PMID- 11442726
OWN - NLM
STAT- MEDLINE
DCOM- 20010726
LR  - 20221207
IS  - 1364-5072 (Print)
IS  - 1364-5072 (Linking)
VI  - 91
IP  - 1
DP  - 2001 Jul
TI  - Effect of galactose and glucose on the exopolysaccharide production and the 
      activities of biosynthetic enzymes in Lactobacillus casei CRL 87.
PG  - 160-7
AB  - AIMS: The objective of this work was to study the influence of the sugar source 
      on exopolysaccharide (EPS) production and the activities of the enzymes involved 
      in the synthesis of sugar nucleotides in Lactobacillus casei CRL 87. The 
      relationship between these enzymes and EPS formation was determined. METHODS AND 
      RESULTS: The concentration of EPS was estimated by the phenol/sulphuric acid 
      method while the chemical composition of purified EPS was investigated using 
      gas-liquid chromatography. Biosynthetic enzyme activities were determined 
      spectrophotometrically by measuring the formation or disappearance of NAD(P)H at 
      340 nm. Polysaccharide production by Lb. casei CRL 87 was 1.7 times greater on 
      galactose than on glucose. The isolated polymer was composed of rhamnose, glucose 
      and galactose. The activities of uridine-diphosphate 
      (UDP)-glucose-pyrophosphorylase, thymidine-diphosphate 
      (dTDP)-glucose-pyrophosphorylase and the dTDP-rhamnose-synthetic enzyme system 
      were higher in galactose-grown than in glucose-grown cells. When an EPS- mutant 
      strain was used, galactokinase activity was not detected on galactose, this sugar 
      not being available for the formation of sugar nucleotides for further EPS 
      production. dTDP-glucose-pyrophosphorylase and dTDP-rhamnose-synthetic enzyme 
      system activities were lower than the values found for the wild type strain. 
      CONCLUSION: The carbon source present in the culture medium affects EPS 
      production by Lb. casei CRL 87. The greater polymer synthesis by galactose-grown 
      cells is correlated with the higher UDP-glucose-pyrophosphorylase, 
      dTDP-glucose-pyrophosphorylase and dTDP-rhamnose-synthetic enzyme system 
      activities. Initial sugar metabolism is also an important step for the synthesis 
      of EPS precursors by this strain. SIGNIFICANCE AND IMPACT OF THE STUDY: Knowledge 
      of the effect of the sugar source on EPS production and the activities of 
      biosynthetic enzymes provides information about the mechanisms of regulation of 
      the synthesis of EPS which can contribute to improving polymer production.
FAU - Mozzi, F
AU  - Mozzi F
AD  - Centro de Referencia para Lactobacilos (CERELA), CONICET Chacabuco, Chacabuco 
      145, 4000-Tucuman, Argentina. fmozzi@cerela.org.ar
FAU - Rollan, G
AU  - Rollan G
FAU - de Giori, G S
AU  - de Giori GS
FAU - Font de Valdez, G
AU  - Font de Valdez G
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - J Appl Microbiol
JT  - Journal of applied microbiology
JID - 9706280
RN  - 0 (Polysaccharides, Bacterial)
RN  - EC 2.7.1.2 (Glucokinase)
RN  - EC 2.7.7.9 (UTP-Glucose-1-Phosphate Uridylyltransferase)
RN  - IY9XDZ35W2 (Glucose)
RN  - X2RN3Q8DNE (Galactose)
SB  - IM
MH  - Enzyme Activation/drug effects
MH  - Galactose/*pharmacology
MH  - Glucokinase/metabolism
MH  - Glucose/*pharmacology
MH  - Lacticaseibacillus casei/*drug effects/enzymology/metabolism
MH  - Polysaccharides, Bacterial/*metabolism
MH  - UTP-Glucose-1-Phosphate Uridylyltransferase/metabolism
EDAT- 2001/07/10 10:00
MHDA- 2001/07/28 10:01
CRDT- 2001/07/10 10:00
PHST- 2001/07/10 10:00 [pubmed]
PHST- 2001/07/28 10:01 [medline]
PHST- 2001/07/10 10:00 [entrez]
AID - jam1367 [pii]
AID - 10.1046/j.1365-2672.2001.01367.x [doi]
PST - ppublish
SO  - J Appl Microbiol. 2001 Jul;91(1):160-7. doi: 10.1046/j.1365-2672.2001.01367.x.