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1.
Samples of the brown alga Caulocystis cephalornithos, from five locations in southern and southeastern Tasmania, were investigated for comparison of their acetogenin content. In contrast with previously studied brown algae, including mainland Australian collections of C. cephalornithos, Tasmanian collections of C. cephalornithos were found to contain unusually high levels of tridec-1-ene, a hydrocarbon not previously reported from a marine alga. The novel metabolite (E)-nonadec-3-en-2-one was also isolated. Compounds previously described from this alga were present, together with a suite of homologues not previously observed in this species. The compounds present suggested that the alkyl chain of the orsellinic acid derivatives was present prior to cyclisation. Large variations in relative metabolite content were observed both within and between collection sites.  相似文献   

2.
Around a third of oral bacteria cannot be grown using conventional bacteriological culture media. Community profiling targeting 16S rRNA and shotgun metagenomics methods have proved valuable in revealing the complexity of the oral bacterial community. Studies investigating the role of oral bacteria in health and disease require phenotypic characterizations that are possible only with live cultures. The aim of this study was to develop novel culture media and use an in vitro biofilm model to culture previously uncultured oral bacteria. Subgingival plaque samples collected from subjects with periodontitis were cultured on complex mucin-containing agar plates supplemented with proteose peptone (PPA), beef extract (BEA), or Gelysate (GA) as well as on fastidious anaerobe agar plus 5% horse blood (FAA). In vitro biofilms inoculated with the subgingival plaque samples and proteose peptone broth (PPB) as the growth medium were established using the Calgary biofilm device. Specific PCR primers were designed and validated for the previously uncultivated oral taxa Bacteroidetes bacteria HOT 365 and HOT 281, Lachnospiraceae bacteria HOT 100 and HOT 500, and Clostridiales bacterium HOT 093. All agar media were able to support the growth of 10 reference strains of oral bacteria. One previously uncultivated phylotype, Actinomyces sp. HOT 525, was cultivated on FAA. Of 93 previously uncultivated phylotypes found in the inocula, 26 were detected in in vitro-cultivated biofilms. Lachnospiraceae bacterium HOT 500 was successfully cultured from biofilm material harvested from PPA plates in coculture with Parvimonas micra or Veillonella dispar/parvula after colony hybridization-directed enrichment. The establishment of in vitro biofilms from oral inocula enables the cultivation of previously uncultured oral bacteria and provides source material for isolation in coculture.  相似文献   

3.
Motile Nocardoid Actinomycetales   总被引:7,自引:2,他引:5       下载免费PDF全文
The properties of 42 strains of nocardoid (nocardioform) bacteria were compared. The results indicate that the organism previously called Nocardia turbata does not belong to the genus Nocardia nor does it fit into any of the previously described genera.  相似文献   

4.
Racemic 5-(trans-2-aminomethylcyclopropyl)indoles, 5-(trans-2-aminomethylcyclopentyl) indoles, and 5-(cis-2-aminomethylcyclopentyl)indoles were synthesized and evaluated as selective serotonin reuptake inhibitors. These analogs followed SAR trends similar to those previously reported for 3-cycloalkyl substituted indoles. The most potent analogs exhibited single digit nanomolar inhibition at the human serotonin transporter but were 10-fold less active than the previously reported compounds.  相似文献   

5.
Objective: In the recent past, adenocarcinoma has become the commonest histological type of lung cancer (LC) in the developed countries. The present study was conducted to assess the change in epidemiology of LC, if any, in North India. Methods: Prospectively collected data on 250 newly diagnosed LC patients presenting to a tertiary care institute was analyzed. Results were compared with the previously published data from this center. Results: No significant differences were observed in the demographical, histological or smoking profiles of LC patients compared to those seen three decades earlier. The mean [standard deviation] age was 57.9 [±11.3] years (previously 54.3 years). Male to female ratio was 4.43:1 (previously 4.48:1; p = 0.952) while the smoker to non-smoker ratio was 2.67:1 (previously 2.68:1; p = 0.980). The commonest histological types were squamous cell (34.8%), adenocarcinoma (26.0%) and small cell (18.4%) while previously these were 34.3%, 25.9% and 20.3%, respectively; p = 0.916. However, in the present study, significant differences were observed between smokers and non-smokers in relation to distribution of gender, histology and disease stage. Conclusions: There has been no significant change in the epidemiology of LC in North India over the past three decades. An absence of change in the smoking pattern of the population could be a possible reason.  相似文献   

