溴代阻燃剂污染底泥与未污染底泥中细菌群落结构之比较分析

【目的】通过免培养的分子生物学方法,比较受溴代阻燃剂污染严重的河流底泥和与未污染水库底泥中细菌多样性差异,解析二者间细菌群落结构,为污染河流的治理与生物修复提供相关的理论依据。【方法】从中国贵屿溴代阻燃剂污染区练江底泥样品和未污染水库底泥样品中分别提取微生物总DNA,用细菌通用引物27F和1500R扩增16S rRNA基因,构建16S rRNA基因文库。用HhaⅠ和HinfⅠ2种限制性内切酶对克隆子进行扩增产物rDNA的限制性酶切分析(ARDRA),挑取不同的操作分类单元OUT中的克隆进行测序并构建系统发育树,比较代表克隆子的基本分类类群和生物多样性构成。【结果】未污染水库底泥中细菌群落组成主要包括变形细菌门(Proteobacteria)的α、β、γ和δ4个亚门、浮霉菌门(Planctomycetes)、酸杆菌门(Acidobacteria)、放线菌门(Actinobacteria)、绿弯菌门(Chloroflexi)、疣微菌门(Verrucomicrobia)和厚壁菌门(Firmicutes)。优势菌是酸杆菌,占文库克隆的30.2%。污染河流底泥中细菌群落组成包括变形细菌门(Proteobacteria)的α、β、δ和ε4个亚门、浮霉菌门(Planctomycetes)、绿菌门或拟杆菌门(Chlorobi orBacteroidetes)、酸杆菌门(Acidobacteria)、放线菌门(Actinobacteria)、绿弯菌门(Chloroflexi)、待定菌群candidatedivision OP01、candidate division OP08和candidate division WS3的相似菌。优势菌是ε-变形细菌和绿弯菌,占文库克隆的44.9%。【结论】受溴代阻燃剂污染河流底泥中的细菌群落具有较高水平的多样性,与未污染底泥有显著区别,主要体现在ε-变形细菌和绿弯菌在细菌群落中具有优势地位。这种优势种群的改变可能与污染物的过度富集具有一定的相关性,对于我们进一步探索和了解溴代阻燃剂的微生物修复具有一定的指导意义。     

我国典型湿热地区变质烟用香精中腐败微生物的多样性分析

【背景】烟用香精是卷烟生产中的重要辅料,有些香精,特别是剩余的加料香精在运输和储存等过程中可能污染微生物,引起腐败变质发生。【目的】分析变质烟用香精中腐败微生物的群落多样性,确定引起加料香精变质的主要腐败微生物。【方法】采用稀释平板法,对我国典型湿热地区云南、福建和广西三地变质加料香精样品中的污染细菌、霉菌或酵母进行分离,分析其16S rRNA、ITS或26S rRNA基因序列,并通过反证试验确定引起变质的主要腐败微生物。【结果】所考察3个典型湿热地区变质加料香精存在不同程度的细菌、霉菌或酵母污染,其中细菌污染最为普遍。分离的76株污染细菌分布在2门4纲5目10科15属,细菌的群落多样性比较丰富,其中雷尔氏菌属(Ralstonia)、柠檬酸杆菌属(Citrobacter)、肠杆菌属(Enterobacter)及芽孢杆菌属(Bacillus)是优势菌群;9株霉菌分布在子囊菌门(Ascomycota)的3纲6属,每个属分离到1-2株霉菌;42株酵母分布在子囊菌门的6个属,其中毕赤酵母属(Pichia)、细枝钩酵母菌属(Wickerhamomyces)及酵母菌属(Saccharomyces)是优势菌群。云南和福建两地样品的细菌菌群组成明显多于广西,广西样品的霉菌菌群组成以及福建样品的酵母菌群组成均分别多于其余两地。反证试验结果显示,柠檬酸杆菌属、肠杆菌属、芽孢杆菌属、雷尔氏菌属和毕赤酵母属是引起烟用加料香精变质的主要腐败微生物。【结论】变质加料香精中污染微生物菌群组成及腐败微生物确定的研究将有助于我国湿热地区香精香料中污染微生物的控制和腐败变质的预防。     

