Abstract:
:The quorum sensing (QS) system controls bacterial group behaviors in response to cell density. In vibrios, LuxR and AphA are two master QS regulators (MQSRs) controlling gene expression in response to high or low cell density. Other regulators involved in the regulation of these two MQSRs and QS pathways remain to be determined. Here, we performed bacterial one-hybrid (B1H)-assay-based screens of transcriptional factors (TFs) to identify TFs that can directly regulate the expression of luxR and aphA from a library of 285 TFs encoded by the fish pathogen Vibrio alginolyticus A total of 7 TFs were identified to bind to the promoters of both luxR and aphA Among these TFs, the novel LysR-type transcriptional regulator (LTTR) VqsA could activate LuxR and repress AphA transcription. Meanwhile, LuxR and AphA exerted feedback inhibition and activation of vqsA expression, respectively, indicating that VqsA coordinates QS and is also regulated by QS. In addition, VqsA inhibited its own expression by directly binding to its own promoter region. The VqsA-binding sites in the promoter regions of luxR and aphA as well as the binding sites of LuxR, AphA, and VqsA in the vqsA gene were uncovered by electrophoretic mobility shift assays (EMSAs) and DNase I footprinting analysis. Finally, VqsA was verified to play essential roles in QS-regulated phenotypes, i.e., type VI secretion system 2 (T6SS2)-dependent interbacterial competition, biofilm formation, exotoxin production, and in vivo virulence of V. alginolyticus Collectively, our data showed that VqsA is an important QS regulator in V. alginolyticusIMPORTANCE Investigation of the mechanism of regulation of quorum sensing (QS) systems will facilitate an understanding of bacterial pathogenesis and the identification of effective QS interference (QSI) targets. Here, we systematically screened transcriptional factors (TFs) that modulate the expression of the master QS regulators (MQSRs) LuxR and AphA, and a novel LysR-type transcriptional regulator, VqsA, was identified. Our data illuminated the mechanisms mediating the interaction among LuxR, AphA, and VqsA as well as the effects of these regulators on the expression and output of QS. The impaired expression of virulence genes as a result of vqsA disruption demonstrated that VqsA is an important player in QS regulation and pathogenesis and may be the third MQSR involved in sensing environmental signals by vibrios to coordinate QS responses. This study will facilitate the development of strategies to interfere with QS and effectively control this pathogen that plagues the aquaculture industry.
journal_name
Appl Environ Microbioljournal_title
Applied and environmental microbiologyauthors
Gao X,Wang X,Mao Q,Xu R,Zhou X,Ma Y,Liu Q,Zhang Y,Wang Qdoi
10.1128/AEM.00444-18subject
Has Abstractpub_date
2018-05-31 00:00:00issue
12eissn
0099-2240issn
1098-5336pii
AEM.00444-18journal_volume
84pub_type
杂志文章abstract::A new virulent phage belonging to the Siphoviridae family and able to infect Lactococcus garvieae strains was isolated from compost soil. Phage GE1 has a prolate capsid (56 by 38 nm) and a long noncontractile tail (123 nm). It had a burst size of 139 and a latent period of 31 min. Its host range was limited to only tw...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.02603-15
更新日期:2015-12-01 00:00:00
abstract::The moderately halophilic bacterium Halobacillus halophilus carries a homologue of LuxS, a protein involved in the activated methyl cycle and the production of autoinducer-2, which mediates quorum sensing between certain species. luxS of H. halophilus is part of an operon that encodes an S-adenosylmethionine-dependent...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.01625-06
更新日期:2007-01-01 00:00:00
abstract::The rates of mineralization of phenol, benzoate, benzylamine, p-nitrophenol, and di(2-ethylhexyl) phthalate added to lake water at concentrations ranging from a few picograms to nanograms per milliliter were directly proportional to chemical concentration. The rates were still linear at levels of <1 pg of phenol or p-...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.43.5.1133-1138.1982
更新日期:1982-05-01 00:00:00
abstract::[This corrects the article on p. 931 in vol. 46.]. ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.47.5.1193-1193.1984
更新日期:1984-05-01 00:00:00
abstract::The ability of certain oral biofilm bacteria to moderate pH through arginine metabolism by the arginine deiminase system (ADS) is a deterrent to the development of dental caries. Here, we characterize a novel Streptococcus strain, designated strain A12, isolated from supragingival dental plaque of a caries-free indivi...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.03887-15
更新日期:2016-01-29 00:00:00
abstract::Adsorbed bovine serum albumin was resistant to exchange with beta-lactoglobulin, and when albumin was adsorbed from a mixture, its surface concentration increased with time. The passivating character of adsorbed albumin and its resistance to desorption were consistent with the level of Listeria monocytogenes adhesion ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.61.5.2013-2015.1995
