产品介绍

NZ3000乳酸菌菌株

Product Description and Application

 Lactococcus lactis strainNZ3000, food grade.

 Host strain for Lactococcusgene expression systems.

 Part of the lacF gene isdeleted, rendering the strain unable togrow on lactose. Growth on lactose can be restored by providing the lacF geneon a plasmid

Genotype

 lacF-, derived from MG5267

Contents

 1 Stab Culture, in M17+0.5%glucose medium.

References

 Gasson MJ (1983) Plasmidcomplements of Streptococcus lactis NCDO 712 and other lactic

streptococci afterprotoplast-induced curing. J Bacteriol 154:1–9

 Platteeuw C, vanAlen-Boerrigter I, van Schalkwijk S, de Vos WM (1996) Food-grade cloning and

expression system forLactococcus lactis. Appl Environ Microbiol 62:1008–1013

Host strains

All supplied strains are derivatives of L.lactis subsp. cremorisMG1363, aplasmid-free progeny of the dairy starter strain NCDO712.

The most commonly used host strain is NZ9000. Toconstruct this strain the genes for NisK and NisR were integrated into the pepN gene of MG1363.The two genes are

transcribed from their own constitutive promoter.

Lactococcus lactis NZ9000 – pepN::nisRnisK;

Standardhost strain for nisin regulated gene expression (NICE). The strain contains theregulatory genes nisR and nisK integrated into the pepN gene (broad range aminopeptidase) (Kuipers et al., 1998; Mierau and Kleerebezem, 2005).

Growth and nisin induction forthe NICEsystem inLactococcus lactis

Various media are available for growth of lactococci. Themost commonly used

laboratory medium is M17 supplemented with glucose,lactose or other sugars as carbon source and a relevant antibiotic for plasmidselection. The basic ingredients for a largescale medium are 1–3% peptone,0.5–2% yeast extract, 1–10% carbon source and small amounts of magnesium andmanganese ions. Individual processes need specific optimization of the mediumcomponents and fermentation conditions.

基本信息