Increased antimetabolite sensitivity with variation of carbon source during growth

Jensen, Roy A.; Calhoun, David H.

doi:10.1128/jb.133.3.1232-1236.1978

Cited by 3 publications

(1 citation statement)

References 13 publications

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“…Intracellular pools of individual amino acids depend on the carbon source and affect the sensitivity of cells towards amino acid analogues [14]. Conditions under which growth inhibition of S. cinnamonensis was achieved are listed in Table 1.…”

Section: Resultsmentioning

confidence: 99%

Regulatory mutants ofStreptomyces cinnamonensisproducing monensin A

Pospı́šil

Peterková

Krumphanzl

et al. 1984

FEMS Microbiology Letters

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We prepared mutants of Streptomyces cinnamonensis resistant to amino acid analogues: 2‐aminobutyrate, norvaline, norleucine, 2‐amino‐3‐chlorobutyrate and ethionine. The regulatory mutants were studied as to their production of oligoketide antibiotics, monensins A and B, as dependent on the formation of valine which is a precursor of the butyrate building unit of monensin A. Strains resistant to both 2‐amino‐3‐chlorobutyrate and norleucine exhibited an increased production of monensin A from 50% to 90–93% of total monensins.

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Section: Resultsmentioning

confidence: 99%

Regulatory mutants ofStreptomyces cinnamonensisproducing monensin A

Pospı́šil

Peterková

Krumphanzl

et al. 1984

FEMS Microbiology Letters

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A carbon source‐dependent antimetabolite sensitivity test in Bacillus megaterium B71 for isolation of ethionine resistant mutants

Roy

Mishra

Nanda

1986

Journal of Applied Bacteriology

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Alteration of carbon sources significantly altered the analogue sensitivity of Bacillus megaterium B71. DL‐Ethionine (ETN) was highly inhibitory with glucose, mannitol, sucrose, citrate, glycerol and arabinose. DL‐Norleucine, L‐homoserine and S(2′‐aminoethyl)‐L‐cysteine were either highly inhibitory, slightly inhibitory or non‐inhibitory depending on the carbon sources used. Maltose markedly overcame the inhibitory effect of ETN in liquid culture. Uninhibited growth was poor on citrate and arabinose when compared with other carbon sources. Six carbon sources showing comparable growth were used to determine minimum inhibitory concentrations (MIC) of the analogues. The MIC of ETN was highest (450 μg/ml) with maltose and lowest (4 μg/ml) with mannitol. ETN sensitivity was inversely related to the endogenous L‐methionine pool size, and was relatively low with mannitol which was used to isolate ETN resistant mutants of B. megaterium B71. The best mutant BUE‐118 produced 435 μg/ml of L‐methionine.

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Hidden overflow pathway to L-phenylalanine in Pseudomonas aeruginosa

Fiske¹,

Whitaker²,

Jensen³

1983

J Bacteriol

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Pseudomonas aeruginosa is representative of a large group of pseudomonad bacteria that possess coexisting alternative pathways to L-phenylalanine (as well as to L-tyrosine). These multiple flow routes to aromatic end products apparently account for the inordinate resistance of P. aeruginosa to end product analogs. Manipulation of carbon source nutrition produced a physiological state of sensitivity to p-fluorophenylalanine and m-fluorophenylalanine, each a specific antimetabolite of L-phenylalanine. Analog-resistant mutants obtained fell into two classes. One type lacked feedback sensitivity of prephenate dehydratase and was the most dramatic excretor of L-phenylalanine. The presence of L-tyrosine curbed phenylalanine excretion to one-third, a finding explained by potent early-pathway regulation of 3-deoxy-D-arabinoheptulosonate 7-phosphate (DAHP) synthase-Tyr (a DAHP synthase subject to allosteric inhibition by L-tyrosine). The second class of regulatory mutants possessed a completely feedback-resistant DAHP synthase-Tyr, the major species (greater than 90%) of two isozymes. Deregulation of DAHP synthase-Tyr resulted in the escape of most chorismate molecules produced into an unregulated overflow route consisting of chorismate mutase (monofunctional), prephenate aminotransferase, and arogenate dehydratase. In the wild type the operation of the overflow pathway is restrained by factors that restrict early-pathway flux. These factors include the highly potent feedback control of DAHP synthase isozymes by end products as well as the strikingly variable abilities of different carbon source nutrients to supply the aromatic pathway with beginning substrates. Even in the wild type, where all allosteric regulation in intact, some phenylalanine overflow was found on glucose-based medium, but not on fructose-based medium. This carbon source-dependent difference was much more exaggerated in each class of regulatory mutants.

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Increased antimetabolite sensitivity with variation of carbon source during growth

Cited by 3 publications

References 13 publications

Regulatory mutants ofStreptomyces cinnamonensisproducing monensin A

Regulatory mutants ofStreptomyces cinnamonensisproducing monensin A

A carbon source‐dependent antimetabolite sensitivity test in Bacillus megaterium B71 for isolation of ethionine resistant mutants

Hidden overflow pathway to L-phenylalanine in Pseudomonas aeruginosa

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