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Lexian Xia Songlin Dai Chu Yin Yuehua Hu Jianshe Liu Guanzhou Qiu 《Journal of industrial microbiology & biotechnology》2009,36(6):845-851
Two sphalerite samples with different iron/sulphur (Fe/S) ratios, Shuikousan ore (Fe/S 0.2) and Dachang ore (Fe/S 0.52), were
processed using three microbial species, Leptospirillum ferriphilum, Acidithiobacillus ferrooxidans and Acidithiobacillus caldus. Following 20 days of bioleaching in shake flask cultures, a higher zinc (Zn) extraction (96%) was achieved with Shuikousan
ore than with Dachange ore (72%). The extraction efficiency increased when elemental S was added to Dachang ore to attain
the same Fe/S ratio as that for Shuikousan ore. Following the addition of S, the redox potential, pH and total dissolved Fe
for Dachang ore demonstrated similar behaviors to those of Shuikousan ore. Acidithiobacillus caldus and L. ferriphilum became the dominant species during the bioleaching of sphalerite with a high Fe/S ratio. In contrast, the dominant species
were A. ferrooxidans and A. caldus during the bioleaching of sphalerite with a low Fe/S ratio. These results show that the Fe/S ratio has a significant influence
on the bioleaching behavior of sphalerite and the composition of the microbial community. 相似文献
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Sinningia lutea (Gesneriaceae) is described and illustrated as a new species from the Pampa Biome, in Southern Brazil. In the literature, this species has hitherto been confused with S. allagophylla from which it can be easily separated using a set of floral and vegetative features (especially corolla color and size and leaf shape). An artificial key to separate S. lutea from S. allagophylla and S. curtiflora (another sympatric species, with some morphological similarities) is presented. Some ecological remarks on the differential distribution of S. lutea and S. allagophylla are also made. 相似文献
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Jeom-Sook Lee Dong Seop Park Byung-Sun Ihm Wook Jae Lee 《Journal of Plant Biology》2007,50(6):605-614
We used morphological and molecular characteristics to perform a taxonomic reappraisal ofSuaeda australis (Brown) Moquin-Tandon from Korea. Populations of this species are dispersed at the bottoms of sand zones, and usually exhibit
a depressed habit. Except for their total heights and leaf lengths, the morphology of these plants does not differ from that
ofS. maritima. Molecular traits were examined based on ITS and psbB-psbH spacer region sequences. The former region included ITS-1, 5.8S,
and ITS-2, which were 629 nucleotide bases long. Pair-wise distances (p-distance) among KoreanSuaeda species ranged from 1.12 to 17.84. The psbB-psbH spacer region sequences were 618 nucleotide bases long, and were conserved
in the alignment of KoreanSuaeda species. In our ML and MrBayesian analysis of ITS sequences aligned with other sequences from GenBank, the plants of KoreanSuaeda made three clades: 1)S. japonica;S. australis, andS. maritima;2)S. malacosperma; and 3) S.glauca. However, the psbB-psbH region sequences could not be resolved amongS. japonica, S. maritima, andS. australis from Korea. Molecular and vegetative characteristics indicated that the plants now classified asS. australis from Korea should instead be named as S.maritima (L.) Dumont. 相似文献
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The effects of NaCl stress on growth, water status, contents of protein, proline, malondialdehyde (MDA), various sugars and
photosynthetic pigments were investigated in seedlings of Salicornia persica and S. europaea grown in vitro. Seeds were germinated under NaCl (0, 100, 200, 300, 400, 500 and 600 mM) on Murashige and Skoog medium for 45 d. The shoot
growth of both species increased under low NaCl concentration (100 mM) and then decreased with increasing NaCl concentrations.
In contrast to S. persica, root length in S. europaea reduced steadily with an increase in salinity. Proline content in S. persica was higher than in S. europaea at most NaCl concentrations. Proline, reducing saccharide, oligosaccharide and soluble saccharide contents increased under
salinity in both species. In contrast, contents of proteins and polysaccharides reduced in both species under salt stress.
MDA content remained close to control at moderate NaCl concentrations (100 and 200 mM) and increased at higher salinities.
