共查询到20条相似文献,搜索用时 31 毫秒
1.
Satoshi Nakaba Shahanara Begum Yusuke Yamagishi Hyun-O Jin Takafumi Kubo Ryo Funada 《Trees - Structure and Function》2012,26(3):743-750
Differences in the timing of cell death, differentiation and function among three different types of ray parenchyma cells
in the hardwood Populus sieboldii × P. grandidentata which form uniseriate and homocellular rays were examined and clarified. Ray parenchyma cells died within 5 years, and the
disappearance of nuclei from ray parenchyma cells did not occur successively from the pith side, even within individual radial
cell lines of a given ray. Cell death occurred earliest in contact cells, which were connected to adjacent vessel elements
through pits, in the fourth annual ring from the cambium. Cell death occurred next in intermediate cells, which were located
within the same cell lines as contact cells but were not adjacent to vessel elements, in the fourth annual ring from the cambium.
Finally, isolation cells, which were located within the other cell lines of a given ray, died in the fifth annual ring from
the cambium. Secondary wall thickenings in contact cells and intermediate cells were initiated before those in isolation cells
in the current year’s xylem. Most starch grains were localized in intermediate cells, and there were more lipid droplets in
contact cells and intermediate cells than in isolation cells. In addition, the largest quantities of protein were found in
contact cells. Our results indicate that the position within a ray and neighboring short-lived vessel elements might affect
the timing of cell death and differentiation and, thus, the function of long-lived ray parenchyma cells in Populus sieboldii × P. grandidentata. 相似文献
2.
Ratul Saha Robert S. Donofrio Susan T. Bagley 《Journal of industrial microbiology & biotechnology》2010,37(8):843-848
A TaqMan quantitative real-time polymerase chain reaction (qPCR) assay was developed for the detection and enumeration of
three Pseudomonas species belonging to the mendocina sublineage (P. oleovorans, P. pseudoalcaligenes, and P. oleovorans subsp. lubricantis) found in contaminated metalworking fluids (MWFs). These microbes are the primary colonizers and serve as indicator organisms
of biodegradation of used MWFs. Molecular techniques such as qPCR are preferred for the detection of these microbes since
they grow poorly on typical growth media such as R2A agar and Pseudomonas isolation agar (PIA). Traditional culturing techniques not only underestimate the actual distribution of these bacteria but
are also time-consuming. The primer–probe pair developed from gyrase B (gyrB) sequences of the targeted bacteria was highly sensitive and specific for the three species. qPCR was performed with both
whole cell and genomic DNA to confirm the specificity and sensitivity of the assay. The sensitivity of the assay was 101 colony forming units (CFU)/ml for whole cell and 13.7 fg with genomic DNA. The primer–probe pair was successful in determining
concentrations from used MWF samples, indicating levels between 2.9 × 103 and 3.9 × 106 CFU/ml. In contrast, the total count of Pseudomonas sp. recovered on PIA was in the range of <1.0 × 101 to 1.4 × 105 CFU/ml for the same samples. Based on these results from the qPCR assay, the designed TaqMan primer–probe pair can be efficiently
used for rapid (within 2 h) determination of the distribution of these species of Pseudomonas in contaminated MWFs. 相似文献
3.
J. Eleazar Barboza-Corona Tomás Ortiz-Rodríguez Norma de la Fuente-Salcido Dennis K. Bideshi Jorge E. Ibarra Rubén Salcedo-Hernández 《Antonie van Leeuwenhoek》2009,96(1):31-42
Bacillus thuringiensis HD-73 was transformed with the endochitinase gene chiA74 under the control of a strong promoter (pcytA) and a 5′ mRNA stabilizing (STAB-SD) sequence (HD-73-pEBchiA74). Expression levels were compared with those observed from
the wild type strain (HD-73) and the recombinant HD-73 strain expressing chiA74 under the control of its native promoter (HD-73-pEHchiA74). The chitinolytic activity of HD-73-pEBchiA74 was markedly elevated,
being ~58- and 362-fold higher than, respectively, HD-73-pEHchiA74 and parental HD-73, representing the highest levels of
chitinase expression in recombinant B. thuringiensis reported to date. Parasporal crystals measured under transmission electron microscopy showed that HD-73 produced crystals
of 1.235 (±0.214) and 1.356 (±0.247) μm in length when the bacterium was grown in respectively, NBS and NBS with glucose.
