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the expanding role of type ii secretion in bacterial pathogenesis and beyond.type ii secretion (t2s) is one means by which gram-negative pathogens secrete proteins into the extracellular milieu and/or host organisms. based upon recent genome sequencing, it is clear that t2s is largely restricted to the proteobacteria, occurring in many, but not all genera in the α-, β-, γ-, and δ- classes. prominent human and/or animal pathogens that express a t2s system(s) include acinetobacter baumannii, burkholderia pseudomallei, chlamydia trachomatis, escherichia coli, klebsiella pne ...201728264910
synthetic investigation, physicochemical characterization and antibacterial evaluation of ternary bi(iii) systems with hydroxycarboxylic acid and aromatic chelator substrates.due to its physical and chemical properties, bismuth (bi(iii)) is widely used in the treatment of several gastrointestinal and skin diseases, and infections caused by bacteria. herein, its known antimicrobial potential was taken into consideration in the synthesis of two new hybrid ternary materials of bi(iii) with the physiological α-hydroxycarboxylic glycolic acid and 1,10-phenanthroline (phen), [bi2(c2h2o3)2(c2h3o3)(no3)]n(.) nh2o (1) and [bi(c12h8n2)(no3)4](c10h8n4) (2), aiming at improving ...201728231455
microbial interactions in the phyllosphere increase plant performance under herbivore biotic stress.the phyllosphere supports a tremendous diversity of microbes and other organisms. however, little is known about the colonization and survival of pathogenic and beneficial bacteria alone or together in the phyllosphere across the whole plant life-cycle under herbivory, which hinders our ability to understand the role of phyllosphere bacteria on plant performance. we addressed these questions in experiments using four genetically and biogeographically diverse accessions of arabidopsis thaliana, t ...201728163703
active multi-enzyme assemblies for long-chain olefinic hydrocarbon biosynthesis.bacteria from different phyla produce long-chain olefinic hydrocarbons derived from an olea-catalyzed claisen condensation of two fatty acyl-coa substrates, followed by reduction and oxygen elimination reactions catalyzed by the proteins oleb, olec, and oled. in this report, olea, oleb, olec, and oled were individually purified as soluble proteins, and all were found to be essential for reconstituting hydrocarbon biosynthesis. recombinant co-expression of tagged oleabcd proteins from xanthomonas ...201728223313
crystal structure and biochemical investigations reveal novel mode of substrate selectivity and illuminate substrate inhibition and allostericity in a subfamily of xaa-pro dipeptidases.xaa-pro dipeptidase (xpd) catalyzes hydrolysis of iminopeptide bond in dipeptides containing trans-proline as a second residue. xpds are found in all living organisms and are believed to play an essential role in proline metabolism. here, we report crystal structures and extensive enzymatic studies of xpd from xanthomonas campestris (xpdxc), the first such comprehensive study of a bacterial xpd. we also report enzymatic activities of its ortholog from mycobacterium tuberculosis (xpdmt). these en ...201727816563
physicochemical and antimicrobial properties of copaiba oil: implications on product quality control.the copaiba oil is a common natural product used in cosmetic industry and as a nutraceutical product. however, lack of quality control and scarce knowledge about its antimicrobial activity is a point of concern. the proposal of this study was to investigate the physicochemical properties and the antimicrobial activity of five commercial brands of copaiba oil.201728068029
growth of bacterial phytopathogens in animal manures.animal manures are routinely applied to agricultural lands to improve crop yield, but the possibility to spread bacterial phytopathogens through field fertilization has not been considered yet. we monitored 49 cattle, horse, swine, sheep or chicken manure samples collected in 14 polish voivodeships for the most important plant pathogenic bacteria - ralstonia solanacearum (rsol), xanthomonas campestris pv. campestris (xcc), pectobacterium carotovorum subsp. carotovorum (pcc), pectobacterium atros ...201728319994
erratum: proteomics analysis of the regulatory role of rpf/dsf cell-to-cell signaling system in the virulence of xanthomonas campestris. 201728301313
online measurement of viscosity for biological systems in stirred tank bioreactors.one of the most critical parameters in chemical and biochemical processes is the viscosity of the medium. its impact on mixing, as well as on mass and energy transfer is substantial. an increase of viscosity with reaction time can be caused by the formation of biopolymers like xanthan or by filamentous growth of microorganisms. in either case the properties of fermentation broth are changing and frequently non-newtonian behavior are observed, resulting in major challenges for the measurement and ...201727861738
high production of xanthan gum by a glycerol-tolerant strain xanthomonas campestris wxlb-006.the superior properties of xanthan gum make it an industrial aginomoto used in many industries, especially in oil recovery. in the present work, xanthan production from glycerol by a mutant strain xanthomonas campestris wxlb-006 reached as high as 17.8 g/l in flask culture. with the adoption of ph control, varied aeration and agitation, and varied glycerol feeding strategy, xanthan production reached 33.9 g/l in a 7-l fermenter and fermentation time decreased to 60 hr. instead of difficultly and ...201728267413
identification of a novel type iii secretion-associated outer membrane-bound protein from xanthomonas campestris pv. campestris.many bacterial pathogens employ the type iii secretion system (t3ss) to translocate effector proteins into eukaryotic cells to overcome host defenses. to date, most of our knowledge about the t3ss molecular architecture comes from the studies on animal pathogens. in plant pathogens, nine hrc proteins are believed to be structural components of the t3ss, of which hrcc and hrcj form the outer and inner rings of the t3ss, respectively. here, we demonstrated that a novel outer membrane-bound protein ...201728198457
immunity at cauliflower hydathodes controls infection by xanthomonas campestris pv. campestris.hydathodes are water pores found on leaves of a wide range of vascular plants and are the sites of guttation. we report here on the detailed anatomy of cauliflower and arabidopsis hydathodes. hydathode surface presents pores resembling stomata giving access to large cavities. beneath, the epithem is composed of a lacunar and highly vascularized parenchyma offering a direct connection between leaf surface and xylem vessels. arabidopsis hydathode pores were responsive to aba and light similar to s ...201728184011
the pseudomonas putida t6ss is a plant warden against phytopathogens.bacterial type vi secretion systems (t6sss) are molecular weapons designed to deliver toxic effectors into prey cells. these nanomachines have an important role in inter-bacterial competition and provide advantages to t6ss active strains in polymicrobial environments. here we analyze the genome of the biocontrol agent pseudomonas putida kt2440 and identify three t6ss gene clusters (k1-, k2- and k3-t6ss). besides, 10 t6ss effector-immunity pairs were found, including putative nucleases and pore-f ...201728045455
