INVESTIGADORES
GONZALEZ Silvia Nelina
congresos y reuniones científicas
Título:
Synthesis of esters by propionibacteria and lactobacilli
Autor/es:
ABEIJÓN C.; MAILLARD M.B.; OLISZEWSKI R.; MEDINA R.; GONZÁLEZ S.
Lugar:
Tucumán, Argentina
Reunión:
Congreso; . VII Congreso Argentino de Migrobiología General SAMIGE del Bicentenario; 2011
Institución organizadora:
Sociedad Argentina de Microbiología
Resumen:
Esters are important contributors to the flavor of many cheese-types, conferring fruity notes.
Among several esters detected in cheese, ethyl butanoate is a common flavor-active
compound. Propionibacteria (PAB) and lactobacilli used as starter/adjunct cultures in the
manufacture of Swiss-type cheeses play a major role in ester synthesis. Esters are synthesized
by esterases from free fatty acids and alcohols (esterification) or triglycerides and alcohols
(alcoholysis). The availability of alcohols is the limiting factor of ester synthesis in Swiss and
Cheddar cheese. Our aim was to evaluate the ester-synthesizing activity of two PAB strains
(Propionibacterium freudenreichii CIRM1 and CIRM508) and two lactobacilli strains
(Lactobacillus fermentum CRL1446 and L. casei CRL1430) isolated from cheeses. PAB were
cultured in YEL broth at 30°C, and lactobacilli in MRS broth at 37°C. Cells were harvested at
stationary phase, and disrupted using glass beads. Cell-free extracts were then incubated in
reaction mixtures containing either butanoic acid + ethanol or tributyrin + ethanol, to investigate
ester synthesis via esterification and alcoholysis, respectively. After 24 h incubation at 30°C
(PAB) or 37°C (lactobacilli), esters and alcohols were determined using dynamic head spacegas
chromatography-mass spectrometry (DHS-GC-MS). Both PAB strains showed ethyl
butanoate-synthesizing activity via esterification, P. freudenreichii CIRM508 activity being 2-fold
higher than P. freudenreichii CIRM1. Ethyl butanoate-synthesizing activities via alcoholysis
were also detected, but were significantly lower than via esterification, P. freudenreichii CIRM1
activity being 2-fold higher than P. freudenreichii CIRM508. Regarding lactobacilli, both strains
showed ethyl butanoate-synthesizing activity. In L. fermentum CRL1446 higher activity via
alcoholysis was observed, whereas in L. casei CRL1430 higher activity via esterification was
detected. Significant pentyl butanoate and butyl butanoate-synthesizing activites via alcoholysis
were also observed in these strains. No direct relationship between the presence of alcohols
and the corresponding esters was observed. Our results demonstrate that the evaluated strains
have the enzymatic potential to synthesize esters that are crucial for flavor development in
Swiss-type cheeses. Supported by ECOS-MINCYT A08B02.Propionibacterium freudenreichii CIRM1 and CIRM508) and two lactobacilli strains
(Lactobacillus fermentum CRL1446 and L. casei CRL1430) isolated from cheeses. PAB were
cultured in YEL broth at 30°C, and lactobacilli in MRS broth at 37°C. Cells were harvested at
stationary phase, and disrupted using glass beads. Cell-free extracts were then incubated in
reaction mixtures containing either butanoic acid + ethanol or tributyrin + ethanol, to investigate
ester synthesis via esterification and alcoholysis, respectively. After 24 h incubation at 30°C
(PAB) or 37°C (lactobacilli), esters and alcohols were determined using dynamic head spacegas
chromatography-mass spectrometry (DHS-GC-MS). Both PAB strains showed ethyl
butanoate-synthesizing activity via esterification, P. freudenreichii CIRM508 activity being 2-fold
higher than P. freudenreichii CIRM1. Ethyl butanoate-synthesizing activities via alcoholysis
were also detected, but were significantly lower than via esterification, P. freudenreichii CIRM1
activity being 2-fold higher than P. freudenreichii CIRM508. Regarding lactobacilli, both strains
showed ethyl butanoate-synthesizing activity. In L. fermentum CRL1446 higher activity via
alcoholysis was observed, whereas in L. casei CRL1430 higher activity via esterification was
detected. Significant pentyl butanoate and butyl butanoate-synthesizing activites via alcoholysis
were also observed in these strains. No direct relationship between the presence of alcohols
and the corresponding esters was observed. Our results demonstrate that the evaluated strains
have the enzymatic potential to synthesize esters that are crucial for flavor development in
Swiss-type cheeses. Supported by ECOS-MINCYT A08B02.Lactobacillus fermentum CRL1446 and L. casei CRL1430) isolated from cheeses. PAB were
cultured in YEL broth at 30°C, and lactobacilli in MRS broth at 37°C. Cells were harvested at
stationary phase, and disrupted using glass beads. Cell-free extracts were then incubated in
reaction mixtures containing either butanoic acid + ethanol or tributyrin + ethanol, to investigate
ester synthesis via esterification and alcoholysis, respectively. After 24 h incubation at 30°C
(PAB) or 37°C (lactobacilli), esters and alcohols were determined using dynamic head spacegas
chromatography-mass spectrometry (DHS-GC-MS). Both PAB strains showed ethyl
butanoate-synthesizing activity via esterification, P. freudenreichii CIRM508 activity being 2-fold
