Grapefruit extract rich in functional substances adjusting pH 5.0 and adding sucrose (final concentration, 2%) was fermented by Leuconostoc mesenteroides CJNU 0147 strain, consequently prepared a fermented grapefruit extract containing dextran. As a result of analyzing the growth inhibitory effect on gut harmful bacterium Clostridium difficile strain using the prepared fermented grapefruit extract, the viable cell count was significantly reduced (p<0.05 vs. control for 0.5 brix as a final concentration; p<0.001 vs. control for 1.0 brix). On the other hand, the proliferative ability of the extract for Bifidobacterium breve strain, which is one of the species of the genus Bifidobacterium well known as human gut beneficial bacteria, was confirmed (p<0.001 vs. control for both 0.5 and 1.0 brix). These results indicate fermented grapefruit extract with Leu. mesenteroides CJNU 0147 strain inhibits the growth of gut harmful bacterium C. difficile and promotes the proliferation of beneficial bacterium B. breve and is expected to be used as a functional food material for gut health.

진세노사이드 Compound K는 트라이터펜계 사포닌으로써 인삼의 잎, 줄기, 뿌리등에서 발견된다. 본 연구는 효소 Plantase를 이용하여 인삼 추출물로부터 고부가가치의 진세노사이드인 Compound K를 생산하는 연구를 하였다. Plantase는 인삼추출물에서 Compound K를 매우 효율적으로 생산함을 보여 주었다. 또한 다양한 온도와 pH에서 Compound K 생산에 대한 최적의 반응을 조사한 결과 pH 5, 50 ℃에서 가장 높은 효율을 보였다. 최적 조건에서 Compound K는 전체 추출물의 35%이상 농축될 수 있음을 확인 하였다. 생물전환된 Compound K 농축물의 항균효과를 검정한 결과 여드름균인 Cutibacterium acnes KCTC 3314에 선택적인 활성을 보였다. Compound K (35% 함유) 인삼 생물전환물의 C. acnes KCTC 3314 균주에 대한 최소저해농도 측정 결과 31.25ug/mL로 확인되었다. 따라서 향후 여드름균 완화용 화장품의 잠재적 소재로 사용될 수 있을 것으로 기대된다.

Nowadays micro-dust is a serious problem in Korea. In particular micro-dust contains heavy metals such as Pb (lead) and Cd (cadmium) which negatively effect on human health. In this study, we intended to isolate lactic acid bacteria which can scavenge the heavy metals. Firstly we isolated two lactic acid bacteria which were resistant to Ag, Cu, and Zn (30-100 mM AgNO3, CuSO4, ZnSO4 in MRS broth). The two lactic acid bacteria CJNU 1877 and JG 15 were identified Lactobacillus paracasei and Enterococcus faecium, respectively. Subsequently the strains were inoculated in MRS broth and agar plate where 100 ppm of Pb(NO3)2 and CdSO4 were added, respectively. They did grow in the conditions and we found aggregations from 24 h cultures, indicating the strains can absorb the heavy metals, which was further proved by scanning electron microscopy (SEM) and Inductively Coupled Plasma-Optical Emission Spectrometer. Therefore the isolated lactic acid bacteria can be used as a probiotics harboring heavy metal scavenging activity.