Publications

high-temperature cultivation and 5' mrna optimization are key factors for the efficient overexpression of thermostable deinococcus geothermalis purine nucleoside phosphorylase in escherichia coli.	overexpression of genes from thermophiles in escherichia coli is an attractive approach towards the large-scale production of thermostable biocatalysts. however, various factors can challenge efficient heterologous protein expression--one example is the formation of stable 5' mrna secondary structures that can impede an efficient translation initiation. in this work, we describe the expression optimization of purine nucleoside phosphorylase from the thermophilic microbe deinococcus geothermalis ...	2011	21871934
utilization of glycosyltransferases for the synthesis of a densely packed hyperbranched polysaccharide brush coating as artificial glycocalyx.	densely packed polysaccharide brushes consisting of α-d-glucose residues were grafted from modified silicon substrates. potato phosphorylase was herein used to grow linear polysaccharide chains from silicon tethered maltoheptaose oligosaccharides using glucose-1-phosphate as donor substrate. the combined use of potato phosphorylase and deinococcusgeothermalis branching enzyme resulted in a hyperbranched brush coating as the latter one redistributes short oligosaccharides from the α(1-4)-linked p ...	2011	21888377
Desert farming benefits from microbial potential in arid soils and promotes diversity and plant health.	To convert deserts into arable, green landscapes is a global vision, and desert farming is a strong growing area of agriculture world-wide. However, its effect on diversity of soil microbial communities, which are responsible for important ecosystem services like plant health, is still not known.	2011	21912695
bacterial community associated with the intestinal tract of p. monodon in commercial farms.	the potentially important roles of intestinal bacteria on immune response, disease resistance, and nutrition for the black tiger shrimp penaeus monodon have been increasingly investigated. however, so far, little is known about the intestinal bacterial community of the shrimp in the commercial aquaculture settings. in this study, the intestinal bacterial communities of juvenile p. monodon (70 individuals) from eight commercial farms in thailand were examined using 16s rdna pcr-dgge, and seven 16 ...	2011	21915632
Pigment-based whole-cell biosensor system for cadmium detection using genetically engineered Deinococcus radiodurans.	In this study, a colorimetric whole-cell biosensor for cadmium (Cd) was designed using a genetically engineered red pigment producing bacterium, Deinococcus radiodurans. Based on the previous microarray data, putative promoter regions of highly Cd-inducible genes (DR_0070, DR_0659, DR_0745, and DR_2626) were screened and used for construction of lacZ reporter gene cassettes. The resultant reporter cassettes were introduced into D. radiodurans R1 to evaluate promoter activity and specificity. Amo ...	2011	21928095
the role of bacillus anthracis recd2 helicase in dna mismatch repair.	dna mismatch repair (mmr) systems can be classified as either muth-dependent or muth-independent. in bacteria, extensive studies have been conducted with the muth-dependent mmr in escherichia coli and its close relatives. the picture of muth-independent mmr in other bacteria is less clear, as mmr components other than muts and mutl have not been identified in the majority of bacteria. bacillus anthracis is one of the muth-less gram(+) bacteria in the phylum of firmicutes. we used papillation as ...	2011	21940221
the deinococcal ddrb protein is involved in an early step of dna double strand break repair and in plasmid transformation through its single-strand annealing activity.	the deinococcus radiodurans bacterium exhibits an extreme resistance to ionizing radiation. here, we investigated the in vivo role of ddrb, a radiation-induced deinococcus specific protein that was previously shown to exhibit some in vitro properties akin to those of ssb protein from escherichia coli but also to promote annealing of single stranded dna. first we report that the deletion of the c-terminal motif of the ddrb protein, which is similar to the ssb c-terminal motif involved in recruitm ...	2011	21968057
gamma radiation-induced proteome of deinococcus radiodurans primarily targets dna repair and oxidative stress alleviation.	the extraordinary radioresistance of deinococcus radiodurans primarily originates from its efficient dna repair ability. the kinetics of proteomic changes induced by a 6-kgy dose of gamma irradiation was mapped during the post-irradiation growth arrest phase by two-dimensional protein electrophoresis coupled with mass spectrometry. the results revealed that at least 37 proteins displayed either enhanced or de novo expression in the first 1 h of post-irradiation recovery. all of the radiation-res ...	2011	21989019
characterization of deinococcus sahariens sp. nov., a radiation-resistant bacterium isolated from a saharan hot spring.	an ultraviolet-radiation-resistant, gram-positive, orange-pigmented, thermophilic and strictly aerobic cocci was isolated from saharan water hot spring in tunisia. the newly isolated bacterium, designated han-23(t), was identified based on polyphasic taxonomy including genotypic, phenotypic and chemotaxonomic characterization. phylogenetic analysis based on 16s rrna gene sequences placed this strain within deinococcus genus. however, strain han-23(t) is different from recognized species of the g ...	2011	22012026
