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1.
Additional data are given on the occurrence and synonymy of this thermophilic soil-borne organism. It is proposed to indicate the species henceforth asPhoma multirostrata (Mathur.et al.) comb. nov.  相似文献   

2.
昂立一号口服液人群试验   总被引:8,自引:6,他引:2  
目的 :观察经优化的菌种和目前生产使用菌种发酵的昂立一号口服液人群服用后 ,调节人体胃肠道、代谢、食欲的效果。方法 :采用随机单盲方法 ,改进组 4 4人 ,对照组 2 9人。结果 :人群服用 10、15、2 0d后与服用前比较 :两组服用效果均比服用前差异有显著性 (P <0 0 1) ,改进组比对照组起效略快 ;两组之间服用不同天数 ,效果差异无显著性 (P >0 0 5 )。结论 :由生产菌种及经优化菌种发酵的昂立一号口服液均具有显著调节人体胃肠道、代谢、食欲的功能。  相似文献   

3.
The interaction of intermediate host (Eogammarus tiuschovi) cells with the cysticercoid of Microsomacanthus lari of the cyclocercus type was examined for the case of damage of the noncellular exocyst surrounding it. Massive penetration of the host cells, supposedly haemocytes characterized by intensive secretion, into the exocyst was observed even during the first several minutes of the experiment. Large accumulations of the product of secretion (fibrous material) were concentrated in the distal areas of the endocyst glycocalix and the microvillar layer of the cysticercoid tail appendage. The results provide evidence for the defensive role of the exocyst of M. lari in the cellular response of an intermediate host organism to invasion.  相似文献   

4.
A new species of extremely thermophilic, glycolytic anaerobic bacterium, Fervidobacterium nodosum isolated from a New Zealand hot spring, is described. Fervidobacterium nodosum strains were Gram-negative, motile, non-sporulating obligately anaerobic rods that existed singly, in pairs or in chains. Electron micrographs of thin sections revealed a two-layered cell wall structure. The outer layer of the cell wall produced spheroids, which was a typical feature of this organism. The optimum temperature for growth was 65 to 70° C, the maximum 80° C and the minimum greater than 40° C. Growth occurred between a pH of 6.0 and 8.0 with the optimum being 7.0 to 7.5. The doubling time of Fervidobacterium nodosum at optimal temperature and pH was 105 minutes. The DNA base composition was 33.7% guanine plus cytosine as determined by thermal denaturation. A wide range of carbohydrates including glucose, sucrose, starch and lactose could be utilized by the organism. Lactate, acetate, hydrogen, and carbon dioxide were the major end products of glucose fermentation with lesser amounts of ethanol being formed. Growth was inhibited by tetracycline, penicillin and chloramphenicol indicating that the organism was a eubacterium.  相似文献   

5.
Long Term Delayed Luminescence (LDL) of green plants ranging from 0.3 s up to several minutes after irradiation has been found to exhibit complex decay kinetics which are highly dependent on nutritional deficiencies and environmental pollutive components. As a model organism we utilized the unicellular green algaScenedesmus obliquus with fairly well understood properties ofLDL probably involving both photosynthetic reaction centers PS I and PS II. It is shown thatLDL is strongly affected both by depletion of the growth medium of various essential elements such as N, Fe, Ca, Mg or K, as well as by growth in the presence of environmental stress factors such as Cu, Hg, Cd or NO 2 . Therefore,LDL offers itself as a convenient, highly sensitive and specific assay for a number of stress factors in photosynthesizing plantsin vivo and in the field.  相似文献   

6.
Maximum Reactive Distance (RDmax) and the area of the Reactive Perceptual Field (RPF) for the fish Macropodus cupanus were determined, using the fourth instar mosquito larva (Culex fatigans) as the prey organism. RDmax and the area of RPF increased with increasing body weight of the fish as well as increasing food deprivation time. Satiation time (St) as a function of the weight of the fish and aquarium temperature were also determined. In larger W classes (570 and 270 mg) St was not influenced by temperature. To get satiated the smallest W class (80 mg) required feeding periods of 40, 30 and 20 minutes at 22 or 27, 32 and 37°C, respectively.  相似文献   