人参(Panax ginseng)根系分泌物成分对人参致病菌的化感效应

采用室内培养结合生物学测定的试验方法,研究了不同浓度人参(Panax ginseng)根系分泌物成分苯甲酸、邻苯二甲酸二异丁酯、十六酸和2,2-二(4-羟苯基)丙烷对人参立枯丝核菌(Rhizoctonia solani)、黑斑菌(Alternaria panax)、疫病菌(Phytophthora cactorum)、菌核菌(Sclerotinia schinseng)、锈腐菌(Cylindrocarpon destructans)和绿色木霉菌(Trichoderma viride)菌落生长及孢子萌发的化感效应.结果显示,不同浓度人参根系分泌物成分对人参致病菌及绿色木霉菌的化感效应存在显著差异.苯甲酸浓度与人参立枯丝核菌、菌核菌和锈腐菌菌落生长以及人参黑斑菌、锈腐菌孢子萌发呈负相关,与人参黑斑菌、绿色木霉菌菌落生长呈正相关;对人参疫病菌菌落生长的化感效应表现为低浓度和高浓度抑制,中浓度促进.邻苯二甲酸二异丁酯浓度与人参立枯丝核菌、黑斑菌、菌核菌和绿色木霉菌菌落生长以及人参黑斑菌孢子萌发呈负相关;对人参锈腐菌菌落生长和孢子萌发表现为低浓度和高浓度抑制,中浓度促进;对人参疫病菌菌落生长表现为低浓度和中浓度抑制,高浓度促进.2,2-二(4-羟苯基)丙烷浓度与人参立枯丝核菌、黑斑菌、疫病菌、绿色木霉菌菌落生长以及人参黑斑菌、锈腐菌孢子萌发呈负相关;对人参菌核菌、锈腐菌菌落生长表现中浓度促进,高浓度抑制.十六酸浓度与人参锈腐菌、疫病菌和绿色木霉菌菌落生长呈正相关,与人参锈腐菌孢子萌发呈负相关,对黑斑菌孢子萌发表现为中浓度抑制.4种根系分泌物的等量混合物浓度与人参致病菌及拮抗木霉菌菌落生长速率呈负相关.     

邳州地区霉腐蒜头致病性真菌的分离鉴定

[目的]分离鉴定江苏邳州地区霉腐蒜头的致病真菌,为防控该地区蒜头腐败,延长蒜头贮藏期提供理论指导。[方法]对江苏邳州霉腐大蒜的腐败真菌采用点接法培养分离纯化,科赫氏法则和粘片法对蒜头霉腐微生物菌落形态、菌丝显微结构进行观察,并进行分子生物学鉴定。[结果]分离得到7株菌株,确定病原菌A为芽枝霉菌(Cladosporium cladosporioides),B为黑霉菌(Cladosporium cladosporioide),C为鲜绿青霉菌(Penicillium verrucosum),D为白腐菌(Trametes versicolor),E、G为芽枝状枝孢霉菌(Cladosporium cladosporioide),F为青霉菌(Penicillium chrysogenum),H为烟曲霉菌(Aspergillus funigatus)。[结论]导致江苏邳州地区大蒜霉腐的真菌主要是芽枝霉菌(Cladosporium cladosporioides)、黑霉菌(Cladosporium cladosporioide)、鲜绿青霉菌(Penicillium verrucosum)、白腐菌(Trametes versicolor)、芽枝状枝孢霉菌(Cladosporium cladosporioide)、青霉菌(Penicillium chrysogenum)、烟曲霉菌(Aspergillus funigatus)。     

浅析微生物检验在化妆品检验中的应用

目的:检验日常化妆品中微生物的污染情况,分析微生物检验在化妆品检验中的应用。方法:对市场上常见的化妆品进行抽检,共200份样品,对样品的菌落总数、粪大肠菌群、金黄色葡萄球菌、铜绿假单胞菌、霉菌和酵母菌进行检测。结果:使用前采样的化妆品微生物合格率为99%,使用前、使用30d后及60d后的化妆品,微生物合格率随其使用时间的延长而依次降低。结论:化妆品在使用过程中存在二次污染,使用时间越长,污染越严重,要正视微生物检验在化妆品检验中的积极作用,对当前存在的问题展开分析,加强检验工作。     

青海高寒草甸土壤放线菌区系研究

2001～2002年从海北高寒草甸生态系统采集土样,用不同方法从中分离放线菌300余株,根据其形态和分类特征,分别归入小单孢菌属(Micromonospora)、诺卡氏菌属(Nocardia)、糖多孢菌属(Saccharopolyspora)、原小单孢菌属(Promicromonospora)和链霉菌属(Streptomyces),并将链霉菌归入7个类群。同时对230株中温菌和110株低温菌的部分酶活性及其对真菌和细菌的拮抗性进行了测定,发现链霉菌不仅具有许多酶活性,而且对真菌和细菌有拮抗性。     

