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224 records returned

Early candidacy for differentiation into heterocysts in the filamentous cyanobacterium Anabaena sp. PCC 7120.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The filamentous cyanobacterium Anabaena sp. PCC 7120 fixes dinitrogen facultatively. Upon depletion of combined nitrogen, about 10% of vegetative cells within the filaments differentiate terminally into nitrogen-fixing cells. The heterocyst has been studied as a model system of prokaryotic cell differentiation, with major focus on signal transduction and pattern formation. The fate of heterocyst differentiation is determined at about the eighth hour of induction (point of no return), well before conspicuous morphological or metabolic changes occur. However, little is known about how the initial heterocysts are selected...
Source: Archives of Microbiology - November 13, 2009 Category: Microbiology Authors: Toyoshima M, Sasaki NV, Fujiwara M, Ehira S, Ohmori M, Sato N Tags: Arch Microbiol Source Type: journals

Characterization of an O-desmethylangolensin-producing bacterium isolated from human feces.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A bacterium that converted daidzein to O-desmethylangolensin was isolated from the feces of healthy humans. It was an obligately anaerobic, nonsporeforming, nonmotile and Gram-positive rod. The isolate used glucose, sucrose, raffinose, maltose, and fructose as carbon sources. It did not hydrolyze gelatin, esculin, or starch. The strain was urease, acid phosphatase, and arginine dihydrolase positive. It was catalase, oxidase, H(2)S, and indole negative. The major products of glucose fermentation were butyrate and lactate. Its mol% G+C was 51.2. The major cellular fatty acids were C(16:0) DMA, C(16:0), and C(16:0) aldehy...
Source: Archives of Microbiology - November 11, 2009 Category: Microbiology Authors: Yokoyama SI, Niwa T, Osawa T, Suzuki T Tags: Arch Microbiol Source Type: journals

The PQQ biosynthetic operons and their transcriptional regulation in Pseudomonas aeruginosa.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Gene PA1990 of Pseudomonas aeruginosa, located downstream of pqqE and encoding a putative peptidase, was shown to be involved in excretion of PQQ into the culture supernatant. This gene is cotranscribed with the pqqABCDE cluster and was named pqqH. A PA1990::Km(r) mutant (VK3) did not show any effect in growth behaviour; however, in contrast to the wild-type, no excretion of PQQ into the culture supernatant was observed. The putative pqqF gene of P. aeruginosa was shown to be essential for PQQ biosynthesis. A pqqF::Km(r) mutant did not grow aerobically on ethanol, because of its inability to produce PQQ. Transcription ...
Source: Archives of Microbiology - November 10, 2009 Category: Microbiology Authors: Gliese N, Khodaverdi V, Görisch H Tags: Arch Microbiol Source Type: journals

Roles of PprA, IrrE, and RecA in the resistance of Deinococcus radiodurans to germicidal and environmentally relevant UV radiation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
To study the role of different DNA repair genes in the resistance of Deinococcus radiodurans to mono- and polychromatic UV radiation, wild-type strain and knockout mutants in RecA, PprA, and IrrE of D. radiodurans were irradiated with UV-C (254 nm), UV-(A + B) (280-400 nm) and UV-A (315-400 nm) radiation, and survival was monitored. The strain deficient in recA was highly sensitive to UV-C radiation compared to the wild-type, but showed no loss of resistance against irradiation with UV-(A + B) and UV-A, while pprA and irrE-deficient strains exhibited elevated sensitivity to UV-A and UV-(A + B) radiation. These results ...
Source: Archives of Microbiology - October 31, 2009 Category: Microbiology Authors: Bauermeister A, Bentchikou E, Moeller R, Rettberg P Tags: Arch Microbiol Source Type: journals

Identification, cloning, and functional characterization of EmrD-3, a putative multidrug efflux pump of the major facilitator superfamily from Vibrio cholerae O395.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A putative multidrug efflux pump, EmrD-3, belonging to the major facilitator superfamily (MFS) of transporters and sharing homology with the Bcr/CflA subfamily, was identified in Vibrio cholerae O395. We cloned the emrD-3 gene and evaluated its role in antimicrobial efflux in a hypersensitive Escherichia coli strain. The efflux activity of this membrane protein resulted in lowering the intracellular concentration of ethidium. The recombinant plasmid carrying emrD-3 conferred enhanced resistance to several antimicrobials. Among the antimicrobials tested, the highest relative increase in minimum inhibitory concentration ...
Source: Archives of Microbiology - October 30, 2009 Category: Microbiology Authors: Smith KP, Kumar S, Varela MF Tags: Arch Microbiol Source Type: journals

Comparison of the metabolic activities of four wild-type Clostridium perfringens strains with their gatifloxacin-selected resistant mutants.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The production of short-chain fatty acids, reductive enzymes, and hydrolytic enzymes by four gatifloxacin-selected, fluoroquinolone-resistant, mutant strains of C. perfringens, with stable mutations either in DNA gyrase or in both DNA gyrase and topoisomerase IV, was compared with that produced by the wild-type parent strains to investigate the effect of mutations associated with the selection of gatifloxacin resistance on bacterial metabolic activities. The mutants differed from their respective wild-type parent strains in the enzymatic activities of azoreductase, nitroreductase, and beta-glucosidase and in the ratio ...
Source: Archives of Microbiology - October 24, 2009 Category: Microbiology Authors: Rafii F, Park M, Gamboa da Costa G, Camacho L Tags: Arch Microbiol Source Type: journals

