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1.
Tuangporn Suthiphongchai Patcharee Boonsiri Bhinyo Panijpan 《Journal of applied phycology》2008,20(3):271-278
Red algae from the Gulf of Thailand were examined for haloperoxidatic activity. Six species, Gracilaria changii, G. edulis, G. firma, G. fisheri, G. salicornia, and G. tenuistipitata, showed bromoperoxidatic activity. Duplicate polyacrylamide electrophoretic gels showed enzyme activity patterns developed
by phenol red staining for bromoperoxidatic activity and by 3,3′-diaminobenzidine staining for peroxidatic activity. All algae
gave isoenzymic bromoperoxidatic activity bands and peroxidatic activity bands, but there were peroxidatic and bromoperoxidatic
activity bands that did not correspond. The bromoperoxidatic activity of the crude enzyme extracts as well as previously dialyzed
enzyme solutions was enhanced significantly by incubation with vanadium pentoxide. The three purified bromoperoxidases from
G. fisheri contained vanadium, and their relative activities corresponded to the ratio of vanadium to enzyme. In addition, they were
not inhibited by H2O2. These data confirm that the enzymes are vanadium bromoperoxidases. 相似文献
2.
To overexpress the chitosanase gene (csn) in F. solani, a vector based on pCAMBIA 1300 was constructed. The csn gene, which is under control of the Aspergillus nidulans
gpdA promoter and A. nidulans trpC terminator, was introduced back into the F. solani genome by Agrobacterium tumefaciens-mediated transformation, and the herbicide-resistance gene bar from Streptomyces hygroscopicus was used as the selection marker. Transformants which showed a significant increase in chitosanase production (~2.1-fold
than control) were obtained. Southern blot analysis indicated that most transformants had a single-copy T-DNA integration. 相似文献
3.
The intron sequence of chloroplast rpS16 and the secondary structure of its pre-mRNA were characterized for the first time in 26 Allium sativum accessions of different ecologo-geographical origins and seven related Allium species. The boundaries and main stem-loop consensus sequences were identified for all six domains of the intron. Polymorphism
was estimated for the total intron and its regions. The structural regions of the rpS16 intron proved to be heterogeneous for mutation rate and spectrum. Mutations were most abundant in domains II and IV, and
transition predominated in domains I, III, V, and VI. In addition to structural elements and motifs typical for group IIB
introns, several Allium-specific micro- and macrostructural mutations were revealed. A 290-bp deletion involving domains III and IV and part of domain
V was observed in A. altaicum, A. fistulosum, and A. schoenoprasum. Several indels and nucleotide substitutions were found to cause a deviation of the pre-mRNA secondary structure from the
consensus model of group II introns. 相似文献
4.
Esterases are known for their involvement in several physiological processes and high degree of polymorphism, in many organisms.
Such polymorphism has been used to characterize species and species groups and to study genetic changes occurred in their
evolutionary history. In the present study, the esterase patterns of 19 strains from 10 species representative of the five
subgroups of the saltans species group were analyzed using polyacrylamide gel electrophoresis and α- and β- naphthyl acetates as substrates. Fifty-one
esterase bands were detected and classified as 31 α-esterases, 18 β-esterases and two α/β-esterases. On the basis of the inhibition
patterns using Malathion and eserine sulfate, 34 bands were classified as carboxylesterases, 14 as acethylesterases and three
as cholinesterases. Ten gene loci were tentatively established on the basis of data on band position in the gel, substrate
preference and inhibition pattern. Twenty bands were species-specific, the remaining being shared by species from the same
or different subgroups. Bands detected exclusively in males and bands with a different frequency or degree of expression between
sexes were also detected. In the gels prepared for analysis of gene expression in the body parts (head, thorax and abdomen),
the degree of expression of the β-esterases was higher in the thorax, while the α-esterases were expressed predominantly in
the abdomen and thorax. A global view of the data available at present on the esterases of the species from the saltans group and their degree of polymorphism are presented, as well as the possibility of using some β-esterases, because of their
characteristics in the gels, as markers for species identification. 相似文献
5.
Marcin Sielezniew Izabela Dziekańska Anna M. Stankiewicz-Fiedurek 《Journal of Insect Conservation》2010,14(2):141-149
Phengaris (=Maculinea) arion is an endangered social parasite of Myrmica ants, and for a very long time was considered as specific to Myrmica sabuleti. Previous studies carried out in Poland suggested some discrepancies within this assumption, and therefore a much more intensive
survey was undertaken. The host ant use of P. arion was studied at five sites in different types of biotopes in Poland, i.e. xerothermal grasslands where Thymus pulegioides was used as a larval food plant by the butterfly, and more or less sandy biotopes with Thymus serpyllum. Altogether nine Myrmica species were recorded, and considerable variation in species composition and density of nests was recorded. At four localities
M. sabuleti proved to be the most common ant. A total of 529 Myrmica nests were examined, and only 20 of them contained larvae and pupae of P. arion. Host ants belonged to five different species, i.e. M. sabuleti, Myrmica scabrinodis, Myrmica schencki, Myrmica lobicornis and Myrmica hellenica. Only at one site (NE Poland) was a significant heterogeneity in parasitation rates among Myrmica species detected. M. lobicornis was the most often infested ant there, which may suggest local specialisation of the butterfly. Overall low parasitism rates
may explain the vulnerability of P. arion in Central Europe but further studies are also necessary. 相似文献
6.