MDA content in S. europaea was significantly higher than S. persica at higher salinities. Salt treatments decreased K+ and P contents in seedlings of both species. Significant reduction in contents of chlorophylls and carotenoids due to NaCl
stress was also observed in seedlings of both species. Some differences appeared between S. persica and S. europaea concerning proteins profile. On the basis of the data obtained, S. persica is more salt-tolerant than S. europaea. 相似文献
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Sargassum C. Agardh is one of the most common but little understood genera of Phaeophyta in Malaysia. The difficulty in species delineation
is due to morphological plasticity. A combination of morphology and random amplified polymorphic DNA (RAPD) studies of selected
Sargassum species was carried out to have a better understanding of the taxonomy. Primer OPA13 was found to be good for discriminating
between Sargassum species. Sargassum binderi was shown to be different from S. oligocystum (SD>0.5 = 14.11%), indicating the importance of the vesicle and receptacle in species differentiation. S. baccularia was clearly separated out from S. polycystum and S. stolonifolium using primer OPA13. RAPD analysis showed that the presence of the stolon is an important character for separating S. baccularia (no stolon) from S. polycystum (stolon) and S. stolonifolium (stolon).
Presented at the 6th Meeting of the Asian Pacific Society of Applied Phycology, Manila, Philippines. 相似文献
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Mohammad Aghaleh Vahid Niknam Hassan Ebrahimzadeh Khadijeh Razavi 《Acta Physiologiae Plantarum》2011,33(4):1261-1270
The effects of salt stress on growth parameters, free proline content, ion accumulation, lipid peroxidation, and several antioxidative
enzymes activities were investigated in S. persica and S. europaea. The seedlings were grown for 2 months in half-strength Hoagland solution and treated with different concentrations of NaCl
(0, 85, 170, 340, and 510 mM) for 21 days. The fresh and dry weights of both species increased significantly at 85 and 170 mM
NaCl and decreased at higher concentrations. Salinity increased proline content in both the species as compared to that of
control. Sodium (Na+) content in roots and shoots increased, whereas K+ and Pi content in both organs decreased. At all NaCl concentrations, the total amounts of Na+ and K+ were higher in shoots than in roots. Malondialdehyde (MDA) content declined at moderate NaCl concentrations (85 and 170 mM)
and increased at higher levels. With increased salinity, superoxide dismutase (SOD), catalase (CAT), and guaiacol peroxidase
(GPX) activities also increased gradually in both species. In addition, it seems that GPX, CAT, and SOD activities play an
essential protective role in the scavenging reactive oxygen species (ROS) in both species. Native polyacrylamide gel electrophoresis
(PAGE) indicated different isoform profiles between S. persica and S. europaea concerning antioxidant enzymes. These results showed that S. persica exhibits a better protection mechanism against oxidative damage and it is more salt-tolerant than S. europaea possibly by maintaining and/or increasing growth parameters, ion accumulation, and antioxidant enzyme activities. 相似文献
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Nasrollah Rezaei‐Ghaleh Nora Wender Hai‐Young Kim Grit Taschenberger Björn H Falkenburger Henrike Heise Ashutosh Kumar Dietmar Riedel Lars Fichtner Aaron Voigt Gerhard H Braus Karin Giller Stefan Becker Alf Herzig Marc Baldus Herbert Jäckle Stefan Eimer Jörg B Schulz Christian Griesinger Markus Zweckstetter 《The EMBO journal》2009,28(20):3256-3268
The relation of α‐synuclein (αS) aggregation to Parkinson's disease (PD) has long been recognized, but the mechanism of toxicity, the pathogenic species and its molecular properties are yet to be identified. To obtain insight into the function different aggregated αS species have in neurotoxicity in vivo, we generated αS variants by a structure‐based rational design. Biophysical analysis revealed that the αS mutants have a reduced fibrillization propensity, but form increased amounts of soluble oligomers. To assess their biological response in vivo, we studied the effects of the biophysically defined pre‐fibrillar αS mutants after expression in tissue culture cells, in mammalian neurons and in PD model organisms, such as Caenorhabditis elegans and Drosophila melanogaster. The results show a striking correlation between αS aggregates with impaired β‐structure, neuronal toxicity and behavioural defects, and they establish a tight link between the biophysical properties of multimeric αS species and their in vivo function. 相似文献
9.
