Založba Univerze v Ljubljani / University of Ljubljana Press
Doi
Abstract
Twenty-one commercial starter cultures were tested for their antibacterial activity against 24 indicator bacteria. Specter of antimicrobial activity and probable presence of bacteriocin-like substances were detected with direct agar spot method. Thirteen of 21 tested commercial starter cultures have shown antibacterial activity against indicator bacteria, while the production of bacteriocin-like substance was found with starter cultures MSK B2, LA-CH-5, L. acid. 145 and MSK/V10. In cell-free supernatant no bacteriocin-like activity was detected. Strains of starter cultures BB 12, L. casei 01, LA-CH-5, L. casei R, MSK/V10 (L. acidophilus) were resistant at pH 2 - 5 and bile salts concentration 0,1% - 1,5%. The most promising as protective cultures or dietary adjuncts are among starter cultures tested L.casei 01, BB12, LA-CH-5, L.casei R, L.acid 145, MSK B2 and MSK/V10.Testirali smo 21 komercialnih starter kultur na protibakterijsko aktivnost proti 24 izbranim indikatorskim bakterijam. Spekter protimikrobne aktivnosti in prisotnost bakteriocina smo določali z metodo neposredne inhibicije na trdnem gojišču. Protibakterijski učinek proti indikatorskim bakterijam smo ugotovili pri 13 od 21 testiranih komercialnih starter kultur. Proizvodnjo protimikrobne snovi proteinske narave pa pri starter kulturah MSK B2, LA-CH-5, L. acid. 145 in MSK/V10. V brezceličnem bakteriocinskem pripravku, pridobljenem iz tekočega gojišča, nismo ugotovili bakteriocinske aktivnosti. Sevi starter kultur BB 12, L. casei 01, LA-CH-5, L. casei R, MSK/V10 (L. acidophilus) so bili odporni proti vrednostim pH 2 - 5 in koncentracijam žolčnih soli 0,1% do 1,5%. Posebno zanimive so se, kot zaščitne kulture ali probiotične kulture, pokazale L.casei 01, BB12, LA-CH-5, L.casei R, L.acid 145, MSK B2 in MSK/V10
