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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
3.
Within eukaryotes, tolerance to DNA damage is determined primarily by the repair pathway controlled by the members of the
RAD6 epistasis group. Genetic studies on a yeast Saccharomyces cerevisiae model showed that the initial stage of postreplication repair (PRR), i.e., initiation of replication through DNA damage,
is controlled by Rad6–Rad18 ubiquitin-conjugating enzyme complex. Mutants of these genes are highly sensitive to various genotoxic
agents and reduce the level of induced mutagenesis. In this case, the efficiency of mutagenesis suppression depends on the
type of damage. In this study we showed that DNA damage induced by hydrogen peroxide at the same mutagen doses causes significantly
more mutations and lethal events in the rad18 mutant cells compared to control wild-type cells. 相似文献
4.
Hua Zhang Rui Xia Zhou Li Jing Zhang Ruo Yu Wang Li Zhe An 《Journal of Plant Biology》2007,50(3):336-343
A novel late embryogenesis abundant (LEA) gene (AY804193), namedCbLEA, has now been isolated fromChorispora bungeana. This rare alpine subnival plant can survive sudden snowstorms and low temperatures. The full-lengthCbLEA is 842 bp, with an open reading frame encoding 169 ami no acids. The putative molecular weight ofCbLEA protein is 17.9 kDa, with an estimatedpl of 6.45. To investigate the functioning of thisCbLEA protein in cold-stress tolerance,CbLEA was introduced into tobacco under the control of the CaMV35S promoter. Second-generation (R1) transgenic tobacco plants exhibited significantly increased tolerance to cold. These transgenics maintained lower malondialdehyde
(MDA) contents and electrolyte leakage (EL) but their relative water content (RWC) was significantly higher compared with
non-transgenic plants under chilling stress. Further experimental results showed that non-transgenic plants had severe freezing
damage after exposure to -2°C for 1 h, whereas the transgenics suffered only slight injury under the same conditions. Moreover,
survival was longer in the latter genotype at that temperature. The extent of increased cold tolerance was positive correlated
with the level ofCbLEA protein accumulation, and was also reflected by the delayed development of damage symptoms. This indicates thatCbLEA is an excellent stress tolerance gene, and holds considerable potential as a new molecular tool for engineering improved
plant genetics. 相似文献
5.
Nanobodies (or VHHs) are single-domain antigen-binding fragments derived from Camelid heavy chain-only antibodies. Their small size, monomeric behaviour, high stability and solubility, and ability to bind epitopes
not accessible to conventional antibodies make them especially suitable for many therapeutic and biotechnological applications.
Here we describe high-level expression, in Nicotiana benthamiana, of three versions of an anti-hen egg white lysozyme (HEWL) nanobody which include the original VHH from an immunized library
(cAbLys3), a codon-optimized derivative, and a codon-optimized hybrid nanobody comprising the CDRs of cAbLys3 grafted onto
an alternative ‘universal’ nanobody framework. His6- and StrepII-tagged derivatives of each nanobody were targeted for accumulation
in the cytoplasm, chloroplast and apoplast using different pre-sequences. When targeted to the apoplast, intact functional
nanobodies accumulated at an exceptionally high level (up to 30% total leaf protein), demonstrating the great potential of
plants as a nanobody production system. 相似文献
6.
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
7.
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
8.
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
9.
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
10.
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
11.
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
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13.
Hiroyoshi Kubo 《Mycoscience》2009,50(5):400-406
Pilobolus crystallinus shows unique photoresponses at various growing stages. cDNAs for putative photoreceptors were cloned from this fungus. Three
genes named pcmada1, pcmada2, and pcmada3 were identified from the PCR fragments, and amplified with degenerated primers for the LOV domain, which is conserved in
many blue-light receptors. Deduced amino acid sequences for PCMADA1, PCMADA2, and PCMADA3 had one light-oxygen-voltage (LOV)-sensing
and two PER-ARNT-SIM (PAS) domains. A zinc finger DNA-binding motif was conserved in the C-terminals of PCMADA1 and PCMADA3.
However, PCMADA2 lacked the zinc finger motif. Expression of pcmada1 was suppressed by blue light whereas that of pcmada3 was promoted by blue-light irradiation. 相似文献
14.
The research on incidence of mistletoe (Viscum album ssp. abietis) on silver fir (Abies alba) was carried out in natural fir stands in Croatia. In the area of Gorski Kotar 32.8 % of the examined dominant fir trees
were infected with mistletoe. The mistletoe incidence was presented according to the damage degrees of silver fir from 0 (healthy
trees) to 4 (dead trees), rated by the crown defoliation and needle discoloration. With the increase of incidence, mistletoe
spreads more onto more vital, i.e. less damaged trees. In the Dinaric Alps 28.6% of the examined fir trees were infected,
this percentage amounting to 27.1% for the mountainous regions between the Sava and Drava rivers.