瓶装饮用纯净水霉菌菌相分析

对瓶装饮用纯净水霉菌菌相进行研究分析。对福建省 5 9家企业生产的 5 8个牌号的瓶装纯净水采样 91件进行调查 ,在 5 8件样品中共检出霉菌 46 1株 ,阳性率 6 3 74%。优势菌群是土壤、空气和植物性材料中的常见菌。霉菌检出与产品的菌落总数等常规卫生细菌学指标无显著相关性 ,而与产品包装方式密切相关。菌相分析表明 ,加工后期的交叉污染是终产品被霉菌污染的主要原因。     

常用食用香辛料霉菌污染状况研究

以不同来源的桂皮、黑胡椒、白胡椒、孜然、小茴香、辣椒、八角、月桂叶、豆蔻、花椒等常用香辛料为实验材料,通过霉菌培养计数及黄曲霉毒素的测定,对常用香辛料加工流通过程中的霉菌污染情况及霉菌毒素残留情况进行了分析评价,并对样品污染霉菌进行了初步的分离鉴定。结果表明:实验所采集的11种香辛料的53个样品中,51%的样品霉菌总数超过国际通行标准,不同品种的香辛料霉菌污染情况存在较大的差异,孜然、小茴香、花椒的霉菌带菌量较高,桂皮、八角的霉菌带菌量较低;样品中黄曲霉素含量与霉菌污染程度存在一定的相关性,闪蒸、辐照处理能够有效减少香辛料中活菌数目,但对霉菌毒素含量影响较小。     

灰毛豆内生真菌淡紫拟青霉菌(TPL04)代谢产物的研究

从灰毛豆叶片中分离出内生真菌-淡紫拟青霉菌Purureocillium lilacinum(TPL04),对其发酵产物采用硅胶柱色谱、Sephadex LH-20凝胶色谱、制备薄层色谱、中压柱色谱及制备液相色谱等方法进行分离纯化,共获得8个单体化合物。通过波谱学方法并结合相关文献数据比对,化合物结构鉴定为5-羟基己酸-4-内酯(1)、(R)-4-苄基-2-噁唑烷酮(2)、2′-脱氧胸苷(3)、对羟基苯甲酸甲酯(4)、光色素(5)、β-胡萝卜苷(6)、尿嘧啶核苷(7)、己六醇(8)。其中化合物1、2、4是首次从淡紫拟青霉菌中分离得到,抑菌实验表明化合物4对水稻纹枯菌(Pellicularia sasakii)、辣椒疫霉菌(Phytophthora capsici)、草莓灰霉菌(Botrytis cinerea)、油菜菌核菌(Sclerotinia sclerotiorum)四种植物病原菌生长有抑制作用。     

螺旋链霉菌遗传操作系统-接合转移体系的建立

背景:螺旋链霉菌(Streptomyces spiramyceticus)为国内螺旋霉素(spiramycin,SPM)的生产菌,但目前工业生产中螺旋链霉菌利用遗传操作进行基因改造还没有成功报道.目的:建立螺旋链霉菌遗传操作系统,利用遗传改造的方法改变SPM的组分比例,降低SPM的分离成本.方法:以大肠杆菌(Esche...     

Microbiology of Ensiled High-Moisture Corn

The effects of gaseous environment and temperature on the microbial populations of ensiled high-moisture corn were investigated. Molds, coliform bacteria, mesophilic aerobic bacteria, and yeasts were enumerated at intervals during ensiling. The numbers of aerobic bacteria were similar in structures containing different concentrations of gas and held at different temperatures. Coliform bacteria could not be detected after 10 days of ensiling. Mold numbers were relatively low, but were important in the deterioration of corn at the surface of the silos. Yeast and bacterial numbers increased rapidly following an initial aeration period, but no increase was observed after a second aeration series. Lack of a growth response to the second aeration series is believed related to the depletion of an assimilable carbon source.     