Otherwise, HD-73-pEBchiA74 synthesized crystals of 1.250 (±0.222) and 1.139 (±0.202) μm in length when cultivated in NBS and
NBS with glucose, respectively, values that showed a diminution of ~10 and 20% compared with crystals produced by HD-73-pEHchiA74
grown under the same conditions. Comparison of viable spore counts per ml showed that HD-73-pEBchiA74 produced fewest viable
spores (1.5 × 109, 1.3 × 109), compared to HD-73-pEHchiA74 (4.9 × 109, 5.3 × 109) and HD-73 (6.8 × 109, 8.8 × 109) when grown in NBS and NBS supplemented with glucose, respectively. No change in cellular protease activity was observed
despite the overproduction of the chitinase. 相似文献
4.
Genetic variability of modulus of elasticity (MOE) was investigated in three genetic trials, including two progeny (16 years
old) and one clonal (19 years old) trials of hybrid larch (Larix x eurolepis Henry). MOE was directly assessed on standing trees using the Rigidimeter, a bending device, and related to other traits
including height, BH diameter and wood density. Mean MOE ranged from 5,183 to 9,228 MPa among families in the progeny trials
and from 4,591 to 11,486 MPa in the clonal trial. Among traits studied, MOE was one of the most variable traits. It was strongly
and positively related to wood density at both the individual and genotype mean levels. Interestingly too, wood stiffness
did not seem, or only weakly, unfavourably linked to stem diameter at the phenotypical level, but it was negatively or not
correlated to diameter at the genetic level. As well, MOE showed a high GxE stability over the two progeny trial sites. Narrow-sense
heritabilities for MOE were moderate (around 0.36). In all three trials, they were lower than those for wood density or total
height, and of the same level as for diameter. Improvement of wood stiffness of hybrid larch using the Rigidimeter seems possible
and promising genetic gains are expected. Impacts of selection for growth traits on MOE are also discussed. 相似文献
5.
The wolf spider Pardosa cribata Simon is the most abundant ground-dwelling spider inhabiting citrus orchards in eastern Spain. However, little is known about
its activity-density and its predatory role in the citrus agrosystem. Here we report on the activity-density of P. cribata monitored by pitfall traps, and on its capacity to prey on two citrus pests that appear both in the citrus canopy and the
ground cover, Ceratitis capitata (Wiedemman) and Myzus persicae (Sulzer), respectively. Pardosa cribata was present in citrus orchards throughout the year, with a peak in spring and a higher peak in summer. Pardosa cribata preyed on adults and third-instar larvae but not on pupae of C. capitata. A type II functional response was obtained for teneral-like adults, with an estimated attack rate (a′) of 0.771 ± 0.213 days−1 and a handling time (T
h) of 0.051 ± 0.013 days. Pardosa cribata also preyed efficiently on M. persicae, giving a type II functional response with an estimated attack rate and handling time of 2.833 ± 0.578 days−1 and 0.031 ± 0.001 days, respectively. The data reported here indicate that this wolf spider could play an important role
in regulating both these pests, and therefore might contribute to developing conservation biological control strategies for
citrus pests.
Handling Editor: Arne Jenssen. 相似文献
6.
