石磺海牛共附生细菌的分离和活性菌株筛选

【目的】研究深圳大鹏半岛海域石磺海牛中可培养的共附生细菌的数量和种类,并对分离获得菌株的代谢产物进行活性筛选。【方法】通过R2A平板培养、分离纯化和16SrRNA测序,分析鉴定石磺海牛中5个部位可培养细菌;使用分离菌株的菌液及发酵液上清,测定对群体感应信号分子降解的活性和抗生物膜活性。【结果】从石磺海牛中共分离到215株细菌,归属于87个种,54个属,有16株菌疑似为新菌。分离获得的菌株分布于变形菌门(Proteobacteria,126株),拟杆菌门(Bacteroidetes,44株),厚壁菌门(Firmicutes,34株),放线菌门(Actinobacteria,10株)和浮霉菌门(Planctomycetes,1株)。石磺海牛卵中的细菌数量和种类最为多样。从分离的菌株中筛选出28株菌能够降解群体感应信号分子,8株菌具有抗生物膜活性。【结论】首次报道了海洋无脊椎动物石磺海牛中具有丰富多样的可培养细菌,包含潜在的新微生物和天然产物资源,为今后研究石磺海牛共附生微生物提供了研究基础和参考。     

松嫩平原盐碱地中耐(嗜)盐菌的生物多样性

【目的】分离纯化松嫩平原盐碱地中可培养的耐盐菌和嗜盐菌,并分析其生物多样性。【方法】采用纯培养法和定向富集法从该地区盐碱土样中分离耐盐菌和嗜盐菌,然后通过16S rRNA基因同源性比对鉴定所分离细菌的系统发育学地位,从而获取松嫩平原盐碱地中耐盐菌和嗜盐菌的多样性信息。【结果】共分离到细菌40株,分属于细菌域中3个门(Actinobacteria,Firmicutes,γ-Proteobacteria)、8个科、16个属、34个种。其中多数菌株属于厚壁菌门(Firmicutes),最优势属为葡球菌属(Staphylococcus)(8株,占总菌株的20%),其次依次为盐单胞菌属(Halomonas)(5株,12.5%)、芽胞杆菌属(Bacillus)(4株,10%)、大洋芽胞杆菌属(Oceanbacillus)(4株,10%)、库克菌属(Kocuria)(4株,10%)和假单胞菌属(Pseudomonas)(3株,7.5%)等。其中9株细菌的16S rRNA基因序列与最近缘种的同源性在97.2%-99.0%之间,可能为新种。菌株耐盐能力主要在5%-10%之间,其中62.5%的菌株为耐盐菌,其余则为中度嗜盐菌。所有菌株的耐碱能力在pH 9-12之间,其中60%的菌株耐碱能力则高达pH 12,除两株为嗜碱菌,其余均为耐碱菌。【结论】研究结果表明,松嫩平原盐碱地中耐盐菌与嗜盐菌种群丰富,主要以葡萄球菌和盐单胞菌为主,菌株不仅耐盐能力高而且耐碱能力也高,并且该地区可能含有丰富的耐盐菌和嗜盐菌的新物种。     

云南兰坪铅锌尾矿区可培养细菌的分离及其酶活筛选

目的 对云南兰坪铅锌尾矿区样品中的可培养细菌进行分离及初步鉴定,同时挖掘具有酶活性功能的菌株。方法 从兰坪铅锌尾矿区及周边农田采集了20份样品,运用10种培养基进行细菌分离,对分离菌株的16S rRNA基因测序以鉴定其分类地位,再以平板透明圈法检测分离菌株的淀粉酶、纤维素酶、蛋白酶和脂肪酶活性。结果 从20份样品中分离获得了320株细菌,隶属于6个纲、14个目、26个科、39个属,有5个潜在新分类单元。其中链霉菌属的菌株数最多,高达102株,占菌株总数的31.88%,为优势种群;其次为芽胞杆菌属菌株40株,肠杆菌属菌株17株。去重后对165株菌进行酶活检测,有41株菌具有淀粉酶活性,占筛选菌株总数的24.70%,主要为链霉菌属和芽胞杆菌属;有40株菌对纤维素酶具有活性,占筛选菌株总数的24.10%,主要为链霉菌属和芽胞杆菌属;有14株菌对蛋白酶具有活性,占筛选菌株总数的8.43%,主要为链霉菌属和芽胞杆菌属;有12株菌对脂肪酶具有活性,占筛选菌株总数的7.23%,主要为链假单胞菌属。结论 兰坪铅锌尾矿区可培养细菌的种类丰富,且蕴藏着大量具有酶活性的菌株。研究结果为了解兰坪铅锌尾矿细菌多...     

