敦煌壁画色变中微生物因素的研究──Ⅰ.色变壁画的微生物类群及优势菌的检测

通过对敦煌莫高窟6个洞窟中的51个典型变色颜料样品的微生物检测,发现其中的细菌有6个属,优势菌为芽孢杆菌属和产碱菌属;霉菌有5个属,优势菌为青霉属。将分离得到的菌种,通过模拟试验证明,枝孢霉、黑曲霉和2种特殊细菌对壁画红色颜料变色和胶结材料的老化均起着重要作用。     

敦煌莫高窟中细菌多样性的研究

【目的】通过对敦煌莫高窟内细菌多样性及生理生化特征的分析,为壁画微生物病害防治提供试验依据。【方法】采用纯培养与16S rDNA等技术对莫高窟245#窟内空气样品、壁画样品进行分析,并在培养基中添加壁画颜料测试其对细菌生长的影响。【结果】分离出可培养细菌76株,分属于8个属。其中空气中有6个属,分别为Bacillus、Arthrobacter、Pseudomonas、Acinetobacter、Enterobacter、Kocuria,优势菌为Bacillus、Arthrobacter。壁画上有Bacillus、Arthrobacter、Paenibacillus、Erythrobacter 4个属,优势菌为Bacillus、Arthrobacter;并发现DHXJ05(Enterobacteriaceae)、DHXJ08(Bacillaceae)、DHXJ15(Erythrobacteraceae)、DHXJ16(Bacillaceae)和DHXJ17(Bacillaceae)能在含有铁红、铅丹、朱砂的环境中良好生长。【结论】为后期研究壁画颜料的变色机理及选择相应的细菌防治制剂提供了条件。     

云南干巴菌子实体内可培养微生物

【背景】微生物在菌根真菌的孢子萌发、菌丝体生长、菌根形成以及子实体发育等过程中起到一定作用。【目的】对采自云南省昆明市嵩明县和楚雄彝族自治州禄丰县的8个干巴菌子实体内的微生物进行分离培养鉴定,为后期研究微生物与干巴菌之间的相互作用奠定基础。【方法】采用传统平板分离法从干巴菌子实体内分离获得微生物群落,t检验分析不同地区采集的干巴菌子实体内微生物菌落总数的差异,16S r RNA基因和ITS序列进行系统发育树构建和微生物多样性分析。【结果】采自嵩明县和禄丰县的8个干巴菌子实体内共分离获得282株可培养的细菌,两个地区的细菌菌落总数无显著差异(P=0.22)。所有细菌分属2门12属15种。其中80%的细菌属于变形菌门,且以γ-变形菌为优势菌群,假单胞菌属(Pseudomonas)为优势菌属。其余20%的细菌属于拟杆菌门。从干巴菌子实体中分离获得114株真菌,两个地区的真菌菌落总数无显著差异(P=0.65)。所有真菌分属2门10属10种。其中62%的真菌属于子囊菌门(Ascomycota),并以分离自禄丰县干巴菌子实体内的Lophiostoma为优势属。38%的真菌属于担子菌门(Basidiomycota),并以Asterotremella为优势属。【结论】两个不同地区采集的干巴菌子实体内细菌和真菌在菌落总数上无显著差异。所有细菌都以γ-变形菌为优势菌群,假单胞菌属为优势菌属。嵩明干巴菌子实体内真菌以担子菌门为优势菌群,Asterotremella为优势属。而禄丰干巴菌子实体内真菌则以子囊菌门为优势菌群,Lophiostoma为优势属。     

温室黄瓜叶部微生物区系

采用稀释分离法和消毒叶片研磨液培养法对温室黄瓜叶围和内生微生物进行了分离,共分离到248个菌株,初步鉴定出13个属的叶围真菌,其中链格孢属(Alternaria)和青霉属(Penicillium)真菌为优势类群;鉴定出4个属的内生真菌,其中曲霉属(Aspergillus)真菌为优势类群;10个属的叶围细菌,其中芽孢杆菌属(Bacillus)和黄单胞菌属(Xanthomonas)细菌为优势类群;6个属的内生细菌,其中芽孢杆菌属和假单胞菌属(Pseudomonas)细菌为优势类群;6个属的叶围酵母菌,其中隐球酵母属(Cryptococcus)为优势类群;已鉴定出2个属的叶围放线菌,分别为链霉菌属(Streptomyces)和小多孢菌属(Micropolpspora).未分离到内生酵母菌和放线菌.     