Interaction of sortase A and lipase 2 in the inhibition of Staphylococcus aureus biofilm formation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Recombinant sortase A (SrtA) was used to immune rabbit, and the inhibitory activity of anti-SrtA serum on Staphylococcus aureus biofilm formation was tested. Biofilm formation was inhibited by anti-SrtA rabbit serum in S. aureus ATCC25923 and two clinical isolated strains. The antiserum was separated into two fractions, and the main component with the inhibitory activity was demonstrated to be the IgG fraction. Two proteins interact with the IgG fraction were identified by using an in vitro pull-down assay and were confirmed to be lipase 2 and gamma-hemolysin by mass spectrometry. Cross-interaction between SrtA and lip...
Source: Archives of Microbiology - October 16, 2009 Category: Microbiology Authors: Xiong N, Hu C, Zhang Y, Chen S Tags: Arch Microbiol Source Type: journals

Anaerobic metabolism of phenol in proteobacteria and further studies of phenylphosphate carboxylase.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Anaerobic phenol metabolism was studied in three facultative aerobic denitrifying bacteria, Thauera aromatica, "Aromatoleum aromaticum" strain EbN1 (Betaproteobacteria), and Magnetospirillum sp. (Alphaproteobacterium). All species formed phenylphosphate and contained phenylphosphate carboxylase but not phenol carboxylase activity. This is in contrast to direct phenol carboxylation by fermenting bacteria. Antisera raised against subunits of the Thauera phenylphosphate synthase and phenylphosphate carboxylase partly cross-reacted with the corresponding proteins in the other species. Some unsolved features of phenylphosph...
Source: Archives of Microbiology - October 16, 2009 Category: Microbiology Authors: Schmeling S, Fuchs G Tags: Arch Microbiol Source Type: journals

Mixotrophic metabolism in Burkholderia kururiensis subsp. thiooxydans subsp. nov., a facultative chemolithoautotrophic thiosulfate oxidizing bacterium isolated from rhizosphere soil and proposal for classification of the type strain of Burkholderia kururiensis as Burkholderia kururiensis subsp. kururiensis subsp. nov.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A thiosulfate-oxidizing facultative chemolithoautotrophic Burkholderia sp. strain ATSB13(T) was previously isolated from rhizosphere soil of tobacco plant. Strain ATSB13(T) was aerobic, Gram-staining-negative, rod shaped and motile by means of sub-terminal flagellum. Strain ATSB13(T) exhibited mixotrophic growth in a medium containing thiosulfate plus acetate. A phylogenetic study based on 16S rRNA gene sequence analysis indicated that strain ATSB13(T) was most closely related to Burkholderia kururiensis KP23(T) (98.7%), Burkholderia tuberum STM678(T) (96.5%) and Burkholderia phymatum STM815(T) (96.4%). Chemotaxonomic ...
Source: Archives of Microbiology - October 15, 2009 Category: Microbiology Authors: Anandham R, Indira Gandhi P, Kwon SW, Sa TM, Kim YK, Jee HJ Tags: Arch Microbiol Source Type: journals

Proteolytic processing of Escherichia coli twin-arginine signal peptides by LepB.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The twin-arginine translocation (Tat) apparatus is a protein targeting system found in the cytoplasmic membranes of many prokaryotes. Substrate proteins of the Tat pathway are synthesised with signal peptides bearing SRRxFLK 'twin-arginine' amino acid motifs. All Tat signal peptides have a common tripartite structure comprising a polar N-terminal region, followed by a hydrophobic region of variable length and a polar C-terminal region. In Escherichia coli, Tat signal peptides are proteolytically cleaved after translocation. The signal peptide C-terminal regions contain conserved AxA motifs, which are possible recogniti...
Source: Archives of Microbiology - October 6, 2009 Category: Microbiology Authors: Lüke I, Handford JI, Palmer T, Sargent F Tags: Arch Microbiol Source Type: journals

Multiple antioxidant proteins protect Chlorobaculum tepidum against oxygen and reactive oxygen species.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The genome of the green sulfur bacterium Chlorobaculum (Cba.) tepidum, a strictly anaerobic photolithoautotroph, is predicted to encode more than ten genes whose products are potentially involved in protection from reactive oxygen species and an oxidative stress response. The encoded proteins include cytochrome bd quinol oxidase, NADH oxidase, rubredoxin oxygen oxidoreductase, several thiol peroxidases, alkyl hydroperoxide reductase, superoxide dismutase, methionine sulfoxide reductase, and rubrerythrin. To test the physiological functions of some of these proteins, ten genes were insertionally inactivated. Wild-type C...
Source: Archives of Microbiology - September 26, 2009 Category: Microbiology Authors: Li H, Jubelirer S, Garcia Costas AM, Frigaard NU, Bryant DA Tags: Arch Microbiol Source Type: journals

Selection of a Clostridium perfringens type D epsilon toxin producer via dot-blot test.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, a standardized dot-blot was used to choose strains of C. perfringens type D that are producers of epsilon toxin. Clones producing epsilon toxin were chosen by limiting dilution; after three passages, lethal minimum dose titers were determined by soroneutralization test in mice. These clones produced epsilon toxin 240 times more concentrated than the original strain. The presence of the epsilon toxin gene (etx) was verified by polymerase chain reaction. All clones were positive, including those determined to be negative by dot-blot tests, suggesting that mechanisms in addition to the presence of the etx gene ...
Source: Archives of Microbiology - September 24, 2009 Category: Microbiology Authors: Gonçalves LA, Lobato ZI, Silva RO, Salvarani FM, Pires PS, Assis RA, Lobato FC Tags: Arch Microbiol Source Type: journals

Response to different oxidants of Saccharomyces cerevisiae ure2Delta mutant.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Growth of Saccharomyces cerevisiae ure2Delta mutant strain was investigated in the presence of diverse oxidant compounds. The inability of the strain to grow on a medium supplemented with H(2)O(2) was confirmed and a relationship between diminishing levels of glutathione (GSH) and peroxide sensitivity was established. Data for the lack of significant effect of URE2 disruption on the cellular growth in the presence of paraquat and menadione were obtained. The possible role of Ure2p in acquiring sensitivity to oxidative stress by means of its regulatory role in the GATA signal transduction pathway was discussed. It was s...
Source: Archives of Microbiology - September 23, 2009 Category: Microbiology Authors: Todorova TT, Petrova VY, Vuilleumier S, Kujumdzieva AV Tags: Arch Microbiol Source Type: journals