6.
Abstract:Four anthraquinones were isolated from the foliose lichen, Lasallia papulosa (Ach.) Llano. Two of the anthraquinones are known compounds, previously isolated from Lasallia papulosa, while the other two were reported previously as secondary metabolites from laboratory-cultured Nephroma laevigatum, and are isolated here for the first time from lichens in their natural habitat. All compounds were characterized by UV spectrophotometry, mass spectrometry, 1H NMR and 13C NMR. The products were identified as 7-chloroemodin, valsarin (7-chloro-5-hydroxyemodin), 5-chloro-1- O -methylemodin and 5-chloro-1- O -methyl-ω-hydroxyemodin.  相似文献   

7.
《Journal of Asia》2022,25(4):101975
The lycaenid butterfly Zizina emelina emelina (de l’Orza) (previously Zizina otis emelina; Lepidoptera, Lycaenidae) has populations distributed across Japan and Korea. Zizina emelina is listed on Japan’s Red List as an endangered species, owing to the loss of its principal plant food and habitat. Researchers previously investigated the genetic diversity and structure in Japanese populations by using mitochondrial and nuclear DNA analyses alongside their Wolbachia infection status to consider the conservation strategy. In this study, we investigated the genetic variation and Wolbachia infection status of Korean populations and compared our findings with these traits in the Japanese populations. Four novel mitochondrial haplotypes were found in the Korean populations, whereas nuclear DNA analysis revealed one new haplotype and another that matched the one reported previously in Japan. The two known strains of Wolbachia in the Japanese populations were also found in the Korean ones. Mitochondrial DNA analysis demonstrated that no gene flow had occurred between the Japanese and Korean populations. The fact that they share the same nuclear haplotype and Wolbachia strains, however, indicates a low level of population differentiation between the two.  相似文献   

8.
Long-Chain N-Acyltyrosine Synthases from Environmental DNA   总被引:1,自引:0,他引:1       下载免费PDF全文
The heterologous expression of DNA extracted directly from environmental samples (environmental DNA [eDNA]) in easily cultured hosts provides access to natural products produced by previously inaccessible microorganisms. When eDNA cosmid libraries were screened in Escherichia coli for antibacterially active clones, long-chain N-acyltyrosine-producing clones were found in every eDNA library. These apparently common natural products have not been previously described from screening extracts of cultured bacteria for biologically active natural products. Of the 11 long-chain N-acyl amino acid synthases (NASs) that were characterized, 10 are unique sequences. A predicted protein of previously unknown function from Nitrosomonas europaea, a gram-negative nitrifying beta-proteobacterium, is 14 to 37% identical to eDNA NASs. When cloned into E. coli, this open reading frame confers the production of long-chain N-acyltyrosines to the host and is therefore the first NAS from a cultured bacterium to be functionally characterized. Understanding the role that long-chain N-acyl amino acids play in soil microbial communities should now be feasible with the identification of a cultured organism that has the genetic capacity to produce these compounds.  相似文献   

9.
Robert Hootkins  Alan Bearden 《BBA》1983,723(1):16-29
Photosynthetic membrane fragments separated from whole cells of the green alga Dunaliella parva, were oriented by incorporation into multilayers on thin Mylar films. These partially dehydrated films were then examined by EPR spectroscopy for evidence of orientation of paramagnetic components. Five previously identified paramagnetic components, the reduced states of iron-sulfur clusters A and B, the intermediate acceptor X?, the reduced Rieske iron-sulfur cluster, and oxidized cytochrome b-559, displayed EPR signals showing orientation. In addition, several previously unknown paramagnetic components were also observed to be oriented. Four components, previously characterized in spinach chloroplast preparations, the iron-sulfur clusters A and B, the intermediate acceptor X?, and cytochrome b-559, were shown to be similar in the green alga, D. parva. The orientations of iron-sulfur clusters A and B, however, were determined unambiguously in this preparation; this was not possible in previous work with spinach. The heme plane orientation of cytochrome b-559 was found to be perpendicular to the membrane plane in agreement with the results in spinach preparations. A new photoinduced EPR signal with g values of 1.88, 1.97 and 2.12 was seen only in the oriented preparations and was indicative of a reduced iron-sulfur cluster with an orientation different from that of iron-sulfur cluster A or B. This suggests the existence of a previously unidentified acceptor in Photosystem I of green plants. These studies clearly show that the orientation of these components in bioenergetic membranes are conserved over a large span of evolutionary development and are, therefore, an important aspect of the mechanism of electron transfer.  相似文献   

