Beneficial Properties and Evaluation of Survival in Model Systems of LAB Isolated from Oral Cavity

Abstract

In this study evaluation of the beneficial properties and survival for eight LAB putative probiotic strain was conducted including their ability to survive at different ox-bile concentrations and in the models representing different parts of digestive tract, ability to produce diacetyl, GABA and specific enzymes. The survival rates and release rates of the cells under the SSDP and AOS models were evaluated by encapsula¬tion using sodium alginate. Interaction between studied LAB and the pathogen in the artificial oral saliva was evaluated. Streptococcus salivarius ST48HK, ST59HK, ST61HK and ST62HK generated positive results for gadL and only Lactobacillus gasseri ST16HK for gadP, genes associated with GABA production. According to bio¬chemical approach in the evaluation of GABA production, strains Str. salivarius ST48HK, ST59HK, and Lactobacillus sakei ST69HK can be considered as the most promising producers, even if other evaluated strains showed levels of assimilation of sodium glutamate. Overall, tests for the beneficial properties, survival rate for the planktonic and encapsulated strains under different ox-bile conditions, SSDP, AOS models, indicates that the studied strains can be promising candidates for oral probiotics application. Evaluation of probiotic properties of new strains is a complex process, with essential basic requirement – survival in the different parts of digestive tract, stability for the extended storage time, expression of beneficial properties and safety characteristics. We have evaluated Str. salivarius ST48HK, ST59HK, ST61HK, and ST62HK, L. plantarum ST63HK and ST66HK, L. sakei ST69HK, and L. gasseri ST16HK as putative probiotics, promising candi-dates for complementary animals’ studies and future human applications.