硇洲岛褐蓝子鱼肠道抗菌活性菌株的分离及多样性

【目的】了解广东湛江硇洲岛褐蓝子鱼(Siganus fuscescen)肠道抗菌物质产生菌的多样性。【方法】采用传统的分离方法与牛津杯扩散法对褐蓝子鱼肠道菌进行分离纯化与抗菌活性测定,运用16S rRNA基因序列的系统发育分析对抗菌活性菌株进行多样性分析。【结果】根据形态观察和部分生理生化实验去冗余,从褐蓝子鱼肠道样品中分离到68株细菌,其中抗菌活性菌株19株,占分离株的27.9%。19株不同种类的活性菌株分属于细菌域的放线杆菌门(Actinobacteria)、变形杆菌门(Proteobacteria)与厚壁菌门(Firmicutes)的11个科、12个属。多数菌株属于厚壁菌门(8株,42.1%),其次是变形杆菌门(7株,36.8%)和放线杆菌门(4株,21.1%)。大多数抗菌活性菌株与其系统发育关系最密切的已知典型菌株之间存在一定的遗传差异(16S rRNA基因序列相似性为96.2%-99.9%),其中有4株代表潜在的新种。【结论】广东湛江硇洲岛褐蓝子鱼肠道中存在较为丰富的细菌抗菌物质产生菌,并蕴藏着较多的微生物新类群。     

白皮锦鸡儿种子内生细菌的分布与分离鉴定

【目的】了解对荒漠环境有良好适应性的白皮锦鸡儿种子可培养内生细菌的多样性。【方法】采用种子表面灭菌、种皮与种仁分离、可培养细菌分离纯化、对p H及盐的耐受性、16S r RNA基因序列扩增和系统发育分析进行系统研究。【结果】从白皮锦鸡儿成熟种子种皮和种仁分别分离纯化到6株和26株内生细菌,其中分离自种皮的菌株最适p H均在9.0以上,且有3株最高可耐受p H 14.0,有5株可耐受10%的Na Cl;分离自种仁的菌株p H耐受范围明显低于种皮,但有12株对Na Cl的耐受性可达10%。16S r RNA基因序列分析显示,30株与芽孢杆菌属(Bacillus sp.)接近,相似率95%-99%,其中13株与枯草芽孢杆菌(Bacillus subtilis)的相似率为96%-99%,11株与地衣芽孢杆菌(Bacillus licheniformis)相似率为95%-99%;1株与单孢菌属(Sphingomonas sp.)相似性为99%,1株与大肠杆菌属(Escherichia sp.)相似性为98%。【结论】白皮锦鸡儿种仁内生菌数量和种类均高于种皮,体现出其可培养内生菌在空间分布的分异性及种类的多样性,且推测其种皮内生菌对盐碱的高度耐受性应与其环境适应性相关。     

宜宾浓香型白酒酿造过程中可培养细菌的系统发育多样性

【目的】为较系统地了解宜宾浓香型白酒酿造过程中可培养细菌的多样性,得到一些潜在的微生物资源。【方法】采用改良的NA培养基和高氏I号培养基分离、去除冗余,测定所得细菌纯培养物的16S rRNA基因,进行系统发育分析。【结果】分离得到603株细菌,4株菌的序列与GenBank中典型菌株序列相似性低于97%,代表着潜在新类群;599株菌与GenBank中34个属、101个种的典型菌株序列相似性大于97%,其中以Bacillus为绝对优势菌(315株),Streptomyces(121株)、Lysinibacillus(35株)、Staphylococcus(45株)为次优势菌,其余各属菌株均在10株以下。而且有16个属均只检测到1株菌。【结论】宜宾浓香型白酒发酵过程中的细菌呈现出较为丰富的多样性和一定的稳定性。     

种植菠菜和生菜对土壤可培养细菌多样性的影响

为了研究种植生菜和菠菜对土壤可培养细菌多样性的影响,了解这两种蔬菜种植对土壤可培养细菌的改变情况,利用R2A培养基,分离细菌菌株,基于16S rRNA基因比对的系统发育分析对菌株进行初步鉴定。种植生菜的土样分离到109株细菌,这109株细菌主要分属4个门,19科,23属。种植菠菜的土壤样品共分离得到126株细菌,主要分属3个门,16科,21属。门水平上,种植生菜的土壤中优势菌为厚壁菌门(Firmicutes,39.4%),放线菌门(Actinobacteria,33.9%)和变形菌门(Proteobacteria,24.8%);种植菠菜的土壤样本中优势菌为放线菌门(64.3%),厚壁菌门(27%)和变形菌门(8.7%)。在属水平上,两类土样分离得到的菌株类别和数量的差异更大。     

