title: Optimum bacteriocin production by Lactobacillus plantarum 17.2b requires absence of NaCl and apparently follows a mixed metabolite kinetics.
abstract: Bacteriocins from lactic acid bacteria are ribosomally synthesized anti-microbial compounds that may find applications from food preservation to healthcare. Food preservation, using in situ bacteriocin production is the most obvious and simple. Frequently, the best conditions for bacteriocin production are those prevailing during food fermentation but a better understanding of the relationship between growth and bacteriocin production is required. In this work, we evaluate the effects of some environmental factors on bacteriocin production by Lactobacillus plantarum 17.2b. A first screening design showed that NaCl, temperature, pH and the type and concentration of carbon and nitrogen sources were most influents. A moderate stimulatory effect of ethanol and oleuropein was also registered. Two consecutive central composite designs were used to examine the effect of the selected variables and to compute its optimum. The evolution of changes produced by the alterations in environmental factors was further examined trough perturbation plots. Bacteriocin production by L. plantarum 17.2b was very sensitive to environmental conditions and uncoupled from growth. Maximum production required suboptimal growth temperatures, pH values above growth's optimum and no NaCl. A preliminary approach to kinetics showed that bacteriocin production by this strain apparently follows mixed metabolite kinetics.
authors.affiliation: Instituto de Tecnologia Química e Biológica, Av. da República, Quinta do Marquês, 2780-505 Oeiras, Portugal. ameliad@itqb.unl.pt
authors.forename: Amélia
authors.initials: A
authors.lastname: Delgado
authors.forename: Francisco Noé
authors.initials: FN
authors.lastname: Arroyo López
authors.forename: Dulce
authors.initials: D
authors.lastname: Brito
authors.forename: Cidália
authors.initials: C
authors.lastname: Peres
authors.forename: Pedro
authors.initials: P
authors.lastname: Fevereiro
authors.forename: António
authors.initials: A
authors.lastname: Garrido-Fernández
mesh_terms: D001430:Bacteriocins / Q000096:biosynthesis*; D001709:Biotechnology / Q000379:methods*; D002244:Carbon / Q000378:metabolism; D005285:Fermentation; D005503:Food Additives; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D048191:Lactiplantibacillus plantarum / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D012965:Sodium Chloride / Q000378:metabolism*; D013696:Temperature
chemical_list: D001430:Bacteriocins; D005503:Food Additives; D012965:Sodium Chloride; D002244:Carbon; D009584:Nitrogen