Isolation and characterization of thermophilic benzothiophene-degrading Mycobacterium sp.

A bacterial strain, SWU-4, capable of using benzothiophene (BT) as a sole carbon and energy source was isolated from a petroleum-contaminated site in Thailand and identified by 16S rRNA gene sequence analysis to be in the genus of Mycobacterium. The strain was Gram-positive, nonspore former, and grew at 50° C. Colonies of the strain on nutrient agar were rod-shaped, smooth with a convex surface, slightly mucoid, and yellow pigmented. The thermophilic Mycobacterium sp. strain SWU-4 rapidly degraded 2% (w/v) BT at 50°C. Interestingly, this strain was able to degrade a wide variety of organosulfur compounds including thiophene, bromo(α)thiophene, and 3-methylthiophene in liquid minimum medium at 50°C, which will be beneficial for industrial applications.     

河南鲁山五大温泉古细菌多样性分析

河南省平顶山市鲁山县有上汤、中汤、下汤、温汤和碱汤等五大温泉,采用Illumina Hisiq2500PE250技术对鲁山五大温泉(上汤、中汤、下汤、温汤和碱汤)古细菌的16S r DNA基因V4-5变异区序列进行测序,应用Uparse、Mothur、SILVA、MUSCLE和Qiime等软件整理和统计样品序列数目和操作分类单元(operational taxonomic unit,OTU)数量,分析物种的丰度和多样性.上汤、中汤、温汤、下汤和碱汤分别获得87 993、67 326、44400、48 611、48 495条有效reads,聚类为520、280、678、451、437个OUTs.古细菌分类分析表明,河南鲁山五大温泉的古细菌可以归入11个门,其中奇古菌门(Thaumarchaeota)占95.25%,是优势菌群;在属分类阶元上,上汤、中汤和温汤的优势菌属为Candidatus-Nitrosocaldus; unidentified-Thaumarchaeota是下汤和碱汤的优势菌属.对河南鲁山五大温泉开展古细菌多样性的研究发现,温泉水中含有较高的参与氨氧化过程的奇古菌门,为后续深入研究和利用河南鲁山五大温泉水中的古细菌资源提供了基础资料.     

10株葡萄源丝状真菌分离鉴定及其致病力分析

采用组织分离法从京郊地区腐烂的葡萄果实及葡萄叶上分离到10株丝状真菌,其中从腐烂的葡萄果实中分离到3株丝状真菌,命名为814#、815#和880#；从葡萄叶上分离到7株丝状真菌,命名为794#、797#、798#、811#、902#、903#和1397#。结合形态学特征及真菌rDNA ITS区序列分析结果,菌株814#为茎点霉(Phoma sp.),菌株815#为刺孢曲霉(Aspergillus aculeatus),菌株880#为灰葡萄孢(Botrytis cinerea),菌株794#为日本曲霉(Aspergillus japonicus),菌株797#为粉红单端孢(Trichothecium roseum),菌株798#为大蒜盲种葡萄孢(Botrytis porri), 菌株811#为果生炭疽菌(Colletotrichum fructicola),菌株902#为链格孢菌(Alternaria eichhorniae),菌株903#为芬芳镰孢菌(Fusarium redolens)和菌株1397#为脉孢菌(Neurospora terricola),其中A. aculeatus、A. japonicus、C. fructicola、A. eichhorniae、F. redolens和N. terricola未见在葡萄上分离到的报道。将10株丝状真菌分别接种到健康的葡萄、圣女果、苹果和梨果实上,B. cinerea、A. japonicus、A. aculeatus、T. roseum、B. porri、C. fructicola、A. eichhorniae和F. redolens均可使4种果实发病,其中B. cinerea、A. japonicus、B. porri和F. redolens致病力较强；而Phoma sp.和N. terricola只能使葡萄和圣女果发病。     

一株软骨霉状菌的纯化方法

从武夷山的一枯枝上分离得到了一株稀有软骨霉状菌,在培养过程中发现,该株黏细菌在人工培养基上只有在与一种未知的细菌共培养的状态下才能长出典型的子实体并保持菌种的活力.然而要从共培养的菌落中纯化这株黏细菌,使用常规的黏细菌纯化技术几乎是不可能.在这种情况下对伴生细菌进行16SrDNA菌种鉴定,再根据鉴定为施氏假单胞菌(Ps...     