更新日期:1995-05-01 00:00:00
abstract::Penicillium decumbens is able to epoxidize cis-propenylphosphonic acid (cPA) to produce the antibiotic fosfomycin [FOM; also referred to as phosphonomycin and (-)-cis-1,2-epoxypropylphosphonic acid], a bioconversion of considerable commercial significance. We sought to improve the efficiency of the process by overexpr...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.65.3.1036-1044.1999
更新日期:1999-03-01 00:00:00
abstract::A monoclonal antibody designated 302 beta that is specific for the beta subunit of the oxygenase component (ISPTOL) of toluene dioxygenase from Pseudomonas putida F1 was used to prepare an immunoaffinity column. ISPTOL in cell extracts of Escherichia coli JM109(pDTG611) bound to the column, and an enzyme-linked immuno...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.62.6.2133-2137.1996
更新日期:1996-06-01 00:00:00
abstract::Escherichia albertii is a recently described species that has been associated with gastroenteritis in humans and with healthy and ill birds. Most recently, it has been identified as the causative agent in a food-borne outbreak in Japan. The distribution and clinical importance of E. albertii are not well studied becau...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.03681-14
更新日期:2015-03-01 00:00:00
abstract::Toluene dioxygenase from Pseudomonas putida F1 has been implicated as an enzyme capable of degrading trichloroethylene. This has now been confirmed with Escherichia coli JM109(pDTG601) that contains the structural genes (todC1C2BA) of toluene dioxygenase under the control of the tac promoter. The extent of trichloroet...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.55.12.3162-3166.1989
更新日期:1989-12-01 00:00:00
abstract::Laccases couple the oxidation of phenolic compounds to the reduction of molecular oxygen and thus span a wide variety of applications. While laccases of eukaryotes and bacteria are well characterized, these enzymes have not been described in archaea. Here, we report the purification and characterization of a laccase (...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.01757-09
更新日期:2010-02-01 00:00:00
abstract::We describe here a new enzyme-coupled assay for the quantitation of d-xylose using readily available enzymes that allows kinetic evaluation of hemicellulolytic enzymes using natural xylooligosaccharide substrates. Hydrogen peroxide is generated as an intermediary analyte, which allows flexibility in the choice of the ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.71.9.5318-5323.2005
更新日期:2005-09-01 00:00:00
abstract::We developed a chemiluminometric assay of beta-galactosidase in coliform bacteria, using a phenylgalactose-substituted 1,2-dioxetane derivative as a substrate. Permeabilization of cells is required to ensure the efficient cellular uptake of this compound. By this method, one coliform seeded in 100 ml of sterile water ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.61.12.4505-4509.1995
更新日期:1995-12-01 00:00:00
abstract::The effects of preexposure of soybean (Glycine max L. Merrill) roots to Rhizobium japonicum strains and subsequent establishment of other strains in the nodules were investigated by using combinations of effective strains (USDA 110 and USDA 138) and effective-ineffective strains (USDA 110 and SM-5). Strain USDA 110 wa...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.46.4.870-873.1983
更新日期:1983-10-01 00:00:00
abstract::The distribution of Clostridium botulinum serotypes A, B, E, and F in Finnish trout farms was examined. A total of 333 samples were tested with a neurotoxin-specific PCR assay. C. botulinum type E was found in 68% of the farm sediment samples, in 15% of the fish intestinal samples, and in 5% of the fish skin samples. ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.64.11.4161-4167.1998
更新日期:1998-11-01 00:00:00
abstract::Nontoxigenic strains of Clostridium botulinum types C and D are converted to toxigenic strains by infection with specific Tox+ bacteriophages. The nucleic acids were extracted from five converting phages, c-st, c-468, c-203, c-d6f, and d-1873, and one nonconverting phage, c-n71, and treated with nucleases. The nucleic...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.54.1.69-73.1988
更新日期:1988-01-01 00:00:00
abstract::A nonmotile, gram-positive, spherical organism was isolated from the intestinal tracts of rabbits. Both hydrogen and methanol were required for growth. No methane was produced from hydrogen-carbon dioxide, formate, acetate, methylamines, ethanol, or isopropanol. The optimum pH was 6.8, and the optimum temperature was ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.54.3.768-771.1988
更新日期:1988-03-01 00:00:00