Characterization of the mineral phosphate solubilizing activity of Serratia marcescens CTM 50650 isolated from the phosphate mine of Gafsa.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study is expected to lead to the development of an environmental-friendly process for fertilizer production considering the capacity of S. marcescens CTM 50650 to achieve yields of P extraction up to 75% from the Gafsa RP. PMID: 19771411 [PubMed - as supplied by publisher] (Source: Archives of Microbiology)
Source: Archives of Microbiology - September 21, 2009 Category: Microbiology Authors: Ben Farhat M, Farhat A, Bejar W, Kammoun R, Bouchaala K, Fourati A, Antoun H, Bejar S, Chouayekh H Tags: Arch Microbiol Source Type: journals

A new beta-galactosidase with a low temperature optimum isolated from the Antarctic Arthrobacter sp. 20B: gene cloning, purification and characterization.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A psychrotrophic bacterium producing a cold-adapted beta-galactosidase upon growth at low temperatures was classified as Arthrobacter sp. 20B. A genomic DNA library of strain 20B introduced into Escherichia coli TOP10F' and screening on X-Gal (5-bromo-4-chloro-3-indolyl-beta-D: -galactopyranoside)-containing agar plates led to the isolation of beta-galactosidase gene. The beta-galactosidase gene (bgaS) encoding a protein of 1,053 amino acids, with a calculated molecular mass of 113,695 kDa. Analysis of the amino acid sequence of BgaS protein, deduced from the bgaS ORF, suggested that it is a member of the glycosyl hydr...
Source: Archives of Microbiology - September 21, 2009 Category: Microbiology Authors: Białkowska AM, Cieśliński H, Nowakowska KM, Kur J, Turkiewicz M Tags: Arch Microbiol Source Type: journals

NifH-based studies on azotobacterial diversity in cotton soils of India.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In order to promote the use of Azotobacter inoculants for cotton crop, a complete characterization of soil isolates of Azotobacter, isolated and screened on the basis of physiological properties, from four different cotton-wheat cropping regions of India was carried out, and their genetic diversity determined by RFLP (restriction fragment length polymorphism) analysis of the functional gene nifH. Genetic analysis of these isolates depicted a similarity coefficient of >/=80% among them, suggesting that though the isolates were obtained from different cotton soils of India, still they have large commonality in the nif...
Source: Archives of Microbiology - September 21, 2009 Category: Microbiology Authors: Bhatia R, Ruppel S, Narula N Tags: Arch Microbiol Source Type: journals

Lysine-91 of the tetraheme c-type cytochrome CymA is essential for quinone interaction and arsenate respiration in Shewanella sp. strain ANA-3.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The tetraheme c-type cytochrome, CymA, is essential for arsenate respiratory reduction in Shewanella sp. ANA-3, a model arsenate reducer. CymA is predicted to mediate electron transfer from quinols to the arsenate respiratory reductase (ArrAB). Here, we present biochemical and physiological evidence that CymA interacts with menaquinol (MQH(2)) substrates. Fluorescence quench titration with the MQH(2) analog, 2-n-heptyl-4-hydroxyquinoline-N-oxide (HOQNO), was used to demonstrate quinol binding of E. coli cytoplasmic membranes enriched with various forms of CymA. Wild-type CymA bound HOQNO with a K (d) of 0.1-1 muM. It w...
Source: Archives of Microbiology - September 16, 2009 Category: Microbiology Authors: Zargar K, Saltikov CW Tags: Arch Microbiol Source Type: journals

Cold-active halophilic bacteria from the ice-sealed Lake Vida, Antarctica.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Lake Vida is a large, permanently ice-covered lake in the Victoria Valley of the McMurdo Dry Valleys, Antarctica and is unique among Dry Valley lakes because it is ice-sealed, with an ice-cover of nearly 19 m. Enrichment cultures of melt-water from Lake Vida 15.9 m ice yielded five pure cultures of aerobic, heterotrophic bacteria. Of these, one strain grew at -8 degrees C and the four others at -4 degrees C. All isolates were either halotolerant or halophilic, with two strains capable of growth at 15% NaCl. Phylogenetic analysis revealed the Lake Vida isolates to be Gammaproteobacteria, related to species of Psychrobac...
Source: Archives of Microbiology - September 15, 2009 Category: Microbiology Authors: Mondino LJ, Asao M, Madigan MT Tags: Arch Microbiol Source Type: journals

Mutagenesis of the enolase-phosphatase gene in Xanthomonas oryzae pv. oryzae affects growth on methylthioadenosine and in vivo S-adenosylmethionine pools.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Enolase-phosphatase (E1), as an enzyme, is involved in methionine salvage pathway in many prokaryotic and eukaryotic organisms. But the identity and function of E1 in Xanthomonas oryzae pv. oryzae (Xoo) remain undetermined. Here, we report the cloning and characterization of E1 gene, named xep, from Xoo. Sequence analysis shows that XEP is highly conserved among the six Xoo strains we investigated and all other Xanthomonas species. The strain with an insertion mutation in xep could not grow when methylthioadenosine (MTA) was used as the sole sulfur source, but its growth in rice leaves was comparable to that of wild-ty...
Source: Archives of Microbiology - September 3, 2009 Category: Microbiology Authors: Zhang Y, Zhang G, Zhang J, Wang X, Wang J Tags: Arch Microbiol Source Type: journals

