Lactococcus lactis NCDO2118 produces anti-hypertensive GABA and exerts acute hypotensive in spontaneously hypertensive rats

Gamma (y)-aminobutyric acid (GABA) is a molecule with nutraceutical interest since it is recognized for its health-promoting properties such as hypotensive effects. Some lactic acid bacteria (LAB) have been shown to be able to produce GABA. In the present investigation, Lactococcus (L.) lactis NCDO2118, a probiotic LAB, was cultured in a medium supplemented with different concentration of glutamate, the substrate for GABA production. This strain was evaluated in SHRSP (Spontaneously Hypertensive Stroke-Prone Rats) to assess its hypotensive effect. The evaluation showed that GABA production is variable depending on the glutamate concentration and incubation time and that the increased GABA production potentiates its hypotensive effect. This work demonstrates that L. lactis NCDO 2118 could be used as a tool for developing health-promoting foods, such as those enriched with GABA as an interesting and novel pharmacological strategy.Fil: Diniz Luerce Saraiva, Tessália. Universidade Federal do Minas Gerais; BrasilFil: Etelvinob, Gisele Maia. Universidade Federal do Minas Gerais; BrasilFil: Oliveirab, Mariana. Universidade Federal do Minas Gerais; BrasilFil: Severiano de Sousaa, Cassiana. Universidade Federal do Minas Gerais; BrasilFil: de Azevedo, Marcela Santiago Pacheco. Universidade Federal do Minas Gerais; BrasilFil: de Moreno, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; ArgentinaFil: Leblanc, Jean Guy Joseph. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; ArgentinaFil: Barhd, Debmalya. Universidade Federal do Minas Gerais; BrasilFil: Ghose, Preetam. Universidade Federal do Minas Gerais; BrasilFil: Venanzif, Franco. Universidade Federal do Minas Gerais; BrasilFil: Pereira Figueiredog, Henrique Cesar. Universidade Federal do Minas Gerais; BrasilFil: Souza Santos, Robson Augusto. Universidade Federal do Minas Gerais; BrasilFil: Azevedo, Vasco. Universidade Federal do Minas Gerais; Brasi

Tight controlled expression and secretion of Lactobacillus brevis SlpA in Lactococcus lactis

© Springer Science+Business Media B.V. 2012Prokaryotes commonly present outer cell wall structures composed of a crystalline array of proteinaceous subunits, known as surface layers (S-layers). The ORF encoding the S-layer protein (SlpA) of Lactobacillus brevis was cloned into Lactococcus lactis under the transcriptional control of the xyloseinducible expression system (XIES). SlpA was secreted into the extracellular medium, as determined by immunoblotting, and assays on the kinetics of SlpA production revealed that repression of the system with glucose did not require the depletion of xylose from the medium that allows transitory ORF expression. The successful use of XIES to express S-layer proteins in the versatile and generally recognized as safe species L. lactis opens new possibilities for an efficient production and isolation of SlpA S-layer protein for its various applications in biotechnology and importantly as an antigen-carrying vehicle