There are three most important bacterial causative agents of serious infections that could be misused for warfare purposes:
Bacillus anthracis (the causative agent of anthrax) is the most frequently mentioned one; however, Fracisella tularensis (causing tularemia) and Yersinia pestis (the causative agent of plague) are further bacterial agents enlisted by Centers for Disease Control and Prevention into the category A of potential biological weapons. This review intends to summarize basic information about these bacterial
agents. Military aspects of their pathogenesis and the detection techniques suitable for field use are discussed. 相似文献
7.
N. Yu. Markelova 《Microbiology》2010,79(6):777-779
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
8.
O. V. Golovanova V. I. Konenkov A. V. Shevchenko M. V. Smolnikova 《Russian Journal of Genetics》2009,45(8):981-986
Based on population analysis of the DRB1, DQA1, DQB1 and TNFA allele frequency distribution patterns, regional features of immunogenetic structure of the population of West Siberia were
investigated. Statistically significant linkage disequilibrium within the HLA class II region, as well as between the TNFA and DRB1, DQA1, and DQB1 was demonstrated. Population frequency distribution patterns of two- and multilocus haplotypes were examined. 相似文献
9.
Wen Yi Zhang Zhi Hong Sun Dong Liang Yu Caicike Airideng Wei Chen He Meng He Ping Zhang 《World journal of microbiology & biotechnology》2010,26(11):1949-1955
The present study was designed to expand genetic knowledge of myo
-inositol (MI) metabolism in Lactobacillus casei. Twenty-four L. casei isolates of dairy origin were tested for the presence of iol cluster. PCR screening revealed eight strains encoded functions involved in MI utilization, of which one strain was able
to use MI as carbon source. To gain a deeper understanding of the function of iol genes, four of the eight observed iol clusters were subjected to the full sequencing procedure. The results showed that the iol cluster was not a common feature among dairy L. casei strains. In addition, the four iol clusters were highly similar to one another in terms of sequence similarity and operon architecture. However, abundant polymorphisms
that comprised a majority of synonymous mutations were detected throughout the full sequences. Three of them distributed among
iolB, iolC, and iolT genes were found in linkage to MI-negative phenotype. Compared with other bacterial iol clusters, the iol cluster of L. casei showed a high similarity with that of Bacillus subtilis. 相似文献
10.
Haoran An Hui Zhou Ying Huang Guohong Wang Chunguang Luan Jing Mou Yunbo Luo Yanling Hao 《Molecular biotechnology》2010,45(2):155-160
Lactic acid bacteria (LAB) are generally sensitive to hydrogen peroxide (H2O2), Lactobacillus sakei YSI8 is one of the very few LAB strains able to degrade H2O2 through the action of a heme-dependent catalase. Lactobacillus rhamnosus strains are very important probiotic starter cultures in meat product fermentation, but they are deficient in catalase. In
this study, the effect of heterologous expression of L. sakei catalase gene katA in L. rhamnosus on its oxidative stress resistance was tested. The recombinant L. rhamnosus AS 1.2466 was able to decompose H2O2 and the catalase activity reached 2.85 μmol H2O2/min/108 c.f.u. Furthermore, the expression of the katA gene in L. rhamnosus conferred enhanced oxidative resistance on the host. The survival ratios after short-term H2O2 challenge were increased 600 and 104-fold at exponential and stationary phase, respectively. Further, viable cells were 100-fold higher in long-term aerated cultures.
Simulation experiment demonstrated that both growth and catalase activity of recombinant L. rhamnosus displayed high stability under environmental conditions similar to those encountered during sausage fermentation. 相似文献
11.
12.
I. Rosario G. Soro S. Déniz O. Ferrer F. Acosta D. Padilla B. Acosta 《Mycopathologia》2010,169(4):315-319
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
13.
14.
Luciano Elias Oliveira Kátia G. Facure Ariovaldo A. Giaretta 《Environmental Biology of Fishes》2012,93(1):89-94
We present data on the habitat, density, and spatial distribution of Rivulus giarettai, and discuss some biotic and abiotic variables related to its abundance in Free Flowing Waters (FFW) and Dam Reservoirs (DR)
in palm grove (Mauritia flexuosa) marshes (Veredas) in Uberlandia, Minas Gerais, southeastern Brazil. The mean density (individuals/plot) of R. giarettai was about 13 times higher in FFW than in DR. In FFW, the density of R. giarettai was highest at intermediate amounts of substrate (plant mass) and it was positively rank-correlated with the depth, and the
number of arthropods. Individuals occurred in an aggregated distribution. The aggregated pattern could be related to a concentration
of individuals in microhabitats neither too much exposed nor completely saturated by plants. R. giarettai was relatively abundant and tolerant to slight man-made habitat modifications. Damming appeared to be especially problematic
by negatively affecting its density. 相似文献
15.