inducible expression of bs2 r gene from capsicum chacoense in sweet orange (citrus sinensis l. osbeck) confers enhanced resistance to citrus canker disease.transgenic expression of the pepper bs2 gene confers resistance to xanthomonas campestris pv. vesicatoria (xcv) pathogenic strains which contain the avrbs2 avirulence gene in susceptible pepper and tomato varieties. the avrbs2 gene is highly conserved among members of the xanthomonas genus, and the avrbs2 of xcv shares 96% homology with the avrbs2 of xanthomonas citri subsp. citri (xcc), the causal agent of citrus canker disease. a previous study showed that the transient expression of pepper bs ...201728155188
correction for ryan et al., cell-cell signal-dependent dynamic interactions between hd-gyp and ggdef domain proteins mediate virulence in xanthomonas campestris. 201728137834
characterization of xanthan gum produced from glycerol by a mutant strain xanthomonas campestris cctcc m2015714.xanthan gum was produced by a mutant strain x. campestris cctcc m2015714 with glycerol as the sole carbon source. the monosaccharide composition and molar ratio of xanthan gum produced from glycerol are glucose: mannose: glucuronic acid=2.0:1.65:1.0. meanwhile, chemical structure of xanthan gum produced from glycerol is similar to that of the commercial xanthan through ft-ir and nmr. remarkably, the molecular weight of xanthan gum produced using our method (3.0±0.14×10(6)da) is about half that o ...201727987957
functional characterization and transcriptional analysis of icd2 gene encoding an isocitrate dehydrogenase of xanthomonas campestris pv. campestris.isocitrate dehydrogenase (idh) catalyzes the oxidative decarboxylation of isocitrate to alpha-ketoglutarate. in the genome of xanthomonas campestris pv. campestris, the phytopathogen that causes black rot in cruciferous plants, two putative idh genes, icd1 and icd2, have been annotated. their physiological roles in x. campestris pv. campestris are unclear. in this study, the icd2 gene from x. campestris pv. campestris was characterized in detail. we demonstrated genetically that icd2 gene encode ...201728378142
fatty acid dsf binds and allosterically activates histidine kinase rpfc of phytopathogenic bacterium xanthomonas campestris pv. campestris to regulate quorum-sensing and virulence.as well as their importance to nutrition, fatty acids (fa) represent a unique group of quorum sensing chemicals that modulate the behavior of bacterial population in virulence. however, the way in which full-length, membrane-bound receptors biochemically detect fa remains unclear. here, we provide genetic, enzymological and biophysical evidences to demonstrate that in the phytopathogenic bacterium xanthomonas campestris pv. campestris, a medium-chain fa diffusible signal factor (dsf) binds direc ...201728369120
molecular functions of xanthomonas type iii effector avrbst and its plant interactors in cell death and defense signaling.xanthomonas effector avrbst interacts with plant defense proteins and triggers cell death and defense response. this review highlights our current understanding of the molecular functions of avrbst and its host interactor proteins. the avrbst protein is a member of a growing family of effector proteins in both plant and animal pathogens. xanthomonas type iii effector avrbst, a member of the yopj/avrrxv family, suppresses plant defense responses in susceptible hosts, but triggers cell death signa ...201727928637
complete nucleotide sequence of a new filamentous phage, xf109, which integrates its genome into the chromosomal dna of xanthomonas oryzae.unlike ff-like coliphages, certain filamentous inoviridae phages integrate their genomes into the host chromosome and enter a prophage state in their infectious cycle. this lysogenic life cycle was first reported for xanthomonas citri cf phage. however, except for the x. citri phages cf and xacf1, complete genome sequence information about lysogenic xanthomonas phages is not available to date. a proviral sequence of xf109 phage was identified in the genome of xanthomonas oryzae, the rice bacteri ...201727743252
the predicted lytic transglycosylase hpah from xanthomonas campestris pv. vesicatoria associates with the type iii secretion system and promotes effector protein translocation.the pathogenicity of the gram-negative plant-pathogenic bacterium xanthomonas campestris pv. vesicatoria depends on a type iii secretion (t3s) system, which spans both bacterial membranes and translocates effector proteins into plant cells. the assembly of the t3s system presumably involves the predicted lytic transglycosylase (lt) hpah, which is encoded adjacent to the t3s gene cluster. bacterial lts degrade peptidoglycan and often promote the formation of membrane-spanning macromolecular prote ...201727895129
an essential regulatory system originating from polygenic transcriptional rewiring of phop-phoq of xanthomonas campestris.how essential, regulatory genes originate and evolve is intriguing because mutations of these genes not only lead to lethality in organisms, but also have pleiotropic effects since they control the expression of multiple downstream genes. therefore, the evolution of essential, regulatory genes is not only determined by genetic variations of their own sequences, but also by the biological function of downstream genes and molecular mechanisms of regulation. to understand the origin of essential, r ...201728550013
internalisation of escherichia coli o157:h7 gfp+ in rocket and swiss chard baby leaves as affected by abiotic and biotic damage.internalisation of human pathogens in edible parts of vegetables eaten raw is a major concern, since once internalised they are protected from sanitising treatments. in this study, we examined invasion of gfp-labelled e. coli o157:h7 into intact and biotically (infection with xanthomonas campestris/pseudomonas syringae) and abiotically (grating with silicon carbide) damaged leaves of wild rocket (diplotaxis tenuifolia) and swiss chard (beta vulgaris subsp. cicla) using laser scanning confocal mi ...201728397273
screening of leaves extracts from calamus aromaticus for their antimicrobial activity by disc diffusion assay.the current research investigates the anti-microbial activities of different solvent extracted samples from the leaves of calamus aromaticus against gram positive, gram negative bacteria and fungi using 500, 1000 and 2000 μg disc(-1) concentrations. escherichia coli, citorbacter freundii and candida albicans showed resistivity to crude methanolic extract and the same microbes were more susceptible to water extracted fractions. maximum activity was measured by hexane extracted fractions against p ...201728653924
dissecting virulence function from recognition: cell death suppression in nicotiana benthamiana by xopq/hopq1-family effectors relies on eds1-dependent immunity.many gram-negative plant pathogenic bacteria express effector proteins of the xopq/hopq1 family which are translocated into plant cells via the type iii secretion system during infection. in nicotiana benthamiana, recognition of xopq/hopq1 proteins induces an effector-triggered immunity (eti) reaction which is not associated with strong cell death but renders plants immune against pseudomonas syringae and xanthomonas campestris pv. vesicatoria strains. additionally, xopq suppresses cell death in ...201728423458
combined biotic stresses trigger similar transcriptomic responses but contrasting resistance against a chewing herbivore in brassica nigra.in nature, plants are frequently exposed to simultaneous biotic stresses that activate distinct and often antagonistic defense signaling pathways. how plants integrate this information and whether they prioritize one stress over the other is not well understood.201728716054