7.
酿酒酵母是第一个完成全基因组测序的真核生物,具有广泛的科研应用价值。利用酿酒酵母的全基因组序列可以进行精确的基因定位及敲除,从而达到对其基因组进行精简的目的,为合成生物学最小基因组的研究工作打下基础。根据Latour system 设计敲除所需引物,构建敲除盒,筛选重组体和缺失体,成功敲除酿酒酵母a型单倍体染色体XIII中339301-352281 nt包含的8个基因,为酿酒酵母染色体精简奠定基础,同时证明了Latour system 可以应用于酿酒酵母大片段敲除。  相似文献   

8.
ABSTRACT. Trichophrya collini has a polygonal, dorsoventrally flattened body (up to 75 μm diam.), with capitate tentacles arranged in 1–3 rows within peripheral fascicles. There is a central polymorphic macronucleus, an associated micronucleus, and numerous peripheral contractile vacuoles with ventral discharge pores. The cell has a multilayered cortex and the cytoplasm contains suctorian organelles such as crescentic bodies, elongate dense bodies, and haptocysts. The highly contractile tentacles have an axoneme with an outer ring of 24 microtubules separated into six groups and an inner ring of six curved lamellae, each with five microtubules. The lamellae at the distal and proximal ends of the axoneme are arranged in a helix, and the outer ring microtubules are joined in a distal connective sheath. In the apical knob of the tentacle, the haptocysts are borne on a central capsule, Reproduction is by endogenous budding to produce a single oval-shaped swarmer, with equatorial ciliature, which metamorphoses within 3 h. These observations suggest that this organism, previously known as Heliophrya collini Saedeleer & Tellier, is synonymous with Platophrya rotunda Gönnert, Craspedophrya rotunda Rieder, and Heliophrya rotunda Matthes. Its endogenous mode of budding assigns it to the genus Trichophrya. but it is distinct from Trichophrya rotunda Hentschel, and should be reclassified to Trichophrya collini (Saedeleer & Tellier).  相似文献   

9.
SYNOPSIS. The structural changes leading to the formation of motile microgametes from a single immobile intracellular gametocyte have been examiued in the electron microscope. After pigeon blood infected with Haemoproteus columbae was exposed to the air at room temperature for a few minutes axonemes appeared in the parasite's cytoplasm and the cytoplasm itself appeared less dense. The axonemes were connected with bundles of intranuclear microtubules that were perhaps spindle fibers. No conventional kinetosomes or centrioles have been observed. After the microgametocyte left the erythrocyte, it assumed the shape of a polarized slug or a dumb-bell. Half of the organism was surrounded by a single membrane and filled by part of the nucleus. The other half was surrounded by the remains of the multiple membranes of the gametocyte and contained pigment granules, mitochondria, axonemes and nuclear extensions. The axonemes and nuclear extensions were segregated at the periphery of the cell, exterior to the gametocyte's inner membrane, and were assembled in situ into microgametes. The mature microgamete appeared to peel off from the gametocyte, leaving a residual body.  相似文献   

10.
The holozoic dinoflagellate, Gymnodinium fungiforme Anissimova, has been observed in both asexually and sexually reproducing cultures. Asexual reproduction is characterized by zoosporangium formation and subsequent new cell release. Sexuality is gametic, and planozygotes and hypnozygotes are present. The life cycle is highly dependent on feeding, and in food-depleted cultures the swimming cells rapidly disappear. These are replaced with resistant long-term resting cysts. Despite its small size (8.5–19 μm), G. fungiforme can feed on prey as large as the ciliated protozoan, Condylostoma magnum Spiegel (600–1000 μm in length), or small injured metazoans, and has been cultured phagotrophically with the chlorophyte, Dunaliella salina Teodoresco as a food source. Eleven additional species of algae including 1 chlorophyte, 7 chrysophytes and 3 rhodophytes, however, were not suitable as food sources. Feeding is characterized by the formation of ‘dynamic aggregations’ of hundreds of dinoflagellates that attach to the surface of a prey organism by a peduncle. G. fungiforme ingests the cytoplasm or body fluids of its prey and a feeding aggregation can ingest a C. magnum in 20–30 minutes.  相似文献   