Hao Zhang Hao Hu Xiaobin Zhang Kelin Wang Tongqing Song Fuping Zeng 《Acta Physiologiae Plantarum》2012,34(2):581-588
Measurements of chlorophyll fluorescence and hyperspectral reflectance were used to detect salinity stress in Suaeda salsa L., beach of Dongtai, Jiangsu Province, China. Three experimental sites were used in our study, which belong to low salinity,
middle salinity and high salinity. The results showed that leaf chlorophyll fluorescence changed along salinity gradient.
To select the sensitive hyperspectral ranges of leaf chlorophyll fluorescence, the correlationship between leaf chlorophyll
fluorescence and hyperspectral reflectance was regressed and analyzed. Statistical results indicated that the 680 and 935 nm
were the most sensitive hyperspectral bands for estimating leaf chlorophyll fluorescence. Then, 11 relative hyperspectral
indices were selected based on the sensitive bands and previous literature. (R
680 − R
935)/(R
680 + R
935) and R
680/R
935 have higher correlationship coefficient (R) and lower root mean square error, may be used for detecting chlorophyll fluorescence, such as F
o, F
m, F
v/F
m, qP, and ΦPSII, while NPQ may be detected by (R
780 − R
710)/(R
780 − R
680). These results suggest that chlorophyll fluorescence of halophyte response to salinity stress could be identified by remote
sensing. 相似文献
16.
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
17.
D. V. Fedorov S. V. Kovaltzova V. T. Peshekhonov V. G. Korolev 《Russian Journal of Genetics》2010,46(6):659-665
The yeast genes IXR1 and HMO1 encode proteins belonging to the family of chromatin nonhistone proteins, which are able to recognize and bind to irregular
DNA structures. The full deletion of gene IXR1 leads to an increase in cell resistance to the lethal action of UV light, γ-rays, and MMS, increases spontaneous mutagenesis and significantlly decreases the level of UV-induced mutations. It was earlier
demonstrated in our works that the hmo1 mutation renders cells sensitive to the lethal action of cisplatin and virtually does not affect the sensitivity to UV light.
Characteristically, the rates of spontaneous and UV-induced mutagenesis in the mutant are increased. Epistatic analysis of
the double mutation hmo1 ixr1 demonstrated that the interaction of these genes in relation to the lethal effect of cisplatin and UV light, as well as UV-induced
mutagenesis, is additive. This suggests that the products of genes HMO1 and IXR1 participate in different repair pathways. The ixr1 mutation significantly increases the rate of spontaneous mutagenesis mediated by replication errors, whereas mutation hmo1 increases the rate of repair mutagenesis. In wild-type cells, the level of spontaneous mutagenesis was nearly one order of
magnitude lower than that obtained in cells of the double mutant. Consequently, the combined activity of the Hmo1 and the
Ixr1 proteins provides efficient correction of both repair and replication errors. 相似文献
18.
Ondřej Koukol 《Mycological Progress》2010,9(3):369-378
Survey of seven strains determined as Septonema ochraceum (Dothideomycetes, inc. sed.) isolated from pine litter or obtained from public collections revealed three new species, Fusicladium cordae, F. sicilianum (Venturiaceae), Cladophialophora matsushimae (Herpotrichiellaceae) and a cryptic species morphologically identical to Devriesia americana (Teratosphaeriaceae), but phylogenetically distinct. Morphological survey and phylogenetic analysis using nucleotide sequence data from the nuclear
ribosomal subunit genes indicate a close relationship within three species colonising pine litter needles, F. cordae, F. pini and F. ramoconidii. F. sicilianum is most related to F. rhodense. C. matsushimae represents a species belonging to one of the lineages of the polyphyletic genus Cladophialophora. None of the strains observed can be classified morphologically as S. ochraceum, of which the type material does not exist. 相似文献
19.
20.
Summary. The paper describes two methods of the synthesis of ethyl (3R,4S)- and (3S,4S)-4-[(benzyloxycarbonyl)amino]-5-[(tert-butyloxycarbonyl)amino]-3-hydroxypentanoates, useful for the syntheses of edeine analogs. Differently N-protected (S)-2,3-diaminopropanoic acid was used as a substrate in both procedures. The absolute configuration of newly generated asymmetric
carbon atoms C-3 in β-hydroxy-γ,δ-diamino products was assigned by means of 1H NMR spectroscopy after their transformation into corresponding piperidin-2-ones.
Received May 24, 2002 Accepted October 10, 2002 Published online December 18, 2002
Acknowledgment The authors are indebted to the Faculty of Chemistry, Technical University of Gdańsk for financial support.
Authors' address: Zbigniew Czajgucki, M. Sc., Department of Pharmaceutical Technology and Biochemistry, Faculty of Chemistry, Technical University
of Gdańsk, 11/12 Narutowicza St., 80-952 Gdańsk, Poland, Fax +48 58 347 11 44, E-mail: zmczaj@wp.pl 相似文献