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Transport of glutamate in Oenococcus oeni 8403
International Journal of Food Microbiology 85 (2003) 307 – 311 www.elsevier.com/locate/ijfoodmicro
Short communication
Transport of glutamate in Oenococcus oeni 8403 Y. Vasserot *, C. Dion, E. Bonnet, I. Tabary, A. Maujean, P. Jeandet Laboratoire d’Oenologie, UPRES EA 2069, URVVC, Faculte´ des Sciences, Universite´ de Reims, B.P. 1039, 51687 Reims Cedex 02, France Received 24 May 2002; received in revised form 26 August 2002; accepted 27 November 2002
Abstract The transport of L-glutamate in Oenococcus oeni 8403 is energy dependent. It could be activated either by carbohydrate or arginine metabolism, and it was shown to be stimulated by L-malic acid at low pH values. Transport was optimal at pH 7.0. The apparent affinity constants for transport (KT) was 0.98 AM at pH 7.0. L-glutamate uptake was inhibited by glutamine, asparagine and L-aspartate. D 2002 Elsevier Science B.V. All rights reserved. Keywords: Oenococcus oeni; Amino acid transport; L-Glutamate
1. Introduction Malolactic fermentation (MLF) is an important stage of sparkling wine production. The conversion of L-malic acid into L-lactic acid and carbon dioxide by lactic acid bacteria reduces the acidity in wines and makes them microbiologically more stable (Kunkee, 1967). In addition, some metabolism of these microorganisms can change favourably the flavour of the wine (Rodriguez et al., 1990). For these reasons, and because improved sanitary conditions in winemaking have resulted in the production of wines in which MLF may not occur spontaneously, or may be very unpredictable, many winemakers tried to induce MLF with starter cultures developed from Oenococcus oeni (Lafon-Lafourcade et al., 1983). Despite the use of these starter cultures, MLF very often remains diffi-
* Corresponding author. Fax: +33-11-333-26-91-33-40. E-mail address: [email protected] (Y. Vasserot).
cult to induce, in particular in Champagne wines. Difficulties in inducing MLF are usually attributed to the cumulative inhibitory effect of low pH, high alcohol and SO2 content of wines (Wibowo et al., 1988). However, since the development of O. oeni requires a number of nutrients (Duplessis, 1963), it can also be suggested that the difficulties in inducing MLF have their origin in the inability of O. oeni to utilise some of these nutrients. Among the nutrients required by O. oeni, amino acids were shown to be of great significance (Garvie, 1967a; Tracey and Britz, 1989). To date, only few studies have focused on the amino acid requirements of O. oeni whose physiological properties noticeably differ from those of other species of lactic acid bacteria (Garvie, 1967b). Though amino acids requirements for O. oeni largely differ from one strain to another, most of the strains have an absolute requirement for isoleucine, glutamic acid, tryptophan and arginine (Fourcassie et al., 1992). Transport of these amino acids by O. oeni has not yet been described. A deficient uptake of one of these
0168-1605/02/$ - see front matter D 2002 Elsevier Science B.V. All rights reserved. doi: 10.1016/S0168-1605(02)00541-X
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Y. Vasserot et al. / International Journal of Food Microbiology 85 (2003) 307–311
essential amino acids could affect MLF and the present work was initiated the study of L-glutamate uptake by O. oeni 8403. glutamate is defined herein as the sum of glutamic acid and glutamate anion present in the solution.
