Open AccessNisin independent induction of the nisA promoter in Lactococcus lactis during growth in lactose or galactose 1
Author(s) -
Chandrapati Sailaja,
O'Sullivan Daniel J
Publication year - 1999
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1999.tb13374.x
Subject(s) - lactococcus lactis , nisin , streptococcus thermophilus , biology , galactose , biochemistry , transcription (linguistics) , lactose , structural gene , chemistry , gene , lactobacillus , microbiology and biotechnology , fermentation , genetics , bacteria , escherichia coli , lactic acid , linguistics , philosophy , antimicrobial
Nisin biosynthesis is autoregulated extracellularly by the mature and modified peptide. To investigate other regulatory effects on nisin biosynthesis, a transcription fusion of the nisA promoter from Lactococcus lactis ATCC 11454 to the promoterless lacZ gene from Streptococcus thermophilus was constructed. This fusion construct, pDOC99, expressed β‐galactosidase in L. lactis ATCC 11454 growing in M17 medium containing glucose (M17G). Consistent with the known model for transcription of nisA , pDOC99 did not express β‐galactosidase in the non‐nisin producer, L. lactis LM0230 grown in M17G, unless the nisRK genes (cloned in pDOC23) were included in trans and nisin was added to the medium. Growth of this strain in M17 containing lactose or galactose, resulted in nisA transcription, even in the absence of exogenous nisin. This expression was independent of pDOC23. Furthermore, nisA transcription in L. lactis LM0230(pDOC99) grown in M17G could be induced by the addition of exogenous galactose, with maximum induction occurring at concentrations >5 mM.