5.6.1. Class I
Bacteriocins of this class contain post-translationally modified amino acids and are also termed lantibiotics. The most extensively characterised of these is nisin which has GRAS status for use as a direct human food ingredient (Federal Register, 1988). It is produced by strains of L. lactis subsp. lactis and has a broad inhibitory spectrum against gram-positive bacteria, including many pathogens and can prevent outgrowth of Bacillus and Clostridium spores (Daeschel, 1989). It sensitises spores of Clostridium to heat allowing a reduction in thermal processing (Hurst, 1981).