Improved Synthetic Medium for the Growth of <i>Rhizobium</i>

Sherwood, Marie T.

doi:10.1111/j.1365-2672.1970.tb02253.x

Cited by 102 publications

(73 citation statements)

References 6 publications

(4 reference statements)

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“…Rhizobium and Agrobacterium strains were grown at 28°C on either TY complex medium (4) or Y minimal medium (34). Escherichia coli strains were grown at 37°C on L medium (31).…”

Section: Methodsmentioning

confidence: 99%

N -Acyl-Homoserine Lactone Inhibition of Rhizobial Growth Is Mediated by Two Quorum-Sensing Genes That Regulate Plasmid Transfer

et al. 2002

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The growth of some strains of Rhizobium leguminosarum bv. viciae is inhibited by N-(3-hydroxy-7-cis tetradecenoyl)-L-homoserine lactone (3OH-C 14:1 -HSL), which was previously known as the small bacteriocin before its characterization as an N-acyl homoserine lactone (AHL). Tn5-induced mutants of R. leguminosarum bv. viciae resistant to 3OH-C 14:1 -HSL were isolated, and mutations in two genes were identified. These genes, bisR and triR, which both encode LuxR-type regulators required for plasmid transfer, were found downstream of an operon containing trb genes involved in the transfer of the symbiotic plasmid pRL1JI. The first gene in this operon is traI, which encodes an AHL synthase, and the trbBCDEJKLFGHI genes were found between traI and bisR. Mutations in bisR, triR, traI, or trbL blocked plasmid transfer. Using gene fusions, it was demonstrated that bisR regulates triR in response to the presence of 3OH-C 14:1 -HSL. In turn, triR is then required for the induction of the traI-trb operon required for plasmid transfer. bisR also represses expression of cinI, which is chromosomally located and determines the level of production of 3OH-C 14:1 -HSL. The cloned bisR and triR genes conferred 3OH-C 14:1 -HSL sensitivity to strains of R. leguminosarum bv. viciae normally resistant to this AHL. Furthermore, bisR and triR made Agrobacterium tumefaciens sensitive to R. leguminosarum bv. viciae strains producing 3OH-C 14:1 -HSL. Analysis of patterns of growth inhibition using mutant strains and synthetic AHLs revealed that maximal growth inhibition required, in addition to 3OH-C 14:1 -HSL, the presence of other AHLs such as N-octanoyl-L-homoserine lactone and/or N-(3-oxo-octanoyl)-L-homoserine lactone. In an attempt to identify the causes of growth inhibition, a strain of R. leguminosarum bv. viciae carrying cloned bisR and triR was treated with an AHL extract containing 3OH-C 14:1 -HSL. N-terminal sequencing of induced proteins revealed one with significant similarity to the protein translation factor Ef-Ts.

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“…Rhizobium and Agrobacterium strains were grown at 28°C on either TY complex medium (4) or Y minimal medium (34). Escherichia coli strains were grown at 37°C on L medium (31).…”

Section: Methodsmentioning

confidence: 99%

N -Acyl-Homoserine Lactone Inhibition of Rhizobial Growth Is Mediated by Two Quorum-Sensing Genes That Regulate Plasmid Transfer

et al. 2002

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“…R. tropici and Agrobacterium tumefaciens strains were grown at 28°C in TY medium (2) or Y minimal medium (43) supplemented with 10 mM ammonium chloride and 0.2% (wt/vol) succinate, glucose, galactose, or mannitol. Escherichia coli strains were grown at 37°C in L medium (31), to which maltose (0.5% [wt/vol]) was added for experiments involving detection of glycogen.…”