Zeinab Salehi Farzaneh Vahabzadeh Morteza Sohrabi Shohreh Fatemi Hussein Tawfiq Znad 《Biodegradation》2010,21(4):645-657
The effect of p-nitrophenol (PNP) concentration with or without glucose and yeast extract on the growth and biodegradative capacity of Ralstonia eutropha was examined. The chemical constituents of the culture medium were modeled using a response surface methodology. The experiments
were performed according to the central composite design arrangement considering PNP, glucose and yeast extract as the selected
variables whose influences on the degradation was evaluated (shaking in reciprocal mode, temperature of 30°C, pH 7 and test
time of about 9 h). Quadratic polynomial regression equations were used to quantitatively explain variations between and within
the models (responses: the biodegradation capacity and the biomass formation). The coefficient of determination was high (R
adjusted2 = 0.9783), indicating the constructed polynomial model for PNP biodegradative capacity explains the variation between the
regressors fairly well. A PNP removal efficiency of 74.5% occurred within 9 h (15 mg/L as the initial concentration of PNP
with use of yeast extract at 0.5 g/L). 相似文献
7.
Lourdes Castelblanque Begoña García-Sogo Benito Pineda Vicente Moreno 《Plant Cell, Tissue and Organ Culture》2010,100(1):107-112
A simple and efficient protocol for plant regeneration from protoplasts of the potted plant Kalanchoe blossfeldiana Poelln. is reported. Mesophyll protoplasts were isolated from axenic leaves after a preculture. The enzymatic digestion of
the tissue with a solution containing 0.4% Cellulase Onozuka R-10 and 0.2% Driselase yielded 6.0 × 105 protoplasts per gram fresh weight after density gradient purification. Protoplasts were cultured in the dark at an initial
density of 1 × 105 protoplasts per milliliter in a liquid medium with 320 mM mannitol, 130 mM sucrose, 2.3 μM 2,4-dichlorophenoxy acetic acid
(2,4-D), 5.4 μM 1-naphthaleneacetic acid (NAA) and 2.2 μM 6-benzyladenine (BA). Cell wall regeneration was observed within
4 days of culture and cell division began after 5–7 days. When cultured in a liquid medium with 5.4 μM NAA and 8.9 μM BA,
protoplast-derived colonies proliferated until small visible calli, and adventitious buds appeared after transfer to photoperiod
conditions. Developed shoots were rooted on a solid medium supplemented with 0.6 μM indole-3-acetic acid (IAA) and successfully
established under greenhouse conditions. The process required 4 months from isolation to rooted plants and the best conditions
found gave a plant regeneration efficiency of 6.4 plants per 1 × 105 protoplasts. This is the first protocol reported for plant regeneration from protoplasts for a Crassulaceae family species. 相似文献
8.
Klaus Lunau Katrin Unseld Franziska Wolter 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2009,195(12):1121-1130
Many flowers display colour patterns comprising a large peripheral colour area that serves to attract flower visitors from
some distance, and a small central, contrastingly coloured area made up by stamens or floral guides. In this study, we scaled
down the size of floral guides to detect the minimal size bumblebees (Bombus terrestris) and honeybees (Apis mellifera) require for guidance. We analyzed the approach and the precise contact of the antennal tips with the floral guide of artificial
flowers which precedes landing and inspection. Both bumblebees and honeybees were able to make antennal contact with circular
floral guides which were 2 mm in diameter; bumblebees performed better than honeybees and antennated also at floral guides
smaller than 2 mm. In discrimination experiments with bumblebees, a minimum floral guide size of 2 mm was required for discrimination
between artificial flowers with and without floral guides. With increasing experience bumblebees targeted close to the site
of reward instead of making antennal contact with the floral guide, whereas honeybees did not alter their initial behaviour
with growing experience. Bumblebees and honeybees spontaneously target diminutive floral guides to achieve physical contact
with flowers by means of their antennae which helps them to inspect flowers. 相似文献
9.