time-resolved energetics of photoprocesses in prokaryotic phytochrome-related photoreceptors.time-resolved photoacoustics (pa) is uniquely able to explore the energy landscape of photoactive proteins and concomitantly detects light-induced volumetric changes (δv) accompanying the formation and decay of transient species in a time window between ca. 20 ns and 5 μs. here, we report pa measurements on diverse photochromic bilin-binding photoreceptors of prokaryotic origin: (1) the chromophore-binding gaf3 domain of the red (r)/green (g) switching cyanobacteriochrome 1393 (slr1393g3) from s ...201728500712
cyclic di-gmp signalling in the virulence and environmental adaptation of xanthomonas campestris. 201728493340
differential accumulation of xanthomonas campestris pv. campestris proteins during the interaction with the host plant: contributions of an in vivo system.xanthomonas campestris pv. campestris (xcc) is the causal agent of black rot, a highly destructive disease that affects all brassicas. this work aimed to study the interaction xcc-brassica oleracea using an in vivo system in an attempt to identify proteins involved in pathogenicity. we used label-free shotgun 2d-nanouplc/ms(e) to analyze xcc proteins in three conditions: in the interaction with susceptible (rek) and resistant (reu) plants and in culture medium (control condition). a model of xcc ...201728471538
direct quantitative evaluation of disease symptoms on living plant leaves growing under natural light.leaf color is an important indicator when evaluating plant growth and responses to biotic/abiotic stress. acquisition of images by digital cameras allows analysis and long-term storage of the acquired images. however, under field conditions, where light intensity can fluctuate and other factors (shade, reflection, and background, etc.) vary, stable and reproducible measurement and quantification of leaf color are hard to achieve. digital scanners provide fixed conditions for obtaining image data ...201728744185
chloroplast redox status modulates genome-wide plant responses during the non-host interaction of tobacco with the hemibiotrophic bacterium xanthomonas campestris pv. vesicatoria.non-host resistance is the most ample and durable form of plant resistance against pathogen infection. it includes induction of defense-associated genes, massive metabolic reprogramming, and in many instances, a form of localized cell death (lcd) at the site of infection, purportedly designed to limit the spread of biotrophic and hemibiotrophic microorganisms. reactive oxygen species (ros) have been proposed to act as signals for lcd orchestration. they are produced in various cellular compartme ...201728725231
an efficient approach to explore and discriminate anomalous regions in bacterial genomes based on maximum entropy.recently, there has been an increase in the number of whole bacterial genomes sequenced, mainly due to the advancing of next-generation sequencing technologies. in face of this, there is a need to provide new analytical alternatives that can follow this advance. given our current knowledge about the genomic plasticity of bacteria and that those genomic regions can uncover important features about this microorganism, our goal was to develop a fast methodology based on maximum entropy (me) to guid ...201728570142
systems and synthetic biology perspective of the versatile plant-pathogenic and polysaccharide-producing bacterium xanthomonas campestris.bacteria of the genus xanthomonas are a major group of plant pathogens. they are hazardous to important crops and closely related to human pathogens. being collectively a major focus of molecular phytopathology, an increasing number of diverse and intricate mechanisms are emerging by which they communicate, interfere with host signalling and keep competition at bay. interestingly, they are also biotechnologically relevant polysaccharide producers. systems biotechnology techniques have revealed t ...201728795660
retraction for ryan et al., cell-cell signaling in xanthomonas campestris involves an hd-gyp domain protein that functions in cyclic di-gmp turnover. 201728784774
the type iii secretion chaperone hpab controls the translocation of effector and non-effector proteins from xanthomonas campestris pv. vesicatoria.pathogenicity of the gram-negative bacterium xanthomonas campestris pv. vesicatoria depends on a type iii secretion (t3s) system, which translocates effector proteins into plant cells. effector proteins contain n-terminal t3s and translocation signals and interact with the t3s chaperone hpab, which presumably escorts effectors to the secretion apparatus. the molecular mechanisms underlying the recognition of effectors by the t3s system are not yet understood. in the present study, we analysed t3 ...201728771395
introgression of black rot resistance from brassica carinata to cauliflower (brassica oleracea botrytis group) through embryo rescue.black rot caused by xanthomonas campestris pv. campestris (xcc) is a very important disease of cauliflower (brassica oleracea botrytis group) resulting into 10-50% yield losses every year. since there is a dearth of availability of resistance to black rot disease in b. oleracea (c genome), therefore exploration of a and b genomes was inevitable as they have been reported to be potential reservoirs of gene(s) for resistance to black rot. to utilize these sources, interspecific hybrid and backcros ...201728769959
genetically engineered bananas resistant to xanthomonas wilt disease and nematodes.banana is an important staple food crop feeding more than 100 million africans, but is subject to severe productivity constraints due to a range of pests and diseases. banana xanthomonas wilt caused by xanthomonas campestris pv. musacearum is capable of entirely destroying a plantation while nematodes can cause losses up to 50% and increase susceptibility to other pests and diseases. development of improved varieties of banana is fundamental in order to tackle these challenges. however, the ster ...201728713567
xanthan gum production using jackfruit-seed-powder-based medium: optimization and characterization.xanthan gum (xg) production by xanthomonas campestris ncim 2961 using jackfruit seed powder (jsp) as a novel substrate was reported. central composite design (ccd) of response surface method (rsm) was used to evaluate the linear and interaction effects of five medium variables (jsp, peptone, citric acid, k2hpo4 and kh2po4) for xg production. maximum xg production (51.62 g/l) was observed at the optimum level of jsp (4 g/l), peptone (0.93 g/l), citric acid (0.26 g/l), k2hpo4 (1.29 g/l) and kh2po4 ...201728711983
xanthomonas campestris pv. musacearum: a major constraint to banana, plantain and enset production in central and east africa over the past decade.taxonomy: bacteria; phylum proteobacteria; class gammaproteobacteria; order xanthomonadales; family xanthomonadaceae; genus xanthomonas; currently classified as x. campestris pv. musacearum (xcm). however, fatty acid methyl esters analysis, genetic and genomic evidence suggest that this pathogen is x. vasicola and resides in a separate pathovar. isolation and detection: xcm can be isolated on yeast peptone glucose agar (ypga), cellobiose cephalexin agar and yeast tryptone sucrose agar (ytsa) com ...201728677256
xc_0531 encodes a c-type cytochrome biogenesis protein and is required for pathogenesis in xanthomonas campestris pv. campestris.the phytopathogenic xanthomonas campestris pv.campestris is a gram-negative bacterium and the causal agent of black-rot disease of cruciferous crops. many gram-negative bacteria possess a family of proteins, called dsbs, which are involved in disulfide bond formation in certain periplasmic proteins. in our preliminary screening of the virulence to the plants we identified that gene xc_0531 which annotated gene dsbd of xanthomonas campestris pv. campestris (xcc) is related to the virulence to the ...201728655353
