广东和广西地区柑橘木虱内生细菌的分离鉴定及多样性分析

[目的] 基于广东和广西地区柑橘木虱内生细菌的分离培养及分子鉴定,明确柑橘木虱可培养内生细菌的多样性,为研究内生细菌与柑橘木虱互作、筛选潜在的共生控制候选细菌提供基础。[方法] 采用虫体捣碎和涂布平板法分离柑橘木虱内生细菌,在线BLAST分析菌株的16S rDNA序列,鉴定内生细菌的种属,并构建优势菌群的系统发育进化树和韦恩图。[结果] 共获得114株柑橘木虱内生细菌,归为细菌界的3个门的15个属,其中芽孢杆菌属59株为优势菌群,占分离细菌总数的51.75%;假单胞菌属14株,占分离细菌总数的12.28%;泛菌属10株,占分离细菌总数的8.77%;其他细菌占分离细菌总数的27.19%。[结论] 芽孢杆菌属细菌广泛分布在两广地区的柑橘木虱体内,值得作为潜在的候选细菌进行共生控制柑橘木虱的研究。     

Diversity,biogeography and host specificity of kelp endophytes with a focus on the genera Laminarionema and Laminariocolax (Ectocarpales,Phaeophyceae)

Endophytic filamentous brown algae are known to invade stipes and fronds of kelps with potentially negative effects for the hosts. They have simple filamentous thalli and are difficult to identify based on morphology. We investigated the molecular diversity of 56 endophytes isolated from seven different kelp species from Europe, Chile, Korea and New Zealand by sequencing two unlinked molecular markers (5’COI and ITS1). A majority of 49 of the isolated endophytes (88%) belonged to the genera Laminarionema and Laminariocolax. The endophyte Laminarionema elsbetiae was isolated from Saccharina latissima and S. japonica tissues in Europe and Korea, respectively, and showed highly similar sequences in both regions. Three different species of the genus Laminariocolax were identified, the most common of which was L. aecidioides, an endophyte with a worldwide distribution and a broad host range. The other two species, L. tomentosoides and a species described here as Laminariocolax atlanticus sp. nov., were associated with different kelp species in the northern hemisphere and the North Atlantic, respectively. Our results suggest that specific host-endophyte patterns could exist locally, as found in kelps in Brittany where all endophytes isolated from S. latissima were L. elsbetiae, all endophytes isolated from Laminaria digitata were Laminariocolax tomentosoides, and those isolated from Laminaria hyperborea were Laminariocolax atlanticus and L. aecidioides. However, this pattern was not consistent with the results from other places, such as Western Scotland and Helgoland where the same kelp species are present.     

Species distribution and antimicrobial resistance of enterococci isolated from surface and ocean water

Aims: The species identification and antimicrobial resistance profiles were determined for enterococci isolated from Southern California surface and ocean waters. Methods and Results: Species identification was determined for 1413 presumptive Enterococcus isolates from urban runoff, bay, ocean and sewage water samples. The most frequently isolated species were Enterococcus faecalis, Enterococcus faecium, Enterococcus hirae, Enterococcus casseliflavus and Enterococcus mundtii. All five of these species were isolated from ocean and bay water with a frequency ranging from 7% to 36%. Enterococcus casseliflavus was the most frequently isolated species in urban runoff making up 36–65% of isolates while E. faecium was the most frequently isolated species in sewage making up 53–78% of isolates. The similar distribution of species in urban runoff and receiving water suggests that urban runoff may be the source of Enterococcus. No vancomycin or high level gentamycin resistance was detected in E. faecalis and E. faecium isolates. Conclusions: Enterococcus faecalis, E. faecium, E. casseliflavus and E. mundtii are the most commonly isolated Enterococcus species from urban runoff and receiving waters in Southern California. Significance and Impact of the Study: Determination of the Enterococcus species isolated from receiving waters and potential pollution sources may assist in determining the sources of pollution.     