abstract::The effective flux between phospholipids and neutral lipids is critical for a high level of biosynthesis and accumulation of very-long-chain polyunsaturated fatty acids (VLCPUFAs), such as arachidonic acid (ARA; 20:4n-6), eicosapentaenoic acid (EPA; 20:5n-3), and docosahexaenoic acid (DHA; 22:6n-3). Here we describe a...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.03250-12
更新日期:2013-03-01 00:00:00
abstract::Cultures of 10 different bacteria were used to serve as food sources for axenically grown Acanthamoeba castellanii, Acanthamoeba polyphaga, and Hartmannella vermiformis. The nonpigmented enterobacteriaceae Escherichia coli K-12 and Klebsiella aerogenes appeared to be excellent feed to all three amoebae. Hardly any gro...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.59.7.2317-2319.1993
更新日期:1993-07-01 00:00:00
abstract::Thermoanaerobacter sp. strain X514 has great potential in biotechnology due to its capacity to ferment a range of C(5) and C(6) sugars to ethanol and other metabolites under thermophilic conditions. This study investigated the central metabolism of strain X514 via (13)C-labeled tracer experiments using either glucose ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.00715-09
更新日期:2009-08-01 00:00:00
abstract::We present a phylogenetic analysis of nine strains of symbiotic nitrogen-fixing bacteria isolated from nodules of tagasaste (Chamaecytisus proliferus) and other endemic woody legumes of the Canary Islands, Spain. These and several reference strains were characterized genotypically at different levels of taxonomic reso...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.64.6.2096-2104.1998
更新日期:1998-06-01 00:00:00
abstract::Since Vibrio cholerae O139 first appeared in 1992, both O1 El Tor and O139 have been recognized as the epidemic serogroups, although their geographic distribution, endemicity, and reservoir are not fully understood. To address this lack of information, a study of the epidemiology and ecology of V. cholerae O1 and O139...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.00066-06
更新日期:2006-06-01 00:00:00
abstract::[This corrects the article on p. 522 in vol. 52.]. ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:
更新日期:1987-01-01 00:00:00
abstract::By targeted deletion of the polyglutamate operon (pga) in Bacillus licheniformis F11, a derivative form, F11.1 (Δpga), was obtained that, along with lacking polyglutamate (PGA) formation, displayed enhanced proteolytic activities. The phenotypic properties were maintained in a strain in which the chiBA operon was addi...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.01404-10
更新日期:2010-12-01 00:00:00
abstract::Two anaerobic bacteria were isolated from polyethylene glycol (PEG)-degrading, methanogenic, enrichment cultures obtained from a municipal sludge digester. One isolate, identified as Desulfovibrio desulfuricans (strain DG2), metabolized oligomers ranging from ethylene glycol (EG) to tetraethylene glycol. The other iso...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.52.4.852-856.1986
更新日期:1986-10-01 00:00:00
abstract::The metabolism of aflatoxin B1 to aflatoxins M1 and Q1 by rat liver microsomes from animals pretreated with polychlorinated or polybrominated biphenyl congeners depended on the structure of the halogenated biphenyl inducers. Microsomes from rats treated with phenobarbital (PB) or halogenated biphenyls that exhibit PB-...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.49.4.882-886.1985
更新日期:1985-04-01 00:00:00
abstract::Sterol demethylation inhibitor (DMI) fungicides are widely used to control fungi pathogenic to humans and plants. Resistance to DMIs is mediated either through alterations in the structure of the target enzyme CYP51 (encoding 14alpha-demethylase), through increased expression of the CYP51 gene, or through increased ex...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.72.4.2581-2585.2006
更新日期:2006-04-01 00:00:00
abstract::Glycogen debranching enzyme (GDE) has 4-alpha-glucanotransferase and amylo-1,6-glucosidase activities in the single polypeptide chain. We analyzed the detailed action profile of GDE from Saccharomyces cerevisiae on amylose and tested whether GDE catalyzes cyclization of amylose. GDE treatment resulted in a rapid reduc...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/aem.68.9.4233-4239.2002
更新日期:2002-09-01 00:00:00
abstract::Lyophilizatin of 13 cyanobacterial cultures belonging to seven genera was attempted in a variety of suspending substances. All organisms survived lyophilization when suspended in lamb serum. Some of the organisms could be successfully lyophilized in horse serum, beef serum, fetal bovine serum, or human ascites fluid. ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.32.6.777-780.1976
更新日期:1976-12-01 00:00:00
abstract::Wood-degrading fungi use a sequence of oxidative and hydrolytic mechanisms to loosen lignocellulose and then release and metabolize embedded sugars. These temporal sequences have recently been mapped at high resolution using directional growth on wood wafers, revealing previously obscured dynamics as fungi progressive...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.00159-18
更新日期:2018-08-01 00:00:00