Akira Inoue Chieco Mashino Teina Kodama Takao Ojima 《Marine biotechnology (New York, N.Y.)》2011,13(2):256-263
Functional recombinant abalone alginate lyase (rHdAly) and β-1,4-endoglucanase (rHdEG66) were expressed as secreted proteins
with baculoviral expression systems. The specific activity of each recombinant enzyme, 2,490 and 18.2 U/mg for rHdAly and
rHdEG66, respectively, was comparable to its native form at 30°C. Purified rHdAly and rHdEG66 showed the highest specific
activity both at 35°C and optimum pH 8.7 and 5.9, respectively. These properties were also comparable to those of the native
enzymes. Protoplast isolation was attempted from Laminaria japonica using both rHdAly and rHdEG66. When L. japonica blades were incubated in artificial seawater containing rHdAly and rHdEG66, very low numbers of protoplasts (<1 × 103 protoplasts/g fresh weight) resulted. However, using blades pretreated with proteinase K, the protoplast was increased up
to 5 × 106 protoplasts/g fresh weight. Since the average diameter of isolated protoplasts was 11.6 μm, these cells were mostly derived
from the epidermal layer rather than the cortical layer. Our results suggest that at least three enzymes, alginate lyase,
cellulase, and protease, are essential for effective protoplast isolation from L. japonica. The protoplast isolation method in this study is more useful than earlier methods because it preferentially yielded protoplasts
of the epidermal layer, which are known to be able to be regenerated. 相似文献
10.
Mario C. N. Saparrat Geraldine E. Fermoselle Sebastián A. Stenglein Mónica B. Aulicino Pedro A. Balatti 《Mycopathologia》2009,168(1):41-47
Pseudocercospora griseola is the causal agent of angular leaf spot of common bean (ALS). It has undergone parallel coevolution with its host and two
major groups have been defined, “Andean” (P. griseola f. griseola) and “Mesoamerican” (P. griseola f. mesoamericana). The aim of this study was to analyze the nature and the level of the dark pigment synthesized by the representatives of
each group. After 21 days of incubation on potato dextrose agar medium, P. griseola f. griseola isolate S3b developed colonies with diameters of 17.5 ± 1.3 mm and concentric rings of pigmentation. Isolate T4 of P. griseola f. mesoamericana presented smaller colonies (9.9 ± 0.3 mm) with a uniform dark-gray color. Both isolates, S3b and T4, produced the same pigment,
a 1,8-dihydroxynaphthalene-melanin, although different in quantity and structural features as suggested by the IR spectrum.
The P. griseola f. griseola isolate S3b had a higher growth rate and melanin content as well as smaller sensitivity to melanin synthesis inhibitors compared
to the isolate T4 of P. griseola f. mesoamericana. These results suggest a possible link between melanin and growth in P. griseola. 相似文献
11.
Leonor Calvo Sara Santalla Luz Valbuena Elena Marcos Reyes Tárrega Estanislao Luis-Calabuig 《Plant Ecology》2008,197(1):81-90
The aim of this study was to analyse the regeneration of Pinus pinaster after wildfire and the possible inter and intraspecific competition during the first 3 years after fire. The study area is
located in a P. pinaster stand in León province (NW Spain). Three study sites (S1, S2 and S3) were established in an area burned in 1998. In each site,
three permanent plots (20 × 1 m) were marked. A total of 20 quadrats of 1 m 2 were studied in each plot. The number and height of pine seedlings 1, 2 and 3 years after fire was recorded in each quadrat.
The regeneration of understorey vegetation in the quadrats was analysed concurrently. The significance of linear correlations
among the number and height of seedlings and understorey vegetation cover was tested by calculating Pearson correlation coefficients.Seed
germination and seedling emergence took place massively during the first year after the fire and decreased through time. The
height growth was constant over the 3 years at site S2, while a growth burst could be observed between years 2 and 3 at sites
S1 and S2. Also, pines from site S2 reached shorter maximum heights in all years compared to pines from site S1 and S3. The
understorey vegetation showed minimal regeneration during the first year but then increased greatly with time. Woody understorey
cover and total vegetation cover were negatively correlated with pine seedling density in sites with a high number of seedlings
(e.g. S1 and S3). When woody cover, total cover and pine seedling density were low (e.g. S2), there were no correlations.
