팽화홍삼에 존재하는 major ginsenoside를 minorginsenoside로 생물전환하기 위하여 β-glucosidase 활성이높은 유산균주를 탐색하였다. 된장으로부터 분리한 YLB 8균주가 β-glucosidase 활성이 가장 높았으며 Leuconostocmesenteroides로 동정되었다. L. mesenteroides YLB 8을MRS 배지에서 배양하였을 경우 최대의 β-glucosidase 효소 활성을 나타내기 위한 최적 배양 조건은 glucose 첨가량 1%(w/v), 초기 pH 8.0, 배양온도 30oC, 배양시간 16시간이었다. L. mesenteroides YLB 8을 이용하여 팽화홍삼추출액을 생물전환하였을 경우 최적 온도는 30oC었으며,팽화홍삼 추출액의 농도는 12oBx이었다. 팽화홍삼 추출액내에 존재하는 major ginsenoside인 Rb1과 Rb2는 minorginsenoside인 Rg3로 전환되었으며, Re는 Rg1으로 전환되었으며, 이 중 일부는 Rh1과 Rh2로 전환되었다.
Lactic acid bacteria producing high levels of β-glucosidase were screened to convert the major ginsenosides into theminor ginsenosides in puffed red ginseng. A strain named YLB 8 isolated from doenjang showed the highest β-glucosidase activity and was identified as Leuconostoc mesenteroides. The optimum conditions for the maximumproduction of β-glucosidase, when L. mesenteroides YLB 8 was cultured in MRS medium, were as follows; glucoseconcentration of 1% (w/v), initial pH 8.0, culture temperature of 30oC, culture time of 16 h. When Puffed red gin-seng extract was bioconverted using L. mesenteroides YLB 8, the optimum temperature and the concentration ofPuffed red ginseng extract was 30oC and 12oBx, respectively. As a result of bioconversion, the major ginsenosidesRb1 and Rb2 were converted into minor ginsenoside Rg3, and Re was converted into Rg3 and successively intoRh1 and Rh2 in part.