3. Results and discussion 3.1. Energy requirements As illustrated in Fig. 1, cells were unable to take up without an exogenous source of energy. Such a result, which indicated that O. oeni cells did not possess an endogenous energy stock, is very similar to those reported for Lactobacillus casei (Strobel et al., 1989) and Lactococcus lactis (Smid et al., 1989). When cells were energized with fructose or Dribose, L-glutamate uptake was stimulated, as compared to the results obtained with glucose. This could be linked to an increase in the ATP content of the cells. Indeed, since a fraction of the fructose could be used as an hydrogen acceptor and reduced to mannitol, its metabolism via the heterofermentative phosphoketolase pathway resulted in more ATP synthesis by substrate-level phosphorylation, via acetate kinase, than glucose metabolism (Salou et al., 1994). Dribose was also metabolized via the phosphoketolase pathway after its conversion into D-xylulose-5P. Since L-glutamate
2. Materials and methods 2.1. Bacterial strain and medium The strain used in this study was O. oeni 8403. It was isolated from wine by the Faculte´ d’Oenologie de Bordeaux. For all uptake experiments MRS broth (De Man et al., 1960) at pH 4.5 was used. 2.2. Measurement of L-glutamate uptake Transport assays were performed according to the method described by Strobel et al. (1989). Batch cultures in the MRS medium were grown to an absorbance (A) at 650 nm of 1 (mid-exponential phase), and cells were harvested by centrifugation (1200 g, 5 min, 20 jC). They were washed twice with physiological water (NaCl, 9 g l 1) and resuspended in 100 mmol l 1 potassium dihydrogenophosphate (pH 7) containing 10 mmol l 1 MgSO4. Unless otherwise stated, cells (approximately 1 mg dry matter) were energized with 20 mmol l 1 glucose for 20 min at 28 jC and transport assays were conducted in 210 Al of buffer containing the appropriate concentration of L-[14C]glutamic acid (100 nCi Amol 1), 10 mmol l 1 MgSO4 and 100 mmol l 1 potassium phosphate (pH 4.0 –7.0). Transport was terminated by adding 48 Al of the reaction mixture in 2 ml icecold 100 mmol l 1 LiCl and filtering this mixture through a 0.45 AM cellulose nitrate membrane filter. Filters were washed once with 3 ml 100 mmol l 1 LiCl and dried for 4 h at 37 jC. They were then solubilized into 5 ml liquid scintillation fluid and radioactivity was measured using a radioisotope flow detector. Kinetic analysis of L-glutamate uptake were determinated at pH 7. Uptake rates were determined from the uptake values obtained at time points up to the first 60 s by using an amino acid concentration range between 0.25 and 3 AM. Results were analysed by Eadie – Hofstee plots (Dixon and Webb, 1979).
Fig. 1. Initial rate of L-glutamic acid uptake in O. oeni 8403. Cells (1 mg [dry weight]/ml of buffer, pH 7.0) were incubated for 20 min at 28 jC before the addition of 2 AM of L-[14C]glutamic acid. Each carbohydrate was used at 20 mM. Initial rates were calculated at 5 s of the kinetic runs and were measured in triplicate. Bars indicate standard deviation.
Y. Vasserot et al. / International Journal of Food Microbiology 85 (2003) 307–311
309
Fig. 2. Uptake of L-glutamic acid uptake by O. oeni 8403 following cells energization with arginine 20 mM (o) and glucose 20 mM ( ). Cells (1 mg [dry weight]/ml of buffer, pH 7.0) were incubated for 20 min at 28 jC with arginine or glucose before addition of 1 AM of L-[14C]glutamic acid. Initial rates were calculated at 5 s of the kinetic runs and were measured in triplicate. Bars indicate standard deviation.
all the acetyl-P generated from the splitting of Dxylulose-5P was then converted into acetate, ATP production from D-ribose metabolism was more important than from glucose metabolism (Kandler, 1983).
at least 60-fold higher than the rate of protonmotive force-driven arginine translocation (Driessen et al., 1987). The uptake of L-glutamate in response to cell energization with malic acid was performed at pH 3, 4 and 5 (Fig. 3). As expected, when malic acid
3.2. Effect of arginine and malic acid Since arginine and malic acid could be used as sources of energy for ATP synthesis in O. oeni (Cox and Henick-Kling, 1989; Arena et al., 1999), their effect on the rate of L-glutamate uptake was studied. With arginine as a source of energy for ATP synthesis instead of glucose, the initial rate of L-glutamate uptake increased (Fig. 2). Such a result differs to those obtained for Streptococcus cremoris and Streptococcus lactis (Poolman et al., 1987). Since the deiminase pathway yields only 1 mol of ATP per mol of arginine converted into ornithine (Arena et al., 1999), arginine metabolism in O. oeni does not lead to more production of ATP than glucose metabolism. Under such conditions, the high rate of L-glutamate uptake in the presence of arginine could result from the ability of O. oeni to take up arginine more rapidly and more completely than glucose. Indeed, many lactic acid bacteria contained an arginine– ornithine antiporter. This system does not require metabolic energy and it was found that it transported arginine at a rate that was
Fig. 3. Effect of malic acid on L-glutamic acid uptake in O. oeni 8403. Cells (1 mg [dry weight]/ml of buffer, pH 7.0) were energized for 20 min at 28 jC with glucose 20 mM (open bars) or with glucose 20 mM + malic acid 20 mM (filled bars). L-Glutamic acid concentration was 2 AM. Rate of uptake following energization with glucose was set to 100%. Cell energization and L-glutamic uptake were performed at pH 3, 4 and 5.