药用植物青蒿不同种类的内生菌抑菌活性分析

为了研究青蒿不同种类的内生菌抑制细菌和抑制真菌的活性,该研究采用组织块法和研磨法从青蒿的根、茎、叶中分离内生细菌、放线菌和真菌,以大肠埃希菌(Escherichia coli)(CICC 23657)、枯草芽孢杆菌(Bacillus subtilis)(CICC 10275)、金黄色葡萄球菌(Staphylococcus aureus)(CICC 10384)、黑曲霉(Aspergillus niger)(CICC 2487)、酿酒酵母(Saccharomyces cerevisiae)(CICC 33032)为指示菌,采用琼脂块法和双层平板法检测内生菌的抑菌活性。结果表明:(1)从青蒿植株中共分离到76株内生菌,其中内生细菌19株、内生放线菌34株、内生真菌23株。从分离部位来看,56株来自于茎段、17株来自于根段、3株来自叶片。(2)内生细菌中抑菌活性菌株占总菌株的比例最高,为95%,内生放线菌和内生真菌中抑菌活性菌株的比例分别为41%、35%。(3)内生细菌的抗菌谱较广;虽然内生放线菌的抗菌谱较窄,但其中高抗菌株较多,尤其对酿酒酵母的抑菌效果好。综上结果显示,药用植物青蒿中存在着丰富的有抑菌活性的内生菌,且不同种类的内生菌抑菌活性不同。     

发酵白酒糟生产饲料蛋白的优良菌种的筛选

采用常规方法从1000多株菌(包括丝状真菌、酵母菌、链霉菌、细菌)中筛选到一批优良菌种,并进行了单菌发酵、多菌株组合发酵,不同原料配方发酵试验。在实验室条件下,发酵产物的粗蛋白含量高达35.9％,比原料本身的粗蛋白含量高50％以上,比所用培养基的粗蛋白含量高30％,发酵产物的粗纤维含量降低率为15％;粗脂肪含量为5.5％左右;产率达80％以上。结果证明,筛选到的菌株确是发酵白酒糟生产饲料蛋白的优良菌种。     

九香虫(椿象)体内可培养细菌的多样性分析

【目的】认识药用昆虫九香虫(Aspongopus chinesis Dallas)成虫体内可培养细菌资源多样性。【方法】运用纯培养法、反转录重复因子扩增(BOXA1R-PCR)分析技术、16S r RNA基因测序和系统发育分析对样品中可培养细菌进行多样性研究,测定了分离菌株的抗菌特性、吲哚乙酸(IAA)含量和产淀粉酶活性等指标。【结果】通过6种不同培养基共分离得到52株菌落特征不同的细菌菌株。基于菌落特征和BOXA1R-PCR图谱选取12株代表菌株用于16S r RNA基因序列测定。16S r RNA基因序列系统发育分析显示,52株菌株分属于芽孢杆菌属(Bacillus)、假单胞菌属(Pseudomonas)、寡养单胞菌属(Stenotrophomonas)和伯克霍尔德氏菌属(Burkholderia)4个属,其中芽孢杆菌属(Bacillus)为优势菌属。分离到的52株细菌有44株(占总分离菌株的84.6%)表现出对供试病原菌具有较好的抑制作用,高达94.2%的分离菌株能产IAA,有43株(占总分离菌株的82.7%)表现出淀粉酶活性。【结论】九香虫内细菌种群较为多样,具有潜在应用价值。     

Foreign exploration for Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) and associated natural enemies on avocado (Persea americana Miller)

Scirtothrips perseae Nakahara was discovered attacking avocados in California, USA, in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados, while adults were collected from 11 different plant species. As part of a management program for this pest, a “classical” biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae, to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico, Guatemala, Costa Rica, the Dominican Republic, Trinidad, and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic, Trinidad, or Brazil. In total, 2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips, and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques, prospects for the importation of thrips natural enemies for use in a “classical” biological control program in California against S. perseae are not promising.     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.     