沙棘通过自主选择塑造根瘤内生微生物组

【背景】解析植物微生物群落结构是利用微生物组工程强化植物抗生物和非生物胁迫水平、提高农林产品质量和品质的基础。固氮根瘤是沙棘具有抗旱、抗寒和抗贫瘠等多种优良生物性状的关键。【目的】比较分析沙棘根际土和根瘤内细菌群落结构的组成及影响因素,为揭示沙棘-弗兰克氏菌共生和植物-微生物互作协同抗逆机制提供理论基础。【方法】从辽宁、陕西和山西采集样品,通过16SrRNA基因V3–V4可变区的高通量测序技术,采用生物信息学方法比较分析沙棘根际土和根瘤内细菌群落组成和丰度差异,并探索土壤土理化性质对根际土细菌群落结构的影响。【结果】沙棘根际土和根瘤内的细菌群落均以放线菌门(Actinobacteria)和变形菌门(Proteobacteria)为主要优势菌门,且根瘤内弗兰克氏菌属(Frankia)为绝对优势菌属;根际土前10个优势菌门的丰度在三地样品间均存在显著差异,仅存在唯一共有的优势菌属(鞘氨醇单胞菌属,Sphingomonas),且前35个优势属中有27个属在三地间存在明显丰度差异;土壤pH和速效钾是沙棘根际土细菌群落多样性的主要影响因子;根瘤内优势门和属在三省份间存在高度的保守性,仅异根瘤菌属...     

不同附生基质金钗石斛根际微生物的比较研究

对同一栽培环境下不同附生基质金钗石斛根际微生物的多样性和差异性进行了研究，以明确基质对其根际微生物的影响。运用高通量测序技术对石质和木质两类5种附生基质的金钗石斛根际微生物进行16S和ITS测序，结合OTU分析、Alpha多样性分析和主成分分析对金钗石斛根际微生物的多样性和差异性进行比较研究。共鉴定了细菌56个门，112个纲，275个目，377个科，621个属；真菌13个门，47个纲，123个目，273个科，503个属。石质基质金钗石斛真菌优势菌属为unidentified＿Cantharellales＿sp菌属，细菌优势菌属为鞘氨醇单胞菌属、粪杆菌属、unidentified＿Chloroplast菌属；木质基质金钗石斛真菌优势菌属为unidentified＿Cantharellales＿sp菌属、粉褶菌属，细菌优势菌属为粪杆菌属。石质基质较木质基质真菌物种相对丰度差异较大，优势菌属种类不同。功能预测分析表明，附生基质与金钗石斛根际微生物群落功能密切相关。本研究为金钗石斛“基质-根际微生物-菌根真菌”的相关性及其生长发育、次生代谢产物积累规律提供了实验依据，为石斛“生石上者胜”、金钗...     

阿尔山地区兴安落叶松林土壤微生物群落结构

土壤微生物在森林生态系统能量流动和物质循环过程中发挥着不可替代的作用。兴安落叶松(Larix gmelinii)是我国大兴安岭地区的优势树种,而阿尔山地区是其在我国分布的最南端,受气候变暖影响较为显著,因此探索兴安落叶松林下土壤微生物群落结构对了解和维护我国东北地区森林生态系统的稳定有重要意义。在本研究中,我们从阿尔山白狼镇、天池镇采集兴安落叶松林下土样,通过高通量测序技术,依据97%相似性原则,将细菌序列划分为5,163个可操作分类单位(operational taxonomic units, OTUs),真菌序列划分为2,439个OTUs,其中门水平优势细菌为放线菌门、变形菌门、疣微菌门、绿弯菌门和酸杆菌门,优势真菌为担子菌门和子囊菌门;属水平上,优势细菌为Candidatus＿Udaeobacter,优势真菌属为丝盖伞属(Inocybe)、蜡壳耳属(Sebacina)、Piloderma和棉革菌属(Tomentella)。天池镇的细菌多样性显著高于白狼镇,而真菌多样性在两地间无显著差异。土壤pH和阳离子交换量是驱动土壤细菌多样性的主要因子,而土壤全氮和有机碳是驱动真菌多样性的主要...     

