Determination of some probiotic properties of Lactobacillus delbrueckii subsp. bulgaricus strains and effect of immobilization on these properties

in the study, ît has been targetted to determine the some probiotic ana starter features of Lactobacülus deibrueckii subsp. bulgaricus strains, isolated from hand-made yoghurt, and the effects of immobilization on these features. ît has been determined antimîcrobîal activity and the production of iactic acid of 23 L deibrueckii subsp. bulgaricus strains. The amount of Sactîc acid, determined by enzyrnatsc method, was found between 0.03-0.1 g/L. The enzymatîc activity of D-LDH determined between 0.63-1.54 jnmol. dk./mg, total lactat dehydrogenaze was determined between 1.51-3,69 \ono\. dk./mg of 4 strains that produce low, medium and high amount of Sactic acid. L. deibrueckii sybsp. bulgaricus strains had an inhibitory effect on the 91% of A, hydrophiia 106 strain, on the 87% R aerog/nosa ATCC 29212 strairt, on the 87% Y, enterocolitica ATCC 1501 straios on the 83% S.RSKK 171 straln, on the 65% B, cereus RSKK 863 strain. 57% M, luteus NRLL-B 4375 strain, strain, on the 48% S. aureus ATCCstraîn and on the 43% E. co/ı" ATCC 11230 straîn. After this point, because of acıd and EPS production and antimîcrobial effect. 4 straîns were seîected to use for other stüdies. lî has been determined the resistance against low acidity and bile salts of these 4 strains. it has been determined that thevi acidity and biie saits of these 4 strasns. it has beeo determined that the most resistance strain against low acidiîy is L. delbnıeckii subsp. buigaricus B3 and îheresistance strain is L. deibrueckii subsp. buigaricus 22. The resistance against 0.3 % bile salt was found between 23.6 %-35.7 % and L. deibrueckii stıbsp. buigaricus B3 was the most resistance strain agaînsî bile salt. For immmobîSizatîon, L. deibrueckii subsp. buigaricus B3 straîn that has important probiotsc propertîes was used. Oy ring first 15 days, it has not seers a decrease of viabiiîty of the îrnmobîiîzed ceils whîch were stored at +4 °C, Bot after these 15 days, a decrease of viabilîty of the immobilized çeliş was started to determirte. St has notany difference between the productîons of Sactic acîd made by imrnobiiîzed çeliş and made by free çeliş. But it has been determined difference between the production of EPS made by immobiİEzed ceiis and roade by free çeliş. At îmmobîiîzed ceils, it has been determined clear resistance against variety concenîration of bile salt Aiso, this ciear resistance was obtained against peniciiiin-G and nişin. For both immobifîzed and free ceffs, there not any difference antimîcrobial effect agaînst B.RSKK 863S P.ATCC and E. coli ATCC 11230 strains. it has been determined that imınobilization has positive effects on probiotic and starter properties. Selence code : 216 Keywords : Probiotîcs,subsp. buigaricus, EPS, iactîc acîd, resistance against iow acidîty and bile salt, antîmicrobia! effect, Immobîilzatiort Page Number : 99 Advises: Prof Dr. Belma ASLIM