Keratinophilic fungi isolated from hospital dust and soils of public places at Gulbarga,India

Keratinophilic fungi were isolated from corridor dust of 11 hospitals and soils of 21 public places using a hair baiting technique. A total of 41 species belonging to 24 genera were recovered. Among the dermatophytes and related species, Microsporum gypseum was predominant, followed by Chrysosporium keratinophilum, Trichophyton mentagrophytes, M. nanum and Ch. tropicum. Other species were represented by 32 species belonging to 21 genera. Most of the species isolated are known to be agents of human and animal infection or have been isolated from human and animal lesions. The fungi observed here are discussed in relation to their global distribution.     

Characterization of fungi isolated from the equipment used in the International Space Station or Space Shuttle

As a part of a series of studies regarding the microbial biota in manned space environments, fungi were isolated from six pieces of equipment recovered from the Japanese Experimental Module “KIBO” of the International Space Station and from a space shuttle. Thirty‐seven strains of fungi were isolated, identified and investigated with regard to morphological phenotypes and antifungal susceptibilities. The variety of fungi isolated in this study was similar to that of several previous reports. The dominant species belonged to the genera Penicillium, Aspergillus and Cladosporium, which are potential causative agents of allergy and opportunistic infections. The morphological phenotypes and antifungal susceptibilities of the strains isolated from space environments were not significantly different from those of reference strains on Earth.     

Occurrence of thermophilic actinomycetes in natural substrates in Nigeria

Thermophilic actinomycetes were isolated from 163 (48.95%) of 333 samples of vegetable substrates and soil from different sites in Anambra and Enugu States in Nigeria.Thermoactinomyces (Tha.) vulgaris was the most common, occurring in 32.4% of samples whileTha. thalpophilus was isolated from 20.1%.Tha. sacchari, Saccharomonospora (Sam.) viridis andSaccharopolyspora (Sap.) rectivirgula were isolated from 3–10.5% of the samples examined.Streptomyces (Stm.) thermovulgaris occurred in 2.7% andThermomonospora spp. in 0.6% of samples. Except forStm. thermovulgaris and, perhaps,Thermomonospora spp., all the species isolated are known to be allergenic in man. The five known allergenic species were abundant in hay and maize silage.T. vulgaris andT. thalpophilus were also frequently isolated from rice straw.Tha. vulgaris, Tha. thalpophilus andSap. rectivirgula were all most numerous in hay whileTha. sacchari was most numerous in maize silage. The widespread occurrence of thermophilic actinomycetes in Nigeria emphasizes the need for investigation of their role in allergic respiratory disorders.     

The isolation of functional pole cells from theDrosophila melanogaster maternal effect mutantmat(3)1

Summary A procedure for pole cell isolation has been developed that takes advantage of theDrosophila melanogaster maternal effect mutantmat(3) 1. Embryos derived from homozygousmat(3)1 mothers form exclusively pole cells. By outcrossing we could substantially increase the expressivity of the original mutant stock. We further introduced theTM8 balancer chromosome, which carries the dominant temperature sensitive mutationDTS-4. This allows the accumulation of large homozygousmat(3) 1 fly populations by eliminating the heterozygous flies at the restrictive temperature.Early embryos were mechanically fragmented and the cells were isolated by means of metrizamide step gradients. The isolated cells were demonstrated to exhibit the various ultrastructural and histochemical characteristics of pole cells. The isolated cells were transplanted into genetically marked host embryos. The germ line mosaics that were obtained indicate that the isolated cells represent functional pole cells.Proteins synthesized by the isolated pole cells during short term in vitro labelling with³⁵S-methionine were compared to the proteins synthesized by blastoderm cells fromOregon-R embryos. At least one protein could be demonstrated in the pole cell samples that is not synthesized byOregon-R blastoderm cells.The method allows a fast and gentle isolation of highly enriched pole cell populations which are a prerequisite for the biochemical analysis of germ cell determination and differentiation.     

Survey ofFusarium species in an arid environment of Bahrain

The prevalence and distribution of soil-inhabitingFusarium species in the soil of vegetable crops grown under custom-made plastic tunnels were studied at three geographical locations on the island of Bahrain. Six species ofFusarium representing a total of 1154 isolates were isolated on modified Komada medium. All species reported in this survey are recorded for the first time from the hot, arid desert of Bahrain.Fusarium solani andF. oxysporum were among the most frequently isolated fungi in all locations and crops.     

