Microbial Synthesis of Antibacterial Phenazine-1,6-dicarboxylic Acid and the Role of PhzG in Pseudomonas chlororaphis GP72AN

2020 ◽  
Vol 68 (8) ◽  
pp. 2373-2380 ◽  
Author(s):  
Shuqi Guo ◽  
Yining Wang ◽  
Muhammad Bilal ◽  
Hongbo Hu ◽  
Wei Wang ◽  
...  
Keyword(s):  
Dicarboxylic Acid ◽  
Pseudomonas Chlororaphis ◽  
Microbial Synthesis

The effect of polyhydroxyalkanoates in Pseudomonas chlororaphis PA23 biofilm formation, stress endurance, and interaction with the protozoan predator Acanthamoeba castellanii

2021 ◽  
pp. 1-15
Author(s):  
Akrm Ghergab ◽  
Nisha Mohanan ◽  
Grace Saliga ◽  
Ann Karen C. Brassinga ◽  
David Levin ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Acanthamoeba Castellanii ◽  
Pseudomonas Chlororaphis ◽  
Enhanced Sensitivity ◽  
Hostile Environments ◽  
The Impact ◽  
Environmental Fitness ◽  
Root Attachment

Pseudomonas chlororaphis PA23 is a biocontrol agent capable of protecting canola against the fungal pathogen Sclerotinia sclerotiorum. In addition to producing antifungal compounds, this bacterium synthesizes and accumulates polyhydroxyalkanoate (PHA) polymers as carbon and energy storage compounds. Because the role of PHA in PA23 physiology is currently unknown, we investigated the impact of this polymer on stress resistance, adherence to surfaces, and interaction with the protozoan predator Acanthamoeba castellanii. Three PHA biosynthesis mutants were created, PA23phaC1, PA23phaC1ZC2, and PA23phaC1ZC2D, which accumulated reduced PHA. Our phenotypic assays revealed that PA23phaC1ZC2D produced less phenazine (PHZ) compared with the wild type (WT) and the phaC1 and phaC1ZC2 mutants. All three mutants exhibited enhanced sensitivity to UV irradiation, starvation, heat stress, cold stress, and hydrogen peroxide. Moreover, motility, exopolysaccharide production, biofilm formation, and root attachment were increased in strains with reduced PHA levels. Interaction studies with the amoeba A. castellanii revealed that the WT and the phaC1 and phaC1ZC2 mutants were consumed less than the phaC1ZC2D mutant, likely due to decreased PHZ production by the latter. Collectively these findings indicate that PHA accumulation enhances PA23 resistance to a number of stresses in vitro, which could improve the environmental fitness of this bacterium in hostile environments.

The role of hydrogen bonds in order-disorder transition of a new incommensurate low temperature phase β-[Zn-(C7H4NO4)2]·3H2O

2018 ◽  
Vol 233 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Masoumeh Tabatabaee ◽  
Morgane Poupon ◽  
Václav Eigner ◽  
Přemysl Vaněk ◽  
Michal Dušek
Keyword(s):  
Low Temperature ◽  
Hydrogen Bonds ◽  
Dicarboxylic Acid ◽  
Room Temperature ◽  
Temperature Phase ◽  
Temperature Structure ◽  
Modulated Structure ◽  
Q Vector ◽  
Low Temperature Phase

AbstractThe room temperature structure withP21/csymmetry of the zinc(II) complex of pyridine-2,6-dicarboxylic acid was published by Okabe and Oya (N. Okabe, N. Oya, Copper(II) and zinc(II) complexes of pyridine-2,6-dicarboxylic acid.Acta Crystallogr. C.2000,56, 305). Here we report crystal structure of the low temperature phaseβ-[Zn(pydcH)2]·3H2O, pydc=C7H3NO4, resulting from the phase transition around 200K. The diffraction pattern of the low temperature phase revealed satellite reflections, which could be indexed with q-vector 0.4051(10)b* corresponding to (3+1)Dincommensurately modulated structure. The modulated structure was solved in the superspace groupX21/c(0b0)s0, whereXstands for a non-standard centring vector (½, 0, 0, ½), and compared with the room temperature phase. It is shown that hydrogen bonds are the main driving force of modulation.

