scholarly journals Genes Involved in Cyclic Lipopeptide Production Are Important for Seed and Straw Colonization by Pseudomonas sp. Strain DSS73

2005 ◽  
Vol 71 (7) ◽  
pp. 4112-4116 ◽  
Author(s):  
Tommy H. Nielsen ◽  
Ole Nybroe ◽  
Birgit Koch ◽  
Michael Hansen ◽  
Jan Sørensen
Keyword(s):  
Sugar Beet ◽  
Regulatory System ◽  
Bulk Soil ◽  
Barley Straw ◽  
Pseudomonas Sp ◽  
Cyclic Lipopeptide ◽  
Carbon Amendment ◽  
Peptide Synthetase ◽  
Two Component

ABSTRACT Survival in natural bulk soil and colonization of sugar beet seeds and barley straw residues were determined for Pseudomonas sp. strain DSS73 and Tn5 mutants in amsY (encoding a peptide synthetase involved in production of the cyclic lipopeptide amphisin) and gacS (encoding the sensory kinase of the two-component GacA/GacS regulatory system). No differences in survival or growth in response to carbon amendment (citrate) were observed in bulk soil. However, both mutants were impaired in their colonization of sugar beet seeds and barley straw residues by an inoculum established in the bulk soil. The two mutants had comparable colonization phenotypes, suggesting that amphisin production is more important for colonization than other gacS-controlled traits.

scholarly journals Lipopeptide Production in Pseudomonas sp. Strain DSS73 Is Regulated by Components of Sugar Beet Seed Exudate via the Gac Two-Component Regulatory System

2002 ◽  
Vol 68 (9) ◽  
pp. 4509-4516 ◽  
Author(s):  
Birgit Koch ◽  
Tommy H. Nielsen ◽  
Dan Sørensen ◽  
Jens Bo Andersen ◽  
Carsten Christophersen ◽  
...  
Keyword(s):  
Sugar Beet ◽  
Stationary Phase ◽  
Regulatory Gene ◽  
Regulatory System ◽  
Pathogenic Fungi ◽  
Gene Encoding ◽  
Peptide Synthetases ◽  
Cyclic Lipopeptide ◽  
Two Component ◽  
Seed Exudate

ABSTRACT Pseudomonas sp. strain DSS73 isolated from the sugar beet rhizosphere produces the cyclic lipopeptide amphisin, which inhibits the growth of plant-pathogenic fungi. By Tn5::luxAB mutagenesis, we obtained two nonproducing mutant strains, DSS73-15C2 and DSS73-12H8. The gene interrupted by the transposon in strain DSS73-15C2 (amsY) encoded a protein with homology to peptide synthetases that was designated amphisin synthetase. DSS73-12H8 carried the transposon in a regulatory gene encoding a protein with homology to the sensor kinase GacS. Growth of strain DSS73-15C2 (amsY) was impaired during the transition to stationary phase in a minimal medium amended with an exudate of sugar beet seeds. This growth phenotype could be complemented by purified amphisin. Seed exudate further induced expression of bioluminescence from the amsY::luxAB reporter during the transition to stationary phase. This agreed with an increase in amphisin production by the DSS73 wild-type strain during early stationary phase. Amphisin synthesis in DSS73 was strictly dependent on GacS, and even induction by seed exudate depended on a functional gacS locus. Hence, a signal triggering the GacS/GacA two-component system appeared to be present in the seed exudate.

scholarly journals Pseudomonas sp. COW3 Produces New Bananamide-Type Cyclic Lipopeptides with Antimicrobial Activity against Pythium myriotylum and Pyricularia oryzae

Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4170 ◽  
Author(s):  
Olumide Owolabi Omoboye ◽  
Niels Geudens ◽  
Matthieu Duban ◽  
Mickaël Chevalier ◽  
Christophe Flahaut ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Genome Mining ◽  
Antagonistic Activity ◽  
Pyricularia Oryzae ◽  
Pseudomonas Sp ◽  
Pythium Myriotylum ◽  
Cyclic Lipopeptides ◽  
Peptide Synthetase ◽  
Kendrick Mass Defect

Pseudomonas species are metabolically robust, with capacity to produce secondary metabolites including cyclic lipopeptides (CLPs). Herein we conducted a chemical analysis of a crude CLP extract from the cocoyam rhizosphere-derived biocontrol strain Pseudomonas sp. COW3. We performed in silico analyses on its whole genome, and conducted in vitro antagonistic assay using the strain and purified CLPs. Via LC-MS and NMR, we elucidated the structures of four novel members of the bananamide group, named bananamides D-G. Besides variability in fatty acid length, bananamides D-G differ from previously described bananamides A-C and MD-0066 by the presence of a serine and aspartic acid at position 6 and 2, respectively. In addition, bananamide G has valine instead of isoleucine at position 8. Kendrick mass defect (KMD) allowed the assignment of molecular formulae to bananamides D and E. We unraveled a non-ribosomal peptide synthetase cluster banA, banB and banC which encodes the novel bananamide derivatives. Furthermore, COW3 displayed antagonistic activity and mycophagy against Pythium myriotylum, while it mainly showed mycophagy on Pyricularia oryzae. Purified bananamides D-G inhibited the growth of P. myriotylum and P. oryzae and caused hyphal distortion. Our study shows the complementarity of chemical analyses and genome mining in the discovery and elucidation of novel CLPs. In addition, structurally diverse bananamides differ in their antimicrobial activity.

scholarly journals Microarray Analysis of a Two-Component Regulatory System Involved in Acid Resistance and Proteolytic Activity in Lactobacillus acidophilus