dna binding is essential for ppri function in response to radiation damage in deinococcus radiodurans.	the extremely radioresistant bacterium deinococcus radiodurans possesses a rapid and efficient but poorly known dna damage response mechanism that mobilizes one-third of its genome to survive lethal radiation damage. deinococcal ppri serves as a general switch to regulate the expression of dozens of proteins from different pathways after radiation, including the dna repair proteins reca, ppra and ssb. however, the underlying mechanism is poorly understood. in this study, we analyzed the dynamic ...	2011	22051194
survival of deinococcus radiodurans against laboratory-simulated solar wind charged particles.	in this experimental study, cells of the radiation-resistant bacterium deinococcus radiodurans were exposed to several different sources of radiation chosen to replicate the charged particles found in the solar wind. naked cells or cells mixed with dust grains (basalt or sandstone) differing in elemental composition were exposed to electrons, protons, and ions to determine the probability of cell survival after irradiation. doses necessary to reduce the viability of cell population to 10% (ld(10 ...	2011	22059692
Cultivable bacteria from ancient algal mats from the McMurdo Dry Valleys, Antarctica.	The McMurdo Dry Valleys in Antarctica are a favorable location for preservation of dormant microbes due to their persistent cold and dry climate. In this study, we examined cultivable bacteria in a series of algal mat samples ranging from 8 to 26539 years old. Cultivable bacteria were found in all samples except one (12303 years old), but abundance and diversity of cultivable bacteria decreased with increasing sample age. Only members of the Actinobacteria, Bacteroidetes, and Firmicutes were fou ...	2012	22065250
Biosynthesis of (+)-catechin glycosides using recombinant amylosucrase from Deinococcus geothermalis DSM 11300.	Amylosucrase (ASase, EC 2.4.1.4) is a glucosyltransferase that hydrolyzes sucrose into glucose and fructose and produces amylose-like glucan polymers from the released glucose. (+)-Catechin is a plant polyphenolic metabolite having skin-whitening and antioxidant activities. In this study, the ASase gene from Deinococcus geothermalis (dgas) was expressed in Escherichia coli, while the recombinant DGAS enzyme was purified using a glutathione S-transferase fusion system. The (+)-catechin glycoside ...	2011	22112416
death by protein damage in irradiated cells.	a founding concept of radiobiology that deals with x-rays, γ-rays and ultraviolet light is that radiation indiscriminately damages cellular macromolecules. mounting experimental evidence does not fit into this theoretical framework. whereas dna lesion-yields in cells exposed to a given dose and type of radiation appear to be fixed, protein lesion-yields are highly variable. extremely radiation resistant bacteria such as deinococcus radiodurans have evolved extraordinarily efficient antioxidant c ...	2011	22112864
On the stoichiometry of Deinococcus radiodurans Dps-1 binding to duplex DNA.	DNA protection during starvation (Dps) proteins, dodecameric assemblies of four-helix bundle subunits, contribute to protection against reactive oxygen species. Deinococcus radiodurans, which is characterized by resistance to DNA damaging agents, encodes two Dps homologs, of which Dps-1 binds DNA with high affinity. DNA binding requires N-terminal extensions preceding the four-helix bundle core. Composed of six Dps-1 dimers, each capable of DNA binding by N-terminal extensions interacting in con ...	2011	22114047
sequence of the hyperplastic genome of the naturally competent thermus scotoductus sa-01.	many strains of thermus have been isolated from hot environments around the world. thermus scotoductus sa-01 was isolated from fissure water collected 3.2 km below surface in a south african gold mine. the isolate is capable of dissimilatory iron reduction, growth with oxygen and nitrate as terminal electron acceptors and the ability to reduce a variety of metal ions, including gold, chromate and uranium, was demonstrated. the genomes from two different thermus thermophilus strains have been com ...	2011	22115438
the structure and enzymatic properties of a novel rnase ii family enzyme from deinococcus radiodurans.	exoribonucleases are vital in nearly all aspects of rna metabolism, including rna maturation, end-turnover, and degradation. rnase ii and rnase r are paralogous members of the rnr superfamily of nonspecific, 3'→5', processive exoribonucleases. in escherichia coli, rnase ii plays a primary role in mrna decay and has a preference for unstructured rna. rnase r, in contrast, is capable of digesting structured rna and plays a role in the degradation of both mrna and stable rna. deinococcus radioduran ...	2011	22133431
comparative survival analysis of deinococcus radiodurans and the haloarchaea natrialba magadii and haloferax volcanii exposed to vacuum ultraviolet irradiation.	abstract the haloarchaea natrialba magadii and haloferax volcanii, as well as the radiation-resistant bacterium deinococcus radiodurans, were exposed to vacuum uv (vuv) radiation at the brazilian synchrotron light laboratory. cell monolayers (containing 10(5) to 10(6) cells per sample) were prepared over polycarbonate filters and irradiated under high vacuum (10(-5) pa) with polychromatic synchrotron radiation. n. magadii was remarkably resistant to high vacuum with a survival fraction of (3.7 ...	2011	22165956
Recombinant D. radiodurans cells for bioremediation of heavy metals from acidic/neutral aqueous wastes.	The stability and superior metal bioremediation ability of genetically engineered Deinococcus radiodurans cells, expressing a non-specific acid phosphatase, PhoN in high radiation environment has already been established. The lyophilized recombinant DrPhoN cells retained PhoN activity and uranium precipitation ability. Such cells also displayed an extended shelf life of 6 mo during storage at room temperature and showed surface associated precipitation of uranium as well as other metals like cad ...	2012	22179144
