found in poultry wastewater. To degrade these refractory and impediment antibiotics more easily, a special method is needed, such as an enzyme method. This research used a special enzyme in an experiment that tested feasibility with an enzyme assay of biological treatment in vitro. The Glutathion S-Transferases (GSTs) are a family of proteins that catalyze the conjugation of reduced glutathione with a variety of hydrophobic chemicals containing electrophilic centers. Using GSTs, these major antibiotics were transformed into components that were non-toxic to the microorganisms that treat manure wastewater. The initial concentration of tetracycline, sulfathiazole, and ampicillin were 100 mg/L, 100 mg/L, and 50 mg/L, respectively, and the concentration of pig feed was the same as usual. The GSTs have made the effect of biotransformation of antibiotics as their mode. They were 60–70% transformed by GSTs at the end of the degradation reaction. This lowered their inhibitory strength against microorganisms.     

Microbiological Characterization of the Accreted Ice of Subglacial Lake Vostok,Antarctica

The accreted ice of subglacial Lake Vostok extends upward from the lake water level (a depth of 3750 m) to the bottom surface of the overlying Antarctic ice sheet. All of the accreted ice samples, taken from depths between 3541 and 3611 m, were found to contain pro- and eukaryotic microorganisms, whose number and diversity varied in different ice horizons and correlated, to a certain degree, with the occurrence of organic and inorganic impurities in a given horizon. Some biological objects found in the accreted lake ice, including bacteria, microalgae, and the pollen of higher plants, were morphologically similar to those found earlier in the glacier ice bulk. The others were not. It is suggested that the microorganisms found in the lake ice may come from different locations—the bottom layer of the glacier ice, the bedrock underlying the glacier, and the lake water.     

一株产葡萄糖氧化酶菌株的筛选、鉴定及酶学性质表征

[背景]海洋中蕴藏着大量未被开发利用的微生物种质资源,而且海洋微生物产的酶类因其具有耐低温、耐高压和耐高盐等明显区别于陆地微生物所产酶类的特点而备受关注.[目的]从渤海海域海泥样品中分离筛选产葡萄糖氧化酶的菌株,并研究其酶学性质.[方法]通过平板初筛和酶活复筛,确定产葡萄糖氧化酶的菌株;通过形态学鉴定和构建系统发育树分...     

Influence of the Degree of Aeration on Halotolerance of Yeasts of the Genera Candida,Rhodotorula, and Malassezia

The biochemical mechanisms were studied that determine different reactions of yeasts of different genera to two simultaneously imposed stressors, hypoxia and osmotic shock. For Candida lipolytica, these two stressors were antagonistic, which resulted in stimulation (and not suppression) of the growth of this yeast by NaCl (in a wide range of concentrations) under microaerobic conditions. The reaction of Malasseziasp. was different: the degree of halotolerance of this microorganism was lower under microaerobic conditions. An intervening reaction pattern was characteristic of Rhodotorula aurantiaca.These differences were found to be determined, above all, by the induction of a salt-resistant respiratory system (oxidase) in C. lipolytica, which could not be induced in Malassezia sp. In addition, the synthesis of catalase was enhanced in C. lipolytica, which provided for neutralization of the active forms of oxygen accumulating as a result of inhibition of other protective enzymes by salt.     

环境微生物培养新技术的研究进展

遍布于地球上各种生境中的微生物具有丰富的物种多样性.迄今为止,能够在实验室条件下培养的微生物仅仅是其中的一小部分,微生物物种的绝大多数还都难以在现有培养技术和条件下进行繁殖和生长.人们把那些尚未在实验室获得培养生长的微生物称之为未培养微生物(Uncultured microorganisms).本文概述了一些制约微生物培养生长的影响因素,重点介绍了近年来出现的一些新颖独特的环境微生物培养技术和方法,包括稀释培养法、高通量培养技术、模拟自然环境的扩散盒技术、土壤基质膜装置、细胞微囊包埋技术等.此外,本文还总结了通过改善微生物培养条件、设计开发新型的微生物培养基等方面取得的令人瞩目的进展.这些新颖培养技术和培养方法的出现,显著提高了微生物的可培养性,发现和鉴定了许多新的微生物物种,极大地丰富了可培养微生物的多样性和微生物资源,并为深入研究和开发微生物奠定了良好的资源研究基础.     

Diversity of halophilic microorganisms: Environments,phylogeny, physiology,and applications

The phylogenetic diversity of microorganisms living at high salt concentrations is surprising. Halophiles are found in each of the three domains: Archaea, Bacteria, and Eucarya. The metabolic diversity of halophiles is great as well: they include oxygenic and anoxygenic phototrophs, aerobic heterotrophs, fermenters, denitrifiers, sulfate reducers, and methanogens. The diversity of metabolic types encountered decreases with salinity. The upper salinity limit at which each dissimilatory process takes place is correlated with the amount of energy generated and the energetic cost of osmotic adaptation. Our understanding of the biodiversity in salt-saturated environments has increased greatly in recent years. Using a combination of culture techniques, molecular biological methods, and chemotaxonomic studies, we have obtained information on the nature of the halophilic Archaea as well as the halophilic Bacteria that inhabit saltern crystallizer ponds. Several halophilic microorganisms are being exploited in biotechnology. In some cases, such as the production of ectoine, the product is directly related to the halophilic behavior of the producing microorganism. In other cases, such as the extraction of β-carotene from Dunaliella or the potential use of Haloferax species for the production of poly-β-hydroxyalkanoate or extracellular polysaccharides, similar products can be obtained from non-halophiles, but halophilic microorganisms may present advantages over the use of non-halophilic counterparts. Journal of Industrial Microbiology & Biotechnology (2002) 28, 56–63 DOI: 10.1038/sj/jim/7000176 Received 20 May 2001/ Accepted in revised form 20 June 2001     

