Galactose transport in Streptococcus thermophilus

R. Hutkins, H. A. Morris, L. L. McKay

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

Although Streptococcus thermophilus accumulated [14C]lactose in the absence of an endogenous energy source, galactose-fermenting (Gal+) cells were unable to accumulate [14C]galactose unless an additional energy source was added to the test system. Both Gal+ and galactose-nonfermenting (Gal-) strains transported galactose when preincubated with sucrose. Accumulation was inhibited 50 or 95% when 10 mM sodium fluoride or 1.0 mM iodoacetic acid, respectively, was added to sucrose-treated cells, indicating that ATP was required for galactose transport activity. Proton-conducting ionophores also inhibited galactose uptake, although N,N'-dicyclohexyl carbodiimide had no effect. The results suggest that galactose transport in S. thermophilus occurs via an ATP-dependent galactose permease and that a proton motive force is involved. The galactose permease in S. thermophilus TS2b (Gal+) had a K(m) for galactose of 0.25 mM and a V(max) of 195 μmol of galactose accumulated per min per g (dry weight) of cells. Several structurally similar sugars inhibited galactose uptake, indicating that the galactose permease had high affinities for these sugars.

Original languageEnglish (US)
Pages (from-to)772-776
Number of pages5
JournalApplied and environmental microbiology
Volume50
Issue number4
StatePublished - Dec 1 1985

Fingerprint

Streptococcus thermophilus
Galactose
sucrose
galactose
sugar
fluoride
sodium
acid
Sucrose
Proton Ionophores
Adenosine Triphosphate
energy source
Iodoacetic Acid
Carbodiimides
Sodium Fluoride
Proton-Motive Force
iodoacetic acid
Lactose
sugars
uptake mechanisms

ASJC Scopus subject areas

  • Biotechnology
  • Food Science
  • Applied Microbiology and Biotechnology
  • Ecology

Cite this

Galactose transport in Streptococcus thermophilus. / Hutkins, R.; Morris, H. A.; McKay, L. L.

In: Applied and environmental microbiology, Vol. 50, No. 4, 01.12.1985, p. 772-776.

Research output: Contribution to journalArticle

Hutkins, R, Morris, HA & McKay, LL 1985, 'Galactose transport in Streptococcus thermophilus', Applied and environmental microbiology, vol. 50, no. 4, pp. 772-776.
Hutkins, R. ; Morris, H. A. ; McKay, L. L. / Galactose transport in Streptococcus thermophilus. In: Applied and environmental microbiology. 1985 ; Vol. 50, No. 4. pp. 772-776.
@article{4be327e44e8547a1ad87c6d0caa6dfa5,
title = "Galactose transport in Streptococcus thermophilus",
abstract = "Although Streptococcus thermophilus accumulated [14C]lactose in the absence of an endogenous energy source, galactose-fermenting (Gal+) cells were unable to accumulate [14C]galactose unless an additional energy source was added to the test system. Both Gal+ and galactose-nonfermenting (Gal-) strains transported galactose when preincubated with sucrose. Accumulation was inhibited 50 or 95{\%} when 10 mM sodium fluoride or 1.0 mM iodoacetic acid, respectively, was added to sucrose-treated cells, indicating that ATP was required for galactose transport activity. Proton-conducting ionophores also inhibited galactose uptake, although N,N'-dicyclohexyl carbodiimide had no effect. The results suggest that galactose transport in S. thermophilus occurs via an ATP-dependent galactose permease and that a proton motive force is involved. The galactose permease in S. thermophilus TS2b (Gal+) had a K(m) for galactose of 0.25 mM and a V(max) of 195 μmol of galactose accumulated per min per g (dry weight) of cells. Several structurally similar sugars inhibited galactose uptake, indicating that the galactose permease had high affinities for these sugars.",
author = "R. Hutkins and Morris, {H. A.} and McKay, {L. L.}",
year = "1985",
month = "12",
day = "1",
language = "English (US)",
volume = "50",
pages = "772--776",
journal = "Applied and Environmental Microbiology",
issn = "0099-2240",
publisher = "American Society for Microbiology",
number = "4",

}

TY - JOUR

T1 - Galactose transport in Streptococcus thermophilus

AU - Hutkins, R.

AU - Morris, H. A.

AU - McKay, L. L.

PY - 1985/12/1

Y1 - 1985/12/1

N2 - Although Streptococcus thermophilus accumulated [14C]lactose in the absence of an endogenous energy source, galactose-fermenting (Gal+) cells were unable to accumulate [14C]galactose unless an additional energy source was added to the test system. Both Gal+ and galactose-nonfermenting (Gal-) strains transported galactose when preincubated with sucrose. Accumulation was inhibited 50 or 95% when 10 mM sodium fluoride or 1.0 mM iodoacetic acid, respectively, was added to sucrose-treated cells, indicating that ATP was required for galactose transport activity. Proton-conducting ionophores also inhibited galactose uptake, although N,N'-dicyclohexyl carbodiimide had no effect. The results suggest that galactose transport in S. thermophilus occurs via an ATP-dependent galactose permease and that a proton motive force is involved. The galactose permease in S. thermophilus TS2b (Gal+) had a K(m) for galactose of 0.25 mM and a V(max) of 195 μmol of galactose accumulated per min per g (dry weight) of cells. Several structurally similar sugars inhibited galactose uptake, indicating that the galactose permease had high affinities for these sugars.

AB - Although Streptococcus thermophilus accumulated [14C]lactose in the absence of an endogenous energy source, galactose-fermenting (Gal+) cells were unable to accumulate [14C]galactose unless an additional energy source was added to the test system. Both Gal+ and galactose-nonfermenting (Gal-) strains transported galactose when preincubated with sucrose. Accumulation was inhibited 50 or 95% when 10 mM sodium fluoride or 1.0 mM iodoacetic acid, respectively, was added to sucrose-treated cells, indicating that ATP was required for galactose transport activity. Proton-conducting ionophores also inhibited galactose uptake, although N,N'-dicyclohexyl carbodiimide had no effect. The results suggest that galactose transport in S. thermophilus occurs via an ATP-dependent galactose permease and that a proton motive force is involved. The galactose permease in S. thermophilus TS2b (Gal+) had a K(m) for galactose of 0.25 mM and a V(max) of 195 μmol of galactose accumulated per min per g (dry weight) of cells. Several structurally similar sugars inhibited galactose uptake, indicating that the galactose permease had high affinities for these sugars.

UR - http://www.scopus.com/inward/record.url?scp=0022406430&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0022406430&partnerID=8YFLogxK

M3 - Article

C2 - 4083879

AN - SCOPUS:0022406430

VL - 50

SP - 772

EP - 776

JO - Applied and Environmental Microbiology

JF - Applied and Environmental Microbiology

SN - 0099-2240

IS - 4

ER -