Exemplar Abstract for Pseudomonas chlororaphis aurantiaca (Nakhimovskaya 1948) Peix et al. 2007 and Pseudomonas aurantiaca Nakhimovskaya 1948 (Approved Lists 1980).

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Sarah Wigley ◽  
George M Garrity
2007 ◽  
Vol 57 (6) ◽  
pp. 1286-1290 ◽  
Author(s):  
Alvaro Peix ◽  
Angel Valverde ◽  
Raúl Rivas ◽  
José M. Igual ◽  
Martha-Helena Ramírez-Bahena ◽  
...  

Pseudomonas chlororaphis, Pseudomonas aureofaciens and Pseudomonas aurantiaca were considered as separate species until 1989, when P. aureofaciens was proposed as a later heterotypic synonym of P. chlororaphis with P. aurantiaca remaining as a separate species. Nevertheless, analysis of the almost complete 16S rRNA gene sequences revealed that the type strain of P. aurantiaca, NCIMB 10068T, shows gene sequence similarities close to 99.5 % with respect to P. chlororaphis DSM 50083T and P. aureofaciens DSM 6698T. DNA–DNA hybridization experiments among strains of P. aurantiaca, P. chlororaphis and P. aureofaciens showed values higher than 70 %, confirming that they represent members of the same species. The results of fatty acid analysis and phenotypic traits showed that these strains are closely related, although there are some differences among the strains belonging to P. aurantiaca, those from P. chlororaphis and those from P. aureofaciens. All these results confirm the previous reclassification of P. aureofaciens into P. chlororaphis and support the reclassification of P. aurantiaca as a synonym of P. chlororaphis. Phenotypic and molecular data permit the description of three novel subspecies within this last species, for which the following names are proposed: P. chlororaphis subsp. chlororaphis subsp. nov. [with the type strain DSM 50083T (=ATCC 9446T=NCIMB 9392T)], P. chlororaphis subsp. aureofaciens subsp. nov., comb. nov. [with the type strain DSM 6698T (=ATCC 13985T=NCIMB 9030T)] and P. chlororaphis subsp. aurantiaca subsp. nov., comb. nov. [with the type strain NCIMB 10068T (=ATCC 33663T=CIP 106718T)].


2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity

Plant Disease ◽  
2002 ◽  
Vol 86 (12) ◽  
pp. 1388-1395 ◽  
Author(s):  
R. J. McGovern ◽  
R. McSorley ◽  
M. L. Bell

Two experiments were conducted during autumn 1997 and 1998 in west-central Florida to evaluate the effectiveness of soil solarization alone and in combination with the biological control agents Streptomyces lydicus (Actinovate) and Pseudomonas chlororaphis (syn. P. aureofasciens, AtEze) and the reduced-risk fungicide fludioxonil (Medallion) in managing soilborne pathogens of impatiens (Impatiens × wallerana, ‘Accent Burgundy’). Naturally infested soil was solarized for 47 or 48 days during September and October using two layers of 25-μm clear, low-density polyethylene mulch, separated by an air space of up to 7.5 cm. Solarization decreased the final incidence and progress of Rhizoctonia crown rot and blight, incidence of Pythium spp. in roots, and root discoloration, and increased shoot biomass in both experiments. The technique also consistently reduced root-knot severity and population densities of Meloidogyne incognita, Dolichodorus heterocephalus, Paratrichodorus minor, and Criconemella spp. The incidence of Rhizoctonia crown rot and blight was reduced by fludioxonil, but not by the biological control agents.


2008 ◽  
Vol 190 (12) ◽  
pp. 4210-4217 ◽  
Author(s):  
Toshihide Sakashita ◽  
Yoshiteru Hashimoto ◽  
Ken-Ichi Oinuma ◽  
Michihiko Kobayashi

ABSTRACT An enormous amount of nitrile hydratase (NHase) is inducibly produced by Pseudomonas chlororaphis B23 after addition of methacrylamide as the sole nitrogen source to a medium. The expression pattern of the P. chlororaphis B23 NHase gene cluster in response to addition of methacrylamide to the medium was investigated. Recently, we reported that the NHase gene cluster comprises seven genes (oxdA, amiA, nhpA, nhpB, nhpC, nhpS, and acsA). Sequence analysis of the 1.5-kb region upstream of the oxdA gene revealed the presence of a 936-bp open reading frame (designated nhpR), which should encode a protein with a molecular mass of 35,098. The deduced amino acid sequence of the nhpR product showed similarity to the sequences of transcriptional regulators belonging to the XylS/AraC family. Although the transcription of the eight genes (nhpR, oxdA, amiA, nhpABC, nhpS, and acsA) in the NHase gene cluster was induced significantly in the P. chlororaphis B23 wild-type strain after addition of methacrylamide to the medium, transcription of these genes in the nhpR disruptant was not induced, demonstrating that nhpR codes for a positive transcriptional regulator in the NHase gene cluster. A reverse transcription-PCR experiment revealed that five genes (oxdA, amiA, nhpA, nhpB, and nhpC) are cotranscribed, as are two other genes (nhpS and acsA). The transcription start sites for nhpR, oxdA, nhpA, and nhpS were mapped by primer extension analysis, and putative −12 and −24 σ54-type promoter binding sites were identified. NhpR was found to be the first transcriptional regulator of NHase belonging to the XylS/AraC family.


2019 ◽  
Vol 10 ◽  
Author(s):  
Claudia E. Calderón ◽  
Sandra Tienda ◽  
Zaira Heredia-Ponce ◽  
Eva Arrebola ◽  
Gerardo Cárcamo-Oyarce ◽  
...  

2006 ◽  
Vol 52 (12) ◽  
pp. 1177-1188 ◽  
Author(s):  
N Poritsanos ◽  
C Selin ◽  
W G.D Fernando ◽  
S Nakkeeran ◽  
T.R. de Kievit

Pseudomonas chlororaphis PA23 is a biocontrol agent that protects against the fungal pathogen Sclerotinia sclerotiorum. Employing transposon mutagenesis, we isolated a gacS mutant that no longer exhibited antifungal activity. Pseudomonas chlororaphis PA23 was previously reported to produce the nonvolatile antibiotics phenazine 1-carboxylic acid and 2-hydroxyphenazine. We report here that PA23 produces additional compounds, including protease, lipase, hydrogen cyanide, and siderophores, that may contribute to its biocontrol ability. In the gacS mutant background, generation of these products was markedly reduced or delayed with the exception of siderophores, which were elevated. Not surprisingly, this mutant was unable to protect canola from disease incited by S. sclerotiorum. The gacS mutant was able to sustain itself in the canola phyllosphere, therefore, the loss of biocontrol activity can be attributed to a reduced production of antifungal compounds and not a declining population size. Competition assays between the mutant and wild type revealed equivalent fitness in aged batch culture; consequently, the gacS mutation did not impart a growth advantage in the stationary phase phenotype. Under minimal nutrient conditions, the gacS-deficient strain produced a tenfold less biofilm than the wild type. However, no difference was observed in the ability of the mutant biofilm to protect cells from lethal antibiotic challenge.Key words: Pseudomonas, biocontrol, gacS, fitness, biofilms.


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