Effects of different spices used in production of fermented sausages on growth of and curvacin A production by Lactobacillus curvatus LTH 1174.

Lactobacillus curvatus LTH 1174, a fermented sausage isolate, produces the listericidal bacteriocin curvacin A. The effect of different spices relevant for the production of fermented sausages was investigated in vitro through laboratory fermentations with a meat simulation medium and an imposed pH profile relevant for Belgian-type fermented sausages. The influence on the growth characteristics and especially on the kinetics of curvacin A production with L. curvatus LTH 1174 was evaluated. Pepper, nutmeg, rosemary, mace, and garlic all decreased the maximum specific growth rate, while paprika was the only spice that increased it. The effect on the lag phase was minor except for nutmeg and especially for garlic, which increased it, yet garlic was stimulatory for biomass production. The maximum attainable biomass concentration (X(max)) was severely decreased by the addition of 0.40% (wt/vol) nutmeg, while 0.35% (wt/vol) garlic or 0.80% (wt/vol) white pepper increased X(max). Nutmeg decreased both growth and bacteriocin production considerably. Garlic was the only spice enhancing specific bacteriocin production, resulting in higher bacteriocin activity in the cell-free culture supernatant. Finally, lactic acid production was stimulated by the addition of pepper, and this was not due to the manganese present because an amount of manganese that was not growth limiting was added to the growth medium. Addition of spices to the sausage mixture is clearly a factor that will influence the effectiveness of bacteriocinogenic starter cultures in fermented-sausage manufacturing.