Isolation of identical nitrilase genes from multiple bacterial strains and real-time PCR detection of the genes from soils provides evidence of horizontal gene transfer.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, an identical nitrilase gene (nit1) was isolated from the four strains, and the nitrilase from strain AJ270 cloned and expressed in Escherichia coli. Analysis of the recombinant nitrilase has shown it to be functional with activity demonstrated towards phenylacetonitrile. A real-time PCR TaqMan((R)) assay was developed that allowed nit1 detection directly from soil enrichment cultures without DNA extraction, with nit1 detected in all samples tested. Real-time PCR screening of isolates from these soils resulted in the isolation of nit1 and also very similar nitrilase gene nit2 from a number of Burkholderia sp....
Source: Archives of Microbiology - September 2, 2009 Category: Microbiology Authors: Coffey L, Clarke A, Duggan P, Tambling K, Horgan S, Dowling D, O'Reilly C Tags: Arch Microbiol Source Type: journals

Display of alpha-amylase on the surface of Corynebacterium glutamicum cells by using NCgl1221 as the anchoring protein, and production of glutamate from starch.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We developed a new cell surface display system in Corynebacterium glutamicum based on the C-terminally truncated NCgl1221 anchor protein to increase L: -glutamate production from starch directly. The C-terminally truncated NCgl1221 protein is a mutant NCgl1221 and leads to the constitutive export of L: -glutamate. The N terminus of alpha-amylase (AmyA) was fused to truncated NCgl1221, and the resulting fusion protein was expressed on the cell surface by IPTG induction. Localization of the fusion protein was confirmed by immunofluorescence microscopy and flow cytometric analysis. The results of L: -glutamate fermentatio...
Source: Archives of Microbiology - September 1, 2009 Category: Microbiology Authors: Yao W, Chu C, Deng X, Zhang Y, Liu M, Zheng P, Sun Z Tags: Arch Microbiol Source Type: journals

Production of diprenylated indole derivatives by tandem incubation of two recombinant dimethylallyltryptophan synthases.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we showed that C4,C7-diprenylated indole derivatives, e.g. 4,7-di-(dimethylallyl)-L: -tryptophan, 4,7-di-(dimethylallyl)-L: -abrine and 4,7-di-(dimethylallyl)-11-methyltryptophan, could be conveniently produced by tandem incubation of both enzymes. The structures of the isolated enzymatic products were elucidated by NMR and MS analyses. High conversion yields of up to 93% were achieved by an incubation sequence of FgaPT2 followed by 7-DMATS. The results reported in this study demonstrated the potential of secondary metabolite enzymes as promising tools for the production of designed compounds. PMID: 1972...
Source: Archives of Microbiology - August 31, 2009 Category: Microbiology Authors: Ruan HL, Stec E, Li SM Tags: Arch Microbiol Source Type: journals

Cyclic AMP regulates the biosynthesis of cellobiohydrolase in Cellulomonas flavigena growing in sugar cane bagasse.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Cellulomonas flavigena produces a battery of cellulase components that act concertedly to degrade cellulose. The addition of cAMP to repressed C. flavigena cultures released catabolic repression, while addition of cAMP to induced C. flavigena cultures led to a cellobiohydrolase hyperproduction. Exogenous cAMP showed positive regulation on cellobiohydrolase production in C. flavigena grown on sugar cane bagasse. A C. flavigena cellobiohydrolase gene was cloned (named celA), which coded for a 71- kDa enzyme. Upstream, a repressor celR1, identified as a 38 kDa protein, was monitored by use of polyclonal antibodies. PM...
Source: Archives of Microbiology - August 22, 2009 Category: Microbiology Authors: Herrera-Herrera JA, Pérez-Avalos O, Salgado LM, Ponce-Noyola T Tags: Arch Microbiol Source Type: journals

Characterization of osmolyte betaine synthesizing sarcosine dimethylglycine N-methyltransferase from Methanohalophilus portucalensis.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
To overcome the extracellular salt stress, Methanohalophilus portucalensis FDF1(T) synthesizes the compatible solute betaine through the methylation of glycine, sarcosine, and N,N-dimethylglycine. S-adenosylmethionine (AdoMet) is the methyl donor. The enzyme sarcosine dimethylglycine N-methyltransferase (SDMT) of M. portucalensis, that catalyzes the formation of N,N-dimethylglycine and glycine betaine, has been purified and characterized. SDMT, a monomer of 33 kDa with a pI at 5.03, has a narrow substrate specificity limited to using only sarcosine and dimethylglycine as substrates for the methyl transferase reaction. ...
Source: Archives of Microbiology - August 19, 2009 Category: Microbiology Authors: Chen SY, Lai MC, Lai SJ, Lee YC Tags: Arch Microbiol Source Type: journals

Yeast protein phosphatases Ptp2p and Msg5p are involved in G1-S transition, CLN2 transcription, and vacuole morphogenesis.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We previously reported that double disruption of protein phosphatase (PPase) genes PTP2 (phosphotyrosine-specific PPase) and MSG5 (phosphotyrosine and phosphothreonine/serine-PPase) causes Ca(2+) sensitive growth, whereas the single disruptions do not. This finding suggests that Ptp2p and Msg5p are involved in Ca(2+)-induced stress response in a redundant manner. To gain insight into the molecular mechanism causing calcium sensitivity of the ptp2 msg5 double disruptant, we performed fluorescence-activated cell sorting analysis and found a delayed G1 phase. This delayed G1 was consistent with the defect in bud emergence...
Source: Archives of Microbiology - August 13, 2009 Category: Microbiology Authors: Hermansyah , Sugiyama M, Kaneko Y, Harashima S Tags: Arch Microbiol Source Type: journals