Diarylheptanoids from Green Alder Bark and Their Potential for DNA Protection

Nine diarylheptanoids, 1 – 9 , catechin ( 11 ), and a phenolic glucoside, 10 , were isolated from the bark of green alder (Alnus viridis). Four of the isolated compounds, i.e., 2, 5, 8, 10 , are new. The structures of 1 – 11 were determined on the basis of spectroscopic data. All isolated compounds were evaluated for their in vitro protective effects on chromosome aberrations in peripheral human lymphocytes using cytokinesis‐block micronucleus (CBMN) assay. Almost all of them exerted a pronounced effect of decreasing DNA damage of human lymphocytes, acting stronger than the known synthetic protector amifostine.     

Cyanobacterial–Bacterial Complexes in Plant Syncyanoses

The morphology and ultrastructure of associative microsymbiont complexes (AMC) isolated from the ferns Azolla pinnata and Azolla sp. and the apogeotropic roots of the cycad Cycas revoluta were studied. The composition of the AMC obtained includes the cyanobionts (symbiotic cyanobacteria) and satellite bacteria (SB). It was found that two types of cyanobacteria that substantially differ in their morphological organization are likely present as cyanobionts in the coralloids of C. revoluta. The isolated cyanobiont strains exhibited the morphological traits and regularities of development typical of the genus Nostoc; they were characterized by the ability of their cells to divide in mutually perpendicular planes. When isolating AMC from different morphological zones of C. revoluta apogeotropic roots, SB growth was revealed only around the pieces corresponding to the coralloid apical zone. No AMC components were revealed around the segments of the basal growth zone. Pure cyanobiont cultures were obtained from the AMC of C. revoluta coralloids. The AMC isolated from the ferns A. pinnata and Azolla sp. are characterized by obligate mutual dependence of the partners (the cyanobiont and SB).     

PHYLOGENETIC POSITION OF SYMBIODINIUM (DINOPHYCEAE) ISOLATES FROM TRIDACNIDS (BIVALVIA), CARDIIDS (BIVALVIA), A SPONGE (PORIFERA), A SOFT CORAL (ANTHOZOA), AND A FREE-LIVING STRAIN

The genus Symbiodinium is the commonly observed symbiotic dinoflagellate (zooxanthellae) that forms mutual associations with various marine invertebrates. Numerous studies have revealed that the genus is comprised of a group of diverse taxa, and information on the phylogenetic relationships among the genus’ members is increasing. In this study, small subunit (SSU) ribosomal RNA (ssrRNA) gene sequences were determined for 15 more Symbiodinium strains from 12 relatively unstudied host taxa (Indo-Pacific tridacnids, cardiids, sponge, and soft coral), 1 hitherto unreported free-living Symbiodinium strain, and 4 other Symbiodinium strains from four other host taxa (Indo-Pacific zoanthid, foraminifer, jellyfish, and mid-Pacific hard coral). Their respective phylogenetic positions were inferred, and strains that are either closely related to or distinct from previously reported Symbiodinium taxa were revealed. The cultured Symbiodinium strains isolated from individuals of six species of tridacnids and three species of cardiids all had identical ssrRNA gene sequences, are closely related to S. microadriaticum Freudenthal, and are indistinguishable from the RFLP Type A strain previously reported. However, the ssrRNA gene sequences of clam symbionts that were obtained via gene cloning were different from those of the cultured isolates and represent strains that are close to the RFLP Type C strains. The Symbiodinium-like dinoflagellate from the Indo-Pacific sponge Haliclona koremella De Laubenfels is distinct from any of the Symbiodinium taxa studied and may be similar to the symbiont previously isolated from the stony coral Montipora patula Quelch. The isolates from the soft coral Sarcophyton glaucum Quoy et Gaimard and from the zoanthid Zoanthus sp. are both very closely related to S. pilosum Trench et Blank. The free-living Symbiodinium isolate is very closely related to the symbiont isolated from the Indo-Pacific foraminifer Amphisorus hemprichii Ehrenberg, which in turn is distinct from the Red Sea strain isolated from a similar host. Theisolate from Cassiopeia sp. is different from S. microadriaticum F., the type species harbored by Cassiopeia xamachana Bigelow, and is instead very closely related to S. pulchrorum Trench isolated from a sea anemone. The symbiont from the stony coral M. verrucosa Lamarck is a sister taxon to the symbionts isolated from the foraminifera Marginopora kudakajimensis Gudmundsson and Sorites orbiculus Forskål. These data suggest that polymorphic symbioses extend from cnidarians to some bivalve, foraminifer, and jellyfish host species.     