The site and stand parameters (exposure, elevation, site quality, forest community and crown closure) were analysed in order
to establish whether there was a correlation between these parameters and mistletoe incidence. There was a negative correlation
between the elevation and mistletoe incidence. Among the compartments with a closed stands there were considerably less compartments
with higher mistletoe incidence than among compartments with a sparsely closed and understocked stands. The other analysed
site and stand parameters individually had no significant influence on mistletoe incidence.
The correlation of silver fir mortality in 2004 and mistletoe incidence in 2002/03 was analysed, and their strong correlation
was established. Mistletoe could be considered as a bioindicator of silver fir decline, and probably a significant contributor
to that decline. In the areas where mistletoe incidence is great it can be presumed that silver fir is significantly damaged. 相似文献
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16.
E. Gatti 《Biologia Plantarum》2008,52(1):146-148
Ailanthus altissima, a fast-growing and contamination-resistant species is investigated for its use in areas contaminated by heavy metals. A
micropropagation protocol for A. altissima was developed, cultured shoots were tested for in vitro heavy metals tolerance. Proliferation rate and shoot length were affected by 6-benzylaminopurine (BAP) and Murashige and
Skoog’s (MS) salt concentrations, best results were obtained in full strength MS medium supplemented with 1.32 or 2.64 μM
BAP. Rooting percentage was strongly influenced by indole-3-butyric acid. Cultures of A. altissima exposed to heavy metals demonstrated a tolerance comparable to species already utilized in phytoremediation. 相似文献
17.
Wang Minqin Zhao Junsheng Peng Zhenying Guo Wei Wang Yun Wang Le Xia Guangmin 《Plant Cell, Tissue and Organ Culture》2008,92(2):121-130
In order to investigate chromosome elimination in symmetric somatic hybridization between Bupleurum scorzonerifolium and Arabidopsis thaliana, protoplasts were isolated from suspension cultures of both A. thaliana and B. scorzonerifolium parents. Biparental protoplasts were mixed at a rate of 1.5:1 and fused with PEG-method. After protoplast fusion, the products
were cultured in the P5 liquid medium for microcallus formation. Single cell lines formed from microcalli after subculturing
on the MB1 (Xia and Chen, Plant Sci 120:197–203, 1996) solid medium. The putative somatic hybrid cell lines were identified
by cytological and molecular analysis. Of the 132 somatic cell lines generated, 16 were identified as somatic hybrids, with
the phenotypes resembled B. scorzonerifolium parent. These hybrids showed a complete set of B. scorzonerifolium chromosome and 0–2 small chromosome(s) of A. thaliana. A few of them showed nuclear and cytoplasmic SSR fragments of A. thaliana. These hybrid cell lines could differentiate to green spots, buds/leaves through complementation of regeneration ability.
The chromosomes elimination of A. thaliana was discussed.
Wang Minqin and Zhao Junsheng contributed equally to the work. 相似文献
18.
A leaf beetle, Crioceris sp. (Coleoptera: Chrysomelidae), was introduced into Australia as a biological control agent of bridal creeper (Asparagus asparagoides L. Druce) during October 2002. Rearing of Crioceris sp. is labour intensive therefore all releases of Crioceris sp. have been under 1000 individuals, which may be too low to ensure establishment if high mortality and high competition
with other agents occurs. The aim of this study is to understand how the presence of two well-established biocontrol agents,
a rust fungus (Puccinia myrsiphylli (Thuem) Wint [Basidiomycota: Uredinales]) and a leafhopper (Zygina sp. [Hemiptera: Cicadellidae]), might influence Crioceris sp. establishment. Crioceris sp. neonate larvae were placed on bridal creeper plants with or without the leafhopper and/or rust. The number of larvae
that pupated was reduced by 38 and 65% in the presence of the rust fungus and leafhopper, respectively and by 45% in the presence
of both agents. As the area infected by the rust increased the area damaged by the leafhopper decreased. The rust appeared
to be negatively impacted by the presence of the leafhopper. In a second experiment, female Crioceris sp. adults were given a choice between uninfested bridal creeper plants and those infested with the rust or the leafhopper.
The females preferred to lay their eggs on plants without leafhoppers but did not seem to be deterred by the presence of the
rust. Consequently, the performance and impact of Crioceris sp. on bridal creeper may be reduced if populations overlap with the other biocontrol agents in the field. 相似文献
19.
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
20.
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