Network approaches can increase our understanding of both changes in ecosystems and the role that individual species play
in such changes. In ecology, networks have been applied mainly to the study of food webs and mutualistic interactions, with
few studies on plant communities. This study used a network approach to examine a semi-arid plant community along a Stipa tenacissima abundance gradient at two locations in SE Spain: (1) an open shrub land where S. tenacissima is a highly competitive species, and (2) an alpha steppe where S. tenacissima forms the end stable successional community. In alpha steppe, the influence of slope was also examined. We detected that
S. tenacissima influenced the network structuring process, and that network organization changed along the gradient. In open shrub land,
when S. tenacissima became abundant, it dominated the community and other species disappeared. This resulted in a reduction of the number of
links that S. tenacissima established. At the alpha-steppe, S. tenacissima coexists with other species, developing more links as it becomes more abundant. On gentle slope zones of alpha steppe, S. tenacissima is more competitive and becomes dominant for high abundance values, reducing its links with other species. The organization
of networks varied similarly in both locations. When plant species reduce their abundance and number, links are more heterogeneously
distributed in networks. This leads to a concentration of most of the links around a few species, particularly S. tenacissima, which is the most abundant in this case. We conclude that, in order to study plant communities, it is convenient to consider
the properties of individual components together with the interaction between them. 相似文献
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Blasco-Costa I Montero FE Gibson DI Balbuena JA Raga JA Shvetsova LS Kostadinova A 《Systematic parasitology》2008,71(1):53-74
The genus Saturnius Manter, 1969 is defined, its species re-examined and a key to the species presented. S. overstreeti n. sp. is described from Mugil soiuy Basilewsky and M. cephalus L. from the Russian coast of the Sea of Japan and distinguished from the morphologically related S. papernai Overstreet, 1977 and S. maurepasi Overstreet, 1977. S. segmentatus Manter, 1969 is redescribed on the basis of the type- and newly collected material from M. cephalus on the Russian coast of the Sea of Japan. The morphometric variation of S. papernai is studied based on newly collected material from Liza aurata (Risso) in the Ebro Delta and off Santa Pola, Spain. The comparisons reveal lower ranges of most metrical features than previously known. A principal component analysis, carried out after adding the new data to those of Blasco-Costa et al. (2006), confirms the species identification. Other valid species recognised are S. mugilis (Yamaguti, 1970), S. maurepasi, S. belizensis Fischthal, 1977, S. dimitrovi Blasco-Costa et al., 2006 and S. minutus Blasco-Costa et al., 2006. Forms considered species inquirendae are S. valamugilis Rekharani & Madhavi, 1984, Bunocotyle constrictus Domnich & Sarabeev, 1999 [=S. papernai of Domnich & Sarabeev (2000a, b, c, d)], B. mugilis Yamaguti, 1970 of Solonchenko (1976) and S. mugilis of Dmitrieva & Gaevskaya (2001). Host and locality information is given in detail for all species. Lisa ramado (Risso) and Chelon labrosus (Cuvier) are new host records for S. papernai (sensu stricto) and S. dimitrovi. L. aurata is a new host record for S. dimitrovi and S. minutus, and L. saliens (Risso) is a new host record for S. minutus. 相似文献
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Karyotype study was performed in 13 populations of 11 Silene species (sect. Auriculatae L., Caryophyllaceae) growing in Iran. All the species studied showed 2n = 2x = 24 chromosome number supporting the earlier report on S. meyeri, while the chromosome number of S. palinotricha, S. sojakii, S. gertraudiae, S. elymaitica, S. pseudonurensis, S. dschuparensis, S. eriocalycina, S. araratica,
S. prilipkoana and S. commelinifolia are new to science. The chromosomes were mainly metacentric or sub-metacentric and their size varied from 1.10 μm in S. pseudonurensis to 7.11 μm in S. dschuparensis. The species studied differed significantly in the total size of the chromosomes, the size of the short arms and the long
arms, indicating the role of quantitative genomic changes in the Silene species diversification. They also differ in their karyotype formulae indicating the occurrence of structural changes in
their chromosomes. The Silene species were placed in 1A, 2A, 1B and 2B classes of Stebbins karyotype symmetry showing symmetrical
karyotypes. Clustering of the species based on karyotype features grouped the species of S. palinotricha, S. prilipkoana, S. commelinifolia, S. eriocalycina, S. meyeri, S. araratica and S. Sojakii together while the species of S. gertraudiae and S. elymaitica showed more similarity and were placed close to each other. 相似文献