a robust protocol for the isolation of cellular proteins from xanthomonas campestris to analyze the effect of methionine on xanthan production in 2d-gel experiments.two-dimensional page (2d-page) is a key technique for the separation of complex protein samples to survey the protein inventory of prokaryotic microorganisms. although the preparation of proteins is a critical step in 2d gel experiments, its effect on the outcome of proteome data is often underestimated. in this work, we show that the choice of protein isolation method can have a profound impact on the quality of 2d gels of protein extracts from prokaryotes. based on xanthomonas campestris, a co ...201728605028
bacterial diseases of bananas and enset: current state of knowledge and integrated approaches toward sustainable management.bacterial diseases of bananas and enset have not received, until recently, an equal amount of attention compared to other major threats to banana production such as the fungal diseases black leaf streak (mycosphaerella fijiensis) and fusarium wilt (fusarium oxysporum f. sp. cubense). however, bacteria cause significant impacts on bananas globally and management practices are not always well known or adopted by farmers. bacterial diseases in bananas and enset can be divided into three groups: (1) ...201728785275
functional roles of the pepper leucine-rich repeat protein and its interactions with pathogenesis-related and hypersensitive-induced proteins in plant cell death and immunity.pepper leucine-rich repeat protein (calrr1) interacts with defense response proteins to regulate plant cell death and immunity. this review highlights the current understanding of the molecular functions of calrr1 and its interactor proteins. plant cell death and immune responses to microbial pathogens are controlled by complex and tightly regulated molecular signaling networks. xanthomonas campestris pv. vesicatoria (xcv)-inducible pepper (capsicum annuum) leucine-rich repeat protein 1 (calrr1) ...201728508261
refined annotation of the complete genome of the phytopathogenic and xanthan producing xanthomonas campestris pv. campestris strain b100 based on rna sequence data.bioinformatics tools and gene expression data were applied to identify new genes and to enhance the accuracy in genomic feature predictions for xanthomonas campestris pv. campestris (xcc) b100, a pathogen of cruciferous plants and model strain for the biosynthesis of xanthan, a polysaccharide with a multitude of commercial applications as a thickening agent. results from 5'-enriched end rna sequencing (rna-seq) and total transcriptome rna-seq experiments were used for this purpose. functional ge ...201728506932
1-methoxypyrrole-2-carboxamide-a new pyrrole compound isolated from streptomyces griseocarneus sww368.a new pyrrole compound, 1-methoxypyrrole-2-carboxamide, was obtained from a culture broth of streptomyces griseocarneus sww368, which was isolated from the rhizospheric soil under a para rubber tree (hevea brasiliensis). the chemical structure was elucidated by 1d nmr, 2d nmr, and ms, as a pyrrole ring with a n-methoxy group and a primary amide group. it exhibited antibacterial properties against kocuria rhizophila, staphylococcus aureus and xanthomonas campestris pv. oryzae; however, cytotoxici ...201728502957
analysis of the zar1 immune complex reveals determinants for immunity and molecular interactions.plants depend on innate immunity to prevent disease. plant pathogenic bacteria, like pseudomonas syringae and xanthomonas campestris, use the type iii secretion system as a molecular syringe to inject type iii secreted effector (t3se) proteins in plants. the primary function of most t3ses is to suppress immunity; however, the plant can evolve nucleotide-binding domain-leucine-rich repeat domain-containing proteins to recognize specific t3ses. the atzar1 nlr induces strong defense responses again ...201728652264
hpab-dependent secretion of type iii effectors in the plant pathogens ralstonia solanacearum and xanthomonas campestris pv. vesicatoria.plant pathogenic bacteria exerts their pathogenicity through the injection of large repertoires of type iii effectors (t3es) into plant cells, a mechanism controlled in part by type iii chaperones (t3cs). in ralstonia solanacearum, the causal agent of bacterial wilt, little is known about the control of type iii secretion at the post-translational level. here, we provide evidence that the hpab and hpad proteins do act as bona fide r. solanacearum class ib chaperones that associate with several t ...201728687734
retraction statement: dynamic complex formation between hd-gyp, ggdef and pilz domain proteins regulates motility in xanthomonas campestris.the following article from molecular microbiology (2012) 86(3), 557-567, 'dynamic complex formation between hd-gyp, ggdef and pilz domain proteins regulates motility in xanthomonas campestris' by robert p. ryan, yvonne mccarthy, patrick a. kiely, rosemary o'connor, chuck s. farah, judith p. armitage and j. maxwell dow published online in wiley online library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal editor-in-chief, john d helmann, and john wiley ...201728421674
xcc2366, a gene encoding a putative tetr family transcriptional regulator, is required for acriflavin resistance and virulence of xanthomonas campestris pv. campestris.xanthomonas campestris pv. campestris (xcc) is the phytopathogen that causes black rot disease in cruciferous plants. the xcc2366 gene product is annotated as a protein belonging to the tetr family of transcriptional regulators. in this study, we evaluated the function and expression of the xcc2366 gene. mutational analysis demonstrated that xcc2366 is involved in the resistance to acriflavin and is necessary for virulence in xcc. in addition, the xcc2366 transcription initiation site was mapped ...201728821943
loss of chloroplast localized protein phosphatase 2cs in arabidopsis thaliana leads to enhancement of the plant immunity and resistance to xanthomonas campestris pv. campestris infection.protein phosphatases (pps) counteract kinases in reversible phosphorylation events during numerous signal transduction pathways in eukaryotes. pp2cs, one of the four major classes of serine/threonine specific pps family is greatly expanded in plants. thus pp2c is thought to have a specific role in a signal transduction pathway. some rice pp2cs classified to subgroup k were responsive to the infection by the compatible xanthomonas oryzae pv. oryzae, the causal agent of bacterial blight. in a. tha ...201728815858
backbone chemical shift assignments for xanthomonas campestris peroxiredoxin q in the reduced and oxidized states: a dramatic change in backbone dynamics.peroxiredoxins (prx) are ubiquitous enzymes that reduce peroxides as part of antioxidant defenses and redox signaling. while prx catalytic activity and sensitivity to hyperoxidative inactivation depend on their dynamic properties, there are few examples where their dynamics has been characterized by nmr spectroscopy. here, we provide a foundation for studies of the solution properties of peroxiredoxin q from the plant pathogen xanthomonas campestris (xcprxq) by assigning the observable (1)h(n), ...201626438558
