Abstract
Two different Lactococcus lactis host strains, L. lactis subsp. lactis MG1363 and L. lactis subsp. cremoris SK1128, both containing plasmid pNZ521, which encodes the extracellular serine proteinase (PrtP) from strain SK110, were used to study the medium and growth-rate-dependent activity of three different enzymes involved in the proteolytic system of lactococci. The activity levels of PrtP and both the intracellular aminopeptidase PepN and the X-prolyl-dipeptidyl aminopeptidase PepXP were studied during batch and continuous cultivation. In both strains, the PrtP activity level was regulated by the peptide content of the medium. The highest activity level was found during growth in milk, and the lowest level was found during growth in the peptide-rich laboratory medium M17. Regulation of the intracellular peptidase activity appeared to be a strain-dependent phenomenon. In cells of strain MG1363, the activity levels of PepN and PepXP were regulated in a similar way to that observed for PrtP. In cells of strain SK1128, the levels of both peptidases were not significantly influenced by the peptide content of the medium. The presence of specific concentrations of the dipeptide prolylleucine could mimic the low activity levels of the regulated proteolytic enzymes, even to the activity level found on M17 medium. The effect of the presence of the dipeptide prolylleucine in the medium on the activity level of the regulated proteolytic enzymes was confirmed at fixed growth rates in chemostat cultures.
Full Text
The Full Text of this article is available as a PDF (204.5 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1016/0003-2697(76)90527-3. [DOI] [PubMed] [Google Scholar]
- Bruinenberg P. G., Vos P., De Vos W. M. Proteinase overproduction in Lactococcus lactis strains: regulation and effect on growth and acidification in milk. Appl Environ Microbiol. 1992 Jan;58(1):78–84. doi: 10.1128/aem.58.1.78-84.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Exterkate F. A., Alting A. C., Bruinenberg P. G. Diversity of cell envelope proteinase specificity among strains of Lactococcus lactis and its relationship to charge characteristics of the substrate-binding region. Appl Environ Microbiol. 1993 Nov;59(11):3640–3647. doi: 10.1128/aem.59.11.3640-3647.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gasson M. J. Plasmid complements of Streptococcus lactis NCDO 712 and other lactic streptococci after protoplast-induced curing. J Bacteriol. 1983 Apr;154(1):1–9. doi: 10.1128/jb.154.1.1-9.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hillier A. J., Jago G. R. L-Lactate dehydrogenase, FDP-activated, from Streptococcus cremoris. Methods Enzymol. 1982;89(Pt 500):362–367. doi: 10.1016/s0076-6879(82)89065-4. [DOI] [PubMed] [Google Scholar]
- Hugenholtz J., Exterkate F., Konings W. N. The Proteolytic Systems of Streptococcus cremoris: an Immunological Analysis. Appl Environ Microbiol. 1984 Dec;48(6):1105–1110. doi: 10.1128/aem.48.6.1105-1110.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hugenholtz J., Veldkamp H., Konings W. N. Detection of Specific Strains and Variants of Streptococcus cremoris in Mixed Cultures by Immunofluorescence. Appl Environ Microbiol. 1987 Jan;53(1):149–155. doi: 10.1128/aem.53.1.149-155.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jensen P. R., Hammer K. Minimal Requirements for Exponential Growth of Lactococcus lactis. Appl Environ Microbiol. 1993 Dec;59(12):4363–4366. doi: 10.1128/aem.59.12.4363-4366.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Juillard V., Laan H., Kunji E. R., Jeronimus-Stratingh C. M., Bruins A. P., Konings W. N. The extracellular PI-type proteinase of Lactococcus lactis hydrolyzes beta-casein into more than one hundred different oligopeptides. J Bacteriol. 1995 Jun;177(12):3472–3478. doi: 10.1128/jb.177.12.3472-3478.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kunji E. R., Hagting A., De Vries C. J., Juillard V., Haandrikman A. J., Poolman B., Konings W. N. Transport of beta-casein-derived peptides by the oligopeptide transport system is a crucial step in the proteolytic pathway of Lactococcus lactis. J Biol Chem. 1995 Jan 27;270(4):1569–1574. doi: 10.1074/jbc.270.4.1569. [DOI] [PubMed] [Google Scholar]
- Marugg J. D., Meijer W., van Kranenburg R., Laverman P., Bruinenberg P. G., de Vos W. M. Medium-dependent regulation of proteinase gene expression in Lactococcus lactis: control of transcription initiation by specific dipeptides. J Bacteriol. 1995 Jun;177(11):2982–2989. doi: 10.1128/jb.177.11.2982-2989.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Platteeuw C., Simons G., de Vos W. M. Use of the Escherichia coli beta-glucuronidase (gusA) gene as a reporter gene for analyzing promoters in lactic acid bacteria. Appl Environ Microbiol. 1994 Feb;60(2):587–593. doi: 10.1128/aem.60.2.587-593.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Smid E. J., Konings W. N. Relationship between utilization of proline and proline-containing peptides and growth of Lactococcus lactis. J Bacteriol. 1990 Sep;172(9):5286–5292. doi: 10.1128/jb.172.9.5286-5292.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Smid E. J., Plapp R., Konings W. N. Peptide uptake is essential for growth of Lactococcus lactis on the milk protein casein. J Bacteriol. 1989 Nov;171(11):6135–6140. doi: 10.1128/jb.171.11.6135-6140.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tan P. S., Chapot-Chartier M. P., Pos K. M., Rousseau M., Boquien C. Y., Gripon J. C., Konings W. N. Localization of peptidases in lactococci. Appl Environ Microbiol. 1992 Jan;58(1):285–290. doi: 10.1128/aem.58.1.285-290.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- de Vos W. M., Vos P., de Haard H., Boerrigter I. Cloning and expression of the Lactococcus lactis subsp. cremoris SK11 gene encoding an extracellular serine proteinase. Gene. 1989 Dec 21;85(1):169–176. doi: 10.1016/0378-1119(89)90477-0. [DOI] [PubMed] [Google Scholar]