Section: Microbiological Techniquesmentioning

confidence: 99%

Enhanced Symbiotic Performance by Rhizobium tropici Glycogen Synthase Mutants

et al. 2001

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We isolated a Tn5-induced Rhizobium tropici mutant that has enhanced capacity to oxidize N,N-dimethylp-phenylendiamine (DMPD) and therefore has enhanced respiration via cytochrome oxidase. The mutant had increased levels of the cytochromes c 1 and CycM and a small increase in the amount of cytochrome aa 3 . In plant tests, the mutant increased the dry weight of Phaseolus vulgaris plants by 20 to 38% compared with the control strain, thus showing significantly enhanced symbiotic performance. The predicted product of the mutated gene is homologous to glycogen synthases from several bacteria, and the mutant lacked glycogen. The DNA sequence of the adjacent gene region revealed six genes predicted to encode products homologous to the following gene products from Escherichia coli: glycogen phosphorylase (glgP), glycogen branching enzyme (glgB), ADP glucose pyrophosphorylase (glgC), glycogen synthase (glgA), phosphoglucomutase (pgm), and glycogen debranching enzyme (glgX). All six genes are transcribed in the same direction, and analysis with lacZ gene fusions suggests that the first five genes are organized in one operon, although pgm appears to have an additional promoter; glgX is transcribed independently. Surprisingly, the glgA mutant had decreased levels of high-molecular-weight exopolysaccharide after growth on glucose, but levels were normal after growth on galactose. A deletion mutant was constructed in order to generate a nonpolar mutation in glgA. This mutant had a phenotype similar to that of the Tn5 mutant, indicating that the enhanced respiration and symbiotic nitrogen fixation and decreased exopolysaccharide were due to mutation of glgA and not to a polar effect on a downstream gene.

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“…S. meliloti strains were grown at 30 uC either in complex tryptone yeast (TY) broth supplemented with 4.5 mM CaCl 2 (Beringer, 1974) or in one of the following minimal media: M9 supplemented with 2 mg biotin ml 21 and succinate (10 mM) replacing glucose as the carbon source, Sherwood (1970) medium with succinate (8.3 mM) replacing mannitol as the carbon source, or Robertsen et al (1981) medium. In experiments designed to evaluate the influence of the nitrogen source on growth, glutamate in Robertsen medium was replaced by NH 4 Cl.…”

Section: Methodsmentioning

confidence: 99%

SMb20651 is another acyl carrier protein from Sinorhizobium meliloti

et al. 2009

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Acyl carrier proteins (ACPs) are small acidic proteins that carry growing acyl chains during fatty acid or polyketide synthesis. In rhizobia, there are four different and well-characterized ACPs: AcpP, NodF, AcpXL and RkpF. The genome sequence of Sinorhizobium meliloti 1021 reveals two additional ORFs that possibly encode additional ACPs. One of these, smb20651, is located on the plasmid pSymB as part of an operon. The genes of the operon encode a putative asparagine synthetase (AsnB), the predicted ACP (SMb20651), a putative long-chain fatty acyl-CoA ligase (SMb20650) and a putative ammonium-dependent NAD+ synthetase (NadE1). When SMb20651 was overexpressed in Escherichia coli, [3H]β-alanine, a biosynthetic building block of 4′-phosphopantetheine, was incorporated into the protein in vivo. The purified SMb20651 was modified with 4′-phosphopantetheine in the presence of S. meliloti holo-ACP synthase (AcpS). Also, holo-SMb20651 was modified in vitro with a malonyl group by malonyl CoA-ACP transacylase. In E. coli, coexpression of SMb20651 together with other proteins such as AcpS and SMb20650 led to the formation of additional forms of SMb20651. In this bacterium, acylation of SMb20651 with C12 : 0 or C18 : 0 fatty acids was detected, demonstrating that this protein is involved in fatty acid biosynthesis or transfer. Expression of SMb20651 was detected in S. meliloti as holo-SMb20651 and acyl-SMb20651.

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Improved Synthetic Medium for the Growth of Rhizobium

Cited by 102 publications

References 6 publications

N -Acyl-Homoserine Lactone Inhibition of Rhizobial Growth Is Mediated by Two Quorum-Sensing Genes That Regulate Plasmid Transfer

N -Acyl-Homoserine Lactone Inhibition of Rhizobial Growth Is Mediated by Two Quorum-Sensing Genes That Regulate Plasmid Transfer

Enhanced Symbiotic Performance by Rhizobium tropici Glycogen Synthase Mutants

SMb20651 is another acyl carrier protein from Sinorhizobium meliloti

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