Chemical contrast in soft x-ray ptychography.	The unique strengths of x-ray microscopy are high penetration depth and near-edge resonances that provide chemical information. We use ptychography, a coherent diffractive imaging technique that disposes of the requirement for isolated specimens, and demonstrate resonant imaging by exploiting resonances near the oxygen K edge to differentiate between two oxygen-containing materials. To highlight a biological system where resonant ptychography might be used for chemical mapping of unsliced cells, ...	2011	22181778
analysis of the bacterial diversity in the fecal material of the endangered yangtze finless porpoise, neophocaena phocaenoides asiaeorientalis.	the aim of this study was to determine the bacteria present in the fecal material of the endangered yangtze finless porpoise, neophocaena phocaenoides asiaeorientalis. fecal samples were collected from 12 yangtze finless porpoises living in the wild at poyang lake, located in jiangxi province, china. to determine the bacterial diversity, a 16s rrna gene clone library using the bacterial pcr primers fd1 and rp2, was prepared. a total of 138 near-full-length sequences were analyzed and 39 operatio ...	2011	22201021
transcriptional regulation of central carbon and energy metabolism in bacteria by redox responsive repressor rex.	redox-sensing repressor rex was previously implicated in the control of anaerobic respiration in response to the cellular nadh/nad(+) levels in gram-positive bacteria. we utilized the comparative genomics approach to infer candidate rex-binding dna motifs and assess the rex regulon content in 119 genomes from 11 taxonomic groups. both dna-binding and nad-sensing domains are broadly conserved in rex orthologs identified in the phyla firmicutes, thermotogales, actinobacteria, chloroflexi, deinococ ...	2011	22210771
structural investigation of the thermostability and product specificity of amylosucrase from the bacterium deinococcus geothermalis.	amylosucrases are sucrose-utilizing α-transglucosidases that naturally catalyze the synthesis of α-glucans, linked exclusively through α-1,4 linkages. side-products and in particular sucrose isomers such as turanose and trehalulose are also produced by these enzymes. here, we report the first structural and biophysical characterization of the most thermostable amylosucrase identified so far, the amylosucrase from deinoccocus geothermalis (dgas). the 3d-structure revealed a homodimeric quaterna ...	2011	22210773
high-pressure tolerance in halobacterium salinarum nrc-1 and other non-piezophilic prokaryotes.	in this study, we examined the high-pressure survival of a range of prokaryotes not found in high-pressure environments to determine the effects of adaptations to osmotic and oxidative stresses on piezo-resistance. the pressure survivals of halobacterium salinarum nrc-1, deinococcus radiodurans r1, and chromohalobacter salexigens were compared to that of escherichia coli mg1655. c. salexigens, which uses the compatible solute ectoine as an osmolyte, was as piezo-sensitive as e. coli mg1655, sugg ...	2012	22212652
the structural basis of the response regulator drrra from deinococcus radiodurans.	drrra, a vital and recently discovered gene product of deinococcus radiodurans, is a member of the ompr/phob family of response regulators that couple with the cognate histidine kinase (hk) to form a typical two component system (tcs). it is known that the drrra is responsible for the transcriptional levels of numerous genes mostly relating to the stress response and dna repair. in this paper, the crystal structures of the effector domain and full-length protein of drrra with resolutions of 1.6 ...	2011	22227191
deinococcus humi sp. nov., isolated from soil.	a gram-staining-positive, strictly aerobic, spherical-shaped, non-motile red-pigmented bacterial strain mk03t, was isolated from a soil sample. a polyphasic approach was applied to study the taxonomic position of strain mk03t. phylogenetic analysis based on 16s rrna gene sequences showed that strain mk03t belonged to the clade formed by members of the genus deinococcus in the family deinococcaceae. the g+c content of the genomic dna was 64.5 mol %. strain mk03t showed highest 16s rrna gene seque ...	2012	22228662
physiology of resistant deinococcus geothermalis bacterium aerobically cultivated in low manganese medium.	this dynamic proteome study describes the physiology of growth and survival of deinococcus geothermalis, in conditions simulating paper machine waters being aerobic, warm, and low in carbon and manganese. industrial environment of this species differ from its natural habitats, geothermal springs and deep ocean subsurfaces, by being highly exposed to oxygen. quantitative proteome analysis using two-dimensional gel electrophoresis and bioinformatic tools showed expression change for 165 proteins f ...	2012	22228732
detoxification of toxins by bacillithiol in staphylococcus aureus.	bacillithiol (bsh), an α-anomeric glycoside of l-cysteinyl-d-glucosaminyl-l-malate, is a major low molecular weight thiol found in bacteria such as bacillus sp., staphylococcus aureus, and deinococcus radiodurans. like other low molecular weight thiols such as glutathione and mycothiol, bsh is likely to be involved in protection against environmental toxins including thiol reactive antibiotics. we report here a bsh dependent detoxification mechanism in s. aureus. when s. aureus newman strain wa ...	2012	22262099