Isolation and identification of mucinolytic actinomycetes

Biochemical and physiological tests, and 16S rRNA gene sequences, were used to classify nine Actinomycete strains isolated from soil and sand samples in Thailand. These strains were isolated based on their ability to readily degrade mucin glycoproteins. A turbidometric based mucinolytic assay was developed to confirm this. In addition all strains showed significant production of proteases. Phylogenetic analysis of the strains revealed that from the nine isolated Actinomycete strains eight were closely related to Streptomyces species and one was identified as belonging to the genus Kitasatospora. The biochemical and physiological tests performed identified two strain pairs that were similar (with only 3.9% difference observed) and this was in accordance with the phylogenetic results obtained. The remaining strains were distinct from each other, with the soil-isolated strains forming a separate clade to the sand-isolated strains in the inferred phylogenetic trees. The isolated mucinolytic Actinomycete strains will be the subject of further investigations into their proteolytic and glycosidic activity. Mucin degrading enzymes such as these are studied for their potential to be used for the development of a drug delivery system.     

Conservation value for birds of traditionally managed isolated trees in an agricultural landscape of Madagascar

Isolated trees have distinctive economic, social and cultural value for the Betsileo people living on the edge of the protected forest corridor between Ranomafana and Andringitra national parks, in South-East Madagascar. Many of these trees are Ficus spp., traditionally protected and respected. At the landscape level, they are isolated features in a heterogeneous mosaic, providing fruit, shade and aesthetic services in open cultivated areas. Within the current management system, isolated trees may also contribute significantly to the provision of ecological services by enhancing bird diversity in open areas outside the forest. We identified practices and values linked to isolated tree uses and management through ethnographic data collection. Bird presence and abundance were sampled by 338 point counts in isolated trees and open areas of the agricultural mosaic. Isolated trees were occupied by 18 out of 32 (56%) bird species in the agricultural mosaic, including 8 (25%) endemic forest species. Endemic forest birds were significantly more numerous in isolated trees than in open habitats, both in species richness and abundance (mean P value < 0.001). Overall bird species richness was significantly higher in open areas containing isolated trees, than in areas without isolated trees. Bird species richness in Ficus spp. was significantly higher than in other isolated tree species, although no differences were detected in abundance or within guilds. Community-based management of isolated trees may thus represent an opportunity for convergence between bird conservation goals outside protected areas and local management values and practices.     

A Comparative Analysis of Stachybotrys chartarum Strains Isolated in Russia

This work deals with a comparative analysis of Stachybotrys chartarum strains isolated from various artificial cellulose-containing materials and natural substrates in geographically distant regions of Russia. The analysis included determination of the spore size; the strain toxicity to Paramecium caudatum; the strain resistance to the fungicides Benomil, Olilen, and Tilt; and the PCR study of the genome structure with the aid of a primer that was complementary to the core sequence of the SINE retrotransposon. It was found that some of the strains that were isolated from different areas and from different substrates differ in their toxicity, fungicide resistance, and genome structure. PCR analysis showed the absence of any correlation between the genome structure, the strain properties, the geographic area, and the substrates from which the strains were isolated. The pheno- and genotypic diversity of the strains and their different vegetative compatibility suggest the existence of an intraspecies diversity of the S. chartarum strains that were isolated in different geographic areas. The absence of any correlation between the pheno- and genotypic properties of the strains and the substrates from which they were isolated implies that the colonization of artificial substrates by S. chartarum occurred occasionally from natural habitats. The S. chartarum populations that live on artificial substrates are unlikely to have their own evolutionary history.     

