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1.
Allophycocyanin (APC) is a minor component of phycobiliproteins in cyanobacteria and red algae. This paper describes a simple and inexpensive extracting method for isolating APC from Spirulina (Arthrospira) platensis with high efficiency. The crude phycobiliprotein extract was pretreated by ammonium sulfate fractionation. Then, by adding hydroxylapatite into crude phycobiliprotein extract dissolved in 20 mM phosphate buffer (pH 7.0), APC was selectively adsorbed by hydroxylapatite but C-phycocyanin (C-PC) was not. The hydroxylapatite was collected and APC was extracted from the crude phycobiliprotein extract. Then, the enriched APC was washed off from the hydroxylapatite using 100 mM phosphate buffer (pH 7.0). In this simple extracting method it was easy to remove C-PC and isolate APC in large amounts. The absorbance ratio A 650/A 280 of extracted APC reached 2.0. The recovery yield was 70%, representing 4.61 mg · g−1 wet weight. The extracted APC could be further purified by a simple anion-exchange chromatography with a pH gradient from 5.6 to 4.0. The absorbance ratio A 650/A 280 of the purified APC reached 5.0, and the overall recovery yield was 43%, representing 2.83 mg · g−1 wet weight. Its purity was confirmed by native polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulfate-PAGE.  相似文献   

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Population genetic structure of silver Prussian carp from the Middle Dnieper basin was established by means of biochemical gene marking and cytometric analysis. In addition to diploid goldfish Carassius auratus, which was the basic species of bisexual colonies, a number of biotypes of triploid silver Prussian carp C. gibelio were identified. These biotypes either formed isolated unisexual populations, or were an admixture to the bisexual colonies. In addition, in bisexual colonies, triploid females of non-clonal origin were identified. Despite the fact that all forms of C. gibelio reproduced by means of gynogenesis, some of them (C. gibelio-1) formed isolated unisexual populations, while the others (C. gibelio-2, -3, and -4) usually coexisted with C. auratus.  相似文献   

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Sequence variation of the mitochondrial COI, cytochrome b, and 16S RNA genes, as well as nuclear RNF213 gene was examined in the genera Lycenchelys and Lycodapus with the purpose of determination of their positions in the system of the family Zoarcidae. It was demonstrated that the genus Lycodapus was considerably closer to the generic group of Lycogramminae (Lycogrammoides, Bothrocara, Allolepis, Bothrocarhichthys) than the genus Lycenchelys. However, on the phylogenetic trees both of these genera were located in the clade of the subfamily Lycodinae. Genetic heterogeneity of the genus Lycenchelys, represented by two species groups differing in distribution patterns (northeastern Pacific and Antarctic) and showing more profound differences than the genera of subfamily Lycodinae, was demonstrated.  相似文献   

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Two exotic fishes, common carp (Cyprinus carpio) and tilapia (Oreochromis niloticus), were introduced more than 20 years ago into Xochimilco for aquaculture, and now dominate the system in terms of biomass and numbers. Over this same period, wild populations of the microendemic axolotl salamander (Ambystoma mexicanum) have been dramatically reduced, and it currently persists in isolated areas of this aquatic system, which is situated at the edge of Mexico City. In this study, we examine potential trophic interactions and niche overlap among two exotic fishes: carp and tilapia, and the native axolotl. Axolotl had more diverse diets and a higher trophic position compared to the exotics. Stable isotope analysis revealed substantial trophic niche overlap among axolotl and the exotics. The two exotics occupied a larger niche area than the axolotl, suggesting higher levels of omnivory and diet specialization. Current exotic fish removal efforts will further our understanding of interactions between the axolotl and exotic species, and are expected to benefit axolotl recovery efforts.  相似文献   

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Fourteen new species of palms (Arecaceae) from Madagascar are described and named, based on material collected over the last 15 years. Twelve species belong to the genus Dypsis, namely D. andilamenensis Rakotoarin. & J. Dransf., D. anjae Rakotoarin. & J. Dransf., D. betsimisarakae Rakotoarin. & J. Dransf., D. culminis Rakotoarin. & J. Dransf., D. dracaenoides Rakotoarin. & J. Dransf., D. gautieri Rakotoarin. & J. Dransf., D. gronophyllum Rakotoarin. & J. Dransf., D. jeremiei Rakotoarin. & J. Dransf., D. metallica Rakotoarin. & J. Dransf., D. reflexa Rakotoarin. & J. Dransf., D. sancta Rakotoarin. & J. Dransf. and D. vonitrandambo Rakotoarin. & J. Dransf. and two species belong to the genus Ravenea: R. beentjei Rakotoarin. & J. Dransf. and R. hypoleuca Rakotoarin. & J. Dransf. Despite the fact that most of these species have been recorded from protected areas that are difficult to access in the eastern region of Madagasacar, they are all threatened. Based on IUCN categories and criteria, seven are Critically Endangered and seven are Vulnerable.  相似文献   