quantitative disease resistance to the bacterial pathogen xanthomonas campestris involves an arabidopsis immune receptor pair and a gene of unknown function.although quantitative disease resistance (qdr) is a durable and broad-spectrum form of resistance in plants, the identification of the genes underlying qdr is still in its infancy. rks1 (resistance related kinase1) has been reported recently to confer qdr in arabidopsis thaliana to most but not all races of the bacterial pathogen xanthomonas campestris pv. campestris (xcc). we therefore explored the genetic bases of qdr in a. thaliana to diverse races of x. campestris (xc). a nested genome-wide ...201626212639
enhancement of 5-keto-d-gluconate production by a recombinant gluconobacter oxydans using a dissolved oxygen control strategy.the rapid and incomplete oxidation of sugars, alcohols, and polyols by the gram-negative bacterium gluconobacter oxydans facilitates a wide variety of biological applications. for the conversion of glucose to 5-keto-d-gluconate (5-kga), a promising precursor of the industrial substance l-(+)-tartaric acid, g. oxydans dsm2343 was genetically engineered to strain zju2, in which the gox1231 and gox1081 genes were knocked out in a markerless fashion. then, a secondary alcohol dehydrogenase (gcd) fro ...201626896860
diversity of xanthomonas campestris isolates from symptomatic crucifers in new york state.to assess the diversity of xanthomonas campestris spp. infecting crucifers in new york, 154 isolates were collected over 10 years across the state. the goal was to determine if isolates of the pathogen were overwintering in new york and serving as primary inoculum in subsequent years, or if novel isolates were entering the state each year. pure cultures of isolates were characterized using multilocus sequence analysis (mlsa), a greenhouse pathogenicity assay, repetitive element-polymerase chain ...201626551450
production of xanthan gum by free and immobilized cells of xanthomonas campestris and xanthomonas pelargonii.production of xanthan gum using immobilized cells of xanthomonas campestris and xanthomonas pelargonii grown on glucose or hydrolyzed starch as carbon sources was investigated. calcium alginate (ca) and calcium alginate-polyvinyl alcohol-boric acid (ca-pva) beads were used for the immobilization of cells. xanthan titers of 8.2 and 9.2g/l were obtained for x. campestris cells immobilized in ca-pva beads using glucose and hydrolyzed starch, respectively, whereas those for x. pelargonii were 8 and ...201626526173
small scale production and characterization of xanthan gum synthesized by local isolates of xanthomonas campestris.xanthan gum is a commercially important microbial exopolysaccharide (eps) produced by xanthomonas campestris. x. campestris is a plant pathogen causing various plant diseases such as black rot of crucifers, bacterial leaf blight and citrus canker disease resulting in crop damage. in this study, we isolated efficient local bacterial isolates which are capable to produce xanthan gum utilizing different sources of carbon (maltose, sucrose and glucose). bacterial isolates from different plant leaves ...201626934783
identification of proteins in susceptible and resistant brassica oleracea responsive to xanthomonas campestris pv. campestris infection.cruciferous plants are important edible vegetables widely consumed around the world, including cabbage, cauli-flower and broccoli. the main disease that affects crucifer plants is black rot, caused by xanthomonas campestris pv. campestris (xcc). in order to better understand this specific plant-pathogen interaction, proteins responsive to xcc infection in resistant (união) and susceptible (kenzan) brassica oleracea cultivars were investigated by 2-de followed by mass spectrometry. a total of 47 ...201626825537
characterization of genes encoding proteins containing hd-related output domain in xanthomonas campestris pv. campestris.the gram-negative plant pathogen xanthomonas campestris pv. campestris (xcc) is the causative agent of black rot in crucifers. the production of xcc virulence factors is regulated by clp and rpff. hd-related output domain (hdod) is a protein domain of unknown biochemical function. the genome of xcc encodes three proteins (gsmr, hdpa, and hdpb) with an hdod. the gsmr has been reported to play a role in the general stress response and cell motility and its expression is positively regulated by clp ...201626821378
biochemical and molecular tools reveal two diverse xanthomonas groups in bananas.xanthomonas campestris pv. musacearum (xcm) causing the banana xanthomonas wilt (bxw) disease has been the main xanthomonad associated with bananas in east and central africa based on phenotypic and biochemical characteristics. however, biochemical methods cannot effectively distinguish between pathogenic and non-pathogenic xanthomonads. in this study, gram-negative and yellow-pigmented mucoid bacteria were isolated from bxw symptomatic and symptomless bananas collected from different parts of u ...201626805624
crystal structure of the yajq-family protein xc_3703 from xanthomonas campestris pv. campestris.as an important bacterial second messenger, bis-(3',5')-cyclic diguanylate (cyclic di-gmp or c-di-gmp) has been implicated in numerous biological activities, including biofilm formation, motility, survival and virulence. these processes are manipulated by the binding of c-di-gmp to its receptors. xc_3703 from the plant pathogen xanthomonas campestris pv. campestris, which belongs to the yajq family of proteins, has recently been identified as a potential c-di-gmp receptor. xc_3703, together with ...201627599864
peroxiredoxin catalysis at atomic resolution.peroxiredoxins (prxs) are ubiquitous cysteine-based peroxidases that guard cells against oxidative damage, are virulence factors for pathogens, and are involved in eukaryotic redox regulatory pathways. we have analyzed catalytically active crystals to capture atomic resolution snapshots of a prxq subfamily enzyme (from xanthomonas campestris) proceeding through thiolate, sulfenate, and sulfinate species. these analyses provide structures of unprecedented accuracy for seeding theoretical studies, ...201627594682
biosynthesis of xanthan gum by xanthomonas campestris lrelp-1 using kitchen waste as the sole substrate.herein, we report the production of xanthan gum by fermentation using kitchen waste as the sole substrate. the kitchen waste was firstly pretreated by a simple hydrolysis method, after which the obtained kitchen waste hydrolysate was diluted with an optimal ratio 1:2. in a 5-l fermentor, the maximum xanthan production, reducing sugar conversion and utilization rates reached 11.73g/l, 67.07% and 94.82%, respectively. the kinetics of batch fermentation was also investigated. ft-ir and xrd characte ...201627474614
xanthan pyruvilation is essential for the virulence of xanthomonas campestris pv. campestris.xanthan, the main exopolysaccharide (eps) synthesized by xanthomonas spp., contributes to bacterial stress tolerance and enhances attachment to plant surfaces by helping in biofilm formation. therefore, xanthan is essential for successful colonization and growth in planta and has also been proposed to be involved in the promotion of pathogenesis by calcium ion chelation and, hence, in the suppression of the plant defense responses in which this cation acts as a signal. the aim of this work was t ...201627464764
molecular mapping of high resistance to bacterial leaf spot in lettuce pi 358001-1.lettuce (lactuca sativa l.) is a diploid (2n = 18) with a genome size of 2,600 mbp, and belongs to the family compositae. bacterial leaf spot (bls), caused by xanthomonas campestris pv. vitians, is a major disease of lettuce worldwide. leaf lettuce pi 358001-1 has been characterized as an accession highly resistant to bls and has white seed. in order to understand inheritance of the high resistance in this germplasm line, an f3 population consisting of 163 families was developed from the cross p ...201627454703