Fungi,feather damage,and risk of predation

Predation is a powerful selective force with important effects on behavior, morphology, life history, and evolution of prey. Parasites may change body condition, health status, and ability to escape from or defend prey against predators. Once a prey individual has been detected, it can rely on a diversity of means of escape from the pursuit by the predator. Here we tested whether prey of a common raptor differed in terms of fungi from nonprey recorded at the same sites using the goshawk Accipiter gentilis and its avian prey as a model system. We found a positive association between the probability of falling prey to the raptor and the presence and the abundance of fungi. Birds with a specific composition of the community of fungi had higher probability of falling prey to a goshawk than individual hosts with fewer fungi. These findings imply that fungi may play a significant role in predator–prey interactions. The probability of having damaged feathers increased with the number of fungal colonies, and in particular the abundance of Myceliophthora verrucos and Schizophyllum sp. was positively related to the probability of having damaged feathers. In addition, we found a significant correlation between the rate of feather growth of goshawk prey with birds with more fungi being more likely to be depredated. These findings are consistent with the hypothesis that survival and feather quality of birds are related to abundance and diversity of fungi.     

威海天鹅湖大叶藻(Zostera marina)与日本鳗草(Zostera japonica)根际微生物群落结构及其驱动机制

[目的] 本文以威海天鹅湖大叶藻和日本鳗草根际沉积物为主要研究对象,探究不同生长时期的海草根际微生物群落结构多样性,并分析导致微生物群落结构差异的内在因素。[方法] 选取威海天鹅湖大叶藻和日本鳗草根际沉积物与非草区表层沉积物,采用高通量测序技术（Illumina MiSeq platform）解析海草不同生长时期下根际与非草区微生物群落特征。[结果] 微生物群落结构差异由海草生长时期以及海草是否定植共同驱动。在海草成熟期,丙酸菌属（Propionigenium）在大叶藻与日本鳗草根际有明显富集,其相对丰度分别为11.58%和14.26%;在海草幼苗期,脱硫球茎菌科（Desulfobulbaceae）在海草根际富集（大叶藻：2.299%,日本鳗草：4.092%）;在海草衰退期时,硫卵菌属（Sulfurovum）的相对丰度在根际较高（大叶藻：5.624%,日本鳗草：3.749%）。此外,海草生长时期对不同样品之间微生物群落结构差异的解释度最大（R²=0.20335,P=0.002）。PICRUSt2功能预测结果表明各功能基因在海草不同生长时期所呈现的趋势一致,但丰度上呈现出幼苗期 > 成熟期 > 衰退期的结果。[结论] 天鹅湖海草床沉积物微生物群落结构在海草不同生长时期呈现不同的多样性特征,具有明显的根际效应且不同种类海草的根际微生物群落无显著差异,不具有物种特异性。     

乌鲁木齐市3~5岁儿童口腔微生物与肠道微生物的构成差异

目的探索乌鲁木齐市3～5岁儿童口腔微生物与肠道微生物的菌群构成及多样性等差异。方法从本团队前期流行病学调查的乌鲁木齐市3～5岁儿童中,按调查时间顺序随机抽取12名儿童。分别收集唾液及粪便样本共计24份,分为口腔微生物组和肠道微生物组。利用16S V3-V4区设计引物来进行PCR扩增,使用MiSeq测序仪进行二代测序,比较两组的微生物构成及多样性差异。结果门水平上:放线菌门(t=5.98,P0.001)、变形菌门(z=20.0,P=0.005)、TM7(z=78.0,P0.001)在口腔中丰度较高;厚壁菌门(z=134.0,P0.001)在肠道中丰度较高。厚壁菌门/拟杆菌门的值在肠道中较大(z=113.0,P=0.017)。属水平上:罗斯菌属、普雷沃菌属、链球菌属为口腔中丰度较高的菌属;粪杆菌属、Ruminococcaceae、拟杆菌属为肠道中丰度较高的菌属(P0.001)。奈瑟菌属、卟啉单胞菌属等仅存在于口腔中。Catenibacterium、肠杆菌属等仅存在于肠道中。菌群功能显示:在细胞运动(z=136.0,P0.001)、碳水化合物代谢(t=-4.71,P0.001)等方面表现出肠道组占优势;在遗传信息的翻译(t=8.17,P0.001)、神经退行性疾病(z=78.0,P0.001)等方面表现出口腔组占优势。结论放线菌门、变形菌门、TM7在口腔中丰度较高;厚壁菌门在肠道中丰度较高。口腔和肠道微生物在菌群功能上差异较大。奈瑟菌属、卟啉单胞菌属、Catenibacterium等可能为某些全身系统性疾病的标志性菌属。