11.
Summary It has been established that the type cultures ofCephaloascus fragrans Hanawa 1920,Ascocybe grovesii Wells 1954 and a culture isolated from oakwood from Japan are identical. Conjugation in this organism has been observed. The taxonomic position of this organism in theAscomycetes was discussed. If this organism is incorporated in the classification ofLodder andKreger-van Rij, it seems justified by taxonomical reasons to create a new subfamily: theCephaloascoideae.  相似文献   

12.
Summary A thermophilic, motile organism producing catalase is described. It belongs certainly to the genusMicrobacterium by reason of its catalase production, although in its morphology, in some secondary characters and in its fermentative properties it more nearly resembles members of the genusLactobacillus. The nameMicrobacterium mobile is proposed for this organism.  相似文献   

13.
Summary and conclusions Sections of necropsy material of scutulum-bearing lesions from a kitten spontaneously infected byT. quinckeanum were stained by P.A.S., Sacpic and haematoxylin to reveal various features of the scutulum and the reaction which the parasite provoked in the tissues of the host.Such sections showed that the scutulum and other fungal structures were strongly Schiff positive.They also showed that, although the parasite was confined to the outermost layer of the epidermis (stratum corneum) it was also capable of invading the hair shaft and inner follicle sheath and of producing arthrospores both within the hair shaft and outside it (ecto-endothrix).The main inflammatory response of the host to the invasion of this organism showed itself in the massive infiltration of the dermal and epidermal tissues in the affected areas by serous exudate and polymorphonuclear leucocytes; other features being the undermining of the scutulum by pools of pus, the formation of discrete perifollicular microabscesses in the dermis, the engorgement of capillaries and oedema and lastly the parakeratosis.Necropsy sections from lesions of mice likewise experimentally infected by this dermatophyte showed much the same features as those found in the necropsy material of the spontaneously infected kitten.Necropsy sections from lesions of guinea-pigs experimentally infected by this organism showed incipient scutulum formation much infiltrated by inflammatory exudate and polymorphonuclear leucocytes. The dermis was also heavily infiltrated and showed perifollicular-abscesses. These sections also revealed invasion of the hair follicles and hair shaft by the dermatophyte.  相似文献   

14.
The taxonomic position of a soil isolate, strain E626, was evaluated using the polyphasic approach. The organism was found to have chemical and morphological features consistent with its assignment to the genus Nonomuraea, a member of the family Streptosporangiaceae. Strain E626 consistently formed a distinct phyletic line within the Streptosporangiaceae 16S rDNA tree using four different algorithms. Furthermore, the taxonomic distinctness of the organism is underpinned by a range of phenotypic properties, notably morphological features. It is, therefore, proposed that the organism be classified in the genus Nonomuraea as Nonomuraea terrinata sp. nov. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

15.
A bacterium capable of utilizing pyrethroid pesticide cypermethrin as sole source of carbon was isolated from soil and identified as a Micrococcus sp. The organism also utilized fenvalerate, deltamethrin, perimethrin, 3-phenoxybenzoate, phenol, protocatechuate and catechol as growth substrates. The organism degraded cypermethrin by hydrolysis of ester linkage to yield 3-phenoxybenzoate, leading to loss of its insecticidal activity. 3-Phenoxybenzoate was further metabolized by diphenyl ether cleavage to yield protocatechuate and phenol as evidenced by isolation and identification of metabolites and enzyme activities in the cell-free extracts. Protocatechuate and phenol were oxidized by ortho-cleavage pathway. Thus, the organism was versatile in detoxification and complete mineralization of pyrethroid cypermethrin  相似文献   

16.
In the spring of 2007, a serious disease on amaranth was noticed in several farms in the major amaranth production area in central Taiwan. Abundant oospores were found in the disease tissues. A species of Phytophthora was consistently isolated from disease tissues. The organism formed abundant oospores with smooth walls and with amphigynous antheridia in single culture. Sporangia were partially deciduous with short‐ to medium‐length pedicels. Morphological characteristics of this organism did not match any reported Phytophthora species, and the organism was named Phytophthora amaranthi. Pathogenicity tests and molecular characterization confirmed the identity of the organism as a new pathogen of amaranth and a new species of Phytophthora.  相似文献   