biophysical and biochemical studies of a major endoglucanase secreted by xanthomonas campestris pv. campestris.endoglucanases are the main cellulolytic enzymes secreted by the bacterium xanthomonas campestris pv. campestris (xcc). the major endoglucanase exported by this bacterium into an external milieu is an enzyme xcccel5a, which belongs to gh5 family subfamily 1 and is encoded by the gene engxca. we purified xcccel5a using ammonium sulfate precipitation followed by size exclusion chromatography and identified it by zymogram analysis. circular dichroism and fluorescence spectroscopy studies showed tha ...201627444323
comparative analysis of different xanthan samples by atomic force microscopy.the polysaccharide xanthan which is produced by the γ-proteobacterium xanthomonas campestris is used as a food thickening agent and rheologic modifier in numerous food, cosmetics and technical applications. its great commercial importance stimulated biotechnological approaches to optimize the xanthan production. by targeted genetic modification the metabolism of xanthomonas can be modified in such a way that the xanthan production efficiency and/or the shear-thickening potency is optimized. usin ...201627919690
substrate trapping in crystals of the thiolase olea identifies three channels that enable long chain olefin biosynthesis.phylogenetically diverse microbes that produce long chain, olefinic hydrocarbons have received much attention as possible sources of renewable energy biocatalysts. one enzyme that is critical for this process is olea, a thiolase superfamily enzyme that condenses two fatty acyl-coa substrates to produce a β-ketoacid product and initiates the biosynthesis of long chain olefins in bacteria. thiolases typically utilize a ping-pong mechanism centered on an active site cysteine residue. reaction with ...201627815501
xanthomonas campestris attenuates virulence by sensing light through a bacteriophytochrome photoreceptor.phytochromes constitute a major photoreceptor family found in plants, algae, fungi, and prokaryotes, including pathogens. here, we report that xanthomonas campestris pv. campestris (xcc), the causal agent of black rot disease which affects cruciferous crops worldwide, codes for a functional bacteriophytochrome (xccbphp). xccbphp possesses an n-terminal pas2-gaf-phy photosensory domain triad and a c-terminal pas9 domain as its output module. our results show that illumination of xcc, prior to pla ...201627621284
multilocus sequence typing of strains of bacterial spot of lettuce collected in the united states.studies on genetic diversity and recombination in bacterial pathogens are providing a better understanding of the mechanisms shaping bacterial diversity, which can affect disease control. xanthomonas campestris pv. vitians, causal agent of bacterial leaf spot of lettuce, is a threat to the worldwide lettuce industry. we examined the genetic variation within a sample of 83 strains from california, florida, and ohio using multilocus sequence typing of six housekeeping genes, totaling 2.7 kb. addit ...201627359264
xanthoferrin, the α-hydroxycarboxylate-type siderophore of xanthomonas campestris pv. campestris, is required for optimum virulence and growth inside cabbage.xanthomonas campestris pv. campestris causes black rot, a serious disease of crucifers. xanthomonads encode a siderophore biosynthesis and uptake gene cluster xss (xanthomonas siderophore synthesis) involved in the production of a vibrioferrin-type siderophore. however, little is known about the role of the siderophore in the iron uptake and virulence of x. campestris pv. campestris. in this study, we show that x. campestris pv. campestris produces an α-hydroxycarboxylate-type siderophore (named ...201627348422
two isocitrate dehydrogenases from a plant pathogen xanthomonas campestris pv. campestris 8004. bioinformatic analysis, enzymatic characterization, and implication in virulence.isocitrate dehydrogenase (idh) is a key enzyme in the tricarboxylate (tca) cycle, which may play an important role in the virulence of pathogenic bacteria. here, two structurally different idhs from a plant pathogen xanthomonas campestris pv. campestris 8004 (xccidh1 and xccidh2) were characterized in detail. the recombinant xccidh1 forms homodimer in solution, while the recombinant xccidh2 is a typical monomer. phylogenetic analysis showed that xccidh1 belongs to the type i idh subfamily and xc ...201627282849
structure of the full-length bacteriophytochrome from the plant pathogen xanthomonas campestris provides clues to its long-range signaling mechanism.phytochromes constitute a major superfamily of light-sensing proteins that are reversibly photoconverted between a red-absorbing (pr) and a far-red-absorbing (pfr) state. bacteriophytochromes (bphps) are found among photosynthetic and non-photosynthetic bacteria, including pathogens. to date, several bphps have been biophysically characterized. however, it is still not fully understood how structural changes are propagated from the photosensory module to the output module during the signal trans ...201627107635
binding of the substrate udp-glucuronic acid induces conformational changes in the xanthan gum glucuronosyltransferase.gumk is a membrane-associated glucuronosyltransferase of xanthomonas campestris that is involved in xanthan gum biosynthesis. gumk belongs to the inverting gt-b superfamily and catalyzes the transfer of a glucuronic acid (glca) residue from uridine diphosphate (udp)-glca (udp-glca) to a lipid-pp-trisaccharide embedded in the membrane of the bacteria. the structure of gumk was previously described in its apo- and udp-bound forms, with no significant conformational differences being observed. here ...201627099353
the structure of the lipooligosaccharide from xanthomonas oryzae pv. oryzae: the causal agent of the bacterial leaf blight in rice.the structure of the lipooligosaccharide (los) from the rice pathogen xanthomonas oryzae pv. oryzae has been elucidated. the characterization of the core oligosaccharide structure was obtained by the employment of two chemical degradation protocols and by analysis of the products via nmr spectroscopy. the structure of the lipid a portion was achieved by maldi mass spectrometry analysis on purified lipid a. the los from xanthomonas oryzae pv. oryzae revealed to possess the same core structure of ...201627085742
low-pressure plasma application for the inactivation of the seed-borne pathogen xanthomonas campestris.the aim of this study was to investigate the effect of low-pressure plasma treatment on seed disinfection and the possible mechanisms underlying this effect. seed-borne disease refers to plant diseases that are transmitted by seeds; seed disinfection is an important technique for prevention of such diseases. in this study, the effectiveness of low-pressure plasma treatment in the inactivation of the seed-borne plant pathogenic bacterium, xanthomonas campestris, inoculated on cruciferous seeds, w ...201627009508
genome wide transcription start sites analysis of xanthomonas campestris pv. campestris b100 with insights into the gum gene cluster directing the biosynthesis of the exopolysaccharide xanthan.xanthomonas campestris pv. campestris (xcc) is the major producer of the exopolysaccharide xanthan, the commercially most important natural polysaccharide of microbial origin. the current work provides deeper insights into the yet uncharacterized transcriptomic features of the xanthan producing strain xcc-b100. towards this goal, rna sequencing of a library based on the selective enrichment of the 5' ends of native transcripts was performed. this approach resulted in the genome wide identificati ...201626975844
