Influence of vitamins and osmolites on growth and bacteriocin production by Lactobacillus salivarius CRL 1328 in a chemically defined medium

VERA PINGITORE, E.; HEBERT, E.M.; SESMA, F.; NADER, M.E.

CANADIAN JOURNAL OF MICROBIOLOGY

NRC Research Press

Año: 2009 vol. 55 p. 304 - 310

0008-4166

The aim of this study was to analyze the influence of vitamins, glycerol and salts on the growth and bacteriocin production by Lactobacillus salivarius CRL 1328, a human vagina isolate, by using a chemically defined medium, in order to define the optimal conditions for salivaricin production. The single omission of d-biotin, thiamine, p-aminobenzoic acid, folic acid or cyanocobalamin did not affect the bacterial growth, while the removal of nicotinic acid, riboflavin and pyridoxal produced a decrease of about 30% in the growth rate. Maximum salivaricin activity was observed after the addition of 5 or 10 g/l of NaCl. On the basis of the nutritional requirements and the levels of salivaricin production, a new optimized and simplified defined medium (SDM-NaCl) for L. salivarius CRL 1328 bacteriocin production was formulated. The kinetics of salivaricin production in SDM-NaCl and in the complex media LAPTg revealed that bacteriocin production was growth linked. A combination of Tricine-SDS-PAGE, Lumitein protein gel staining and a bioassay for antibacterial activity indicated that the molecular weight of salivaricin CRL 1328 is about 4.5 kDa. The partially purified bacteriocin, obtained from SDM-NaCl after concentration, allowed designing a relatively simple method for the recovery of a biologically active protein.