培菌白蚁菌圃和粪便微生物多样性分析

【背景】培菌白蚁是属于白蚁科的一类与鸡枞菌属真菌共生的高等白蚁,其与体内肠道微生物和体外菌圃微生物形成三维共生体系。【目的】分析培菌白蚁菌圃和粪便的微生物多样性,并与肠道微生物进行比较。【方法】通过Illumina MiSeq高通量测序方法对培菌白蚁菌圃和粪便样品进行细菌16S rRNA基因和真菌ITS测序分析。【结果】高通量测序获得培菌白蚁菌圃和粪便样品细菌和真菌的有效序列和OTU数目。5个样品细菌OTU数目在90-199之间,而真菌OTU在10-58之间,细菌的种类多样性明显大于真菌。不论是细菌还是真菌,粪便样品的OTU数目多于菌圃样品。经物种分类分析,菌圃样品主要优势细菌是变形菌门(Proteobacteria),其相对含量超过82.4%;其次是拟杆菌门(Bacteroidetes)和厚壁菌门(Firmicutes);粪便样品中优势细菌为拟杆菌门,其次是变形菌门,粪便优势菌属为别样杆菌属和营发酵单胞菌属,这与培菌白蚁肠道菌多样性组成一致。培菌白蚁菌圃和粪便样品共生真菌主要为担子菌门(Basidiomycota)和子囊菌门(Ascomycota)。菌圃优势真菌为鸡枞菌属(Termi...     

贵州典型煤矸石堆场微生物群落结构及功能特征

【背景】煤矸石堆场用于堆放煤矿开采过程中产生的一种热值低、含重金属的固体废弃物,会产生大量的酸性废水,对堆场周边的生态环境造成严重影响。【目的】探究煤矸石堆场的微生物群落结构和功能特征。【方法】选择贵州省六枝特区典型煤矸石堆场作为研究对象,采集堆场表层土壤、矸石层土壤、废水浸出口沉积物和堆场下游河道沉积物,通过宏基因组学技术进行分析。【结果】细菌的优势菌门为变形菌门(Proteobacteria)和放线菌门(Actinobacteria),优势菌属为钩端螺菌属(Leptospirillum)和硫化杆菌属(Sulfobacillus);古菌的优势菌门为Candidatus＿Thermoplasmatota和泉古菌门(Crenarchaeota),优势菌属为热原体属(Thermoplasma)和金属球菌属(Metallosphaera)。不同采样点细菌和古菌的优势菌属存在显著差异,矸石层土壤和废水浸出口沉积物中的铁氧化细菌和硫氧化细菌比其他2个样点丰富。煤矸石堆场中微生物的碳、氮、硫代谢基因丰度较高,共检测到6条固碳途径、6条氮代谢途径和3条硫代谢途径。主要的固碳基因为ACAT和E2.2....     

优异杂交水稻亲本灌浆期种子内生细菌多样性研究

通过传统微生物培养方法,对处于灌浆期的杂交水稻亲本"深08S"、"和620S"及"16A007"种子内生细菌群落结构多样性进行研究。实验表明,处于灌浆期的杂交水稻亲本种子仍然存在内生细菌群落结构的多样性。"深08S"种子内生细菌含6个OTU,第一优势菌属为Pantoea,丰度为52.04%,第二和第三优势菌属分别为Pseudomonas和Rhizobium;"和620S"种子内生细菌含10个OTU,第一优势菌属为Pantoea,丰度为69.02%,第二优势菌属为Pseudomonas,并列第三优势菌属为Rhizobium和Sphingomonas;"16A007"种子内生细菌含11个OTU,第一优势菌属为Pseudomonas,丰度为45.12%,第二优势菌属和第三优势菌属分别为Pantoea和Sphingomonas。由研究结果可见,具有遗传相关性的水稻种子"深08S"和"和620S"内生细菌的第一和第二优势菌属相同,同时,三种水稻亲本种子优势菌属都有Pantoea和Pseudomonas,表明水稻种子基因型对其内生细菌结构多样性具有一定的影响。     