applying dna affinity chromatography to specifically screen for sucrose-related dna-binding transcriptional regulators of xanthomonas campestris.at a molecular level, the regulation of many important cellular processes is still obscure in xanthomonads, a bacterial group of outstanding relevance as world-wide plant pathogens and important for biotechnology as producers of the polysaccharide xanthan. transcriptome analysis indicated a sucrose-dependent regulation of 18 genes in xanthomonas campestris pv. campestris (xcc) b100. the expression of 12 of these genes was clearly increased in the presence of sucrose. only part of these genes was ...201627060555
activation of glycerol metabolism in xanthomonas campestris by adaptive evolution to produce a high-transparency and low-viscosity xanthan gum from glycerol.many studies have focused on using crude glycerol from biodiesel to obtain valuable products, but few of these studies have focused on obtaining polysaccharides. a mutant strain of xanthomonas campestris cctcc m2015714 that could use glycerol to produce high-transparency and low-viscosity xanthan gum was obtained by adaptive evolution, and the yield of xanthan gum reached 11.0g/l. we found that transcriptional levels of genes related to glycerol metabolism (glpf, glpk, glpd, and fbp) in the muta ...201627030959
co-expression of endoglucanase and β-glucosidase in corynebacterium glutamicum dm1729 towards direct lysine fermentation from cellulose.the aim of the present study is the development of a consolidated bioprocess for the production of lysine with recombinant corynebacterium glutamicum dm1729 strains expressing endoglucanase and β-glucosidase genes. here, the endoglucanase genes from xanthomonas campestris xcc3521 and xcc2387 and betaglucosidase gene from saccharophagus degradans sde1394 were cloned in c. glutamicum dm1729 and expressed either extracellularly or on cell surface. the highest β-glucosidase activity of 9±0.5u/od600 ...201627020126
functional characterization and transcriptome analysis reveal multiple roles for prc in the pathogenicity of the black rot pathogen xanthomonas campestris pv. campestris.gram-negative phytopathogenic xanthomonas campestris pv. campestris (xcc) is the causal agent of black rot in crucifers. the ability of xcc to incite this disease in plants depends on a number of factors, including exopolysaccharides, extracellular enzymes and biofilm production. in this study, transposon mutagenesis led to identification of the prc gene, encoding a tail-specific protease, which plays a role in xcc pathogenesis. mutation of prc resulted in decreased virulence, extracellular prot ...201626804425
the rpfb-dependent quorum sensing signal turnover system is required for adaptation and virulence in rice bacterial blight pathogen xanthomonas oryzae pv. oryzae.xanthomonas oryzae pv. oryzae, the bacterial blight pathogen of rice, produces diffusible signal factor (dsf) family quorum sensing signals to regulate virulence. the biosynthesis and perception of dsf family signals require components of the rpf (regulation of pathogenicity factors) cluster. in this study, we report that rpfb plays an essential role in dsf family signal turnover in x. oryzae pv. oryzae pxo99a. the production of dsf family signals was boosted by deletion of the rpfb gene and was ...201626667598
two-component signaling system vgrrs directly senses extracytoplasmic and intracellular iron to control bacterial adaptation under iron depleted stress.both iron starvation and excess are detrimental to cellular life, especially for animal and plant pathogens since they always live in iron-limited environments produced by host immune responses. however, how organisms sense and respond to iron is incompletely understood. herein, we reveal that in the phytopathogenic bacterium xanthomonas campestris pv. campestris, vgrs (also named cols) is a membrane-bound receptor histidine kinase that senses extracytoplasmic iron limitation in the periplasm, w ...201628036380
the type iii effector avrxccb in xanthomonas campestris pv. campestris targets putative methyltransferases and suppresses innate immunity in arabidopsis.xanthomonas campestris pv. campestris (xcc) causes black rot, one of the most important diseases of brassica crops worldwide. the type iii effector inventory plays important roles in the virulence and pathogenicity of the pathogen. however, little is known about the virulence function(s) of the putative type iii effector avrxccb in xcc. here, we investigated the immune suppression ability of avrxccb and the possible underlying mechanisms. avrxccb was demonstrated to be secreted in a type iii sec ...201627241588
toxicity of twenty-two plant essential oils against pathogenic bacteria of vegetables and mushrooms.asbtract toxicity of twenty-two essential oils to three bacterial pathogens in different horticultural systems: xanthomonas campestris pv. phaseoli (causing blight of bean), clavibacter michiganensis subsp. michiganensis (bacterial wilt and canker of tomato), and pseudomonas tolaasii (causal agent of bacterial brown blotch on cultivated mushrooms) was tested. control of bacterial diseases is very difficult due to antibiotic resistance and ineffectiveness of chemical products, to that essential o ...201627494458
new insights on molecular regulation of biofilm formation in plant-associated bacteria.biofilms are complex bacterial assemblages with a defined three-dimensional architecture, attached to solid surfaces, and surrounded by a self-produced matrix generally composed of exopolysaccharides, proteins, lipids and extracellular dna. biofilm formation has evolved as an adaptive strategy of bacteria to cope with harsh environmental conditions as well as to establish antagonistic or beneficial interactions with their host. plant-associated bacteria attach and form biofilms on different tiss ...201626377849
synthesis of silver nanoparticles by endosymbiont pseudomonas fluorescens ca 417 and their bactericidal activity.the present study emphasizes on biogenic synthesis of silver nanoparticles and their bactericidal activity against human and phytopathogens. nanoparticle synthesis was performed using endosymbiont pseudomonas fluorescens ca 417 inhabiting coffea arabica l. synthesized nanoparticles were characterized using hyphenated spectroscopic techniques such as uv-vis spectroscopy which revealed maximum absorption 425nm. fourier transform infrared spectroscopy (ftir) analysis revealed the possible functiona ...201627866607
(1)h, (13)c, and (15)n resonance assignments and secondary structure information for methylobacterium extorquens pqqd and the complex of pqqd with pqqa.the ribosomally synthesized and post-translationally modified peptide (ripp), pyrroloquinoline quinone (pqq), is a dehydrogenase cofactor synthesized by, but not exclusively used by, certain prokaryotes. ripps represent a rapidly expanding and diverse class of natural products-many of which have therapeutic potential-and the biosynthetic pathways for these are gaining attention. five gene products from the pqq operon (pqqa, pqqb, pqqc, pqqd, and pqqe) are essential for pqq biosynthesis. the subs ...201627638737
effects of different heat treatments on lysozyme quantity and antimicrobial activity of jenny milk.thermal treatments are used to improve milk microbial safety, shelf life, and biological activity of some of its components. however, thermal treatments can reduce the nutritional quality of milk, affecting the molecular structure of milk proteins, such as lysozyme, which is a very important milk component due to its antimicrobial effect against gram-positive bacteria. jenny milk is characterized by high lysozyme content. for this reason, in the last few years, it has been used as an antimicrobi ...201627157571
