中国南方可培养嗜角蛋白真菌群落组成和多样性及影响因素

以鸡羽毛为钓饵,对采自中国南方13个地区的39所医院土壤中的嗜角蛋白真菌富集培养。通过稀释平板法对土壤中可培养真菌进行分离,探究不同地区嗜角蛋白真菌群落组成及多样性特征,并揭示土壤理化因子与嗜角蛋白真菌之间的相关性。结果表明,从不同地区医院土壤中共分离到嗜角蛋白真菌11 916株,隶属于4门,10纲,23目,42科,76属,各地区优势属不同,其中奈尼兹皮菌属Nannizzia、青霉属Penicillium和被孢霉属Mortierella为13个地区的共有属。在属水平上,重庆地区嗜角蛋白真菌多样性和均匀度最高,福建地区多样性及均匀度最低。Chao1和ACE丰富度指数表明,广东和江苏两地区的丰富度均较高。相关性分析表明,土壤中有机碳(OC)、pH、速效氮(AN)、全磷(TP)、有机质(SOM)、碳氮比(C/N)显著影响嗜角蛋白真菌的群落组成和多样性,其中AN与嗜角蛋白真菌多样性指数相关性最强,是影响可培养嗜角蛋白真菌群落组成和多样性的主要因子。本研究结果揭示了13个地区的嗜角蛋白真菌群落组成、相对多度及优势类群皆存在差异且受到土壤理化因子的影响。该研究为了解嗜角蛋白真菌的种类和分布提供科学...     

大兴安岭不同落叶松林植被土壤微生物多样性

利用选择性培养基,研究了杜香-落叶松林(LLV)、草类-落叶松林(HLV)、柴桦-落叶松林(BLV)、皆伐-落叶松林(CL)、火烧-落叶松林(LFB)5个样地土壤微生物的数量、种群组成、Shannon指数(H)、丰富度(S)、Pielou均匀度指数(J)、Simpson优势度(D)。从5个样地共分离到细菌24属,优势菌属主要为短杆菌属(Brevibacterium)、芽孢杆菌属(Bacillus)、棒杆菌属(Corynebacterium)、微球菌属(Micrococcus);放线菌为链霉菌的6个类群,优势类群主要为白色类群(Albosporus)和黄色类群(Flavus);真菌20属,优势菌属为青霉属(Penicillium)和头孢属(Cephalosporium)。兴安落叶松林不同样地微生物的多样性指数(H)、丰富度指数(S)、均匀度指数(J)及优势度指数(D)随样地不同而发生变化,细菌的多样性和丰富度指数为LLVHLVLFBCLBLV,放线菌为BLVHLVLLVLFBCL,真菌为CLHLVBLVLFBLLV。     

金钗石斛内生细菌的组成及多样性分析

采用9种培养基对贵州省的赤水市旺隆镇(P1)、贵阳市贵州师范大学生命科学学院大棚(P2)和金沙县台金生态农业观光园(P3)内栽培的金钗石斛(Dendrobium nobile Lindl.)根、茎和叶中的内生细菌进行了分离,并采用扩增核糖体DNA限制性分析(ARDRA)法对分离的内生细菌进行了多样性分析。结果表明:从3个样地金钗石斛的根、茎和叶中共分离出1 081株内生细菌,隶属2门5科12属40种1亚种,可分成41个OTUs;其中,芽孢杆菌属(Bacillus)和短芽孢杆菌属(Brevibacillus)为优势属,Bacillus subtilis subsp.subtilis和Brevibacillus invocatus为优势种(亚种)。金钗石斛的内生细菌在不同器官中的分布存在差异,根中内生细菌的菌株数量最多(695),且根中内生细菌的Shannon-Wiener多样性指数(2.20)和Margalef丰富度指数(5.81)均高于茎和叶中内生细菌,而叶中内生细菌的Pielou均匀度指数却最高(0.69);并且,茎和叶间内生细菌的Sorenson相似性系数最高(0.82),显著高于根和茎间以及根和叶间内生细菌的Sorenson相似性系数。3个样地金钗石斛内生细菌的共有OTUs有14个,分离菌株数占金钗石斛内生细菌分离菌株总数的96.5%;并且,3个样地金钗石斛内生细菌的Shannon-Wiener多样性指数和Pielou均匀度指数差异较小,仅P1样地金钗石斛内生细菌的Margalef丰富度指数明显高于P2和P3样地。NA、TSA、LB、KB、R2A和TB培养基从金钗石斛中分离出的内生细菌菌落数和OTU数量均高于YPD、YT和YG培养基。研究结果显示:金钗石斛体内含有丰富的内生细菌资源,并且,其内生细菌的组成和多样性与分离器官、种植地和培养基密切相关。     