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reported for S. lactis and S. cremoris (Poolman et al., 1987). The double reciprocal plot of substrate dependent uptake kinetic of L-glutamate in relation to L-aspartate concentration indicated the competitive nature of the inhibition (Ki = 2.13 AM) at pH 7.0. This result supported the conclusion that L-aspartate and L-glutamate were taken up by the same carrier. The uptake of L-glutamate was tested by varying pH. When glucose was used as the energy source, the initial rate of uptake reached a maximum at pH 7 (Fig. 4). Since the same buffers were used for cells energization and L-glutamate uptake, it is possible that the pH dependance of L-glutamate uptake reflects the pH dependence of cells energization.
Fig. 4. Effect of external pH on the initial rate of L-glutamic acid uptake by O. oeni 8403. L-Glutamic acid concentration was 1 AM. Cells (1 mg [dry weight]/ml of buffer) were incubated at 28 jC. Initial rates were calculated at 5 s of the kinetic runs.
and glucose were used in association to energize cells, the initial rate of uptake of L-glutamate increased as compared to the results obtained when glucose was used alone. Moreover, the stimulation of L-glutamate uptake reached a maximum when energization and kinetics were performed at pH 3 and it was almost absent when energization and kinetics were performed at pH 5. This result is in agreement with the fact that the maximum amount of ATP produced from malolactic conversion occurred at pH values below 4.5 (Cox and Henick-Kling, 1989). 3.3. Kinetic properties of L-glutamate transport Transformation of the experimental data into Eady –Hofstee plots yield a single straight line, indicating the presence of only one kinetically distinguishable glutamate transport system. The Michaelis constant (Km) and the maximum velocity (Vmax) for glutamate uptake were estimated to be 1.02 AM and 9.18 pmol mg 1 min 1, respectively. L-glutamate uptake was found to be completely inhibited by a 10-fold excess of L-aspartate, asparagine or glutamine. Though it was rather unusual, Lglutamate uptake inhibition by glutamine has yet been
References Arena, M.E., Saguir, F.M., Manca de Nadra, M.C., 1999. Arginine, citrulline and ornithine metabolism by lactic acid bacteria from wine. Int. J. Food Microbiol. 52, 155 – 156. Cox, D.J., Henick-Kling, T., 1989. Chemiosmotic energy from malolactic fermentation. J. Bacteriol. 171, 5750 – 5752. De Man, J.C., Rogosa, M., Sharpe, M.E., 1960. A medium for the cultivation of lactobacilli. J. Appl. Bacteriol. 23, 130 – 135. Dixon, M., Webb, E.C., 1979. Enzymes, 3rd ed. Longman Group, London. Driessen, A.J., Poolman, B., Kiewiet, R., Konings, W.N., 1987. Arginine transport in Streptococcus lactis is catalyzed by a cationic exchanger. Proc. Natl. Acad. Sci. U. S. A. 84, 6093 – 6097. Duplessis, L.W., 1963. The microbiology of South African winemaking: Part V. Vitamin and amino acid requirements of lactic acid bacteria from dry wines. S. Afr. J. Agric. Sci. 6, 485 – 494. Fourcassie, P., Makaga-Kabinda-Massard, E., Belarbi, A., Maujean, A., 1992. Growth, D-glucose utilization and malolactic fermentation by Leuconostoc oenos strains in 18 media deficient in one amino acid. J. Appl. Bacteriol. 73, 489 – 496. Garvie, E., 1967a. The growth factor and amino acid requirements of the genus Leuconostoc, including Leuconostoc paramesenteroı¨des (sp. nov) and Leuconostoc œnos. J. Gen. Microbiol. 48, 439 – 447. Garvie, E., 1967b. Leuconostoc oenos species nov. J. Gen. Microbiol. 48, 431. Kandler, O., 1983. Carbohydrate metabolism in lactic acid bacteria. Antonie van Leeuwenhoek 49, 209 – 224. Kunkee, R.E., 1967. Malolactic fermentation. Adv. Appl. Microbiol. 9, 235 – 279. Lafon-Lafourcade, S., Carre, E., Lonvaud-Funel, A., RibereauGayon, P., 1983. Induction de la fermentation malolactique des vins par inoculation d’une biomasse industrielle congele´e de Leuconostoc œnos apre`s re´activation. Connaiss. Vigne Vin 17, 55 – 71.