敦煌壁画色变中微生物因素的研究：Ⅱ.微生物对模拟石窟壁画颜料 …

通过对微生物生长后的模拟壁画的分析测定,发现微生物对壁画颜料有很大影响：微生物形成的可溶性色素直接造成壁画色度的改变,在生长代谢过程中形成大量的草酸盐,并使颜粒晶体的晶形发生变化。此外,微生物的作用使铅丹的价态改变,在铅丹的色变中起着重要的作用。     

16S rDNA sequence analysis of bacterial isolates from biodeteriorated mural paintings in the Servilia tomb (Necropolis of carmona, Seville, Spain)

Bacteria were isolated from damaged mural paintings of the Servilia tomb (necropolis of Carmona, Seville, Spain). Selected strains, representative for different clusters of isolates with similar fatty acid profiles, were analysed by 16S rDNA sequence analysis. Bacillus is the dominant genus among the isolates: members of the rRNA species complexes of B. megaterium, B. pumilus and B. firmus were found as well as several other Bacillus species. One group of halotolerant isolates falls in the Bacillus sensu lato group, with closest relatedness to the genera Salibacillus and Virgibacillus. Other genera found are Artbrobacter, Micrococcus, Streptomyces, Sphingomonas, Paenibacillus, and a genus closely related to Paracraurococcus. Many isolates showed low 16S rDNA sequence similarities with the closest related database entries, a strong indication for the presence of several new species among the isolates.     

敦煌壁画色变中微生物因素的研究：Ⅲ.枝孢霉在石窟壁画铅丹变色 …

从敦煌莫高窟分离的枝孢霉在模拟壁画表面萌发的条件为：２０℃,ＲＨ６０％或３０℃,ＲＨ５０％。部分石窟在特定时间内可满足这一条件。骨胶对铅丹起到保护作用,而枝孢霉可以分解骨胶,并利用其生长和形成草酸等代谢产物。这些作用使铅丹处于一个特殊的化学环境,造成稳定性下降,并促进了铅丹向铅白的转变。     

高盐盐湖可分离嗜盐耐盐菌的种群多样性及四氢嘧啶产量评价

为了解柴达木盆地茶卡盐湖、柯柯盐湖和小柴旦盐湖等三大硫酸镁亚型高盐盐湖可分离嗜盐耐盐菌的种群多样性,采用RM中、高盐培养基筛选分离可培养的嗜盐菌和耐盐菌,扩增16S rRNA基因序列进行种属鉴定和环境因子典范对应分析(CCA),选取优势菌属构建系统发育树,并采用高效液相色谱法(HPLC)检测次级代谢产物四氢嘧啶(Ect...     

元阳梯田地方水稻品种根部内生菌及根际微生物的分离与鉴定

采用组织分离法和土壤稀释涂板法,对元阳哈尼梯田2个地方品种‘月亮谷’和‘红脚老粳’的根部内生细菌及根际土壤细菌进行了分离,研究元阳梯田传统水稻品种特殊的内生菌组成.结果表明: 试验共得到399个菌株.经形态特征及生理生化鉴定,月亮谷根部和其根际土壤分别分离到8和5个属,其中5个属是共有的;红脚老粳的根部和其根际土壤中分别分离到10和7个属,其中6个属是共有的.经分子生物学鉴定,月亮谷根部分离到11个种和5个属,根际土壤分离到8个种和4个属,其中5个种和4个属是共有的;红脚老粳根部分离到9个种和5个属,根际土壤分离到10个种和3个属,其中4个种和2个属是共有的.通过分子生物学鉴定,大部分菌株都可以鉴定到种,而通过形态及生理生化特性只能初步鉴定到属,但两种方法在属层次上的鉴定结果基本一致.元阳地方水稻根部内生细菌及根际土壤细菌具有一定的种属同源性与特异性.     