长白山北坡次生林的树种多样性与胸径多样性

采用野外调查与室内分析相结合的方法,以长白山北坡露水河林业局次生林为对象,应用Margalef物种丰富度指数、Shannon-Wiener多样性指数、Pielou均匀度指数、Simpson优势度指数定量分析了长白山北坡次生林的树种多样性和胸径多样性,并与原始红松林进行了对比。结果表明,(1)与原始红松林相比,次生林的树种多样性指数H与均匀度指数J较大,丰富度指数S与生态优势度指数D较小。次生林的胸径生态优势度较大,丰富度S与多样性H较小,均匀度相差不大。3种次生林型中,杨桦林的胸径丰富度与多样性指数最高,杂木林次之,胡桃楸林最小,但均匀度指数与优势度指数变化正好相反;(2)不同林龄杨桦林和胡桃楸林的树种多样性和胸径多样性变化规律一致,随着林龄的增长,树种多样性指数和均匀度指数、胸径丰富度指数和多样性指数逐渐增大,树种和胸径的优势度指数逐渐减小;(3)无论是原始红松林还是次生林,采伐后树种多样性都会降低,采伐强度越大,降低程度越大。林木胸径多样性对采伐强度的响应较复杂,与采伐方式有关。     

织金洞钟乳石沉积物表面可培养细菌多样性和网络分析

【背景】洞穴环境中蕴含丰富而独特的细菌资源,对洞穴环境中细菌的分离培养有助于了解洞穴细菌多样性及细菌资源的挖掘和利用。【目的】利用不同培养基分离细菌,探究钟乳石表面可培养细菌的多样性及其种间互作关系。【方法】通过11种培养基对织金洞内钟乳石沉积物表面的细菌进行分离纯化,并利用16S rRNA基因序列分析初步确定分离菌株的分类地位。在R软件下,通过Bipartite包分析可培养细菌属间的相互作用。【结果】从钟乳石沉积物表面共分离出206株细菌,它们隶属于4门25属45种,香农(Shannon)指数为4.78,辛普森(Simpson)指数为0.95。变形菌门(Proteobacteria)和芽孢杆菌属(Bacillus)分别为样品中可培养细菌的优势门(47.09%)和优势属(29.61%)。无机寡营养培养基有助于洞穴钟乳石沉积物细菌的分离。属水平-采样点网络分析表明,可培养细菌分布具有非随机、显著的嵌套性。芽孢杆菌属(Bacillus)、德沃斯氏菌属(Devosia)、产碱杆菌属(Alcaligenes)、节杆菌属(Arthrobacter)和短杆菌属(Brevibacterium)在细菌群落中存在较多的有效合作值(Effective Partners)和亲密度(Closeness),被其他细菌所依赖程度(Species Strength)较高,是该群落中的重要组成类群。【结论】织金洞内钟乳石沉积物表面存在丰富的细菌资源,分析细菌类群在群落中的作用应结合细菌相对丰度和网络分析。     

抗感枯萎病西瓜根际细菌群落多样性比较

本文通过传统微生物培养方法,结合现代分子生物学技术对抗感枯萎病西瓜根际可培养细菌群落进行了比较研究.结果表明,抗病西瓜根际可培养细菌的多样性要高于感病西瓜,且细菌分布的均匀度也高于感病西瓜.表现为抗病西瓜根际可培养细菌的多样性指数H'(1.29)和1/D(30.28)分别高于感病西瓜的H'(1.12)和1/D(2.482).抗病西瓜根际可培养细菌的均匀度指数E(0.72)也高于感病西瓜的E(0.69).抗感西瓜根际分别具有不同的可培养优势群落,抗病西瓜根际可培养优势基因型为基因型1,占51.1%,感病西瓜根际可培养优势基因型为基因型7,占58.7%.     

