Peptide Utilization Encoded by Lactococcus lactis subsp. lactis SSL135 Chromosomal DNA
AUTOR(ES)
Tynkkynen, Soile
RESUMO
A cloned chromosomal fragment of Lactococcus lactis subsp. lactis SSL135 on plasmid p VS8 in an L. lactis subsp. lactis MG1614 background enabled proteinase-negative strain MG1614 to grow in autoclaved milk. The strain (VS230) did not, however, degrade milk proteins and did not grow in pasteurized milk. In contrast, a strain (VS150) carrying p VS9, the proteinase plasmid of SSL135, in an MG1614 background degraded β-casein but did not grow in milk. VS230 was shown to utilize peptides produced by VS150 in growth experiments in pasteurized milk preincubated with the latter strain. The peptide utilization phenotype linked with p VS8 was further confirmed by growth of VS230 on tryptic peptide fractions, on which the plasmid-free but otherwise isogenic strain MG1614 failed to grow. Plasmid p VS8 produced 69-, 42-, 38-, and 36-kilodalton proteins, as determined by in vitro transcription-translation. At least three of these proteins affected the peptide utilization phenotype. We suggest that there could be a coupled peptidase-peptide transport system encoded by the chromosomal fragment.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=203145Documentos Relacionados
- Thermosensitive plasmid replication, temperature-sensitive host growth, and chromosomal plasmid integration conferred by Lactococcus lactis subsp. cremoris lactose plasmids in Lactococcus lactis subsp. lactis.
- The plasmid-encoded lactococcal envelope-associated proteinase is encoded by a chromosomal gene in Lactococcus lactis subsp. cremoris BC101.
- Divergence of Genomic Sequences between Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris
- Chromosomal integration of plasmid DNA by homologous recombination in Enterococcus faecalis and Lactococcus lactis subsp. lactis hosts harboring Tn919.
- Sugar Utilization and Acid Production by Free and Entrapped Cells of Streptococcus salivarius subsp. thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, and Lactococcus lactis subsp. lactis in a Whey Permeate Medium