Assessment of mold concentrations in Singapore shopping centers using mold-specific quantitative PCR (MSQPCR) analysis

Molds can pose a human health threat and may amplify in buildings in humid climates. The objective of this study was to evaluate the mold growth in Singapore shopping centers based on the collection of 40 dust samples from 15 shopping centers, including one with a history of water damage. The dust was analyzed by a DNA-based technology called mold-specific quantitative PCR (MSQPCR). In a water-damaged shopping center, most of the 26 water-damage indicator species were detected at some concentration and many were much more abundant than the average in the shopping centers. MSQPCR is a useful method for quantifying indoor molds in tropical climates.     

Combined Effects of Ultrahigh Vacuum and Temperature on the Viability of Some Spores and Soil Organisms

Considerably fewer spores of Bacillus stearothermophilus, B. megaterium, and Clostridium sporogenes were recovered than were spores of B. subtilis var. niger and Aspergillus niger after 4 to 5 days at 53 and 60 C in ultrahigh vacuum. There were no significant differences in the recoveries of these five organisms at 25 C and atmospheric pressure, and after exposure to 25 and -190 C in vacuum. At 60 C, a far greater decrease in viability was demonstrated for B. stearothermophilus, B. megaterium, and C. sporogenes in ultrahigh vacuum than at atmospheric pressure. Viable B. subtilis var. niger spores were not detected in an initial 10⁷ spores after retention at 90 C and ultrahigh vacuum, and 10⁴ spores were viable after 5 days at 90 C and atmospheric pressure from an initial 10⁶ spores. Molds and actinomycetes in soil were particularly resistant up to 69 C in vacuum. Actinomycetes were the only soil organisms recovered so far at 120 C.     

宣威火腿成熟产品中主要微生物菌相构成分析

目的 :了解宣威火腿成熟产品中的微生物菌相构成 ,探讨微生物在宣威火腿中所起的作用。方法 :采用选择性培养基对宣威火腿成熟产品中的主要微生物菌相进行分离和计数。结果 :与发酵香肠不同 ,宣威火腿中的优势菌群为葡萄球菌和微球菌、霉菌 ,它们的数量在火腿表面均达到了 10 6 CFU/ g以上 ,而乳酸菌及肠杆菌、肠球菌的数量均明显低于优势菌群 (P<0 .0 1)。结论 :耐盐性的葡萄球菌和微球菌的代谢活动以及火腿表面大量霉菌的生长是宣威火腿独特风味形成的基础。     

Tissue engineering of autologous cartilage for craniofacial reconstruction by injection molding

Each year, more than one million patients undergo some type of procedure involving cartilage reconstruction. Polymer hydrogels such as alginate have been demonstrated to be effective carriers of chondrocytes for subcutaneous cartilage formation. The goal of this study was to develop a simple method to create complex structures with good three-dimensional tolerance in order to form cartilage in specific shapes in an autologous animal model. Six alginate implants that had been seeded with autologous chondrocytes through an injection molding process were implanted subcutaneously in sheep, harvested after 6 months, and analyzed histologically, biochemically, and biomechanically, in comparison with original auricular cartilage. Molds of craniofacial implants were prepared with Silastic E RTV (Dow Corning, Midland, Mich.). Chondrocytes were harvested from sheep auricular cartilage and suspended in 2% alginate at a concentration of 50 x 10(6) cells/ml. The mixture of cells and gel was injected into the Silastic molds and removed after 20 minutes. Chondrocyte-alginate constructs were implanted subcutaneously in the necks of the sheep from which the cells had originally been harvested, and the constructs were removed after 30 weeks. Analyses of the implanted constructs indicated cartilage formation with three-dimensional shape retention. The proteoglycan and collagen contents of the constructs increased with time to approximately 80 percent of the values for native tissue. The equilibrium modulus and the hydraulic permeability were 74 and 105 percent of those of native sheep auricular cartilage, respectively.     

The enrichment and early detection of Streptococcus pyogenes in skin lesions, using colistin, oxolinic acid, Todd Hewitt broth and latex agglutination

An improved selective broth, colistin, oxolinic acid, Todd Hewitt broth (COTHB) for the isolation of Streptococcus pyogenes and other streptococci from swabs is described. Staphylococci, coryneforms and Gram negative organisms are inhibited in COTHB inoculated with swabs from skin lesions. Streptococcus pyogenes could be detected by a fluorescent antibody method and by the Streptex and Phadebact streptococcal grouping methods after 6 and 24 h incubation. Other streptococci of groups B, C and G, were also detected. Streptex was the most sensitive and specific method for the detection of streptococci of groups A, B, C and G in this broth. The method detected 78% of these streptococci in COTHB after 6 h incubation and 93% after 24 h incubation. Of the Strep. pyogenes isolated, 82% were detected in the broth by the Streptex method.     

