Table 1.
Safety, technological and antagonistic properties of LAB strains applied as native starter cultures
| Genotype | Antibiotic resistance1 | Biogenic amine genes2 | Acidification3 | Proteolytic activity4 | Lypolitic activity5 | Antimicrobial activity6 | ||
|---|---|---|---|---|---|---|---|---|
| ΔpH after 24 h | ΔpH after 7 d | Casein | Sarcoplasmic proteins | |||||
| Lb. sakei | ||||||||
| LS0713 | – | – | 0.46 | 2.27 | – | – | + + + | Sa/W/Bc |
| LS0296 | – | – | 1.92 | 2.24 | + | – | – | Sa/St/Bc |
| Le. mesenteroides | ||||||||
| LM0532 | – | – | 2.06 | 2.43 | – | – | + + | Ec/St |
1Antibiotic resistance was tested according to EFSA where lactobacilli and leuconostocs were tested against ampicillin (2 µg—Amp), gentamicin (10 µg—Gen), erythromycin (2 µg—Ery), tetracycline (5 µg—Tet), kanamycin (30 µg—Kan), clindamycin (2 µg—Cli) and chloramphenicol (30 µg—Chl)
2Biogenic amine genes were detected by PCR assays for histamine (hdc), putrescine (odc), tyramine (tdc) and cadaverine (ldc)
3Acidification is shown as a pH change (ΔpH). pH change (ΔpH) was calculated according to the formula: ΔpH = pH1 − pH2, where pH1 is the pH of lyophilized pork meat media and pH2 is the mean pH value of lyophilized pork meat media measured 7 or 24 h after the inoculation of selected strains
4Proteolytic activity was tested on skim milk agar and media enriched with sarcoplasmic proteins. Proteolytic activity was detected as a clear zone around colonies. The diameter of the clear zone was measured and expressed as mean value in mm and compared to the proteolytic activity of Pseudomonas fluorescens WCS 417r
5Lypolitic activity was detected as a clear zone around colonies grown on tributyrin agar. The diameter of the clear zone was measured and expressed as a mean value in mm and compared to the lipolytic activity of Pseudomonas fluorescens WCS 417r
6Antimicrobial activity was tested against selected indicator bacteria: Sa—Salmonella enterica subsp. enterica (DSM 14221); L—Listeria innocua (ATCC 33090); Ec—Escherichia coli (ATCC 25922); St—Staphylococcus aureus subsp. aureus (DSM 20231); Bt—Brochotrix termospachta (LMG 17208); W—Weissella viridescens (DSM 20410); Bc—Bacillus cereus (DSM 6791)