Polyphasic taxonomic studies of lactic acid bacteria associated with Tunisian fermented meat based on the heterogeneity of the 16S-23S rRNA gene intergenic spacer region.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The objective of this work was to investigate the structure and diversity of lactic acid bacteria (LAB) communities in traditionally fermented meat collected from different areas of Tunisia. A polyphasic study, which involves phenotypic tests and ribosomal DNA-based techniques, was used to identify Gram-positive and catalase-negative isolates. PCR amplification of the 16S-23S rDNA ISR of 102 isolates and other reference LAB strains gave (1) one type of rrn operon (M-ISR) for lactococci, (2) two types of rrn operon (S-ISR and M-ISR) for enterococci, (3) two types of rrn operon (S-ISR and L-ISR) for Lactobacilli, and (4) thr...
Source: Archives of Microbiology - August 10, 2009 Category: Microbiology Authors: Ben Belgacem Z, Dousset X, Prévost H, Manai M Tags: Arch Microbiol Source Type: journals

Phenotypic, genomic and phylogenetic characteristics of rhizobia isolated from root nodules of Robinia pseudoacacia (black locust) growing in Poland and Japan.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Rhizobial strains, rescued from the root nodules of Robinia pseudoacacia growing in Japan and Poland, were characterized for the phenotypic properties, genomic diversity as well as phylogeny and compared with the reference strains representing different species and genera of nodule bacteria. They had a moderately slow growth rate, a low tolerance to antibiotics, a moderate resistance to NaCl and produced acid in yeast mannitol agar. Cluster analysis based on the phenotypic features divided all bacteria involved in this study into four phena, comprising: (1) Rhizobium sp. + Sinorhizobium sp., (2) Bradyrhizobium sp., (3)...
Source: Archives of Microbiology - August 7, 2009 Category: Microbiology Authors: Mierzwa B, Wdowiak-Wróbel S, Małek W Tags: Arch Microbiol Source Type: journals

Anticandidal cytotoxicity, antitumor activities, and purified cell wall modulation by novel Schiff base ligand and its metal (II) complexes against some pathogenic yeasts.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The preparation of metal (II) complexes [CoCl(2).6H(2)O, Ni(CH(3)COO)(2).4H(2)O, Cu(CH(3)COO)(2).2H(2)O, and Zn (CH3COO)(2) .2H(2)O] with 2[N-(cinnamlidene) amino]-5-nitro phenol as a novel ligands and their biological evaluation against candida species was studied. The inhibitory effects of the tested metal complexes were tested against six pathogenic yeasts (Candida albicans, C. fructus, C. glabrata, C. oleophila, C. parapsilosis, and C. tropicalis). The effect of the most efficient metal complex (Zn(II) complex) was more pronounced at 1.25 mug/ml, while Ni(II) complex was exhibited the least suppressive effect. Co(I...
Source: Archives of Microbiology - August 4, 2009 Category: Microbiology Authors: Geweely NS Tags: Arch Microbiol Source Type: journals

Signal peptide of Arabinosidase enhances secretion of interferon-alpha2b protein by Bifidobacteria longum.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Bifidobacteria can potentially be used for gene therapy. Here, we reported that 65% of the total hIFN-alpha2b produced from Bifidobacteria longum transformed with pBAD-SPIFN plasmids encoding a fusion protein of the arabinosidase signal peptide and human IFN-alpha2b (hIFN-alpha2b), was secreted. For B. longum transformed with pBAD-IFN plasmids (hIFN-alpha2b without the signal peptide), only 15% of the total IFN-alpha2b was secreted and western blotting and N-terminal amino-acid sequence analysis revealed cleavage of the arabinosidase signal peptide from the secreted hIFN-alpha2b. Moreover, the active level of the secre...
Source: Archives of Microbiology - August 3, 2009 Category: Microbiology Authors: Deng Q, Zeng W, Yu Z Tags: Arch Microbiol Source Type: journals

The analysis of core and symbiotic genes of rhizobia nodulating Vicia from different continents reveals their common phylogenetic origin and suggests the distribution of Rhizobium leguminosarum strains together with Vicia seeds.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this work, we analysed the core and symbiotic genes of rhizobial strains isolated from Vicia sativa in three soils from the Northwest of Spain, and compared them with other Vicia endosymbionts isolated in other geographical locations. The analysis of rrs, recA and atpD genes and 16S-23S rRNA intergenic spacer showed that the Spanish strains nodulating V. sativa are phylogenetically close to those isolated from V. sativa and V. faba in different European, American and Asian countries forming a group related to Rhizobium leguminosarum. The analysis of the nodC gene of strains nodulating V. sativa and V. faba in differ...
Source: Archives of Microbiology - July 14, 2009 Category: Microbiology Authors: Alvarez-Martínez ER, Valverde A, Ramírez-Bahena MH, García-Fraile P, Tejedor C, Mateos PF, Santillana N, Zúñiga D, Peix A, Velázquez E Tags: Arch Microbiol Source Type: journals

Characterization of Bacillus subtilis YfkE (ChaA): a calcium-specific Ca(2+)/H (+) antiporter of the CaCA family.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
YfkE, a protein from Bacillus subtilis, exhibits homology to the Ca(2+):Cation Antiporter (CaCA) Family. In a fluorescence-based assay of everted membrane vesicles prepared from Na(+)(Ca(2+))/H(+) antiporter-defective mutant Escherichia coli KNabc, YfkE exhibited robust Ca(2+)/H(+) antiport activity, with a K (m) for Ca(2+) estimated at 12.5 muM at pH 8.5 and 113 muM at pH 7.5. Neither Na(+) nor K(+) served as a substrate. Mg(2+) also did not serve as a substrate, but inhibited the Ca(2+)/H(+) antiporter activity. The Ca(2+) transport capability of YfkE was also observed directly by transport assays in everted membrane...
Source: Archives of Microbiology - June 18, 2009 Category: Microbiology Authors: Fujisawa M, Wada Y, Tsuchiya T, Ito M Tags: Arch Microbiol Source Type: journals