10.
《Biological Control》2006,36(1):65-73
To evaluate the potential benefits and risks associated with releasing Semielacher petiolatus Girault (Hymenoptera: Eulophidae) in a classical biological control project directed against the citrus leafminer Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) in Florida, we evaluated the ability of S. petiolatus females to discriminate between hosts previously parasitized by Ageniaspis citricola Logvinovskaya (Hymenoptera: Encyrtidae) and unparasitized hosts. In laboratory trials, S. petiolatus females did not discriminate between hosts previously parasitized and oviposited and fed on each host category equally. Hatch rate of S. petiolatus eggs on hosts previously parasitized by A. citricola was normal and development time was not different. However, mortality of immatures was significantly higher on previously parasitized hosts when compared to hosts that were not parasitized by A. citricola, and size of adult females reared on hosts previously parasitized was reduced. The relative survivorship of S. petiolatus adults compared with adults of P. citrella and another parasitoid, A. citricola, under three relative humidities (RHs) (55, 76, and 95% at 28 °C) indicated that S. petiolatus survives longer than A. citricola at all RHs tested, but did not survive as long as the citrus leafminer. Finally, the leafminer Liriomyza trifolii Burgess (Diptera: Agromyzidae) was evaluated as a possible host for S. petiolatus but no progeny were produced in choice and no-choice tests. The lack of discrimination raises the concern that S. petiolatus could disrupt the efficacy of A. citricola, which is already established in Florida, without providing substantial reduction of citrus leafminer populations during early spring.  相似文献   

11.
《Phytochemistry》1987,26(8):2381-2384
A reinvestigation of the whole plants ofTripterospermum lanceolatum gave, in addition to compounds isolated previously, two new xanthones, named lanceolin and methyllanceolin, respectively. The compound previously reported to be oleanolic acid was re-examined and identified as ursolic acid by a13C NMR study. An isomeric mixture, oleanolic acid and ursolic acid, and sweroside were isolated from the whole plants ofSwertia arisanensis.  相似文献   

12.
Formulae were derived for the genetic differentiation between populations within a metapopulation (FSM), and between metapopulations (FMT) as functions of migration and mutation rates, size and number of populations and metapopulations. We show that FMT = 1/(1 + 4Nem), where Ne is the effective size of a metapopulation, and where the migration rate between metapopulations is m. The formulae for FMT and FSM were more general than previously proposed since we have relaxed some previously made hypotheses and we included the effect of the mutation rate. Using our formula, some unexpected result of estimation of gene flow, previously obtained, can be explained readily.  相似文献   

13.
14.
M. E. Carr 《Economic botany》1985,39(3):336-345
About 500 plant species from various regions of the United States have been screened previously at the USDA Northern Regional Research Center for their multipurpose, energy-producing potential. Most collections have been from the rich flora of central Illinois. For this report, 92 additional species were collected from southern Illinois and evaluated by criteria previously established at this Center. Plant samples were analyzed for “oil,” “polyphenol,” “hydrocarbon,” and protein. Oil fractions of selected species were analyzed for classes of lipid constituents and were saponified to determine yields of unsaponifiable matter and fatty acids. Hydrocarbon fractions of selected species were analyzed for rubber, gutta, and waxes. Average molecular weight and molecular weight distribution of rubber and gutta were determined. of the 92 species, complete analytical data are presented for 16 selected species. Substantial quantities of oil were obtained fromPhiladelphias coronarius (5.0%; dry, ash-free sample basis),Cacalia muhlenbergii (4.1%),Lindera benzoin (4.1 %), andKoelreuteria paniculata (4.0%). High yields of polyphenol were obtained fromAcer ginnala (33.1%),Cornus obliqua (20.8%), andSalix caprea (20.0%). Maximum yields of hydrocarbon and protein were fromElymus virginicus (0.6%) andLindera benzoin (11.1%), respectively. Data are discussed with respect to species previously analyzed at this Center.  相似文献   

15.
16.
The porcine RN locus affects muscle glycogen content and meat quality. We previously mapped the RN locus to chromosome 15. This study describes the identification of polymorphisms for four class I and four class II markers located in the RN region. Resource families were genotyped with F-SSCP markers (fluorescent single strand conformation polymorphism) and microsatellite markers. Subsequent multipoint linkage analysis revealed the order FN1-IGFBP5-S1000-S1001-IL8RB-VIL1-RN-Sw936-Sw906. The gene order is identical to the previously reported porcine RH map of the same region. The described map will facilitate positional cloning of the RN gene.  相似文献   