水溶性壳聚糖对小鼠肠道菌群的影响

目的应用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术研究水溶性壳聚糖对正常小鼠肠道菌群的影响。方法使用SPF级昆明小鼠18只,随机分为3组,每组6只,依次为正常对照组(NC)、水溶性壳聚糖高(WSC-H)和低浓度组(WSC-L),灌服对应药物30d后收取鼠便,细菌基因组DNA提取,PCR-DGGE电泳得到肠道菌群图谱,计算菌群结构多样性指数,聚类分析相似性并鉴定优势条带序列。结果水溶性壳聚糖处理后小鼠肠道菌群结构发生改变,多样性指数、丰富度和均匀度较低,乳杆菌成为肠道中的优势菌型。结论水溶性壳聚糖能够增加肠道中乳杆菌的种类和数量,起到益生元的作用来调节肠道微生态平衡。     

伊犁野生羊肚菌根际土壤微生物功能多样性分析

为研究羊肚菌根际土壤微生物的多样性,采用Biolog-ECO法分析羊肚菌不同深度(土层0～10 cm、土层10～20 cm、土层20～30 cm)土壤根际微生物的多样性;结果表明,培养72 h后,微生物的颜色平均变化率(AWCD)随培养时间的延长而增加,符合微生物培养生长曲线;微生物的代谢活性、对碳源的利用能力、AWCD、多样性指数U、多样性指数H′、丰富度指数S、优势度指数D等随土层加深而减弱,且上层土壤微生物的AWCD、U、H′、S、D等指数显著高于中、下层的;均匀度指数随土层加深而增强,均匀度指数越高,群落一致性越好,多样性则越低,因此羊肚菌根际土壤微生物功能多样性随土层加深而减小,上层具有较高的多样性。     

樱桃属(Cerasus)植物根围微生物多样性

研究了樱桃属(Cerasus) 5种植物本溪山樱(Cs)、大青叶(Cp)、马哈利(Cm)、考特(Cap)、早红宝石(Ca)各主要生长期根围微生物数量、种群组成、Shannom-Wiener指数(H)、丰富度(S)、Pielou均匀度指数(J)、Simpson 优势度(D)和优势微生物种群变化动态.从樱桃根围共分离到细菌18属,优势菌属主要为假单胞菌属(Pseudomonas)、芽孢杆菌属(Bacillus)和黄杆菌属(Flavobacterium);放线菌为链霉菌的12个类群,优势类群主要为白色类群(Albosporus)、吸水类群(Hygroscopicus)和黄色类群(Flavus);真菌6属,优势菌属为青霉属(Penicillium).樱桃根围微生物的多样性指数(H)、丰富度指数(S)、均匀度指数(J) 及优势度指数(D) 随樱桃种类不同而发生变化,细菌的多样性和丰富度指数为Ca＞Cs＞Cp＞Cm＞Cap,放线菌为Ca＞Cp＞Cs＞Cm＞Cap,真菌为Cm＞Ca＞Cp＞Cs＞Cap.各生长期根围微生物种类与数量发生变化,新梢迅速生长期Ca、Cs、Cp和Cm根围微生物种类与数量较多,新梢停长期Cap根围微生物种类与数量较多,落叶期5种樱桃属植物根围微生物种类与数量均较少.     

贵州格凸河国家级风景名胜区蝴蝶多样性调查

为了解贵州省格凸河国家级风景名胜区的蝴蝶资源状况,2014—2016年对景区内蝴蝶进行调查,共采集蝴蝶标本528号,隶属于11科63属94种。凤蝶科Papilionidae个体数最多(140只),蛱蝶科Nymphalidae属、种最多,计21属27种。蛱蝶科多样性指数(2.783)、丰富度指数(4.247)最高,弄蝶科Hesperiidae均匀度指数(0.963)最高。蝶类群落多样性具时序性特征,5月优势度指数(0.556)最高; 6月均匀度指数(0.952)最高; 7月多样性指数(3.681)、丰富度指数(9.555)最高; 9月多样性指数(3.451)、丰富度指数(8.672)最低。森林蝶类的多样性指数(3.607)与丰富度指数(9.051)最高,但均匀度指数(0.861)与优势度指数(0.060)最低。群落相似性分析表明,6月与7月的群落相似性系数最高,田间与河滩的群落相似性系数最高。生境破坏是蝴蝶群落多样性降低的原因。     

Role for dopamine in malonate-induced damage in vivo in striatum and in vitro in mesencephalic cultures