Y. Vasserot et al. / International Journal of Food Microbiology 85 (2003) 307–311 Poolman, B., Smid, E.J., Konings, W.N., 1987. Kinetic properties of a phosphate-bond-driven glutamate – glutamine transport system in Streptococcus lactic and Streptococcus cremoris. J. Bacteriol. 169, 2755 – 2761. Rodriguez, S.B., Amberg, E., Thornton, R.J., 1990. Malolactic fermentation in Chardonnay: growth and sensory effects of commercial strains of Leuconostoc œnos. J. Appl. Bacteriol. 68, 139 – 144. Salou, P., Loubie`re, P., Pareilleux, A., 1994. Growth and energetics of Leuconostoc oenos during cometabolism of glucose with citrate or fructose. Appl. Environ. Microbiol. 60, 1459 – 1466. Smid, E.J., Driessen, A.J.M., Konings, W.N., 1989. Mechanism and
311
energetics of dipeptide transport in membrane vesicles of Lactococcus lactis. J. Bacteriol. 171, 292 – 298. Strobel, H.J., Russel, J.B., Driessen, A.J.M., Konings, W.N., 1989. Transport of amino acids in Lactobacillus casei by proton-motive-force-dependent and non-proton-motive-force-dependent mechanisms. J. Bacteriol. 171, 280 – 284. Tracey, R.P., Britz, T.J., 1989. The effect of amino acids on malolactic fermentation by Leuconostoc œnos. J. Appl. Bacteriol. 67, 589 – 595. Wibowo, D., Fleet, G.H., Lee, T.H., Eschenbruch, R.E., 1988. Factors affecting the induction of malolactic fermentation in red wines with Leuconostoc œnos. J. Appl. Bacteriol. 64, 421 – 428.
Short communication
Transport of glutamate in Oenococcus oeni 8403 Y. Vasserot *, C. Dion, E. Bonnet, I. Tabary, A. Maujean, P. Jeandet Laboratoire d’Oenologie, UPRES EA 2069, URVVC, Faculte´ des Sciences, Universite´ de Reims, B.P. 1039, 51687 Reims Cedex 02, France Received 24 May 2002; received in revised form 26 August 2002; accepted 27 November 2002
Abstract The transport of L-glutamate in Oenococcus oeni 8403 is energy dependent. It could be activated either by carbohydrate or arginine metabolism, and it was shown to be stimulated by L-malic acid at low pH values. Transport was optimal at pH 7.0. The apparent affinity constants for transport (KT) was 0.98 AM at pH 7.0. L-glutamate uptake was inhibited by glutamine, asparagine and L-aspartate. D 2002 Elsevier Science B.V. All rights reserved. Keywords: Oenococcus oeni; Amino acid transport; L-Glutamate
1. Introduction Malolactic fermentation (MLF) is an important stage of sparkling wine production. The conversion of L-malic acid into L-lactic acid and carbon dioxide by lactic acid bacteria reduces the acidity in wines and makes them microbiologically more stable (Kunkee, 1967). In addition, some metabolism of these microorganisms can change favourably the flavour of the wine (Rodriguez et al., 1990). For these reasons, and because improved sanitary conditions in winemaking have resulted in the production of wines in which MLF may not occur spontaneously, or may be very unpredictable, many winemakers tried to induce MLF with starter cultures developed from Oenococcus oeni (Lafon-Lafourcade et al., 1983). Despite the use of these starter cultures, MLF very often remains diffi-
* Corresponding author. Fax: +33-11-333-26-91-33-40. E-mail address: [email protected] (Y. Vasserot).
