Peptones from autohydrolysed fish viscera for nisin and pediocin production.

Various peptones obtained from hydrolysed visceral homogenates of four fishery residues showed their suitability for promoting the growth of lactic acid bacteria, micro-organisms with particularly complex requirements regarding peptidic nutrients. The assay of several treatments with two bacterial species, producers of the two main bacteriocins (nisin and pediocin) demostrated that optimum conditions only imply a brief autohydrolysis at natural pH and room temperature, with subsequent steam-flow stabilisation. Later kinetic analysis of the cultures of both bacteria in the best media provided parameters which, for production of both biomass and bacteriocins (the latter behaved in the majority of cases as a mixed metabolite), indicate comparable or superior results to those found in costly commercial media, specifically recommended for culture of lactic acid bacteria.