Defects in mitochondrial energy metabolism have been implicated in the pathology of several neurodegenerative disorders. In addition, the reactive metabolites generated from the metabolism and oxidation of the neurotransmitter dopamine (DA) are thought to contribute to the damage to neurons of the basal ganglia. We have previously demonstrated that infusions of the metabolic inhibitor malonate into the striata of mice or rats produce degeneration of DA nerve terminals. In the present studies, we demonstrate that an intrastriatal infusion of malonate induces a substantial increase in DA efflux in awake, behaving mice as measured by in vivo microdialysis. Furthermore, pretreatment of mice with tetrabenazine (TBZ) or the TBZ analogue Ro 4-1284 (Ro-4), compounds that reversibly inhibit the vesicular storage of DA, attenuates the malonate-induced DA efflux as well as the damage to DA nerve terminals. Consistent with these findings, the damage to both DA and GABA neurons in mesencephalic cultures by malonate exposure was attenuated by pretreatment with TBZ or Ro-4. Treatment with these compounds did not affect the formation of free radicals or the inhibition of oxidative phosphorylation resulting from malonate exposure alone. Our data suggest that DA plays an important role in the neurotoxicity produced by malonate. These findings provide direct evidence that inhibition of succinate dehydrogenase causes an increase in extracellular DA levels and indicate that bioenergetic defects may contribute to the pathogenesis of chronic neurodegenerative diseases through a mechanism involving DA.     

Scurvy in capybaras bred in captivity in Argentine

In order to determine if the absence of vitamin C in the diet of capybaras (Hydrochoerus hydrochaeris) causes scurvy, a group of seven young individuals were fed food pellets without ascorbic acid, while another group of eight individuals received the same food with 1 g of ascorbic acid per animal per day. Animals in the first group developed signs of scurvy-like gingivitis, breaking of the incisors and death of one animal. Clinical signs appeared between 25 and 104 days from the beginning of the trial in all individuals. Growth rates of individuals deprived of vitamin C was considerably less than those observed in the control group. Deficiency of ascorbic acid had a severe effect on reproduction of another population of captive capybaras. We found that the decrease in ascorbic acid content in the diet affected pregnancy, especially during the first stages. The results obtained suggest that it is necessary to supply a suitable quantity of vitamin C in the diet of this species in captivity.     

Changes in lactate dehydrogenase activity in chicken tissues in hyperthyreosis in ontogenesis

The lactate dehydrogenase activity in reactions of lactate oxidation and synthesis was studied in subfractions of the chicken brain, heart and liver at the embryonal, early postembryonal and adult stages of development after thyroxine administration. It has been shown that during embryogenesis thyroxine predominantly enhanced the rate of lactate oxidation in the mitochondrial tissues. A marked increase in the lactate synthesis was found in cytoplasm of the adult chicken tissues. Specificity of enzyme activity alterations was detected in the chicken brain during ontogenesis after thyroxine administration.     

SSTR5 ablation in islet results in alterations in glucose homeostasis in mice

Somatostatin (SST) peptide is a potent inhibitor of insulin secretion and its effect is mediated via somatostatin receptor 5 (SSTR5) in the endocrine pancreas. To investigate the consequences of gene ablation of SSTR5 in the mouse pancreas, we have generated a mouse model in which the SSTR5 gene was specifically knocked down in the pancreatic beta cells (betaSSTR5Kd) using the Cre-lox system. Immunohistochemistry analysis showed that SSTR5 gene expression was absent in beta cells at three months of age. At the time of gene ablation, betaSSTR5Kd mice demonstrated glucose intolerance with lack of insulin response and significantly reduced serum insulin levels. Insulin tolerance test demonstrated a significant increase of insulin clearance in vivo at the same age. In vitro studies demonstrated an absence of response to SST-28 stimulation in the betaSSTR5Kd mouse islet, which was associated with a significantly reduced SST expression level in betaSSTR5Kd mice pancreata. In addition, betaSSTR5Kd mice had significantly reduced serum glucose levels and increased serum insulin levels at 12 months of age. Glucose tolerance test at an older age also indicated a persistently higher insulin level in betaSSTR5Kd mice. Further studies of betaSSTR5Kd mice had revealed elevated serum C-peptide levels at both 3 and 12 months of age, suggesting that these mice are capable of producing and releasing insulin to the periphery. These results support the hypothesis that SSTR5 plays a pivotal role in the regulation of insulin secretion in the mouse pancreas.