There was a positive correlation between vegetation cover and the maximum height of Pinus seedlings in all study sites. 相似文献
12.
Primary cell cultures (n = 16) were initiated from tissues of embryonic and neonatal larval Ornithodoros moubata following methods developed for hard ticks. After maintenance for 20–25 months in vitro, cell multiplication commenced in
surviving cultures, leading to the establishment of six cell lines designated OME/CTVM21, 22, 24, 25, 26 and 27. All lines
are maintained at 28°C, with subculture at 2–8 week intervals. The cultures comprise heterogeneous populations of large cells
of 15–100 μm in diameter, often with finger-like protrusions and/or intracellular crystals, rarely attached, predominantly
floating and forming clumps or hollow multicellular vesicles up to 1 mm in diameter. Attempts to cryopreserve the cells are
described. Tick-borne encephalitis virus has been serially passaged ten times in OME/CTVM21 cells without significant decrease
in virus production and with no change in its biological properties as shown by the size and morphology of plaques produced
in porcine kidney cells. 相似文献
13.
Anber Hassanein Latifa Hamama Karine Loridon Noëlle Dorion 《Plant cell reports》2009,28(10):1521-1530
Direct genetic transformation of mesophyll protoplasts was studied in Pelargonium × hortorum. Calcein and green-fluorescent protein (GFP) gene were used to set up the process. Electroporation (three electric pulses
from a 33-μF capacitor in a 250-V cm−1 electric field) was more efficient than PEG 6000 for membrane permeation, protoplast survival and cell division. Transient
expression of GFP was detected in 33–36% of electroporated protoplasts after 2 days and further in colonies. A protoplast
suspension conductivity of >1,500 μS cm−1 allowed high colony formation and plant regeneration. Stable transformation was obtained using the plasmid FAJ3000 containing
uidA and nptII genes. When selection (50 mg l−1 kanamycin) was achieved 6 weeks after electroporation, regenerated shoots were able to grow and root on 100 mg l−1 kanamycin. The maximum transformation efficiency was 4.5%, based on the number of colonies producing kanamycin-resistant
rooted plants or 0.7% based on the number of cultured protoplasts. Polymerase chain reaction (PCR) analysis on in vitro micropropagated
plants showed that 18 clones out of 20 contained the nptII gene, while the uidA gene was absent. These results were confirmed after PCR analyses of five glasshouse-acclimatized clones. 相似文献
14.
Swasti S. Swain Tapasi Tripathy Pradipta K. Mohapatra Pradeep K. Chand 《In vitro cellular & developmental biology. Plant》2010,46(2):134-141
In vitro regeneration of black nightshade (Solanum nigrum L.) plants was achieved through callus-mediated shoot organogenesis followed by 30 d indoor ex vitro adaptation to nutritional stress under environmental ambience and thereafter 6-d outdoor acclimatization in pots prior to
field establishment. Relevant physiological parameters including pigment content, chlorophyll a fluorescence, net photosynthetic rate (P
N), transpiration rate (E), and stomatal conductance (g
s) of in vitro-regenerated plants were investigated during the course of ex vitro adaptation. During the first 4 d of indoor transplantation to potting substrate, there was a marginal reduction in the leaf
chlorophyll and carotenoid contents but P
N and E were strongly reduced. The stomatal conductance and E/P
N ratio were significantly higher in plants up to 20 d of indoor adaptation than those of comparable age grown naturally from
seeds. The shape of the OJIP fluorescence transient varied significantly with acclimatization, and the maximum change was
observed at 2.0 ms. The 2.0 ms variable fluorescence (V
j), 30 ms relative fluorescence (M
0), photon trapping probability (TR0/Abs), and photosystem II (PSII) trapping rate (TR0/RC) showed initial disturbance and subsequent stabilization during 30 d of indoor acclimatization. Energy dissipation (DI0/RC) and electron transport probability (ET0/TR0) showed an initial phase of increase during the 4 d after plants were transplanted outdoors. During the 6-d outdoor acclimatization
after transfer of plants to soil, no significant change in total chlorophylls and carotenoids, E, and g
s were observed, but P
N improved after reduction on the first d. The OJIP-derived parameters experienced change on the first d but were stabilized
quickly thereafter. There was no significant difference between outdoor acclimatized plants and those of the seed-grown plants
of comparable age with respect to photosynthetic and fluorescence parameters. Direct transfer of plants without indoor acclimatization,
however, showed a completely different trend with respect to P
N, E, and OJIP fluorescence transients. The bearing of this study on optimizing micropropagation is discussed. 相似文献
15.
