Can I read Adaptation to high salt in Lactobacillus: role of peptides and proteolytic enzymes on EtoBox?

Adaptation to high salt in Lactobacillus: role of peptides and proteolytic enzymes by M. Piuri; C. Sanchez-Rivas; S.M. Ruzal is a Biochemistry, Genetics and Molecular Biology article available to read on EtoBox.

What is Adaptation to high salt in Lactobacillus: role of peptides and proteolytic enzymes about?

## Aims: To study the influence of peptides and proteolytic enzymes in the osmotic adaptation of lactobacillus casei. ## Methods and results: Di- and tri-peptides added individually increased the osmotolerance of lact. casei when grown in a chemically defined medium (cdm) containing nacl. growth stimulation and the re-establishment in their presence of plasmid dna supercoiling (recovery of the linking number) in hyperosmotic medium indicated that they are used as osmocompatible solutes as carnithine a known osmoprotector does. the investigation of the proteolytic system showed that in high osmolarity medium, the cell envelope-associated proteinase (prtp), and pepx (x-prolyl-dipeptidyl aminopeptidase) increased activity and lost repression by peptides. pepi, an iminopeptidase was also derepressed. pepq, a prolidase that specifically liberated proline from dipeptides, was almost unaffected. derepression in the presence of peptides took place at the transcriptional level. however, the twofold activation of prtp in cdm hyperosmotic medium was essentially through an increase of the apparent vmax of the enzyme. ## Conclusions: These results strongly suggest a contribution of the proteoly

Who reads Adaptation to high salt in Lactobacillus: role of peptides and proteolytic enzymes?

Author

M. Piuri; C. Sanchez-Rivas; S.M. Ruzal

Publisher

Oxford University Press (OUP)

Published

2003

Language

EN

Field

Biochemistry, Genetics and Molecular Biology (Life Sciences)