ChemInform Abstract: BIOSYNTHESIS OF PHENAZINES - THE ROLE OF PHENAZINE-1,6-DICARBOXYLIC ACID

1976 ◽  
Vol 7 (48) ◽  
pp. no-no
Author(s):  
U. HOLLSTEIN ◽  
G. E. KRISOV ◽  
D. L. MOCK
Keyword(s):  
Dicarboxylic Acid

scholarly journals Role of extracellular matrix components in the formation of biofilms and their contribution to the biocontrol activity of Pseudomonas chlororaphis   PCL1606

2020 ◽  
Author(s):  
Zaira Heredia‐Ponce ◽  
José Antonio Gutiérrez‐Barranquero ◽  
Gabriela Purtschert‐Montenegro ◽  
Leo Eberl ◽  
Antonio de Vicente ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Pseudomonas Chlororaphis ◽  
Extracellular Matrix Components ◽  
Biocontrol Activity ◽  
Matrix Components

Biosynthesis of phenazines - the role of phenazine-1,6-dicarboxylic acid

1976 ◽  
Vol 17 (37) ◽  
pp. 3267-3270 ◽  
Author(s):  
Ulrich Hollstein ◽  
Galen E. Krisov ◽  
David L. Mock
Keyword(s):  
Dicarboxylic Acid

Quorum sensing and the anaerobic regulator (ANR) control Polyhydroxyalkanoate (PHA) production in Pseudomonas chlororaphis PA23

2019 ◽  
Author(s):  
Nisha Mohanan ◽  
April Gislason ◽  
Parveen K Sharma ◽  
Akrm Ghergab ◽  
Jocelyn Plouffe ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Minimal Medium ◽  
Biocontrol Agent ◽  
Antifungal Compounds ◽  
Pseudomonas Chlororaphis ◽  
Promoter Regions ◽  
Consensus Sequences ◽  
Energy Sink ◽  
Pha Production

Abstract Pseudomonas chlororaphis PA23 is a biocontrol agent that, in addition to producing antifungal compounds, synthesizes polyhydroxyalkanoate (PHA) polymers as a carbon and energy sink. Quorum sensing (QS) and the anaerobic regulator (ANR) are required for PA23-mediated fungal suppression; however, the role of these regulators in PHA production is unknown. Strains lacking either QS or ANR accumulated less PHA polymers when propagated on Ramsay's Minimal Medium (RMM) with glucose or octanoate as the carbon source. In the AHL-deficient background, all six of the genes in the pha locus (phaC1, phaC2, phaZ, phaD, phaF, phaI) showed reduced expression in RMM-glucose, and all except phaC2 were repressed in RMM-octanoate. While changes in gene activity were observed in the anr mutant, they were less pronounced. Analysis of the promoter regions for QS- and ANR-binding consensus sequences revealed putative phz-boxes upstream of phaZ and phaI, but no anr-boxes were identified. Our findings indicate that altered pha gene expression likely contributes to the lower PHA accumulation in the QS- and ANR-deficient strains, which may be in part indirectly mediated. This study is the first to show that mcl-PHA production is under QS and ANR control.

scholarly journals The dar Genes of Pseudomonas chlororaphis PCL1606 Are Crucial for Biocontrol Activity via Production of the Antifungal Compound 2-Hexyl, 5-Propyl Resorcinol

2013 ◽  
Vol 26 (5) ◽  
pp. 554-565 ◽  
Author(s):  
Claudia E. Calderón ◽  
Alejandro Pérez-García ◽  
Antonio de Vicente ◽  
Francisco M. Cazorla
Keyword(s):  
Genomic Dna ◽  
Genetic Basis ◽  
Genomic Library ◽  
Open Reading Frames ◽  
Antifungal Compound ◽  
Pseudomonas Chlororaphis ◽  
Phylogenetic Studies ◽  
Biocontrol Activity ◽  
Reading Frames

To determine the genetic basis by which 2-hexyl, 5-propyl resorcinol (HPR) is produced by the biocontrol rhizobacterium Pseudomonas chlororaphis (formerly known as P. fluorescens) PCL1606, the presence and role of dar genes were investigated. To accomplish this aim, the pCGNOV-1 plasmid was isolated from a PCL1606 genomic library and was shown to hybridize to various dar probes by Southern blot. An analysis of the pCGNOV-1 genomic DNA revealed the presence of five open reading frames that were homologous to dar genes and had an organization that resembled the arrangement of previously described P. chlororaphis strains. Phylogenetic studies resulted in the clustering of PCL1606 with the P. chlororaphis subgroup, which supported the renaming of this strain from P. fluorescens to P. chlororaphis PCL1606. The construction of insertional mutants for each homologous dar gene in P. chlororaphis PCL1606 along with their corresponding complemented derivative strains restored HPR production and confirmed the key role of the dar A and darB genes in HPR production and in the antagonistic phenotype. Finally, biocontrol assays were performed on avocado–Rosellinia and tomato–Fusarium test systems using the HPR-defective and -complemented derivative strains generated here and demonstrated the crucial role of the biosynthetic dar genes in the biocontrol phenotype of P. chlororaphis PCL1606. This biocontrol phenotype is dependent on the dar genes via their production of the HPR antibiotic. Some of the dar genes not directly involved in the biosynthesis of HPR, such as darS or darR, might contribute to regulatory features of HPR production.

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