We studied the oviposition performance of Fopius arisanus (Sonan) (Hymenoptera: Braconidae) attacking eggs of four fruit flies of the genus Anastrepha Schiner (Diptera: Tephritidae) under laboratory conditions. The complete process of oviposition on an individual egg of Anastrepha ludens (Loew) lasts in average 85.4 ± 2.9 s, including a tremor (25.8 ± 1.03 s) observed in the middle of this process related to
the egg’s descent. The average parasitism of A. ludens egg was 60.9 ± 7.5%, with only 1.2% of superparasitized eggs. During individual acts of oviposition, we noted that F. arisanus possesses a highly flexible ovipositor that curves easily as it searches for additional suitable eggs, which may be of particular
benefit when a female finds large clutches of eggs. The individual oviposition of F. arisanus in host fruits attacked by Anastrepha spp. varies with the egg clutch size of each fruit fly species: A. serpentina laid the biggest egg clutches (21.3 ± 1.4), followed by A. ludens (14.2 ± 0.9), and A. striata (1.0 ± 0.0) (=A. obliqua). The time spent by F. arisanus in individual ovipositions was parallel to these findings, reinforcing the idea that F. arisanus attacks several eggs in each individual insertion of its ovipositor. Neither formal oviposition acts, nor adult emergences
of F. arisanus were registered in A. obliqua. We discuss the potential of F. arisanus as natural enemy of fruit flies of the genus Anastrepha, and explore the eventual developing of its mass rearing.
Handling Editor: Torsten Meiners. 相似文献
16.
17.
Maria M. van Dyk Mogamat Khashief Soeker Iwan F. Labuschagne David Jasper G. Rees 《Tree Genetics & Genomes》2010,6(3):489-502
In the Western Cape region of South Africa, dormancy release and the onset of growth does not occur normally in apple (Malus x domestica Borkh.) trees during spring due to the mild winter conditions experienced and fluctuations in temperatures experienced during
and between winters. In this region, the application of chemicals to induce the release of dormancy forms part of standard
orchard management. Increasing awareness of the environmental impact of chemical sprays and global warming has led to the
demand for new apple cultivars better adapted to local climatic conditions. We report the construction of framework genetic
maps in two F1 crosses using the low chilling cultivar ‘Anna’ as common male parent and the higher chill requiring cultivars
‘Golden Delicious’ and ‘Sharpe’s Early’ as female parents. The maps were constructed using 320 simple sequence repeats, including
116 new markers developed from expressed sequence tags. These maps were used to identify quantitative trait loci (QTL) for
time of initial vegetative budbreak (IVB), a dormancy related characteristic. Time of IVB was assessed four times over a 6-year
period in ‘Golden Delicious’ x ‘Anna’ seedlings kept in seedling bags under shade in the nursery. The trait was assessed for
3 years on adult full-sib trees derived from a cross between ‘Sharpe’s Early’ and ‘Anna’ as well as for 3 years on replicates
of these seedlings obtained by clonal propagation onto rootstocks. A single major QTL for time of IVB was identified on linkage
group (LG) 9. This QTL remained consistent in different genetic backgrounds and at different developmental stages. The QTL
may co-localize with a QTL for leaf break identified on LG 3 by Conner et al. (1998), a LG that was, after the implementation of transferable microsatellite markers, shown to be homologous to the LG now known
to be LG 9 (Kenis and Keulemans 2004). These results contribute towards a better understanding regarding the genetic control of IVB in apple and will also be
used to elucidate the genetic basis of other dormancy related traits such as time of initial reproductive budbreak and number
of vegetative and reproductive budbreak. 相似文献
18.
