Characterization of autochthonous lactic acid bacteria in Bom Jesus do Itabapoana (Brazil): antagonist action against Listeria monocytogenes and biochemical evidences

Abstract

Lactic Acid Bacteria (LAB) are used in the elaboration of industrial and artisanal dairy and fermented products, and have a wide diversification, which can influence the characterization of the products and guarantee food safety. The present work aims to isolate and characterize autochthonous LAB from Bom Jesus do Itabapoana (Brazil), from raw milk and artisanal fresh cheese, verifying their antagonistic potential against L. monocytogenes, diacetyl production and the profile of lacto-fermentation. For isolation, the MRS and M17 media were used, incubated at 37 ºC and 30 ºC for 48 h, respectively. Ten strains that showed characteristics for LAB were evaluated for antagonistic action against the pathogen, production of diacetyl and profile of lacto-fermentation. Seven of them showed antagonistic action, diacetyl production and caseous lacto-fermentation, while three did not show antagonistic action and diacetyl production, however one maintained the caseous lacto-fermentation type and two presented gelatinous type.