cult to induce, in particular in Champagne wines. Difficulties in inducing MLF are usually attributed to the cumulative inhibitory effect of low pH, high alcohol and SO2 content of wines (Wibowo et al., 1988). However, since the development of O. oeni requires a number of nutrients (Duplessis, 1963), it can also be suggested that the difficulties in inducing MLF have their origin in the inability of O. oeni to utilise some of these nutrients. Among the nutrients required by O. oeni, amino acids were shown to be of great significance (Garvie, 1967a; Tracey and Britz, 1989). To date, only few studies have focused on the amino acid requirements of O. oeni whose physiological properties noticeably differ from those of other species of lactic acid bacteria (Garvie, 1967b). Though amino acids requirements for O. oeni largely differ from one strain to another, most of the strains have an absolute requirement for isoleucine, glutamic acid, tryptophan and arginine (Fourcassie et al., 1992). Transport of these amino acids by O. oeni has not yet been described. A deficient uptake of one of these
0168-1605/02/$ - see front matter D 2002 Elsevier Science B.V. All rights reserved. doi: 10.1016/S0168-1605(02)00541-X
308
Y. Vasserot et al. / International Journal of Food Microbiology 85 (2003) 307–311
essential amino acids could affect MLF and the present work was initiated the study of L-glutamate uptake by O. oeni 8403. glutamate is defined herein as the sum of glutamic acid and glutamate anion present in the solution.
3. Results and discussion 3.1. Energy requirements As illustrated in Fig. 1, cells were unable to take up without an exogenous source of energy. Such a result, which indicated that O. oeni cells did not possess an endogenous energy stock, is very similar to those reported for Lactobacillus casei (Strobel et al., 1989) and Lactococcus lactis (Smid et al., 1989). When cells were energized with fructose or Dribose, L-glutamate uptake was stimulated, as compared to the results obtained with glucose. This could be linked to an increase in the ATP content of the cells. Indeed, since a fraction of the fructose could be used as an hydrogen acceptor and reduced to mannitol, its metabolism via the heterofermentative phosphoketolase pathway resulted in more ATP synthesis by substrate-level phosphorylation, via acetate kinase, than glucose metabolism (Salou et al., 1994). Dribose was also metabolized via the phosphoketolase pathway after its conversion into D-xylulose-5P. Since L-glutamate
2. Materials and methods 2.1. Bacterial strain and medium The strain used in this study was O. oeni 8403. It was isolated from wine by the Faculte´ d’Oenologie de Bordeaux. For all uptake experiments MRS broth (De Man et al., 1960) at pH 4.5 was used. 2.2. Measurement of L-glutamate uptake Transport assays were performed according to the method described by Strobel et al. (1989). Batch cultures in the MRS medium were grown to an absorbance (A) at 650 nm of 1 (mid-exponential phase), and cells were harvested by centrifugation (1200 g, 5 min, 20 jC). They were washed twice with physiological water (NaCl, 9 g l 1) and resuspended in 100 mmol l 1 potassium dihydrogenophosphate (pH 7) containing 10 mmol l 1 MgSO4. Unless otherwise stated, cells (approximately 1 mg dry matter) were energized with 20 mmol l 1 glucose for 20 min at 28 jC and transport assays were conducted in 210 Al of buffer containing the appropriate concentration of L-[14C]glutamic acid (100 nCi Amol 1), 10 mmol l 1 MgSO4 and 100 mmol l 1 potassium phosphate (pH 4.0 –7.0). Transport was terminated by adding 48 Al of the reaction mixture in 2 ml icecold 100 mmol l 1 LiCl and filtering this mixture through a 0.45 AM cellulose nitrate membrane filter. Filters were washed once with 3 ml 100 mmol l 1 LiCl and dried for 4 h at 37 jC. They were then solubilized into 5 ml liquid scintillation fluid and radioactivity was measured using a radioisotope flow detector. Kinetic analysis of L-glutamate uptake were determinated at pH 7. Uptake rates were determined from the uptake values obtained at time points up to the first 60 s by using an amino acid concentration range between 0.25 and 3 AM. Results were analysed by Eadie – Hofstee plots (Dixon and Webb, 1979).
Fig. 1. Initial rate of L-glutamic acid uptake in O. oeni 8403. Cells (1 mg [dry weight]/ml of buffer, pH 7.0) were incubated for 20 min at 28 jC before the addition of 2 AM of L-[14C]glutamic acid. Each carbohydrate was used at 20 mM. Initial rates were calculated at 5 s of the kinetic runs and were measured in triplicate. Bars indicate standard deviation.
