• Journal of Dairy Science and Biotechnology
• /
• 제29권1호
• /
• pp.17-22
• /
• 2011

Milk intake is widely recommended for healthy diet, not only for bone growth and maintenance, but also as a protein, calcium and magnesium sources as part of an adequate diet. Many research suggest that milk and dairy products are associated with a lower risk of type 2 diabetes mellitus (T2DM). Milk and dairy products are low Glycemic index (GI) and Glycemic load (GL) foods. The GI and GL are useful tools to choose foods to help control blood glucose levels in people with diabetes. The GI and GL of milk are 32~42 and 4~5, respectively, and which are about 1/2 and 1/5 of boiled rice. The mechanisms underlying the effects of dairy on T2DM development includes the calcium and vitamin D content in dairy foods and the possible positive effect of high milk and calcium intake on weight control. The role of dairy products on reducing the risk of diabetes can be inferred from the reports that lower serum IGF-1 levels were positively associated with diabetes and the girls with low milk intake had significantly lower IGF-1. Accumulating data from both patients and animal models suggest that microbial ecosystems associated with the human body, especially the gut microbiota, may be associated with several important diseases, such as inflammatory bowel disease, obesity, diabetes and cardiovascular disease. It was thought that fermented milk containing lots of probiotics can be useful for controling blood glucose levels and preventing complication of diabetes, but sucrose in commercial yogurt should be substituted. There are some reports of oligosaccharide, xylitol, and stevia as a potentially useful sweetener in the diabetic diet.

• 대한화장품학회지
• /
• 제48권2호
• /
• pp.105-112
• /
• 2022

2'-fucosyllactose (2'-FL)는 사람의 모유에 가장 많이 존재하는 올리고당(human milk oligosaccharides, HMOs)으로, 장내 유용 미생물의 성장을 촉진시키고 알레르기, 염증 반응을 완화시키는 것에 도움을 준다. 다양한 긍정적 기능을 가진 2'-FL의 미백 화장품 소재로써의 가능성을 확인하고자, 본 연구를 통해 멜라닌 생성 저해 효능 및 자가포식 유도 가능성을 검토하였다. 인간 유래 멜라닌 생성 세포로 알려진 MNT-1 세포에서 독성 실험을 진행하여 40 g/L 이하에서 세포독성이 없음을 확인하였고, 동일 세포에서 20 g/L 농도로 7 일간 처리하여 멜라닌 생성량을 분석한 결과, 40% 멜라닌 생성 감소를 확인하였다. 멜라닌 생성 관련 인자 TYR 및 TYRP1의 단백질 발현량을 western blot 법을 이용하여 분석한 결과, 2'-FL 처리는 이들을 감소시켰으며, 더불어 자가포식 표지자인 microtubule-associated protein 1 light chain 3 (LC3)의 형태가 LC3-I에서 LC3-𝚷로 변환을 확인할 수 있었다. 공초점 현미경을 통해 2'-FL 처리에 따른 LC3 puncta의 증가가 확인되었다. 따라서, 2'-FL로 활성화된 자가포식이 TYR 및 TYRP1 단백질 발현량을 저해시킴으로서 멜라닌 생성을 감소시키는 것으로 시사된다. 결론적으로 2'-FL은 자가포식을 유도하여 멜라닌 생성이 억제됨이 확인되어 미백 화장품 소재로써의 가능성이 기대된다.

• Journal of Microbiology and Biotechnology
• /
• 제32권11호
• /
• pp.1471-1478
• /
• 2022

2'-Fucosyllactose (2'-FL), the most abundant fucosylated oligosaccharide in human milk, has multiple beneficial effects on human health. However, its biosynthesis by metabolically engineered Escherichia coli is often hampered owing to the insolubility and instability of α-1,2-fucosyltransferase (the rate-limiting enzyme). In this study, we aimed to enhance 2'-FL production by increasing the expression of soluble α-1,2-fucosyltransferase from Helicobacter pylori (FucT2). Because structural information regarding FucT2 has not been unveiled, we decided to improve the expression of soluble FucT2 in E. coli via directed evolution using a protein solubility biosensor that links protein solubility to antimicrobial resistance. For such a system to be viable, the activity of kanamycin resistance protein (Kan^R) should be dependent on FucT2 solubility. Kan^R was fused to the C-terminus of mutant libraries of FucT2, which were generated using a combination of error-prone PCR and DNA shuffling. Notably, one round of the directed evolution process, which consisted of mutant library generation and selection based on kanamycin resistance, resulted in a significant increase in the expression level of soluble FucT2. As a result, a batch fermentation with the ΔL M15 pBCGW strain, expressing the FucT2 mutant (F#1-5) isolated from the first round of the directed evolution process, resulted in the production of 0.31 g/l 2'-FL with a yield of 0.22 g 2'-FL/g lactose, showing 1.72- and 1.51-fold increase in the titer and yield, respectively, compared to those of the control strain. The simple and powerful method developed in this study could be applied to enhance the solubility of other unstable enzymes.