Gwénaelle Crénès Corinne Moundras Marie-Véronique Demattei Yves Bigot Agnès Petit Sylvaine Renault 《Genetica》2010,138(5):509-517
The eukaryotic transposon Mos1 is a class-II transposable element that moves using a “cut-and-paste” mechanism in which the transposase is the only protein
factor required. The formation of the excision complex is well documented, but the integration step has so far received less
investigation. Like all mariner-like elements, Mos1 was thought to integrate into a TA dinucleotide without displaying any other target selection preferences. We set out to
synthesize what is currently known about Mos1 insertion sites, and to define the characteristics of Mos1 insertion sequences in vitro and in vivo. Statistical analysis can be used to identify the TA dinucleotides that are non-randomly
targeted for transposon integration. In vitro, no specific feature determining target choice other than the requirement for
a TA dinucleotide has been identified. In vivo, data were obtained from two previously reported integration hotspots: the
bacterial cat gene and the Caenorhabditis elegans rDNA locus. Analysis of these insertion sites revealed a preference for TA dinucleotides that are included in TATA or TA × TA
motifs, or located within AT-rich regions. Analysis of the physical properties of sequences obtained in vitro and in vivo
do not help to explain Mos1 integration preferences, suggesting that other characteristics must be involved in Mos1 target choice. 相似文献
19.
John P Bannantine Darrell O Bayles W Ray Waters Mitchell V Palmer Judith R Stabel Michael L Paustian 《Proteome science》2008,6(1):5
Background
Our laboratories have previously reported on the experimental infection of cattle with Mycobacterium avium subsp paratuberculosis (M. paratuberculosis) using an intratonsillar infection model. In addition, we have recently developed a partial protein array representing 92 M. paratuberculosis coding sequences. These combined tools have enabled a unique look at the temporal analysis of M. paratuberculosis antigens within the native host. The primary objective of this study was to identify M. paratuberculosis antigens detected by cattle early during infection. A secondary objective was to evaluate the humoral immune response in cattle during the initial year of infection. 相似文献20.
Rui Fernando da Silva Andréa Carla de Almeida Barros Márcia Pletsch Adriana Carla Cavalcante Malta Argolo Brancilene Santos de Araujo 《World journal of microbiology & biotechnology》2010,26(10):1761-1767
Scavenging and anti-Staphylococcus
aureus activities of extracts, fractions and subfractions from the in vitro mycelium of two strains of the edible mushroom Volvariella volvacea were determined. Chloroform subfractions of the ATCC62890 strain showed the highest inhibition percentage of the DPPH radical
(over 80%) after 180 min. When chloroform and hexane subfractions of the R83 strain were combined they showed moderate (inhibition
zone of 8.99 ± 0.78 mm) to high (inhibition zone of 13.06 ± 0.41 mm) activity against the Gram-positive bacteria Staphylococcus
aureus, which are 74.4 and 51.2% of tetracycline (inhibition zone of 17.55 ± 0.11 mm). Partitioning suggested that the substances
in the chloroform and hexane fractions of the R83 strain act synergistically to give the antimicrobial activity, while separating
the substances of the ATCC62890 subfractions reduced their activity. In general, the R83 strain seems to be a source of antimicrobial
substances, while the ATCC62890 strain appears to be an alternative source of antioxidants. 相似文献