紫色红曲霉Mp-21次级代谢产物抗氧化及抑制α-葡萄糖苷酶活性的研究

[目的]紫色红曲霉(Monascuspurpureus)Mp-21次级代谢产物的分离纯化与生物活性研究.[方法]综合运用硅胶柱、反相C18柱和Sephadex LH-20凝胶柱等柱色谱分离技术对紫色红曲霉Mp-21的次级代谢产物进行分离纯化,运用波谱学技术(核磁共振和高分辨质谱技术)鉴定化合物的结构.对鉴定的化合物进行...     

红曲霉繁殖相关wetM基因的克隆与生物信息学分析

红曲霉(Monascus spp.)是一类次级代谢产物极为丰富的食药用丝状真菌,其繁殖能力是大规模工业化生产的前提.以实验室保藏紫色红曲霉(Monascus purpureus)Mp-21为研究对象,通过高通量转录组(RNA-Seq)测序获得菌株转录本数据后进行注释分析,首次克隆出红曲霉繁殖相关wetM基因并进行生物信...     

基于RNA-Seq分析MpigE在红曲霉色素生物合成中的转录调控

[目的]分析MpigE的缺失在转录水平对红曲色素产生的影响.[方法]对实验室保存的野生型紫色红曲霉(Monascus purpureus) Mp-21和△MpigE菌株进行高通量转录组测序、注释、表达差异基因功能富集分析和基因通路富集分析,在转录水平揭示MpigE缺失后红曲霉色素产量变化的原因.[结果]通过RNA-Se...     

红色红曲霉Mr-1的次级代谢产物生物活性成分分析

【背景】红曲霉(Monascus)是一种重要的药食同源性真菌,其自身产生的次级代谢产物具有多种生理活性功能,然而红曲霉中的生物活性成分却鲜有报道。利用红曲霉发酵液进行药效物质成分追溯,对了解红曲霉药效物质基础具有十分重要的意义。【目的】对红色红曲霉(M.ruber)Mr-1次级代谢产物中的生物活性成分和生物学功能进行研究。【方法】采用硅胶柱、SephadexLH-20凝胶柱等色谱技术对活性成分进行分离纯化,通过核磁共振和高分辨质谱技术对化合物结构进行解析;对鉴定的化合物进行体外抗氧化、抑菌和酶活性测定。【结果】从红色红曲霉Mr-1次级代谢产物中分离得到4个活性化合物,鉴定为3个黄酮类化合物Luteolin(1)、Hesperetin(2)、Glycitein(3)和1个萜类化合物Ursolic acid(4)。化合物1、2、4为首次从红曲菌科中分离得到。在抗氧化试验中,化合物1对ABTS⁺、DPPH和OH^-自由基具有较强的清除能力,IC₅₀分别为13.36、8.74和32.75μg/mL;在抑菌试验中,化合物4对金黄色葡萄球菌(Staphylococcus aureus)和李斯特菌(Listeria monocytogenes)表现出中等强度的抑菌能力,抑菌圈直径分别为13.4 mm和11.9 mm;在α-葡萄糖苷酶抑制活性试验中,化合物4表现出很强的抑制能力,IC₅₀为21.34μg/mL。【结论】红色红曲霉Mr-1是宝贵的微生物种质资源,其产生的次级代谢产物生物活性成分多样,具有开发成功能性食品原料的潜能。     

一株海洋真菌Penicillium sp.QF046的细菌群体感应抑制剂的分离和鉴定

目的:从海洋真菌中筛选得到新型群体感应抑制剂,并对其进行活性评价。方法:首先利用紫色杆菌CV026指示菌株对真菌发酵粗提物进行活性筛选。其次通过18S r DNA序列比对进行菌种鉴定,同时采用硅胶柱色谱、凝胶柱色谱和高效液相色谱等技术并结合活性追踪检测分离纯化的活性化合物,再通过核磁质谱分析确定其结构。最后利用定量测定方法检测其在亚抑菌浓度下对紫色杆菌紫色菌素产量影响以及RT-PCR检测与QS调控相关基因的m RNA表达的影响。结果:从海藻共生菌中筛选到一株具有紫色杆菌群体感应抑制活性的海洋真菌Penicillium sp.QF046,其次级代谢产物中纯化到的活性化合物根据结构鉴定为一种星形曲霉毒素(asteltoxin)。该化合物对于紫色杆菌群体感应抑制浓度低于阳性对照化合物呋喃酮C30,同时抑制了群体感应相关基因m RNA水平的表达。结论:从海洋真菌Penicillium sp.QF046代谢产物中发现了一种抑制紫色杆菌群体感应的星形曲霉毒素,为进一步通过结构改造研发新型抗菌药物提供良好的前体化合物。     

北桑寄生内生真菌的分离及其次级代谢产物分析

首次对药用植物北桑寄生叶片中的内生真菌进行分离纯化,从中筛选出具有较高生物活性的菌株,鉴定此菌株并对其次级代谢产物进行初步分离。采用组织块法分离内生真菌,对其进行抗氧化活性和抑菌活性筛选;通过形态学和分子生物学方法鉴定其种属;运用柱色谱、重结晶等方法分离次级代谢产物,波谱学鉴定其结构。从北桑寄生叶片中分离纯化得到29株内生真菌,检测得到一株具有较高抗氧化和抑菌活性的菌株,鉴定为Alternaria alternata,从该菌次级代谢产物中首次分离得到3个单体化合物,分别为alternariol-5-O-methyl ether(1)、alternariol(2)、cis,cis-9,12-octadecadienoic acid(3)。化合物1和2具有较弱的抗氧化活性,化合物1和3表现出一定的抑菌活性。     