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Synopsis We investigated the ultrastructure of the egg membrane surface (unfertilized egg) of Hypophthalmichthys molitrix using scanning electron microscopy. The eggs of silver carp like most other teleosts are surrounded by a relatively thick egg membrane, and have a type III micropyle at the animal pole. The micropyle is almost circular in shape and the micropyle canal is located in its center. The micropyle region is not flat. Round or oval accessory pores are also observed in the canal. The surface of zona radiata is wavy and uneven with a uniform distribution of almost round pores with lips. Microvilli like structure are found in the pore opening region.  相似文献   

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Beata Zimowska 《Biologia》2010,65(4):603-608
In the years 2004–2006 the species P. sclareae was isolated from sage stems showing the symptoms in the form of bark peeling off and breaking. On the basis of 5 isolates randomly chosen from the fungus population, morphology and the conditions of temperatures favourable for the most intensive growth and creation of the fungus infectious material were studied. The temperature of −6°C was viewed as unfavourable for the fungus growth, and that of 32°C was considered to prevent the formation of picnidia and conidia. The dynamic growth of the colonies and the formation of numerous picnidia and conidia were observed at the temperatures ranging from 20°C to 28°C.  相似文献   

9.
Following a re-examination of the material treated under Barleria brevispina (Fiori) Hedrén in the recent Flora of Somalia account of the Acanthaceae, it is concluded that two distinct species are involved and Barleria compacta Malombe & I. Darbysh. is described here from north-eastern Somalia. Its affinities and conservation status are discussed.  相似文献   

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Columba livia is an important reservoir and carrier of Cryptococcus neoformans, Cryptococcus uniguttulatus, Cryptococcus laurentii and Cryptococcus albidus. Upper digestive tract of this species is also known as a habitat for Cryptococcus neoformans. Given the increasing clinical interest of this microorganism, 331 swabs from crop and 174 dropping samples from pigeon lofts in Grand Canary Island have been studied. The obtained results show an extensive presence samples 81 positive (24.47%) of Cryptococcus spp. in analysed crops: 32 (9.66%) for C. neoformans, 24 (7.2%) for C. uniguttulatus, 23 (6.9%) for C. albidus and 2 (0.6%) for C. laurentii. In the same way, Cryptococcus spp was also isolated in 82 (47.13%), dropping samples: C. neoformans in 59 (33.9%), C. uniguttulatus, in 9 (5.17%), C. laurentii in 8 (4.59%) and C. albidus in 6 (3.44%) of the investigated samples, respectively. The cryptococcosis produced by species of cryptococci other than C. neoformans has become more important during the last decade, supporting the study on the role of pigeon in the epidemiology of this disease.  相似文献   

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Introduction  

SPARC is a matricellular protein, which, along with other extracellular matrix components including collagens, is commonly over-expressed in fibrotic diseases. The purpose of this study was to examine whether inhibition of SPARC can regulate collagen expression in vitro and in vivo, and subsequently attenuate fibrotic stimulation by bleomycin in mouse skin and lungs.  相似文献   

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Interaction of Bdellovibrio bacteriovorus 100NCJB with bacteria Campylobacter jejuni (strains 1, 2, 3, 4, and 5) and Helicobacter pylori, strain TX30a, was confirmed. The results indicate that lytic activity of bdellovibrios both in liquid media and cells attached to a surface was observed. The potential use of the antimicrobial activity of predatory bacteria for environmental bioprotection and public health is discussed.  相似文献   

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Three Lactobacillus strains (LOCK 0900, LOCK 0908, LOCK 0919) out of twenty-four isolates were selected according to their antagonistic activity against pathogenic bacteria, resistance to low pH and milieu of bile salts. Intragastric administration of a mixture of these strains to Balb/c mice affected cytokine TH1-TH2 balance toward nonallergic TH1 response. Spleen cells, isolated from lactobacilli-treated mice and re-stimulated in vitro with the mixture of heat-inactivated tested strains, produced significantly higher amounts of anti-allergic tumor necrosis factor- and interferon-γ than control animals whereas the level of pro-allergic interleukin-5 was significantly lower. Lactobacillus cells did not translocate through the intestinal barrier into blood, liver and spleen; a few Lactobacillus cells found in mesenteric lymph nodes could create antigenic reservoir activating the immune system. The mixture of Lactobacillus LOCK 0900, LOCK 0908 and LOCK 0919 strains represents a probiotic bacterial preparation with possible use in prophylaxis and/or therapy of allergic diseases.  相似文献   

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