title: Heterologous expression of Oenococcus oeni malolactic enzyme in Lactobacillus plantarum for improved malolactic fermentation.
abstract: Lactobacillus plantarum is involved in a multitude of food related industrial fermentation processes including the malolactic fermentation (MLF) of wine. This work is the first report on a recombinant L. plantarum strain successfully conducting MLF. The malolactic enzyme (MLE) from Oenococcus oeni was cloned into the lactobacillal expression vector pSIP409 which is based on the sakacin P operon of Lactobacillus sakei and expressed in the host strain L. plantarum WCFS1. Both recombinant and wild-type L. plantarum strains were tested for MLF using a buffered malic acid solution in absence of glucose. Under the conditions with L-malic acid as the only energy source and in presence of Mn2+ and NAD+, the recombinant L. plantarum and the wild-type strain converted 85% (2.5 g/l) and 51% (1.5 g/l), respectively, of L-malic acid in 3.5 days. Furthermore, the recombinant L. plantarum cells converted in a modified wine 15% (0.4 g/l) of initial L-malic acid concentration in 2 days. In conclusion, recombinant L. plantarum cells expressing MLE accelerate the malolactic fermentation.
authors.affiliation: Food Biotechnology Lab, Department of Food Sciences and Technology, University of Natural Resources and Life Sciences, Vienna, Austria. thu-ha.nguyen@boku.ac.at.
authors.forename: Christina
authors.initials: C
authors.lastname: Schümann
authors.forename: Herbert
authors.initials: H
authors.lastname: Michlmayr
authors.forename: Reinhard
authors.initials: R
authors.lastname: Eder
authors.forename: Andrés M
authors.initials: AM
authors.lastname: Del Hierro
authors.forename: Klaus D
authors.initials: KD
authors.lastname: Kulbe
authors.forename: Geir
authors.initials: G
authors.lastname: Mathiesen
authors.forename: Thu-Ha
authors.initials: TH
authors.lastname: Nguyen