Effect of X-propyl dipeptidyl aminopeptidase deficiency on Lactococcus lactis

Article Abstract:

X-propyl dipeptidyl aminotransferase (PepXP) releases dipeptides from oligopeptides and has been detected in a wide range of lactic acid bacteria. The pepXP gene has been identified, along with an adjacent open reading frame, ORF1. The role of pepXP for Lactococcus lactis growth and milk fermentation and the role of ORF1 in pepXP expression were investigated. The results showed that ORF1 is not required for PepXP activity or bacterial growth. However, mutation in pepXP resulted in the alteration of the peptide composition of fermented milk products.

Physiological aspects, Lactic acid, Fermented milk, Cultured milk, Aminopeptidases

---

A chloride-inducible gene expression cassette and its use in induced lysis of Lactococcus lactis

Article Abstract:

Research was conducted to study the exploitation of a chloride-inducible promoter isolated from the chromosome of the Lactococcus lactis operon for the inducible expression of homologous and heterologous genes. Cell extracts were prepared by shaking the cells in the presence of glass beads while four restriction enzyme sites were introduced to aid in cloning. Results indicated that cytoplasmic proteins could be detected in supernatants. Moreover, an induction of lytPR or acmA expression had an effect on the culture.

Gene expression, Operons

---

Autolysis of Lactococcus lactis caused by induced overproduction of its major autolysin, AcmA

Article Abstract:

The autolysis of Lactococcus lactis caused by induced overproduction of its major autolysin , AcmA, was examined to prove that AcmA is an autolysin involved in stationary-phase of lysis of L. lactis. The study used a system based on the recently characterized promoter/operator region of a temperate lactococcal bacteriophage. Results show that the optical density of a culture of L. lactis was reduced during prolonged stationary phase. L. lactis was required for autolysis of an organism during stationary phase.

Bacterial proteins

Similar abstracts:

• Abstracts: Cloning and sequencing of pepC, a cysteine aminopeptidase gene from Lactococcus lactis subsp. cremoris AM2
• Abstracts: Properties of Nisin Z and distribution of its gene, nisZ, in Lactococcus lactis. Improvement of solubility and stability of the antimicrobial peptide nisin by protein engineering
• Abstracts: Priming effect of substrate addition in soil-based biodegradation tests. Testing of some assumptiions about biodegradability in soil as measured by carbon dioxide evolution
• Abstracts: Contacts in context: promoter specificity and macromolecular interactions in transcription. Transcript cleavage factors from E. coli
• Abstracts: Long-term production of ergot peptides by immobilized Claviceps purpurea in semicontinuous and continuous culture

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.