17.
Amplified fragment length polymorphism (AFLP) was tested as an alternative to the DNA-DNA hybridization technique (DDH) to delineate genomospecies and the phylogenetic structure within the genus Frankia. Forty Frankia strains, including representatives of seven DDH genomospecies, were typed in order to infer current genome mispairing (CGM) and evolutionary genomic distance (EGD). The constructed phylogeny revealed the presence of three main clusters corresponding to the previously identified host-infecting groups. In all instances, strains previously assigned to the same genomospecies were grouped in coherent clusters. A highly significant correlation was found between DDH values and CGM computed from AFLP data. The species definition threshold was found to range from 0.071 to 0.098 mismatches per site, according to host-infecting groups, presumably as a result of large genome size differences. Genomic distances allowed new Frankia strains to be assigned to nine genomospecies previously determined by DDH. The applicability of AFLP for the characterization of uncultured endophytic strains was tested on experimentally inoculated plants and then applied to Alnus incana and A. viridis field nodules hosting culture refractory spore-positive (Sp+, that sporulate in planta) strains. Only 1.3% of all AFLP fragments were shown to be generated by the contaminant plant DNA and did not interfere with accurate genomospecies identification of strains. When applied to field nodules, the procedure revealed that Alnus Sp+ strains were bona fide members of the Alnus-Myrica host infecting group. They displayed significant genomic divergence from genomospecies G1 of Alnus infecting strains (i.e. Frankia alni) and thus may belong to another subspecies or genomospecies.  相似文献   

18.
The distributions of Haemonchus contortus, Ostertagia circumcincta and Trichostrongylus axei during their development in lambs were studied by freezing and sectioning the abomasum and then recovering the worms from the contents and mucosa of each section. In previously worm-free lambs, the distribution of fourth stage H. contortus was very regular, the frequency of larvae being highest in the anterior fundic area and then decreasing in each section towards the pylorus. The distributions of the early larval stages of O. circumcincta and T. axei were variable but tended to be biomodal, with one peak of larvae in the fundic area and a second in the pyloric area. It is suggested that the difference in distribution between H. contortus and the other two species may be due to a difference in the rate of response of exsheathed third stage larvae to stimuli in the abomasum. In the later stages of development, H. contortus and O. circumcincta tended to migrate towards the pyloric area. In previously infected lambs, the distribution of inhibited early-fourth stage H. contortus was similar to that of normally developing fourth stage larvae in previously worm-free lambs and appeared to be unaffected by the host response which caused an altered distribution and rejection of late-fourth stage and adult worms. The rate of rejection of adult O. circumcincta differed between the fundic and pyloric areas of the abomasum, which suggests that the host response in these two areas may be different.  相似文献   

19.
Synthetic bioregulators of poly-cis carotenoid biosynthesis   总被引:1,自引:0,他引:1  
Seventeen new bioregulators were synthesized and tested for their ability to induce the biosynthesis of poly-cis carotenes in the flavedo of Marsh white seedless grapefruit. The effects of these new bioregulators are the same as that of the previously reported dibenzylamines, but several of the new compounds are more effective and cause the accumulation of up to 162 μg/g dry wt of poly-cis carotenes in the flavedo as compared to the maximum of 74 μg/g dry wt observed previously. The compounds tested were substituted N-benzyl furfurylamines, N-benzyl, N-methyl furfurylamines and N-alkyl, N-methyl benzylamines. They demonstrate the ability of tertiary as well as secondary amines to stimulate the formation of poly-cis carotenes. The interaction of N-(4-bromobenzyl) furfurylamine, one of the more effective of the new compounds, with lycopene and β-carotene inducers is also reported.  相似文献   

20.
The fatty acid (FA) composition of Demospongiae species from the Sea of Okhotsk was studied. Fifteen sponge species were investigated for the first time, and the previously studied species Desmacella rosea and Myxilla incrustans were reexamined for their FA composition. Gas chromatography-mass spectrometry revealed 150 different fatty acids, of which 15 have not been identified in sponge lipids previously. The relative content of saturated FAs varied from 7.6 in Melonachora kobjakovae to 29.6% in Amphilectus digitata, with an average of 14.6% of total FAs. The relative content of monoenic FAs ranged from 12.8 in T. dirhaphis to 27.0% in Polymastia sp., with an average of 20.6% of total FAs. Non-methylen-interrupted, primarily unsaturated Δ5,9-FAs contributed a significantly to the amount of polyunsaturated fatty acids of sponges; this being a distinguishing feature of the FA composition of the investigated group of organisms.  相似文献   

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