Amiodarone inhibits multiple drug resistance in yeast Saccharomyces cerevisiae.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Amiodarone is a widely used antiarrhythmic drug. There is also evidence that amiodarone decreases multidrug resistance in human cell lines. In this paper, we have shown that amiodarone has similar effect on yeast, Saccharomyces cerevisiae, decreasing multiple drug resistance. Amiodarone stimulates the accumulation of ethidium bromide by inhibiting its efflux from the cells. The effect of amiodarone is much stronger on wild-type cells compared to the mutant with inactivated ABC-transporters. Interestingly, the action of amiodarone is additive with the one of chloroquine, a known inhibitor of ABC-transporters. We specula...
Source: Archives of Microbiology - June 17, 2009 Category: Microbiology Authors: Knorre DA, Krivonosova TN, Markova OV, Severin FF Tags: Arch Microbiol Source Type: journals

Inhibition of uropathogens by lactic acid bacteria isolated from dairy foods and cow's intestine in western Nigeria.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, an unusual high rate of co-trimoxazole, quinolones and macrolides resistance among uropathogens from south west Nigeria was discovered. Based on their sensitivity to Weissella spp., there is a potential for using these LAB as a natural approach for the protection against the uropathogens assayed. PMID: 19529917 [PubMed - as supplied by publisher] (Source: Archives of Microbiology)
Source: Archives of Microbiology - June 15, 2009 Category: Microbiology Authors: Ayeni FA, Adeniyi BA, Ogunbanwo ST, Tabasco R, Paarup T, Peláez C, Requena T Tags: Arch Microbiol Source Type: journals

A potential antimicrobial treatment against ESBL-producing Klebsiella pneumoniae using the tellurium compound AS101.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Due to the extensive spread of antibiotic-resistant Klebsiella pneumoniae, the non-toxic immunomodulator, ammonium trichloro (dioxoethylene-o, o') tellurate (AS101), was introduced for the first time in this study. Eleven strains of K. pneumoniae were tested: five were extended spectrum beta lactamase (ESBL)-producing strains and six were non-ESBL-producing strains. The MIC and MBC of ten strains were 9 mug/ml AS101 and 18 mug/ml for one strain. AS101 treatment inhibited bacterial growth in a dose-dependent manner on protein-rich media. No inhibition by AS101 was observed on poorer media. In combination with beta-merca...
Source: Archives of Microbiology - June 15, 2009 Category: Microbiology Authors: Daniel-Hoffmann M, Albeck M, Sredni B, Nitzan Y Tags: Arch Microbiol Source Type: journals

Comparative study of Bifidobacterium animalis, Escherichia coli, Lactobacillus casei and Saccharomyces boulardii probiotic properties.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In conclusion, for a probiotic use, S. boulardii presented better characteristics in terms of immunomodulation, and B. animalis and L. casei for antagonistic substance production. The knowledge of the different probiotic properties could be used to choice the better microorganism depending on the therapeutic or prophylactic application. PMID: 19526225 [PubMed - as supplied by publisher] (Source: Archives of Microbiology)
Source: Archives of Microbiology - June 12, 2009 Category: Microbiology Authors: Martins FS, Silva AA, Vieira AT, Barbosa FH, Arantes RM, Teixeira MM, Nicoli JR Tags: Arch Microbiol Source Type: journals

Resistance of the cell wall to degradation is a critical parameter for isolation of high quality RNA from natural isolates of Bacillus subtilis.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Natural isolates of Bacillus subtilis are known for their ability to produce a large panel of bioactive compounds. Unfortunately, their recalcitrance to conventional molecular techniques limits their transcript studies. In this work, difficulties to isolate RNA attributed to the cell wall were overcome, finally authorising powerful RT-PCR's. PMID: 19521677 [PubMed - as supplied by publisher] (Source: Archives of Microbiology)
Source: Archives of Microbiology - June 12, 2009 Category: Microbiology Authors: Guez JS, Coutte F, Drucbert AS, Chihib NE, Danzé PM, Jacques P Tags: Arch Microbiol Source Type: journals

Gene-specific disruption in the filamentous fungus Cercospora nicotianae using a split-marker approach.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
To determine if DNA configuration, gene locus, and flanking sequences will affect homologous recombination in the phytopathogenic fungus Cercospora nicotianae, we evaluated and compared disruption efficiency targeting four cercosporin toxin biosynthetic genes encoding a polyketide synthase (CTB1), a monooxygenase/O-methyltransferase (CTB3), a NADPH-dependent oxidoreductase (CTB5), and a FAD/FMN-dependent oxidoreductase (CTB7). Transformation of C. nicotianae using a circular plasmid resulted in low disruption frequency. The use of endonucleases or a selectable marker DNA fragment flanked by homologous sequence either a...
Source: Archives of Microbiology - June 9, 2009 Category: Microbiology Authors: You BJ, Lee MH, Chung KR Tags: Arch Microbiol Source Type: journals

Functional analysis of a putative regulatory gene, tadR, involved in aniline degradation in Delftia tsuruhatensis AD9.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Delftia tsuruhatensis AD9 contains the chromosomally encoded tad gene cluster responsible for the complete metabolism of aniline to TCA cycle intermediates. The tadQTA1A2B genes encode a multi-component aniline dioxygenase, the first enzyme of aniline metabolism, and the tadR gene directly downstream of this gene cluster encodes a putative LysR-type regulatory protein. Inactivation of tadR resulted in the inability to degrade aniline and to grow on aniline. Transcriptional assays using a tadQ promoter (P( tadQ ))-lacZ fusion revealed that the transcriptional activation of tadQ from P( tadQ ) was dependent on the presen...
Source: Archives of Microbiology - June 7, 2009 Category: Microbiology Authors: Geng L, Chen M, Liang Q, Liu W, Zhang W, Ping S, Lu W, Yan Y, Wang W, Takeo M, Lin M Tags: Arch Microbiol Source Type: journals

