title: Expression of plant flavor genes in Lactococcus lactis.
abstract: Lactic acid bacteria, such as Lactococcus lactis, are attractive hosts for the production of plant-bioactive compounds because of their food grade status, efficient expression, and metabolic engineering tools. Two genes from strawberry (Fragaria x ananassa), encoding an alcohol acyltransferase (SAAT) and a linalool/nerolidol synthase (FaNES), were cloned in L. lactis and actively expressed using the nisin-induced expression system. The specific activity of SAAT could be improved threefold (up to 564 pmol octyl acetate h-1 mg protein-1) by increasing the concentration of tRNA1Arg, which is a rare tRNA molecule in L. lactis. Fermentation tests with GM17 medium and milk with recombinant L. lactis strains expressing SAAT or FaNES resulted in the production of octyl acetate (1.9 microM) and linalool (85 nM) to levels above their odor thresholds in water. The results illustrate the potential of the application of L. lactis as a food grade expression platform for the recombinant production of proteins and bioactive compounds from plants.
authors.affiliation: NIZO food research, P.O. Box 20, 6710 BA Ede, The Netherlands.
authors.forename: Igor
authors.initials: I
authors.lastname: Hernández
authors.forename: Douwe
authors.initials: D
authors.lastname: Molenaar
authors.forename: Jules
authors.initials: J
authors.lastname: Beekwilder
authors.forename: Harro
authors.initials: H
authors.lastname: Bouwmeester
authors.forename: Johan E T
authors.initials: JE
authors.lastname: van Hylckama Vlieg
mesh_terms: D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism*; D001709:Biotechnology / Q000379:methods; D005421:Flavoring Agents / Q000378:metabolism*; D031985:Fragaria / Q000201:enzymology* / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D017343:Genes, Plant; D013294:Lactococcus lactis / Q000235:genetics / Q000378:metabolism*; D008025:Ligases / Q000235:genetics / Q000378:metabolism*; D009561:Nisin / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism*; D012717:Sesquiterpenes / Q000378:metabolism
chemical_list: D005421:Flavoring Agents; D010940:Plant Proteins; D011994:Recombinant Proteins; D012717:Sesquiterpenes; D009561:Nisin; D000217:Acyltransferases; C411082:alcohol acyltransferase, Fragaria ananassa; D008025:Ligases; C037055:nerolidol