diffusible signal factor family signals provide a fitness advantage to xanthomonas campestris pv. campestris in interspecies competition.diffusible signal factor (dsf) represents a new class of widely conserved quorum sensing signals, which regulates various biological functions through intra- or interspecies signaling. the previous studies identified that there is an antagonistic interaction between xanthomonas and bacillus species bacteria in natural ecosystem, but the detailed molecular mechanism of interspecies competition is not clear. this study showed that xanthomonas campestris pv. campestris (xcc) interfered with morphol ...201626913592
the use of stable and unstable green fluorescent proteins for studies in two bacterial models: agrobacterium tumefaciens and xanthomonas campestris pv. campestris.fluorescent proteins have been used to track plant pathogens to understand their host interactions. to be useful, the transgenic pathogens must present similar behaviour than the wild-type isolates. herein, a gfp marker was used to transform two plant pathogenic bacteria, agrobacterium and xanthomonas, to localize and track the bacteria during infection. the transgenic bacteria were evaluated to determine whether they showed the same fitness than the wild-type strains or whether the expression o ...201627995281
designing potent antimicrobial peptides by disulphide linked dimerization and n-terminal lipidation to increase antimicrobial activity and membrane perturbation: structural insights into lipopolysaccharide binding.the remarkable rise in multi-drug resistant gram-negative bacterial pathogens is a major concern to the well being of humans as well as susceptible plants. in recent years, diseases associated with inflammation and septicemia have already become a global health issue. therefore, there is a rising demand for the development of novel "super" antibiotics. in this context, antimicrobial peptides offer an attractive, alternate therapeutic solution to conventional antibiotics.201626407061
an in vitro attempt for controlling severe phytopathogens and human pathogens using essential oils from mediterranean plants of genus schinus.growing concerns about food safety and environmental protection enhanced the need for new and safe plant disease control strategies. the chemical composition of the three essential oils (eos) extracted from leaves and fruits of schinus terebinthifolius and leaves of schinus molle, growing in tunisia, was studied by gc and gc-ms. in all, 12 compounds were identified. the oils were mainly composed of terpene compounds. α-pinene, α-phellandrene, and d-limonene were the major constituents. the aim o ...201626836214
7-hydroxycalamenene effects on secreted aspartic proteases activity and biofilm formation of candida spp.the 7-hydroxycalamenenene-rich essential oil (eo) obtained from the leaves of croton cajucara (red morphotype) have been described as active against bacteria, protozoa, and fungi species. in this work, we aimed to evaluate the effectiveness of 7-hydroxycalamenenene against candida albicans and nonalbicans species.201627019560
characterization of the gntr family regulator hpar1 of the crucifer black rot pathogen xanthomonas campestris pathovar campestris.the gntr family transcription regulator hpar1 identified from xanthomonas campestris pv. campestris has been previously shown to positively regulate the genes responsible for hypersensitive reaction and pathogenicity and to autorepress its own expression. here, we demonstrated that hpar1 is a global regulator that positively regulates diverse biological processes, including xanthan polysaccharide production, extracellular enzyme activity, cell motility and tolerance to various stresses. to inves ...201626818230
from discovery to production: biotechnology of marine fungi for the production of new antibiotics.filamentous fungi are well known for their capability of producing antibiotic natural products. recent studies have demonstrated the potential of antimicrobials with vast chemodiversity from marine fungi. development of such natural products into lead compounds requires sustainable supply. marine biotechnology can significantly contribute to the production of new antibiotics at various levels of the process chain including discovery, production, downstream processing, and lead development. howev ...201627455283
cobalt(ii) complexes of sparfloxacin: characterization, structure, antimicrobial activity and interaction with dna and albumins.the cobalt(ii) complexes with the quinolone sparfloxacin (hsf) in the absence or presence of the nitrogen-donor heterocyclic ligands 2,2'-bipyridine (bipy), 1,10-phenanthroline (phen) or 2,2'-bipyridylamine (bipyam) were prepared and characterized physicochemically and spectroscopically. the crystal structures of complexes [co(sf)2(bipy)]∙3meoh∙2h2o and [co(sf)2(phen)]∙4meoh were determined by x-ray crystallography. the antimicrobial activity of the complexes was tested against four different mi ...201627501348
iminimycin a, the new iminium metabolite produced by streptomyces griseus os-3601.a new natural product, designated iminimycin a, was isolated from the cultured broth of a streptomycin-producing microbial strain, streptomyces griseus os-3601, via a physicochemical screening method using hp-20, silica gel and ods column chromatographies and subsequent preparative hplc. iminimycin a is an indolizidine alkaloid, containing of an unusual iminium group and a cyclopropane ring with a triene side chain. the absolute configuration of iminimycin a was elucidated by nmr studies and ele ...201626758492
antimicrobial activity and chemical composition of three essential oils extracted from mediterranean aromatic plants.there is a growing interest in essential oils (eos) as possible alternatives for traditional chemical pesticides. this study was carried out to characterize the chemical composition of the three eos extracted from verbena officinalis, majorana hortensis, and salvia officinalis using gas chromatography (gc) and gc-mass spectrometry (gc-ms) and to evaluate in vitro their efficacy against some phyto or human pathogens. the antifungal activity was investigated against colletotrichum acutatum and bot ...201627792456
crystal structure of truncated flgd from the human pathogen helicobacter pylori.flagellin component d (flgd) participates in the assembly of flagella, helical tubular structures that provide motility in non-filamentous bacteria. flgd guides and controls the polymerization of flge that builds the hook, a short curved and hollow cylinder that connects the flagellar basal body spanning the cell envelope to the protruding filament. crystal structures of truncated forms of helicobacter pylori flgd from two different strains in two space groups, i422 and p2, are reported here, at ...201626868107
natural products from marine fungi--still an underrepresented resource.marine fungi represent a huge potential for new natural products and an increased number of new metabolites have become known over the past years, while much of the hidden potential still needs to be uncovered. representative examples of biodiversity studies of marine fungi and of natural products from a diverse selection of marine fungi from the author's lab are highlighting important aspects of this research. if one considers the huge phylogenetic diversity of marine fungi and their almost ubi ...201626784209
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