The enrichment and early detection of Streptococcus pyogenes in skin lesions, using colistin, oxolinic acid, Todd Hewitt broth and latex agglutination

An improved selective broth, colistin, oxolinic acid, Todd Hewitt broth (COTHB) for the isolation of Streptococcus pyogenes and other streptococci from swabs is described. Staphylococci, coryneforms and Gram negative organisms are inhibited in COTHB inoculated with swabs from skin lesions. Streptococcus pyogenes could be detected by a fluorescent antibody method and by the Streptex and Phadebact streptococcal grouping methods after 6 and 24 h incubation. Other streptococci of groups B, C and G, were also detected. Streptex was the most sensitive and specific method for the detection of streptococci of groups A, B, C, and G in this broth. The method detected 78% of these streptococci in COTHB after 6 h incubation and 93% after 24 h incubation. Of the Strep. pyogenes isolated, 82% were detected in the broth by the Streptex method.     

微生物酶解法产生阿拉伯糖——菌种筛选与初步鉴定

使用半纤维素平板法从土壤分离菌中筛选到产半纤维素酶活较高的真菌。将这些菌株在含玉米芯半纤维素的培养基中发酵,鉴定发酵液中还原糖产量,从中筛选出3株产还原糖较多的菌。将其发酵产物经柱前衍生,HPLC检测,发现其中DHC菌株的发酵产物以木糖和阿拉伯糖为主,而培养基中的葡萄糖大部分被利用,可用于发酵法联产阿拉伯糖和木糖。对DHC菌株通过菌落形态、孢子形态以及ITS区基因序列测序分析,初步确定该菌为亮白曲霉(Aspergillus candidus)。对于亮白曲霉产生的半纤维素酶国内外尚较少研究报导,可为开发利用新的微生物资源奠定基础。     

Environmental Mold and Mycotoxin Exposures Elicit Specific Cytokine and Chemokine Responses

BackgroundMolds can cause respiratory symptoms and asthma. We sought to use isolated peripheral blood mononuclear cells (PBMCs) to understand changes in cytokine and chemokine levels in response to mold and mycotoxin exposures and to link these levels with respiratory symptoms in humans. We did this by utilizing an ex vivo assay approach to differentiate mold-exposed patients and unexposed controls. While circulating plasma chemokine and cytokine levels from these two groups might be similar, we hypothesized that by challenging their isolated white blood cells with mold or mold extracts, we would see a differential chemokine and cytokine release.ConclusionsThese findings demonstrate that chronic mold exposures induced changes in inflammatory and immune system responses to specific mold and mycotoxin challenges. These responses can differentiate mold-exposed patients from unexposed controls. This strategy may be a powerful approach to document immune system responsiveness to molds and other inflammation-inducing environmental agents.     

Effect of Inoculation Techniques and Relative Humidity on the Growth of Molds on the Surfaces of Yellow Layer Cakes

Four inoculation techniques were compared for initiation of growth on cake surfaces: spot, air cabinet, spray (atomizer), and talc addition methods. Molds were isolated from commercial cakes and were identified as Aspergillus sydowii, Aspergillus ochraceus, Penicillium funiculosum, and Eurotium herbariorum. Cake surfaces were inoculated with mold spores and incubated under three equilibrium relative humidity (ERH) levels: 97, 85, and 75%. Random contamination by spores in a ventilated air cabinet was the simplest method of inoculation, but standard deviations in the inoculation rates (20% on a relative scale) were almost twice those observed with the other methods. The spot method was the most reproducible. Cake samples inoculated in the air cabinet had colony counts 10 times lower than those obtained for potato dextrose agar plates at 97% ERH, which was not the case with the spray and talc methods. Growth of molds was much slower in the samples incubated in 75% relative humidity, with all methods. Colony counts were generally similar in systems adjusted at 85 to 97% ERH but were lower for samples incubated at 75% ERH. In comparisons of the shelf life estimates obtained by the various inoculation methods, a correlation coefficient (r²) of 0.70 was obtained between the spot method and the other methods of inoculation, while talc, air cabinet, and spray shelf life data were correlated better (r² ≈ 0.97). The spot method appeared to be the method of choice in consideration of ease of use, precision, and the ability to enable the study of the effects of the environment on mold-free shelf life as well as on the rate of growth of molds on cakes.