Croissance et prise de l'acide glutamique par les bactéries du genre Streptococcus en fonction de la source d'énergie

Benateya, Amina; Bracquart, Patrice; Deaut, J.Y. Le; Linden, G.

doi:10.1051/lait:1986317

“…Although no amino acid and di-tripeptide transport systems have been characterised in detail in S. thermophilus, growth experiments have shown that amino acids as well as mixtures of very short peptides have a stimulatory effect on growth [112]. In addition, only preliminary experimental evidence for transport of glutamate [127,128] and BCAA is available for this species [129]. The LMG18311 and CNRZ1066 genomes contain a proton-dependent di-tripeptide transporter, homologous to DtpT from Lc.…”

Section: Amino Acid and Peptide Transport Systemsmentioning

confidence: 99%

New insights in the molecular biology and physiology of revealed by comparative genomics

Hols

¹

,

Hancy

²

,

Fontaine

³

et al. 2005

FEMS Microbiology Reviews

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Streptococcus thermophilus is a major dairy starter used for the manufacture of yoghurt and cheese. The access to three genome sequences, comparative genomics and multilocus sequencing analyses suggests that this species recently emerged and is still undergoing a process of regressive evolution towards a specialised bacterium for growth in milk. Notably, S. thermophilus has maintained a well-developed nitrogen metabolism whereas its sugar catabolism has been subjected to a high level of degeneracy due to a paucity of carbon sources in milk. Furthermore, while pathogenic streptococci are recognised for a high capacity to expose proteins at their cell surface in order to achieve cell adhesion or to escape the host immune system, S. thermophilus has nearly lost this unique feature as well as many virulence-related functions. Although gene decay is obvious in S. thermophilus genome evolution, numerous small genomic islands, which were probably acquired by horizontal gene transfer, comprise important industrial phenotypic traits such as polysaccharide biosynthesis, bacteriocin production, restriction-modification systems or oxygen tolerance.

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“…Although no amino acid and di‐tripeptide transport systems have been characterised in detail in S. thermophilus , growth experiments have shown that amino acids as well as mixtures of very short peptides have a stimulatory effect on growth [112]. In addition, only preliminary experimental evidence for transport of glutamate [127,128] and BCAA is available for this species [129]. The LMG18311 and CNRZ1066 genomes contain a proton‐dependent di‐tripeptide transporter, homologous to DtpT from Lc.…”

Section: Nitrogen Metabolism and Regulationmentioning

confidence: 99%

New insights in the molecular biology and physiology ofStreptococcus thermophilusrevealed by comparative genomics

Hols

¹

,

Hancy

²

,

Fontaine

³

et al. 2005

View full text Add to dashboard Cite

Streptococcus thermophilus is a major dairy starter used for the manufacture of yoghurt and cheese. The access to three genome sequences, comparative genomics and multilocus sequencing analyses suggests that this species recently emerged and is still undergoing a process of regressive evolution towards a specialised bacterium for growth in milk. Notably, S. thermophilus has maintained a well-developed nitrogen metabolism whereas its sugar catabolism has been subjected to a high level of degeneracy due to a paucity of carbon sources in milk. Furthermore, while pathogenic streptococci are recognised for a high capacity to expose proteins at their cell surface in order to achieve cell adhesion or to escape the host immune system, S. thermophilus has nearly lost this unique feature as well as many virulence-related functions. Although gene decay is obvious in S. thermophilus genome evolution, numerous small genomic islands, which were probably acquired by horizontal gene transfer, comprise important industrial phenotypic traits such as polysaccharide biosynthesis, bacteriocin production, restriction-modification systems or oxygen tolerance.

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“…In contrast to vertebrates (Slotboom et al 1999), requirement for glutamate (Glu) remains poorly characterized in bacteria (Ledesma et al 1977;Morishita et al 1981;Benateya et al 1986;Konings et al 1994). Despite amino acid transport now being well described in some lactic acid bacteria (Konings et al 1994), only a few papers have been devoted to amino acid uptake in the genus Lactobacillus (Strobel et al 1989;de Giori and de Valdez 1994;Nakajima et al 1998).…”

Section: Introductionmentioning

confidence: 99%

Glutamate uptake in Lactobacillus delbrueckii subsp. bulgaricus CNRZ 208 and its enhancement by a combination of Mn2+ and Mg2+

Giori

¹

,

Foucaud-Scheunemann

²

,

Ferchichi

³

et al. 2002

Lett Appl Microbiol

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Aims: To demonstrate the mechanism of glutamate uptake in the dairy strain Lactobacillus delbrueckii subsp. bulgaricus CNRZ 208, and to characterize key aspects of the system. Methods and Results: Glutamate uptake proceeded via an active transport system requiring an exogenous source of energy. The system also transported aspartate and glutamine. It was unique, with a K t of 2AE8 lmol l )1 and a V max of 900 lmol s )1 (g dry weight) )1 . The activity was optimal at pH 7AE3 and 50°C, was independent of the glutamate charge, and was enhanced by Mn 2+ + Mg 2+ in combination. Inhibition of the activity by uncouplers and ionophores showed that transport was driven by an ATP-dependent mechanism involving the proton-motive force. This inhibition was partially abolished in the presence of both Mn 2+ and Mg 2+. Conclusions:We demonstrated for the first time that an active transport system governs the uptake of the essential amino acid glutamate in Lact. delbrueckii subsp. bulgaricus CNRZ 208, the activity of which is enhanced by a combination of Mn 2+ and Mg 2+ . Significance and Impact of the Study: The potential of the findings is discussed with reference to the growth of Lact. delbrueckii subsp. bulgaricus in mixed-strain cultures for the dairy industry.

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Croissance et prise de l'acide glutamique par les bactéries du genre Streptococcus en fonction de la source d'énergie

Cited by 5 publications

References 29 publications

New insights in the molecular biology and physiology of revealed by comparative genomics

New insights in the molecular biology and physiology of revealed by comparative genomics

New insights in the molecular biology and physiology ofStreptococcus thermophilusrevealed by comparative genomics

Glutamate uptake in Lactobacillus delbrueckii subsp. bulgaricus CNRZ 208 and its enhancement by a combination of Mn2+ and Mg2+

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