TY - JOUR
T1 - Fructose 6-phosphate phosphoketolase activity in wild-type strains of Lactobacillus, isolated from the intestinal tract of pigs
AU - Bolado-Martínez, E.
AU - Acedo-Félix, E.
AU - Peregrino-Uriarte, A. B.
AU - Yepiz-Plascencia, G.
N1 - Funding Information:
This work was supported by the Consejo Nacional de Ciencia y Tecnologia grant no. SEP–2004–C01– 47691. Authors are thankful to E. Valenzuela, PhD and C. Figueroa, MSc for the invaluable technical assistance in absorption spectra analysis.
PY - 2012/9/1
Y1 - 2012/9/1
N2 - Phosphoketolases are key enzymes of the phosphoketolase pathway of heterofermentative lactic acid bacteria, which include lactobacilli. In heterofermentative lactobacilli xylulose 5-phosphate phosphoketolase (X5PPK) is the main enzyme of the phosphoketolase pathway. However, activity of fructose 6-phosphate phosphoketolase (F6PPK) has always been considered absent in lactic acid bacteria. In this study, the F6PPK activity was detected in 24 porcine wild-type strains of Lactobacillus reuteri and Lactobacillus mucosae, but not in the Lactobacillus salivarius or in L. reuteri ATCC strains. The activity of F6PPK increased after treatment of the culture at low-pH and diminished after porcine bile-salts stress conditions in wild-type strains of L. reuteri. Colorimetric quantification at 505 nm allowed to differentiate between microbial strains with low activity and without the activity of F6PPK. Additionally, activity of F6PPK and the X5PPK gene expression levels were evaluated by real time PCR, under stress and nonstress conditions, in 3 L. reuteri strains. Although an exact correlation, between enzyme activity and gene expression was not obtained, it remains possible that the xpk gene codes for a phosphoketolase with dual substrate, at least in the analyzed strains of L. reuteri. © 2012 Pleiades Publishing, Ltd.
AB - Phosphoketolases are key enzymes of the phosphoketolase pathway of heterofermentative lactic acid bacteria, which include lactobacilli. In heterofermentative lactobacilli xylulose 5-phosphate phosphoketolase (X5PPK) is the main enzyme of the phosphoketolase pathway. However, activity of fructose 6-phosphate phosphoketolase (F6PPK) has always been considered absent in lactic acid bacteria. In this study, the F6PPK activity was detected in 24 porcine wild-type strains of Lactobacillus reuteri and Lactobacillus mucosae, but not in the Lactobacillus salivarius or in L. reuteri ATCC strains. The activity of F6PPK increased after treatment of the culture at low-pH and diminished after porcine bile-salts stress conditions in wild-type strains of L. reuteri. Colorimetric quantification at 505 nm allowed to differentiate between microbial strains with low activity and without the activity of F6PPK. Additionally, activity of F6PPK and the X5PPK gene expression levels were evaluated by real time PCR, under stress and nonstress conditions, in 3 L. reuteri strains. Although an exact correlation, between enzyme activity and gene expression was not obtained, it remains possible that the xpk gene codes for a phosphoketolase with dual substrate, at least in the analyzed strains of L. reuteri. © 2012 Pleiades Publishing, Ltd.
UR - http://www.scopus.com/inward/record.url?scp=84866135250&partnerID=8YFLogxK
U2 - 10.1134/S000368381205002X
DO - 10.1134/S000368381205002X
M3 - Article
SN - 0003-6838
VL - 48
SP - 444
EP - 451
JO - Applied Biochemistry and Microbiology
JF - Applied Biochemistry and Microbiology
IS - 5
ER -