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Siderastrea stellata and S. radians are scleractinian coral species that present a remarkable overlap of diagnostic characteristics and sympatric distribution. Moreover, both are viviparous with similar reproductive strategies and with a gregarious larval behavior. Samples of both species from the Brazilian coast were analyzed using 18 isozymic loci to quantify their genetic variability and populational structure. Results confirmed species identity, high intrapopulational variability and revealed moderate genetic structuring among all samples (S. stellata: F (ST) = 0.070; S. radians: F (ST) = 0.092). Based on genotypic diversity analysis, there was evidence that local recruitment may have a minor role in the populations (mean, G ( o ):G ( e )= 1.00 +/- 0.0003 SD for S. stellata and 0.99 +/- 0.0023 SD for S. radians). Deviations towards heterozygote deficiencies found in both Siderastrea species could be explained by the Wahlund effect, since there was evidence that populations might be composed of colonies of different ages. In S. radians it is also likely that there is some inbreeding occurring in the studied populations. Despite the brooding pattern and the gregarious larval behavior, our data suggest the occurrence of gene flow along the Brazilian coast. This is the first study on population genetics of Brazilian reef corals. 相似文献
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Characterization of 27 novel microsatellite loci in Sinibotia superciliaris (Günther 1892) and cross‐species transferability in Sinibotia reevesae (Chang 1944)
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The Chinese golden loach, Sinibotia superciliaris and its congener Sinibotia reevesae, are endemic to China and extraordinary similar in morphological traits. However, few genetic studies have been conducted on them, especially those based on nuclear markers. Here, we developed 27 novel polymorphic microsatellite markers from S. superciliaris and further tested the cross‐species transferability of those loci in S. reevesae. The cross‐species amplification test showed that 19 loci demonstrate polymorphism in S. reevesae. The mean number of alleles (NA) were both 3 in S. superciliaris and S. reevesae, the mean expected heterozygosities (HE) were 0.57 and 0.54, the Shannon‐Wiener Diversity Indices (SW) were 0.84 and 0.82, and the evenness (E) were 0.09 and 0.08, respectively. The polymorphic information content (PIC) showed a high level of polymorphism for the two species (mean 0.54 and 0.50, respectively). In addition, the cross‐species transferability (100%) of those markers was clearly high, which confirmed that the microsatellite markers developed here could be used effectively for other related species. 相似文献
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T. Y. Orujova S. M. Bayramov U. A. Gurbanova H. G. Babayev M. N. Aliyeva N. M. Guliyev Y. M. Feyziyev 《Photosynthetica》2018,56(4):1107-1112
The effects of the diurnal variations in ambient temperature on some C3 and C4 enzymes in the Salsola dendroides and Suaeda altissima species of Chenopodiaceae family were studied during the intensive vegetation period. Activities of phosphoenolpyruvate carboxylase (PEPC) and cytosolic aspartate aminotransferase (AsAT) were shown to decrease in both species in the afternoon and evening. The activity of the mitochondrial AsAT decreased in S. altissima, remained relatively constant in S. dendroides during the day. The activity of alanine aminotransferase was high in the S. dendroides species in the morning and evening and decreased in the S. altissima species by the evening. Glucose-6-phosphate activated PEPC in both species throughout the day. The study of the redox status-regulated C3 enzymes showed temperature-related increases in NADP-glyceraldehyde 3-phosphate dehydrogenase activity in both plants, in fructose-2,6-bisphosphatase activity in the S. altissima species, and in NADP-MDH activity in the S. dendroides species in the afternoon. 相似文献
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To understand the speciation process of Salvia isensis (Lamiaceae), a species endemic to a special environment (serpentine areas in the Ise-Tokai district, central Honshu, Japan),
chloroplast DNA (cpDNA) and nuclear ribosomal DNA (nrDNA) were employed to analyze the phylogenetic relationships of S. isensis with related species in Japan. Allozymic polymorphisms were also used to analyze genetic relationships among Salvia species. A contradiction in the phylogenetic positions of species studied was detected when phylogenetic trees were constructed
using cpDNA or nrDNA, i.e., S. isensis was a sister to the other species in phylogenetic trees generated from cpDNA, while S. japonica was a sister to the other species in the case of nrDNA. Genetic relationships between Salvia species estimated from allozymic polymorphisms did not contradict to the topology for nrDNA. Using the present results, the