江苏盐城盐场中度嗜盐菌的分离与鉴定

采用高盐的牛肉膏蛋白胨培养基(盐浓度为8%NaCl),研究江苏省盐城市盐场土壤里中度嗜盐菌的分布情况及种群特征。从盐城市的射阳、新滩、灌东三处盐场土壤中共采集和分离得到13株中度嗜盐菌。通过形态观察、生理生化分析、16S rRNA序列分析和系统进化分析等方法进行初步鉴定,结果表明:分离到的中度嗜盐菌分属3个属,Virgibacillus属4株、Halomonas属7株和Marinobacter属2株。研究结果揭示盐城市的盐场存在较为丰富的中度嗜盐菌,具有较高的研究和利用价值。     

An experimental and theoretical study on the dissolution of mural fibrin clots by tissue-type plasminogen activator.

During thrombolytic therapy and after recanalization is achieved, reduction in the volume of mural thrombi is desirable. Mural thrombi are known to contribute to rethrombosis and reocclusion. The lysis rate of mural thrombi has been demonstrated to increase with fluid flow in different experimental models, but the mechanisms responsible are unknown. An experimental and a theoretical study were developed to determine the contribution of outer convective transport to the lysis of mural fibrin clots. Normal human plasma containing recombinant tissue-type plasminogen activator (tPA; 0.5 microg/mL) was (re)perfused over mural fibrin clots with fluorescently labeled fibrin at low arterial, arterial, or higher wall shear stresses (4, 18, or 41 dyn/cm(2), respectively) and lysis was monitored in real time. Flow accelerated lysis, but significantly only at the highest shear stress: The average lysis front velocity was 3 x 10(-5) cm/s at 41 dyn/cm(2) vs. almost half of that at the lower shear stresses. Confocal microscopy showed fibrin fibers dissolving only in a narrow region close to the surface when permeation velocity was predicted to be low. A heterogeneous transport-reaction finite element model was used to describe mural fibrinolysis. After scaling the effects of outer and inner convection, inner diffusion, and chemical reactions, a simplified inner diffusion/reaction model was used. Correlation to fibrin lysis data in purified systems dictated higher rates of plasmin(ogen) and tPA adsorption onto fibrin and a decreased catalytic rate of plasmin-mediated fibrin degradation, compared with published parameters. At each shear stress, the model predicted a temporal pattern of lysis of mural fibrin (similar to that observed experimentally), and protease accumulation in a narrow fibrin region and significant lysis inhibition by plasma alpha(2)-antiplasmin (according to the literature). Increasing outer convection accelerated mural fibrinolysis, but the model did not predict the big increase in lysis rate at the highest shear stress. At higher than arterial flows, additional mechanisms not accounted for in the current model, such as fibrin collapse at the fibrin front, may regulate the lysis of mural clots and determine the outcome of thrombolytic therapy.     

The influence of selected antibiotics on aquatic microorganisms.

This paper presents the influence of penicillin, erythromycin, oxytetracycline and streptomycin on aquatic microorganisms isolated from three reservoirs with varied extent of environmental pollution (Sulej6w Reservoir, Zegrze Reservoir and Vistula River). The experiments were conducted in especially prepared microcosms (aerated 151 aquariums). From among the examined antibiotics streptomycin showed the longest activity in the water environment (27 days), followed by oxytetracycline (22 days). Erythromycin had 13 days activity while the penicillin only 4 days. The highest number of bacteria was observed in the Vistula, fewer in Zegrze Reservoir. Sulejów Reservoir was characterized by the lowest number of bacteria. The strains isolated from Sulej6w Reservoir were characterized by higher degree of biodiversity than those from Zegrze Reservoir or Vistula River. The dominant genera were Pseudomonas (49%), followed by Acinetobacter (21%), Flavomonas (9%), Alcaligenes (9%), Vibrio, Moraxella and Oligella. The Vistula River was dominated by Aeromonas (88%) and Pseudomonas (12%) genera. The strains isolated from Sulej6w Reservoir were more sensitive to antibiotics than those from the much more polluted Vistula, this being evidenced by lower MIC and MBC values.