higher than P. freudenreichii CIRM1. Ethyl butanoate-synthesizing activities via alcoholysis
were also detected, but were significantly lower than via esterification, P. freudenreichii CIRM1
activity being 2-fold higher than P. freudenreichii CIRM508. Regarding lactobacilli, both strains
showed ethyl butanoate-synthesizing activity. In L. fermentum CRL1446 higher activity via
alcoholysis was observed, whereas in L. casei CRL1430 higher activity via esterification was
detected. Significant pentyl butanoate and butyl butanoate-synthesizing activites via alcoholysis
were also observed in these strains. No direct relationship between the presence of alcohols
and the corresponding esters was observed. Our results demonstrate that the evaluated strains
have the enzymatic potential to synthesize esters that are crucial for flavor development in
Swiss-type cheeses. Supported by ECOS-MINCYT A08B02.P. freudenreichii CIRM508 activity being 2-fold
higher than P. freudenreichii CIRM1. Ethyl butanoate-synthesizing activities via alcoholysis
were also detected, but were significantly lower than via esterification, P. freudenreichii CIRM1
activity being 2-fold higher than P. freudenreichii CIRM508. Regarding lactobacilli, both strains
showed ethyl butanoate-synthesizing activity. In L. fermentum CRL1446 higher activity via
alcoholysis was observed, whereas in L. casei CRL1430 higher activity via esterification was
detected. Significant pentyl butanoate and butyl butanoate-synthesizing activites via alcoholysis
were also observed in these strains. No direct relationship between the presence of alcohols
and the corresponding esters was observed. Our results demonstrate that the evaluated strains
have the enzymatic potential to synthesize esters that are crucial for flavor development in
Swiss-type cheeses. Supported by ECOS-MINCYT A08B02.P. freudenreichii CIRM1. Ethyl butanoate-synthesizing activities via alcoholysis
were also detected, but were significantly lower than via esterification, P. freudenreichii CIRM1
activity being 2-fold higher than P. freudenreichii CIRM508. Regarding lactobacilli, both strains
showed ethyl butanoate-synthesizing activity. In L. fermentum CRL1446 higher activity via
alcoholysis was observed, whereas in L. casei CRL1430 higher activity via esterification was
detected. Significant pentyl butanoate and butyl butanoate-synthesizing activites via alcoholysis
were also observed in these strains. No direct relationship between the presence of alcohols
and the corresponding esters was observed. Our results demonstrate that the evaluated strains
have the enzymatic potential to synthesize esters that are crucial for flavor development in
Swiss-type cheeses. Supported by ECOS-MINCYT A08B02.P. freudenreichii CIRM1
activity being 2-fold higher than P. freudenreichii CIRM508. Regarding lactobacilli, both strains
showed ethyl butanoate-synthesizing activity. In L. fermentum CRL1446 higher activity via
alcoholysis was observed, whereas in L. casei CRL1430 higher activity via esterification was
detected. Significant pentyl butanoate and butyl butanoate-synthesizing activites via alcoholysis
were also observed in these strains. No direct relationship between the presence of alcohols
and the corresponding esters was observed. Our results demonstrate that the evaluated strains
have the enzymatic potential to synthesize esters that are crucial for flavor development in
Swiss-type cheeses. Supported by ECOS-MINCYT A08B02.P. freudenreichii CIRM508. Regarding lactobacilli, both strains
showed ethyl butanoate-synthesizing activity. In L. fermentum CRL1446 higher activity via
alcoholysis was observed, whereas in L. casei CRL1430 higher activity via esterification was
detected. Significant pentyl butanoate and butyl butanoate-synthesizing activites via alcoholysis
were also observed in these strains. No direct relationship between the presence of alcohols
and the corresponding esters was observed. Our results demonstrate that the evaluated strains
have the enzymatic potential to synthesize esters that are crucial for flavor development in
Swiss-type cheeses. Supported by ECOS-MINCYT A08B02.L. fermentum CRL1446 higher activity via
alcoholysis was observed, whereas in L. casei CRL1430 higher activity via esterification was
detected. Significant pentyl butanoate and butyl butanoate-synthesizing activites via alcoholysis
were also observed in these strains. No direct relationship between the presence of alcohols
and the corresponding esters was observed. Our results demonstrate that the evaluated strains
have the enzymatic potential to synthesize esters that are crucial for flavor development in
Swiss-type cheeses. Supported by ECOS-MINCYT A08B02.L. casei CRL1430 higher activity via esterification was
detected. Significant pentyl butanoate and butyl butanoate-synthesizing activites via alcoholysis
were also observed in these strains. No direct relationship between the presence of alcohols
and the corresponding esters was observed. Our results demonstrate that the evaluated strains
have the enzymatic potential to synthesize esters that are crucial for flavor development in
Swiss-type cheeses. Supported by ECOS-MINCYT A08B02.Supported by ECOS-MINCYT A08B02.