17.
Summary Legionella pneumophila serogroup 1 has been demonstrated by indirect immunofluorescence in human lung tissue fixed in 10% formal saline and embedded in epoxy resin. The organism was visualised using Rabbit serogroup 1 antibody and Sheep anti rabbit fluorescein conjugate. The fluorescent labelled organism was found distributed throughout the tissue with focal areas in alveolar spaces and also visualised by electron microscopy in the same tissue. This method therefore enables specific identification of the L. pneumophila organism with the antiserum and also affords the opportunity of studying the bacterium ultrastructurally in the same tissue.  相似文献   

18.
Regulation of xylanase, and β-xylosidase synthesis in Cellulomonas flavigenawas studied by culturing non-induced cells on mono-, oligo-, and poly-saccharides. The concomitant formation of these enzymes occurred on polysaccharides having structural resemblances with lignocellulosics, namely, cellulose, cellodextrin and xylan. Among disaccharides, cellobiose was the best inducer for their synthesis. Increased levels of enzymes were synthesized by the organism even under repressed conditions. Cell-free supernatants of the organism exhibited greater endo-xylanase than cell-associated β-xylosidase activity. Among inexpensive materials produced on saline lands, the salt tolerant grass Leptochloa fusca supported maximum xylanolytic activities followed by Sesbania aculeate (dhancha). The former could be effectively used for bulk production of xylanolytic enzymes by this organism.  相似文献   

19.
An experimental set-up which enabled non-invasive, real-time reactive oxygen species (ROS) visualization on a whole plant level was constructed. In the test organism, Lemna minor L. (common duckweed), apoplastic and symplastic oxidative stress was evaluated by exposure to menadione (50 μM), menadione (50 μM) + ascorbate (100 μM) or neither for control. Menadione (50 μM) caused a statistically significant increase in H2DCFDA fluorescence in the apoplast after 60 minutes of exposure. The addition of ascorbate (100 μM) in the test medium significantly decreased apoplastic oxidative stress. 50 μM menadione caused an increase in symplastic H2DCFDA fluorescence in 57% of fronds. The exposure of L. minor plants to both menadione and ascorbate decreased the rate of fluorescence intensity accumulation in the symplast to control levels. The method has proven to be quick and straightforward and could be applied to a range of chemicals in various physiological and toxicological plant studies. The advantages of the set-up and different possible artefacts are discussed.  相似文献   

20.
Grids of 17 to 50 stations in the German Bight were sampled 18 times within the framework of the multidisciplinary programmes ZISCH and PRISMA in winter and spring of 1988/89 and from April 1991–April 1992. The frequent abundance ofCoscinodiscus wailesii Gran & Angst, a recently established large diatom, was noteworthy, as it dominated the phytoplankton biomass over long periods (e.g. 12/88–3/89 and 8/91–11/91). The bulk of the phytoplankton carbon during these periods (up to 90%) could be attributed to this species. Blooms ofCoscinodiscus wailesii producing up to 1400 μg carbon 1−1, were recorded in early spring of 1989 and autumn of 1991. The potential consequences for the whole ecosystem refer to the huge size of this organism, which may cause reduced exploitation of its primary production by native consumers. Furthermore, sedimentation and remineralisation processes may be affected. ForC. wailesii, a doubling of biomass in 70 h could be estimated on the basis of data from four successive surveys in 1991. Results from laboratory cultures under comparable conditions confirm this rate. In the survey area, no increase in biomass was recorded for the relatedCoscinodiscus granii Gough, although there was sufficient silicate supply for growth. Field data showed 8–10 times lower copper and 10–20 times lower cadmium and zinc accumulation inC. wailesii, compared to concentrations found in native phytoplankton species. Subsequent laboratory tests suggested that one reason for the remarkable success ofC. wailesii, mainly in inshore regions, may be derived from its tolerance of higher doses of heavy metals due to very low sorption.  相似文献   

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