Current drying and encapsulation methods for probiotics manufacturing are complicate and cost-burdened processes. The aim of this study was to develop a simple ingredient mixture to make probiotic granules via one-step process, providing not only a cryoprotective effect during freezing and drying but also high survival ratio in gastrointestinal tract. As cryoprotectans, commercially available ingredients including skim milk, monosaccharide (trehalose or glycerin), maltodextrins (with low or high degree of equivalents) were used. Their cryoprotective effect during lyophilization and survival ratios in artificial gastric juice and bile salt were measured against 3 strains of lactic acid bacteria (LAB) (Lactobacillus plantarum, Lb. brevis, and Lactococcus lactis). As results, 3 mixtures with different compositions showed a cryprotective effect on LAB tested and the best compostion was dependant upon LAB; skim milk 10%, trehalose 15%, glycerin 0.5%, and NaCl 1% was for Lb. plantarum and Lc. lactis, and maltodextrin 10% instead of skim milk was for Lb. brevis. In addition, those mixtures showed similar survival effect on LAB tested. These results demonstrate that skim milk or maltodextrins with trehalose, glycerin, and NACl can be effectively used for onestep lyophilization of LAB as an alternative method of encapsulation.

Abstract:1) The occurrence of dental caries is mainly associated with oral pathogens, especially cariogenic Streptococcus mutans. The aim of this study was to isolate and characterize lactic acid bacterium showing inhibitory activity against cariogenic Streptococcus mutans. As results, an isolate with strong inhibitory activity was obtained from Kimchi and it was identified as Lactobacillus sakei by API and 16S rRNA gene analyses. This strain secreted an inhibitory compound in cell growth medium and the activity of the compound was completely disappeared by proteinase K revealing the fact that the compound is proteinous substance, bacteriocin. Optimal culture condition for bacteriocin production by Lb. sakei K-7 was at pH 7.5 and 37℃ for 18 h. Oral administration of this isolate may give anticariogenic and probiotic effects on hosts. 최근에는 구강내에서효과적인 항충치 작용을 가진 소재를 발굴하기 위해서 1) St. mutans의 증식을 저해하는 작용 [4,5] 2) sucrose로부터 glucan형성에 관여하는 GTase활성 저해 작용 [6,7]

1) This study w as conducted to optim ize the com position of CEM (cabbage extract m edium ) and cryoprotectants on the growth of Lactobacillus plantarum, a probiotics growing in plant and milk. For this, we analyzed the growth characteristics of Lb. plantarum in CEM and subsequently optimized the medium composition by addition of carbon, nitrogen sources and buffering agents. Among carbon sources, glucose showed the best result to increase the cell density after dilution of CEM. When 0.5% yeast extract and 1% soy peptone were supplemented in the diluted CEM, Lb. plantarum grew up to the maximum cell density. Addition of buffering agents in CEM was not significantly effective to increase the cell density. Meanwhile, addition of 12% skim milk, 5% sucrose and 0.5% glycerol showed a