Genetic and biochemical analyses of chlorobenzene degradation gene clusters in Pandoraea sp. strain MCB032.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, two gene clusters encoding chlorobenzene metabolic functions have been cloned. Within the cbs gene cluster, CbsA and CbsB are similar to the chlorobenzene dioxygenase and the cis-chlorobenzene dihydrodiol dehydrogenase in Ralstonia sp. JS705 and shown to transform chlorobenzene to 3-chlorocatechol. The clc gene cluster shows strong similarity to the clc genes of Ralstonia sp. JS705 and encodes chlorocatechol 1,2-dioxygenase (ClcA) and other enzymes, which catalyze the conversion of chlorocatechol to 3-oxoadipate. The Michaelis constants (K (m)) values of ClcA for catechol, 3-methylcatechol and 3-chlorocatech...
Source: Archives of Microbiology - June 1, 2009 Category: Microbiology Authors: Jiang XW, Liu H, Xu Y, Wang SJ, Leak DJ, Zhou NY Tags: Arch Microbiol Source Type: journals

Enzymatic, outer membrane proteins and plasmid alterations of starved Vibrio parahaemolyticus and Vibrio alginolyticus cells in seawater.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The marine bacteria Vibrio parahaemolyticus and V. alginolyticus were incubated in seawater for 8 months to evaluate their adaptative responses to starvation. The starved cells showed an altered biochemical and enzymatic profiles, respectively, on Api 20E and Api ZYM systems and an evolution to the filterable minicells state capable to pass membrane pore size 0.45 microm. Outer membrane proteins patterns of stressed bacteria were also altered. Indeed, these modifications were manifested by the appearance and/or disappearance of bands as well as in the level of expression of certain proteins. Plasmids profiles analysis ...
Source: Archives of Microbiology - June 1, 2009 Category: Microbiology Authors: Abdallah FB, Kallel H, Bakhrouf A Tags: Arch Microbiol Source Type: journals

Characterization of chsA, a new gene controlling the chemotactic response in Azospirillum brasilense Sp7.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We report, here, the characterization of a mutant strain of Azospirillum brasilense Sp7 impaired in surface motility and chemotactic response. Presence of flagella in the mutant strain was confirmed by western blot analysis, using antisera raised against the polar and lateral flagellins, and by electron microscopy. Genetic complementation and nucleotide sequencing led to the identification of a new gene, named chsA. The deduced translation product, ChsA protein, contained a PAS sensory domain and an EAL domain. As ChsA displayed characteristic signaling protein architecture, it is thought that this protein is a component o...
Source: Archives of Microbiology - June 1, 2009 Category: Microbiology Authors: Carreño-López R, Sánchez A, Camargo N, Elmerich C, Baca BE Tags: Arch Microbiol Source Type: journals

Rapid oxidation of ring methyl groups is the primary mechanism of biotransformation of gemfibrozil by the fungus Cunninghamella elegans.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The hypolipidemic agent gemfibrozil (GEM), which has been studied for its metabolism in humans and animals, was investigated to elucidate its primary metabolism by Cunninghamella elegans. The fungus produced ten metabolites (FM1-FM9 and FM6') from the biotransformation of GEM. Based on LC/MS/MS and NMR analyses, a major metabolite, FM7, was identified as 2'-hydroxymethyl GEM. FM6 was considered to be 5'-hydroxymethyl GEM, after comparison of results LC/MS, LC/MS/MS, and UV absorption spectra to FM7. The combined concentration of FM6 and FM7 was found to increase up to 0.83 mM by day 2, and then decreased gradually with...
Source: Archives of Microbiology - June 1, 2009 Category: Microbiology Authors: Kang SI, Kang SY, Kanaly RA, Lee E, Lim Y, Hur HG Tags: Arch Microbiol Source Type: journals

Conjugative plasmid pLD-TEX-KL promotes growth of host bacterium Legionella dumoffii at low temperatures.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Legionella (Fluoribacter) dumoffii is a resident of various aquatic environments and occasionally causes pneumonia in humans. We found that L. dumoffii strain TEX-KL carries a 66-kb circular plasmid. As predicted by the presence of tra genes similar to those of other transferable plasmids, we showed that pLD-TEX-KL was actually capable of transferring itself to a plasmid-cured derivative of the original strain. Unexpectedly, this plasmid-free derivative turned out to be partially defective in terms of growth at temperatures 30 degrees C or lower. Subsequent works revealed that the growth defect was attributable to the ...
Source: Archives of Microbiology - June 1, 2009 Category: Microbiology Authors: Qin T, Iida K, Hirakawa H, Shiota S, Nakayama H, Yoshida S Tags: Arch Microbiol Source Type: journals

Characterization of multiple promoters and transcript stability in the sacB-sacC gene cluster in Zymomonas mobilis.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In Zymomonas mobilis, the extracellular levansucrase (SacB) and extracellular sucrase (SacC) are involved in sucrose hydrolysis. Genes coding for these two enzymes (sacB and sacC) are arranged in a cluster in the genome and separated by a short intervening sequence. The level of sacC transcript was 12-fold higher than that of sacB transcript. On the other hand, transcript stability analysis in sucrose grown cultures revealed that the half-life of the sacB transcripts (153 s) was more than twofold higher than that of sacC transcript (66 s). The decay curves of sacB and sacC transcripts analyzed by the semi-quantitative ...
Source: Archives of Microbiology - June 1, 2009 Category: Microbiology Authors: Senthilkumar V, Rajendhran J, Busby SJ, Gunasekaran P Tags: Arch Microbiol Source Type: journals