南海珊瑚来源真菌Aspergillus sp.SCSIO 40435的分离鉴定及其次级代谢产物研究

【目的】南海珊瑚共附生真菌Aspergillus sp. SCSIO 40435次级代谢产物分离鉴定及抑菌活性筛选。【方法】利用稀释涂布平板法分离珊瑚共附生真菌。采用单菌多代谢产物方法(one strain many compounds,OSMAC)对分离菌株进行化学多样性筛选,并采用滤纸片扩散法对真菌发酵产物进行抑菌活性分析。通过ITS测序鉴定活性菌株SCSIO 40435的分类地位,运用多种色谱手段从其粗提物中分离纯化单体化合物,并利用各种波谱手段(HRESIMS、1D和2D NMR、单晶X-ray衍射法等)确定化合物的结构。最后,采用微量肉汤稀释法对单体化合物的抑菌活性进行评估。【结果】从南海珊瑚样品中分离得到19株共附生真菌,结合化学多样性和抑菌活性分析,筛选出1株产物丰富且具有多种抑菌活性的菌株SCSIO40435。利用ITS测序分析将其鉴定为曲霉属真菌(Aspergillus sp.),进一步从其发酵产物中分离鉴定了4个对三联苯类化合物：dicandidusin A(1)、candidusin A(2)、terphenyllin(3)和4″-deoxyterphenylli...     

抗菌活性海洋真菌HN4-13的鉴定及其发酵优化

[目的]鉴定一株来源于连云港近岸海域沉积物并具有分泌抗菌活性代谢产物的真菌菌株HN4-13,优化其合成抗菌活性物质的发酵条件.[方法]通过形态学观察及ITS序列分析方法对菌株HN4-13进行鉴定;通过基础发酵培养基筛选、碳氮源及无机盐的单因素试验,继而采用正交试验设计优化其合成抗菌活性物质的发酵条件.[结果]菌株HN4-13被鉴定为黄柄曲霉(Aspergillus flavipes),其分泌抗菌活性产物的发酵条件为:4％蔗糖、0.5％蛋白胨、0.1％ KCl、0.06％ NaH2PO4、28℃、1％接种量、160 r/min培养9d.[结论]实验结果为进一步分离纯化菌株HN4-13所产抗菌活性代谢产物提供了基础.     

高速逆流色谱分离真菌Aspergullus versicolor中二苯醚类化合物

首次运用高速逆流色谱(HSCCC)技术从经表观遗传试剂诱导的曲霉属真菌Aspergullus versicolor的次级代谢产物中快速分离纯化得到二苯醚类化合物diorcinol,建立了快速分离制备杂色曲霉次级代谢产物中的二苯醚类化合物的方法。本研究首先对经过表观遗传试剂诱导的菌株DJ013的发酵液用乙酸乙酯浸提,萃取富集二苯醚类成分,然后以石油醚-乙酸乙酯-甲醇-水(4∶5∶4∶5,v/v)为两相溶剂系统进行高速逆流色谱分离纯化,上相为固定相,下相为流动相,流速5.0 m L/min,实验温度25℃,转速为800 rpm,检测波长为220 nm。对所得到的目标化合物经超高效液相色谱(UPLC)纯度分析,其纯度在97%以上。通过质谱、核磁等波谱技术鉴定所分离得到的目标化合物为二苯醚类化合物diorcinol。与前期研究中采用的柱色谱法、HPLC等多种方法相结合的长达48 h的制备周期相比,高速逆流色谱法仅需55 min,效率大大提高。该结果表明,本研究建立的高速逆流色谱方法可高效高纯度获得具有抗菌活性的二苯醚类化合物,将为二苯醚化合物的进一步研究提供高效制备方法。     

卡伍尔氏链霉菌NA4的Ⅱ型聚酮基因簇的靶向激活及其产物鉴定

【目的】以基因组信息为导向,定向激活海洋来源卡伍尔氏链霉菌（Streptomyces cavourensis） NA4中沉默的Ⅱ型聚酮类次级代谢产物生物合成基因簇,鉴定新产生的次级代谢产物的结构和抑菌活性。【方法】通过添加启动子和敲除负调控基因的方法激活实验室培养条件下沉默或低表达的生物合成基因簇,并完成目标化合物的分离与纯化,通过电喷雾质谱（electrospray ionization-mass spectrometry,ESI-MS）和核磁共振（nuclear magnetic resonance,NMR）数据分析鉴定目标化合物结构,对目标化合物进行抑菌活性鉴定,基于生物信息学信息推导化合物的生物合成途径。【结果】根据基因组生物信息学分析,从海洋来源链霉菌Streptomyces cavourensis NA4中选取一个编码PKSⅡ型次级代谢产物的生物合成基因簇开展研究,成功激活目标基因簇,从中分离到1个PKSⅡ型化合物,推导了其生物合成途径并进行了抑菌活性鉴定。【结论】基因组导向下的天然产物挖掘,可以目标明确地分离产物,充分挖掘链霉菌编码次级代谢产物的潜力。     

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.