**7. Bacteriocin production**

Strains from many LAB species excrete anti-listerial bacteriocins, of which nisin produced by *Lc. lactis* and pediocin produced by *Pc. acidilactici* are the most wellknown. Besides,


The Role of Lactic Acid Bacteria in Safety and Flavour Development of Meat and Meat Products 139

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as the traditional manganese dioxide agar. However, it is more sensitive and, it is also more easily prepared and delivers results more quickly. A representative number of strains was

As to the production of H2O2, the study revealed large differences within the *Lb. sakei/curvatus* group. The bacteriocin producers frequently seemed to be relatively weak peroxide producers, while many commercial starter cultures were recognized as more or less strong peroxide producers. More recent field isolates of *Lb. sakei/curvatus* from prepackaged sliced Bologna-type sausage gave an essentially similar picture. In this case,

however, only one of ten isolates of *Lb. curvatus* gave rise to a positive reaction.

 *(Lb. curvatus ssp. melibiosus)* DSM 15740 +

Species strainsa) PB MnO2 *Lb. sakei* (*Lb. bavaricus*) DSM 20494 - nd

*Lb. sakei ssp. carnosus* Lb1047 - + *Lb. sakei ssp. carnosus* DSM 15831T ++ ++ *Lb. sakei ssp. carnosus (ssp. sakei)* 23K +++ ++ *Lb. sakei ssp. carnosus* Lb790 +++ ++ *Lb. sakei ssp. sakei* DSM 20017T +++ + *Lb. brevis* DSM 20054T ++ - *Lb. farciminis* DSM 20180T - nd *Lb. hilgardii* DSM 20176T - - *Weissella paramesenteroides* DSM 20288T +++ nd *Weissella minor* DSM 20014T +++ nd *Leuconostoc carnosum* Lb1259 + + *Leuconostoc carnosum* Lb1054 ++ + *Leuconostoc carnosum* Lb1045 ++ +

a) strains have been obtained from the German Collection of Microorganisms (DSM) and the strain collections of MRI

**Table 2.** Reaction of different LAB species on PB agar with BHI or MRS base, and on MnO2 agar. -, no production of H2O2 ; +/++/+++, moderate to strong production of H2O2 ; nd, not determined [69].

A B C

**Figure 5.** Reaction of different LAB species on MnO2 agar (A) and on PB agar with MRS (B) or BHI (C)

base. Production of H2O2 is indicated by bright and blue halos, resp. [69].

used in the evaluation of the new medium (Table 2).

Location Kulmbach (Lb) and INRA at Jouy-en-Josas (23K)

*Lb. sakei ssp. carnosus* 

n. d., not determined; D, Germany; CH, Switzerland.

**Table 1.** Detection of probiotic cultures in probiotic raw fermented sausages from retail [57].

bacteriocin-producing LAB with anti-listerial activity naturally occur on a wide range of ready-to-eat foods, including meats [63-65]. From a meat point of view the sakacins of *Lb. sakei* are the most interesting because of the high competitivity of this species in the meat environment [22,49]. The pediocin producer *Pc. acidilactici* is commonly used by the Spanish meat industry as a starter culture [66].
