Table 1 Plasmids and bacterial strains used in this study

Strains

 Escherichia coli DH5α

F⁻ supE44 ∆lacU169 Ф80lacZ ∆M15 hsdR17 recA1 endA1 gyrA96 thi-1 relA1

Novagen

 Lactococcus lactis strains

  NZ9000

Derivative of MG1363, pepN::nisRK

[33]

  IGn

Derivative of NZ9000, galK::pG⁺UD-nP-pheS*

This work

  dA

Derivative of NZ9000, ∆aldB

This work

 Lactobacillus casei BL23

Derivative of L. casei ATCC 393 (pLZ15⁻)

[36]

 Plasmids

  pG⁺host9

Erm^r; temperature-sensitive vector

[16]

  pG⁺UD

pG⁺host9 derivative with up and down homology arms of the part of galactose operon

This work

  pG⁺UD-nP-pheS*

pG⁺UD derivative with pheS* driven by n P_ldh

This work

  pG⁺-nP-pheS*

pG⁺host9 derivative with pheS* driven by n P_ldh

This work

  pG⁺UD2-5P-pheS*

pG⁺-5P-pheS* derivative with upstream and downstream sequences of the aldB gene

This work

  pUC19

Amp^r; cloing vector

This work

  pSec:Leiss:Nuc

pWV01 replicon; expresses Nuc under PnisA control; Cm^r

[34]

  pleiss-P-pheS*

pSec:Leiss:Nuc derivative with pheS* driven by a P_ldh

This work

  pTRKH2

Erm^r; expressing vector

[37]

  pOgfp

Source of gfp gene

[18]