Optimization of a method for isolating plasmid DNA from lactic acid bacteria from wine.

F.M. SAGUIR AND MANCA DE NADRA MC

ENVIRONMENTAL MICROBIOLOGY. Methods and Protocols

Humana Press

Lugar: Totowa, New Jersey; Año: 2004; p. 269 - 273

Lactic acid bacteria play an important role in the manufacture of wines. They produce the deacidification of wine, contributing to the flavor and the microbiology stability of final product (1, 2). Many of the phenotypes that are paramount from a technological point of view could depend on plasmid-encoded determinants. These include exopolysacharide or bacteriocin production (3, 4), proteinase activity (5), biogenic amines formation (6), malate or citrate fermentation (7), etc.  This fact justifies the research based on their presence and characterization in wine lactic acid bacteria. Physical evidence for plasmids in bacteria was first presented in the early 1960s from the results buoyant-density centrifugation in the presence of intercalating dyes and electron microscope techniques (8). The discovery of plasmid DNA in the lactic acid bacteria was generally attributed to Cords et al. (9). Procedures for the detection and analysis of plasmids in bacteria were greatly simplified by the development of agarose gel electrophoresis methods for plasmid DNA (10) applied to the lactic acid bacteria by Klaenhammer et al. (11). We investigated the presence of plasmids in strains of wine lactic acid belonging to the genera Lactobacillus, Oenococcus and Pediococcus and only in Lactobacillus hilgardii 5w, we found plasmid DNA. We associated the low yield with a deficient purification procedure by an inefficient cellular lysis or lost of them together with chromosomal DNA. This study was conducted to optimize the method applied for the isolation and purification of plasmids in wine lactic acid bacteria.