TY  - JOUR
TI  - Induction of Natural Competence in Genetically-modified Lactococcus lactis
AU  - Mulder, Joyce 
AU  - Wels, Michiel 
AU  - Kuipers, Oscar Paul
AU  - Kleerebezem, Michiel  
AU  - Bron, Peter Allard
VL  - 8
IS  - 13
PY  - 2018
DA  - 2018/07/05
SP  - e2922
C1  - Bio-protocol 2018;8:e2922
DO  - 10.21769/BioProtoc.2922
UR  - https://doi.org/10.21769/BioProtoc.2922
AB  - Natural competence can be activated in Lactoccocus lactis subsp lactis and cremoris upon overexpression of ComX, a master regulator of bacterial competence. Herein, we demonstrate a method to activate bacterial competence by regulating the expression of the comX gene by using a nisin-inducible promoter in an L. lactis strain harboring either a chromosomal or plasmid-encoded copy of nisRK. Addition of moderate concentrations of the inducer nisin resulted in concomitant moderate levels of ComX, which led to an optimal transformation rate (1.0 x 10-6 transformants/total cell number/g plasmid DNA). Here, a detailed description of the optimized protocol for competence induction is presented.
KW  - Natural competence
KW  - Transformation
KW  - Lactococcus lactis
KW  - ComX overexpression
KW  - NICE system
JF  - Bio-protocol
SN  - 2331-8325
PB  - Bio-protocol LLC.
BIO101  - False