A genetic analysis of in vivo selenate reduction by Salmonella enterica serovar Typhimurium LT2 and Escherichia coli K12.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The twin-arginine transport (Tat) system is dedicated to the translocation of folded proteins across the bacterial cytoplasmic membrane. Proteins are targeted to the Tat system by signal peptides containing a twin-arginine motif. In Salmonella enterica serovar Typhimurium and Escherichia coli many Tat substrates are known or predicted to bind a molybdenum cofactor in the cytoplasm prior to export. In the case of N- and S-oxide reductases, co-ordination of molybdenum cofactor insertion with protein export involves a 'Tat proofreading' process where chaperones of the TorD family bind the signal peptides, thus preventing ...
Source: Archives of Microbiology - June 1, 2009 Category: Microbiology Authors: Guymer D, Maillard J, Sargent F Tags: Arch Microbiol Source Type: journals

The hybrid histidine kinase Slr1759 of the cyanobacterium Synechocystis sp. PCC 6803 contains FAD at its PAS domain.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The cyanobacterium Synechocystis sp. PCC 6803 harbours 47 histidine kinases (Hiks). Among these are hybrid histidine kinases with one or two response regulator domains as well as numerous Hiks with several sensory domains. One example is the hybrid histidine kinase Slr1759 (Hik14) that has two PAS domains arranged in tandem linked to a predicted GAF domain. Here, we show that a Slr1759 derivative recombinantly expressed in Escherichia coli has a flavin cofactor. Using truncated Slr1759 variants, it is shown that the flavin associates with the first PAS domain. The cofactor reconstitutes the activity of D: -amino acid o...
Source: Archives of Microbiology - June 1, 2009 Category: Microbiology Authors: Michel KP, Schröder AK, Zimmermann M, Brandt S, Pistorius EK, Frankenberg-Dinkel N, Staiger D Tags: Arch Microbiol Source Type: journals

Involvement of digalactosyldiacylglycerol in cellular thermotolerance in Synechocystis sp. PCC 6803.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The effects of digalactosyldiacylglycerol (DGDG) deficiency on photosynthesis at high temperatures were examined using a dgdA mutant of Synechocystis sp. PCC 6803 incapable of DGDG biosynthesis. The dgdA mutant cells showed significant growth retardation when the temperature was increased from 30 to 38 degrees C, although wild-type cells grew normally. The degree of growth retardation was enhanced by increasing light intensity. In addition, dgdA mutant cells showed increased sensitivity to the photoinhibition of photosynthesis when illuminated at 38 degrees C. Analysis of photosynthesis in intact cells suggested that t...
Source: Archives of Microbiology - May 26, 2009 Category: Microbiology Authors: Mizusawa N, Sakata S, Sakurai I, Sato N, Wada H Tags: Arch Microbiol Source Type: journals

Deletion analysis of the C-terminal region of a molecular chaperone DnaK from Bacillus licheniformis.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, the full-length BlDnaK and its T86W and three C-terminally truncated mutants were constructed to evaluate the role of up to C-terminal 255 amino acids of the protein. The steady-state ATPase activity for BlDnaK, T86W, T86W/DeltaC120, T86W/DeltaC249, and T86W/DeltaC255 was 65.68, 53.21, 116.04, 321.38, and 90.59 nmol Pi/min per mg, respectively. In vivo, BldnaK, T86W and T86W/DeltaC120 genes allowed an E. coli dnaK756-ts mutant to grow at 44 degrees C. Except for T86W/DeltaC255, simultaneous addition of B. licheniformis DnaJ and GrpE, and NR-peptide synergistically stimulated the ATPase activity of BlDnaK, T8...
Source: Archives of Microbiology - May 20, 2009 Category: Microbiology Authors: Liang WC, Lin MG, Chi MC, Hu HY, Lo HF, Chang HP, Lin LL Tags: Arch Microbiol Source Type: journals

Differential composition of culture supernatants from wild-type Brucella abortus and its isogenic virB mutants.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, extracellular proteins from B. abortus 2308 (wild type, WT) and its isogenic virB10 polar mutant were compared. Culture supernatants harvested in the early stationary phase were concentrated and subjected to 2D electrophoresis. Spots present in the WT strain but absent in the virB10 mutant (differential spots) were considered extracellular proteins released in a virB-related manner, and were identified by MALDI-TOF analysis and matching with Brucella genomes. Among the 11 differential proteins identified, DnaK chaperone (Hsp70), choloylglycine hydrolase (CGH) and a peptidyl-prolyl cis-trans isomerase (PPIase...
Source: Archives of Microbiology - May 13, 2009 Category: Microbiology Authors: Delpino MV, Comerci DJ, Wagner MA, Eschenbrenner M, Mujer CV, Ugalde RA, Fossati CA, Baldi PC, Delvecchio VG Tags: Arch Microbiol Source Type: journals

Transcriptional regulation and structural modeling of the FutC subunit of an ABC-type iron transporter in Synechocystis sp. strain PCC 6803.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The futC gene encodes a subunit of an ATP-binding cassette (ABC)-type iron transporter in Synechocystis sp. strain PCC 6803. In the present study, we have focused on the environmental regulation of futC transcription in the model organism Synechocystis sp. strain PCC 6803 and, moreover, studied the transcriptional regulation of the other transporter subunits, futA1, futA2 and futB. The steady-state amounts of the futA1, futA2, futB and futC transcripts were regulated under several conditions studied including darkness, temperature, alternative nitrogen source, salt and osmotic stresses and iron deficiency. Transcriptio...
Source: Archives of Microbiology - May 9, 2009 Category: Microbiology Authors: Brandt AM, Raksajit W, Mulo P, Incharoensakdi A, Salminen TA, Mäenpää P Tags: Arch Microbiol Source Type: journals