Y. Vasserot et al. / International Journal of Food Microbiology 85 (2003) 307–311
309
Fig. 2. Uptake of L-glutamic acid uptake by O. oeni 8403 following cells energization with arginine 20 mM (o) and glucose 20 mM ( ). Cells (1 mg [dry weight]/ml of buffer, pH 7.0) were incubated for 20 min at 28 jC with arginine or glucose before addition of 1 AM of L-[14C]glutamic acid. Initial rates were calculated at 5 s of the kinetic runs and were measured in triplicate. Bars indicate standard deviation.
all the acetyl-P generated from the splitting of Dxylulose-5P was then converted into acetate, ATP production from D-ribose metabolism was more important than from glucose metabolism (Kandler, 1983).
at least 60-fold higher than the rate of protonmotive force-driven arginine translocation (Driessen et al., 1987). The uptake of L-glutamate in response to cell energization with malic acid was performed at pH 3, 4 and 5 (Fig. 3). As expected, when malic acid
3.2. Effect of arginine and malic acid Since arginine and malic acid could be used as sources of energy for ATP synthesis in O. oeni (Cox and Henick-Kling, 1989; Arena et al., 1999), their effect on the rate of L-glutamate uptake was studied. With arginine as a source of energy for ATP synthesis instead of glucose, the initial rate of L-glutamate uptake increased (Fig. 2). Such a result differs to those obtained for Streptococcus cremoris and Streptococcus lactis (Poolman et al., 1987). Since the deiminase pathway yields only 1 mol of ATP per mol of arginine converted into ornithine (Arena et al., 1999), arginine metabolism in O. oeni does not lead to more production of ATP than glucose metabolism. Under such conditions, the high rate of L-glutamate uptake in the presence of arginine could result from the ability of O. oeni to take up arginine more rapidly and more completely than glucose. Indeed, many lactic acid bacteria contained an arginine– ornithine antiporter. This system does not require metabolic energy and it was found that it transported arginine at a rate that was
Fig. 3. Effect of malic acid on L-glutamic acid uptake in O. oeni 8403. Cells (1 mg [dry weight]/ml of buffer, pH 7.0) were energized for 20 min at 28 jC with glucose 20 mM (open bars) or with glucose 20 mM + malic acid 20 mM (filled bars). L-Glutamic acid concentration was 2 AM. Rate of uptake following energization with glucose was set to 100%. Cell energization and L-glutamic uptake were performed at pH 3, 4 and 5.
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Y. Vasserot et al. / International Journal of Food Microbiology 85 (2003) 307–311
reported for S. lactis and S. cremoris (Poolman et al., 1987). The double reciprocal plot of substrate dependent uptake kinetic of L-glutamate in relation to L-aspartate concentration indicated the competitive nature of the inhibition (Ki = 2.13 AM) at pH 7.0. This result supported the conclusion that L-aspartate and L-glutamate were taken up by the same carrier. The uptake of L-glutamate was tested by varying pH. When glucose was used as the energy source, the initial rate of uptake reached a maximum at pH 7 (Fig. 4). Since the same buffers were used for cells energization and L-glutamate uptake, it is possible that the pH dependance of L-glutamate uptake reflects the pH dependence of cells energization.
Fig. 4. Effect of external pH on the initial rate of L-glutamic acid uptake by O. oeni 8403. L-Glutamic acid concentration was 1 AM. Cells (1 mg [dry weight]/ml of buffer) were incubated at 28 jC. Initial rates were calculated at 5 s of the kinetic runs.
