• Journal of Dairy Science and Biotechnology
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• v.29 no.1
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• pp.17-22
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• 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.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.2
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• pp.105-112
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• 2022

2'-fucosyllactose (2'-FL) is the most abundant human milk oligosaccharide (HMO) present in breast milk, promoting the growth of beneficial microorganisms in the gut and aiding in the relief of allergic and inflammatory reactions. In this study, the anti-melanogenic effects of 2'-FL, and its potential for application in whitening cosmetics, were evaluated. MTT assay was performed on MNT-1 cells, human-derived melanocytes. 2'-FL was treated and replaced at 48 h intervals for 7 days, and it was confirmed that there was no cytotoxicity at 20 g/L or less, while a 40% reduction in melanin production was also observed. Western blot analysis of TYR and TYRP1, factors involved in melanogenesis, revealed that 2'-FL treatment reduced their expression levels. In addition, 2'-FL application and observation of the autophagy marker microtubule-associated protein 1 light chain 3 (LC3) revealed it was converted from LC3-I to LC3-𝚷, indicating increased autophagy. Likewise, confocal microscopy revealed an increase in LC3 puncta after 2'-FL treatment. Therefore, it is suggested that 2'-FL-mediated activation of autophagy reduces melanogenesis by inhibiting the expression levels of TYR and TYRP1 proteins. In conclusion, it has been confirmed that 2'-FL induces autophagy and suppresses melanin production, so its potential as a whitening cosmetic material is expected.

• Journal of Microbiology and Biotechnology
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• v.32 no.11
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• pp.1471-1478
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• 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.