Natural Dietary Compound Xanthohumol Regulates the Gut Microbiota and Its Metabolic Profile in a Mouse Model of Alzheimer’s Disease

Discovering new and effective drugs for the treatment of Alzheimer’s disease (AD) is a major clinical challenge. This study focuses on chemical modulation of the gut microbiome in an established murine AD model. We used the 16S rDNA sequencing technique to investigate the effect of xanthohumol (Xn) on the diversity of intestinal microflora in 2-month- and 6-month-old APP/PS1 mice, respectively. APP/PS1 and wild-type mice were treated by gavage with corn oil with or without Xn every other day for 90 days. Prior to and following treatment, animals were tested for spatial learning, cognitive and memory function. We found Xn reduced cognitive dysfunction in APP/PS1 mice and significantly regulated the composition and abundance of gut microbiota both in prevention experiments (with younger mice) and therapeutic experiments (with older mice). Differential microflora Gammaproteobacteria were significantly enriched in APP/PS1 mice treated with Xn. Nodosilineaceae and Rikenellaceae may be the specific microflora modulated by Xn. The penicillin and cephalosporin biosynthesis pathway and the atrazine degradation pathway may be the principal modulation pathways. Taken together, oral treatment with Xn may have a neuroprotective role by regulating the composition of intestinal microflora, a result that contributes to the scientific basis for a novel prophylactic and therapeutic approach to AD.     

中国酱油发酵酱醪中嗜盐四联球菌的鉴定

从采用传统露天酿造工艺的中国酱油发酵酱醪中分离筛选嗜盐乳酸球菌,对其进行形态、生理生化特性研究及16S rDNA序列分析,在此基础上确定其分类地位,为研究其在酱油酿造中的作用奠定基础.研究结果表明,筛选菌株为四联球型,革兰氏染色阳性,不运动;接触酶反应阴性,能从葡萄糖产酸而不产气;NaC l含量为18%的培养环境下乳酸产量达2.2%;基于16S rDNA序列的系统发育分析表明筛选菌株与嗜盐四联球菌的亲缘关系最近,从而初步确定其为嗜盐四联球菌.     

西藏冬虫夏草无性型5.8S rDNA,ITS间区系统发育分析

 采用相对较低的培养温度(5~12℃),从西藏那曲当年产风干冬虫夏草[Cordyceps sinensis(Berk.)Sacc.]分离得到菌株C21,综合其菌丝形态学特征及5.8S rDNA和ITS间区的系统发育分析结果,证实菌株C21为冬虫夏草菌的无性型,即中国被毛孢(Hirsutella sinensis).     

大鼠肝细胞核仁超微结构与rDNA分布位点

以常规电镜及NAMA－Ur DNA特异染色技术对Wistar大鼠肝细胞核仁的超微结构和rRNA的分布进行了观察。常规电镜技术表明大鼠肝细胞核仁纤维中心（FC）是电子透明区，数量较多，形状不规则。密集纤维组分（DFC）是围绕FC的环状结构部分，电子密度很高。FC中的染色质存在着一个介于集缩和解集缩状态之间的变化过程。NAMA－Ur DNA特异染色技术表明核仁内rDNA呈分散性分布，主要分布于DFC中（包括FC）的边缘），同时观察到与核仁相随染色质相连的核仁内rDNA呈念珠状结构。     

蜡状芽孢杆菌对番茄青枯雷尔氏菌致病性的影响

青枯雷尔氏菌（Ralstonia solanacearum）从其致病性上可分为能使植株发病的强致病力菌株和不能使植株发病的弱致病力菌株．利用蜡状芽孢杆菌（Bacillus cereus）与致病性稳定的青枯雷尔氏菌强致病力菌株进行共培养，处理后的青枯雷尔氏菌在TTC平板上表现为弱毒株的菌落特征，出现了致弱现象．经过16S rDNA基因序列测定，证明了用蜡状芽孢杆菌处理前后的菌株为青枯雷尔氏菌，并非是其它的污染菌株，通过回接番茄盆栽苗发现致弱前的青枯雷尔氏菌能有效引起番茄发生青枯病，而致弱后的菌株丧失致病力．不能引起番茄发病，     

西北太平洋浮游有孔虫的SSU rDNA序列及其古海洋学意义

研究对采集于西北太平洋冲绳海槽表层水体中的活浮游有孔虫进行DNA分析尝试，获得了西北太平洋浮游有孔虫Pulleniatina obliquiloculata 和Globigerina sp.等的SSU rDNA序列特征，并与南太平洋地区属种的DNA序列进行对比. 结果显示两不同海区P.obliquiloculata个体的SSU rDNA差异与同一个体内不同拷贝序列间差异类似，仅为0.7%—1.2%. 详细比较研究认为，传统微体古生物形态学定义种对西北太平洋与南太平洋的P.obliquiloculata来说具有可靠的分子生物学证据.