白及内生真菌多样性研究

白及( Bletilla striata)是兰科地生型多年生植物,也是我国传统中药材之一。利用菌根技术进行白及的保护和人工栽培,需要获得白及可培养的内生真菌。该研究以广西野生的白及根和叶为材料,采用分离培养法分离内生真菌,并结合真菌形态特征,及其核糖体的转录间隔区( ITS)序列分析,确定内生真菌的分类地位。结果表明：从2株白及植物90块组织中分离获得37株内生真菌,鉴定为15个分类单元,由9个属组成,分属于2门4纲7目8科,包括锤舌菌纲( Leotiomycetes)、座囊菌纲( Dothideomycetes)和粪壳菌纲( Sordariomy-cetes),伞菌纲( Agaricomycetes)。从根中分离获得内生真菌12种,蜡壳菌属为优势属;从叶中分离获得内生真菌3种,刺盘孢属为优势属;刺盘孢菌属( Colletotrichum)和蜡壳菌属( Sebacina)真菌的相对多度值均达到20％;4株担子菌均分布于根中,叶组织中未有分布。根组织中内生真菌的多样性指数(H＝1.863)高于叶组织(1.098)。该研究结果及其所分离培养的担子菌类真菌,为更好地利用菌根技术进行白及等兰科植物资源的保护与可持续利用奠定了基础。     

Isolation of endophytic fungi from leaves of Pasania edulis and their within-leaf distributions

 Endophytic fungi were isolated from leaves of Pasania edulis, one of the most important trees of the warm temperate forests in southern Kyushu, by the surface sterilization method using H₂O₂ as a sterilizing agent. From a tree in the Experimental Nursery of Kagoshima University, located at the city of Kagoshima, Phyllosticta sp. and Colletotrichum spp. were frequently isolated. From a stand in a laurel forest in Mt. Takakuma, an ascomycetous fungus (Ascomycete sp. 1) and Phomopsis sp. were frequently isolated. Phyllosticta sp. was isolated more frequently from petiole segments and leaf segments with midrib and Phomopsis sp. from petiole segments and leaf-base segments with midrib than other segments. Colletotrichum spp. were isolated less frequently from petioles and Ascomycete sp. 1 from petiole segments and leaf-base segments with midrib than other segments. As possible causes of such biases in within-leaf distributions of the endophytes, differences in infection modes and negative interactions of major endophytes within leaves are suggested. Received: December 13, 2001 / Accepted: June 7, 2002 Acknowledgments The authors thank the staff members of the Experimental Forests of Kagoshima University for enabling the present study. Correspondence to:K. Hata     

Five new Candida species

Summary The following five new yeast species are described:Candida beechii isolated from cider,C. blankii isolated from a mink,C. cacaoi isolated from fermenting cacao,C. freyschussii isolated from wood pulp andC. melibiosica isolated from sputum.     

Isolation of Ewingella americana from mollusks

Twenty-three of 2446 strains of Enterobacteriaceae isolated from mollusks were identified as Ewingella americana both biochemically and by DNA hybridization with strain S6/1111. The biochemical characteristics of the new strains showed few differences from previously reported strains obtained from human clinical specimens. These are the first strains of E. americana isolated from animals.     

Three new species of Penicillium belonging to Subgenus Biverticillium Dierckx,isolated from different substrates

P. samsonii, n.sp., isolated from apples damaged by indeterminate insects, P. rademirici, n.sp., isolated from air, and P. pittii, n.sp., isolated from clayed soil, were found to be different from previously described species and therefore are proposed as new taxa.     

Genetic Characterization of Epilithic Cyanobacteria and Their Associated Bacteria

Epilithic phototrophic biofilms develop inside Roman Necropolis and Catacombs on rock surfaces exposed to artificial light sources and are composed by a microbial consortium dominated by cyanobacteria. In this work, six non-axenic cultures of Leptolyngbya sp. strains isolated from biofilms from different Roman hypogea and maintained in cultures from 11 to 20 years were analysed along with their associated bacteria isolated in culture. The employment of PCR-fingerprinting techniques, using HIP1 and ERIC derived primers, allowed the clustering in three groups of the six Leptolyngbya strains and the typing of their isolated bacteria. The bacterial fingerprinting patterns were in agreement with the 16S rRNA gene sequencing and showed the presence in Leptolyngbya isolates of Pseudomonas, Stenotrophomonas, Agrobacterium and Bacillus representatives that were detected also in biofilms sampled from catacombs.