and glucose were used in association to energize cells, the initial rate of uptake of L-glutamate increased as compared to the results obtained when glucose was used alone. Moreover, the stimulation of L-glutamate uptake reached a maximum when energization and kinetics were performed at pH 3 and it was almost absent when energization and kinetics were performed at pH 5. This result is in agreement with the fact that the maximum amount of ATP produced from malolactic conversion occurred at pH values below 4.5 (Cox and Henick-Kling, 1989). 3.3. Kinetic properties of L-glutamate transport Transformation of the experimental data into Eady –Hofstee plots yield a single straight line, indicating the presence of only one kinetically distinguishable glutamate transport system. The Michaelis constant (Km) and the maximum velocity (Vmax) for glutamate uptake were estimated to be 1.02 AM and 9.18 pmol mg 1 min 1, respectively. L-glutamate uptake was found to be completely inhibited by a 10-fold excess of L-aspartate, asparagine or glutamine. Though it was rather unusual, Lglutamate uptake inhibition by glutamine has yet been
References Arena, M.E., Saguir, F.M., Manca de Nadra, M.C., 1999. Arginine, citrulline and ornithine metabolism by lactic acid bacteria from wine. Int. J. Food Microbiol. 52, 155 – 156. Cox, D.J., Henick-Kling, T., 1989. Chemiosmotic energy from malolactic fermentation. J. Bacteriol. 171, 5750 – 5752. De Man, J.C., Rogosa, M., Sharpe, M.E., 1960. A medium for the cultivation of lactobacilli. J. Appl. Bacteriol. 23, 130 – 135. Dixon, M., Webb, E.C., 1979. Enzymes, 3rd ed. Longman Group, London. Driessen, A.J., Poolman, B., Kiewiet, R., Konings, W.N., 1987. Arginine transport in Streptococcus lactis is catalyzed by a cationic exchanger. Proc. Natl. Acad. Sci. U. S. A. 84, 6093 – 6097. Duplessis, L.W., 1963. The microbiology of South African winemaking: Part V. Vitamin and amino acid requirements of lactic acid bacteria from dry wines. S. Afr. J. Agric. Sci. 6, 485 – 494. Fourcassie, P., Makaga-Kabinda-Massard, E., Belarbi, A., Maujean, A., 1992. Growth, D-glucose utilization and malolactic fermentation by Leuconostoc oenos strains in 18 media deficient in one amino acid. J. Appl. Bacteriol. 73, 489 – 496. Garvie, E., 1967a. The growth factor and amino acid requirements of the genus Leuconostoc, including Leuconostoc paramesenteroı¨des (sp. nov) and Leuconostoc œnos. J. Gen. Microbiol. 48, 439 – 447. Garvie, E., 1967b. Leuconostoc oenos species nov. J. Gen. Microbiol. 48, 431. Kandler, O., 1983. Carbohydrate metabolism in lactic acid bacteria. Antonie van Leeuwenhoek 49, 209 – 224. Kunkee, R.E., 1967. Malolactic fermentation. Adv. Appl. Microbiol. 9, 235 – 279. Lafon-Lafourcade, S., Carre, E., Lonvaud-Funel, A., RibereauGayon, P., 1983. Induction de la fermentation malolactique des vins par inoculation d’une biomasse industrielle congele´e de Leuconostoc œnos apre`s re´activation. Connaiss. Vigne Vin 17, 55 – 71.
Y. Vasserot et al. / International Journal of Food Microbiology 85 (2003) 307–311 Poolman, B., Smid, E.J., Konings, W.N., 1987. Kinetic properties of a phosphate-bond-driven glutamate – glutamine transport system in Streptococcus lactic and Streptococcus cremoris. J. Bacteriol. 169, 2755 – 2761. Rodriguez, S.B., Amberg, E., Thornton, R.J., 1990. Malolactic fermentation in Chardonnay: growth and sensory effects of commercial strains of Leuconostoc œnos. J. Appl. Bacteriol. 68, 139 – 144. Salou, P., Loubie`re, P., Pareilleux, A., 1994. Growth and energetics of Leuconostoc oenos during cometabolism of glucose with citrate or fructose. Appl. Environ. Microbiol. 60, 1459 – 1466. Smid, E.J., Driessen, A.J.M., Konings, W.N., 1989. Mechanism and
311
energetics of dipeptide transport in membrane vesicles of Lactococcus lactis. J. Bacteriol. 171, 292 – 298. Strobel, H.J., Russel, J.B., Driessen, A.J.M., Konings, W.N., 1989. Transport of amino acids in Lactobacillus casei by proton-motive-force-dependent and non-proton-motive-force-dependent mechanisms. J. Bacteriol. 171, 280 – 284. Tracey, R.P., Britz, T.J., 1989. The effect of amino acids on malolactic fermentation by Leuconostoc œnos. J. Appl. Bacteriol. 67, 589 – 595. Wibowo, D., Fleet, G.H., Lee, T.H., Eschenbruch, R.E., 1988. Factors affecting the induction of malolactic fermentation in red wines with Leuconostoc œnos. J. Appl. Bacteriol. 64, 421 – 428.