Accumulation of trehalose by Escherichia coli K-12 at high osmotic pressure depends on the presence of amber suppressors

Journal Article · Mon Aug 01 00:00:00 EDT 1988 · Journal of Bacteriology; (USA)

OSTI ID:6827834

Cunningham, P R; Clark, D P ^[1]

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1. Southern Illinois Univ., Carbondale (USA)

When grown at high osmotic pressure, some strains of Escherichia coli K-12 synthesized substantial levels of free sugar and accumulated proline if it was present in the growth medium. The sugar was identified as trehalose. Strains of E. coli K-12 could be divided into two major classes with respect of osmoregulation. Those of class A showed a large increase in trehalose levels with increasing medium osmolarity and also accumulated proline from the medium, whereas those in class B showed no accumulation of trehalose or proline. Most class A strains carried suppressor mutations which arose during their derivation from the wild type, whereas the osmodefective strains of class B were suppressor free. When amber suppressor mutations at the supD, supE, or supF loci were introduced into such sup{sup o} osmodefective strains, they became osmotolerant and gained the ability to accumulate trehalose in response to elevated medium osmolarity. It appears that the original K-12 strain of E. coli carries an amber mutation in a gene affecting osmoregulation. Mutants lacking ADP-glucose synthetase (glgC) accumulated trehalose normally, whereas mutants lacking UDP-glucose synthetase (galU) did not make trehalose and grew poorly in medium of high osmolarity. Trehalose synthesis was repressed by exogenous glycine betaine but not by proline.

• OSTI ID: 6827834
• Journal Information: Journal of Bacteriology; (USA), Vol. 170:8; ISSN 0021-9193
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
DISACCHARIDES
BIOSYNTHESIS
ESCHERICHIA COLI
MOLECULAR BIOLOGY
OSMOSIS
BIOCHEMICAL REACTION KINETICS
GENE REPRESSORS
MUTATIONS
PROLINE
TOLERANCE
AMINES
AMINO ACIDS
AZOLES
BACTERIA
CARBOHYDRATES
CARBOXYLIC ACIDS
DIFFUSION
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
KINETICS
MICROORGANISMS
NUCLEOPROTEINS
OLIGOSACCHARIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PROTEINS
PYRROLES
PYRROLIDINES
REACTION KINETICS
SACCHARIDES
SYNTHESIS
550400* - Genetics