2005 ◽  
Vol 71 (10) ◽  
pp. 5794-5804 ◽  
Author(s):  
M. Andrea Azcarate-Peril ◽  
Olivia McAuliffe ◽  
Eric Altermann ◽  
Sonja Lick ◽  
W. Michael Russell ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Proteolytic Activity ◽  
Lactobacillus Acidophilus ◽  
Regulatory System ◽  
Probiotic Bacterium ◽  
Transport Systems ◽  
Logarithmic Phase ◽  
Histidine Protein Kinase ◽  
Regulatory Systems ◽  
Two Component

ABSTRACT Two-component regulatory systems are one primary mechanism for environmental sensing and signal transduction. Annotation of the complete genome sequence of the probiotic bacterium Lactobacillus acidophilus NCFM revealed nine two-component regulatory systems. In this study, the histidine protein kinase of a two-component regulatory system (LBA1524HPK-LBA1525RR), similar to the acid-related system lisRK from Listeria monocytogenes (P. D. Cotter et al., J. Bacteriol. 181:6840-6843, 1999), was insertionally inactivated. A whole-genome microarray containing 97.4% of the annotated genes of L. acidophilus was used to compare genome-wide patterns of transcription at various pHs between the control and the histidine protein kinase mutant. The expression pattern of approximately 80 genes was affected by the LBA1524HPK mutation. Putative LBA1525RR target loci included two oligopeptide-transport systems present in the L. acidophilus genome, other components of the proteolytic system, and a LuxS homolog, suspected of participating in synthesis of the AI-2 signaling compound. The mutant exhibited lower tolerance to acid and ethanol in logarithmic-phase cells and poor acidification rates in milk. Supplementation of milk with Casamino Acids essentially restored the acid-producing ability of the mutant, providing additional evidence for a role of this two component system in regulating proteolytic activity in L. acidophilus.

AgmR controls transcription of a regulon with several operons essential for ethanol oxidation in Pseudomonas aeruginosa ATCC 17933

Microbiology ◽  
2004 ◽  
Vol 150 (6) ◽  
pp. 1851-1857 ◽  
Author(s):  
Nicole Gliese ◽  
Viola Khodaverdi ◽  
Max Schobert ◽  
Helmut Görisch
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Ethanol Oxidation ◽  
Response Regulator ◽  
Regulatory System ◽  
Pyrroloquinoline Quinone ◽  
Kanamycin Resistance ◽  
Kanamycin Resistance Cassette ◽  
Two Component ◽  
Ethanol Dehydrogenase ◽  
Oxidation System

The response regulator AgmR was identified to be involved in the regulation of the quinoprotein ethanol oxidation system of Pseudomonas aeruginosa ATCC 17933. Interruption of the agmR gene by insertion of a kanamycin-resistance cassette resulted in mutant NG3, unable to grow on ethanol. After complementation with the intact agmR gene, growth on ethanol was restored. Transcriptional lacZ fusions were used to identify four operons which are regulated by the AgmR protein: the exaA operon encodes the pyrroloquinoline quinone (PQQ)-dependent ethanol dehydrogenase, the exaBC operon encodes a soluble cytochrome c 550 and an aldehyde dehydrogenase, the pqqABCDE operon carries the PQQ biosynthetic genes, and operon exaDE encodes a two-component regulatory system which controls transcription of the exaA operon. Transcription of exaA was restored by transformation of NG3 with a pUCP20T derivative carrying the exaDE genes under lac-promoter control. These data indicate that the AgmR response regulator and the exaDE two-component regulatory system are organized in a hierarchical manner. Gene PA1977, which appears to form an operon with the agmR gene, was found to be non-essential for growth on ethanol.

scholarly journals The Two-Component Regulatory System TCS08 Is Involved in Cellobiose Metabolism of Streptococcus pneumoniae R6

2006 ◽  
Vol 189 (4) ◽  
pp. 1342-1350 ◽  
Author(s):  
Stuart J. McKessar ◽  
Regine Hakenbeck
Keyword(s):  
Streptococcus Pneumoniae ◽  
Response Regulator ◽  
Regulatory System ◽  
Phosphotransferase System ◽  
Two Component System ◽  
Transcription Profiles ◽  
Regulatory Systems ◽  
Two Component ◽  
Cognate Response Regulator ◽  
Gram Positive Cocci

ABSTRACT The two-component system TCS08 is one of the regulatory systems that is important for virulence of Streptococcus pneumoniae. In order to investigate the TCS08 regulon, we have analyzed transcription profiles of mutants derived from S. pneumoniae R6 by microarray analysis. Since deletion mutants are often without a significant phenotype, we constructed a mutation in the histidine kinase HK08, T133P, in analogy to the phosphatase mutation T230P in the H box of the S. pneumoniae CiaH kinase described recently (D. Zähner, K. Kaminski, M. van der Linden, T. Mascher, M. Merai, and R. Hakenbeck, J. Mol. Microbiol. Biotechnol. 4:211-216, 2002). In addition, a deletion mutation was constructed in rr08, encoding the cognate response regulator. The most heavily suppressed genes in the hk08 mutant were spr0276 to spr0282, encoding a putative cellobiose phosphoenolpyruvate sugar phosphotransferase system (PTS). Whereas the R6 Smr parent strain and the Δrr08 mutant readily grew on cellobiose, the hk08 mutant and selected mutants with deletions in the PTS cluster did not, strongly suggesting that TCS08 is involved in the catabolism of cellobiose. Homologues of the TCS08 system were found in closely related streptococci and other gram-positive cocci. However, the genes spr0276 to spr0282, encoding the putative cellobiose PTS, represent a genomic island in S. pneumoniae and homologues were found in Streptococcus gordonii only, suggesting that this system might contribute to the pathogenicity potential of the pneumococcus.

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