speciation process of S. isensis is discussed with regard to introgressive gene exchanges between related species.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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Sargassum muticum (Phaeophyceae, Fucales) has recently been introduced to Limfjorden (Denmark) where its closest relative is the indigenous Halidrys siliquosa. Previous studies have demonstrated large quantitative (canopy biomass) and qualitative (canopy persistence) differences in the habitat available to epibiota within the canopies of these two macroalgae. We therefore hypothesised that these algae would support different epibiota communities and tested this by sampling the epibiota of S. muticum and H. siliquosa on seven occasions throughout 1997 by enclosing entire thalli in mesh bags. We found 53 epibiota taxa and, with only one exception, they were all recorded on both host species. Species richness and abundance of epibiota exhibited clear seasonal variation on both host species, although epibiota biomass was seasonally constant on H. siliquosa but not on S. muticum. These patterns were consistent with the different life histories of the host species. There was a weakly negative correlation between thallus size and epibiota biomass for both host species. When taking species-specific seasonal variation in thallus size into consideration, S. muticum and H. siliquosa were found to support significantly different epibiota biomasses. Multivariate analyses showed that epibiota community structure was different, although highly overlapping, between the two species, whereas there was an almost parallel temporal development in epibiota community structure. We conclude that it is unlikely that the introduction of S. muticum to Limfjorden has caused major changes in local epibiota community structure. However, the standing stock of epibiota is likely to have increased.Communicated by H.-D. Franke 相似文献
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The endemic Chinese cavefish genus Sinocyclocheilus possesses very rich species diversity. Specimens of this genus collected from Guilin, Guangxi, China, were originally described
in an unpublished document in 1982. Later, they were recognized as Sinocyclocheilus jii. Comparison to the type specimens of S. jii leads to the conclusion that, though similar, they represent two different species. Herein we describe them as a new species,
Sinocyclocheilus guilinensis sp. nov. It can be distinguished from all congeners by its possession of soft, unbranched dorsal ray without serrations,
19–20 (11–12) scale rows above (below) the lateral line, 34–36 circumpeduncular scales and 8–9 pre-dorsal vertebrae. Sinocyclocheilus guilinensis sp. nov. is most similar to S. jii. In addition to the scale count differences, a morphometrics-based principal component analysis (PCA) also supports designation
of S. guilinensis and S. jii as two distinct species. 相似文献
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This work is directed at continuous studies of cyclicity of long-term (1980–2010) population dynamics of odonates in the basin of Lake Chany (in the south of Western Siberia). Four sympatric species of the genus Sympetrum have been investigated by spectral analysis method. The cycle spectra of population dynamics have been constructed for each species; the basic parameters of these cycles (period, phase, and power) have been calculated. Special number cycles have been found for each species. Interspecies differences increased in the direction from high to low frequencies of the spectrum. In the cases of similar cycles, interspecies differences have been shown in the ratio of cycle powers and/or phases: identical phases can indicate the ability of species to increase their number synchronously with any of close species; different phases can indicate the possibility of a small-numbered species to reach its maximum number against the minimum number of numerous species. A comparison of sympatric species spectra of the genera Coenagrion and Sympetrum has led to the conclusion that, the more similarity there is in environmental standards among species inside a genus (as for Sympetrum), the more specific the species frequency spectra are. All species of the genus Sympetrum can synchronize their number fluctuations with 2- to 3 and 4- to 5-year fluctuations of the local climate. Also specific synchronization with important nature-climatic rhythms was found for each species: for S. danae, with an 18-year rhythm of the level of Lake Chany and with a 16-year rhythm of June temperatures; for S. flaveolum, with a 24-year Brickner cycle, with an 8-year cycle of rainfall, and with a 28-year cycle of April and May temperatures; for S. vulgatum, with a 40- to 42-year cycle of the level of Lake Chany, with 12-year cycle of rainfall, and with a 7-year cycle of April and June temperatures; and for S. sanguineum, with a 7-year cycle of April and June temperatures. Perhaps the adaptation mechanism of species to each other and to environments is enclosed in the cyclicity of long-term fluctuations of species number. 相似文献