Biological control of three floating water weeds,<Emphasis Type="Italic">Eichhornia crassipes,Pistia stratiotes</Emphasis>, and <Emphasis Type="Italic">Salviniamolesta</Emphasis> in the Republic of Congo

Since 1999, four specific weevils (Coleoptera, Curculionidae) were released in the Republic of Congo against three exotic floating water weeds: Neochetina eichhorniae Warner and N. bruchi Hustache against water hyacinth, Neohydronomus affinis Hustache against water lettuce, and Cyrtobagous salviniae Calder and Sands against water fern. Recoveries of exotic weevils were made from all 24 release sites except one, and all four species have established and spread (up to 800 km for water hyacinth weevils). Within a few years of releases, control of water fern and water lettuce was such that fishing and navigation could be resumed, while reductions of water hyacinth populations were only beginning.     

A molecular phylogeny of Hebeloma species from Europe

In order to widen the scope of existing phylogenies of the ectomycorrhizal agaric genus Hebeloma a total of 53 new rDNA ITS sequences from that genus was generated, augmented by sequences retrieved from GenBank, and analysed using Bayesian, strict consensus and neighbour joining methods. The lignicolous Hebelomina neerlandica, Gymnopilus penetrans, and two species of Galerina served as outgroup taxa. Anamika indica, as well as representatives of the genera Hymenogaster and Naucoria, were included to test the monophyly of Hebeloma, which is confirmed by the results. Hebeloma, Naucoria, Hymenogaster and Anamika indica cluster in a strongly supported monophyletic hebelomatoid clade. All trees largely reflect the current infrageneric classification within Hebeloma, and divide the genus into mostly well-supported monophyletic groups surrounding H. crustuliniforme, H. velutipes, H. sacchariolens, H. sinapizans, and H. radicosum, with H. sarcophyllum being shown at an independent position; however this is not well supported. The section Indusiata divides with strong support into three groups, the position of the pleurocystidiate Hebeloma cistophilum suggests the possible existence of a third subsection within sect. Indusiata. Subsection Sacchariolentia is raised to the rank of section.     

Taxonomic status of the species of the green algal genusNeochloris

Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.     

Die GattungKarschia — Bindeglied zwischen bitunicaten Ascomyceten und lecanoralen Flechtenpilzen?

The genusKarschia, in the earlier sense, including saprophytes and parasites on lichens, has been thought to be a non-lichenized parallel genus of the lichen genusBuellia. Modern workers included it on the one hand inBuellia, on the other hand combined it with bitunicate ascomycetes. It is now proved thatKarschia is heterogeneous and contains but superficially similar members both of the genusBuellia of theLecanorales and of typical or masked bitunicateAscomycetes. Therefore, it can not be regarded as a link betweenLecanorales andDothideales. The type species ofKarschia belongs to theDothideales.

     

Demographic characteristics of an intertidal bay goby (Lepidogobius lepidus)

Synopsis In a fourteen month study (May 1976 – June 1977) I examined the following characteristics of an intertidal bay goby (Lepidogobius lepidus) in Morro Bay, California, U.S.A.: annual and seasonal patterns of abundance, age composition and growth rates, survivorship and mortality patterns, and the reproductive cycle for female gobies. Fishes were collected with the aid of quinaldine and otoliths and ovaries removed. Age and growth rates were estimated from otolith annuli using a back calculation formula and a Brody-Bertalanffy growth curve. Mortality rates were derived using the methods of Heincke (1913), Robson & Chapman (1960), mean age, and a catch curve (Ricker 1975). A gonad index was used to describe the annual reproductive cycle. Results indicated that abundance fluctuated seasonally and that these fluctuations appeared to be caused by reproductive emigrations. Bay gobies reached an age of 7+ and a standard length of 87 mm. Growth was relatively constant (6 mm yr⁻¹) until age 5, at which point it began to decline. The mean rates of survivorship, mortality, and instantaneous mortality were 0.75, 0.25, and 0.29 respectively. Mortality rates for individual age classes ranged from 0.13 to 0.51 and increased with age. This stock appears to reproduce mainly during the winter.     

Systematic significance of mature embryo of bamboos

The mature embryo of seven species belonging to five genera of Indian bamboos is described. In all these the basic pattern of embryo organisation is same: the scutellar and coleoptilar bundles are not separated by an internode, the epiblast is absent, the lower portion of the scutellum and the coleorhiza are separated by a cleft and the margins of embryonic leaves overlap. The features unique to fleshy fruited bamboos are: presence of a massive scutellum, the juxtaposition of plumule and radicle and the occurrence of a bud in the axil of the coleoptile. The fleshy fruit bearing bamboos should be classified into one group, the tribeMelocanneae. Evidence is provided to recognise additional groups in the subfamilyBambusoideae.