Time filter

Source Type

Yeongi, South Korea

Ho J.-N.,Kyung Hee University | Choi J.-W.,Korea University | Lim W.-C.,Korea University | Kim M.-K.,DMJ Biotech Corporation | And 2 more authors.
Journal of the Science of Food and Agriculture | Year: 2013

Background: Kefir, a traditional fermented milk composed of microbial symbionts, is reported to have various health benefits such as anti-tumour, anti-inflammatory, anti-neoplastic and pro-digestive effects. In this study, to elucidate the effects of kefir on adipocyte differentiation and lipid accumulation, three fractions were prepared from kefir culture broth. The inhibitory effects of kefir liquid culture broth fraction (Fr-1), soluble fraction (Fr-2) and insoluble fraction (Fr-3), prepared by sonication of kefir solid culture broth, on adipocyte differentiation in 3T3-L1 preadipocytes were examined. Results: Fr-3 (0.1 mg mL-1) significantly decreased lipid accumulation and glycerol-3-phosphate dehydrogenase (GPDH) activity by 60 and 68% respectively without affecting cell viability. In addition, Fr-3 treatment down-regulated the mRNA expression of adipogenic transcription factors including C/EBPα (32%), PPARγ (46%) and SREBP-1c (34%) during adipocyte differentiation compared with untreated control cells. The mRNA expression of adipocyte-specific genes (aP2, FAS and ACC) was also clearly decreased. Conclusion: The results suggest that the insoluble fraction of kefir (Fr-3) mediates anti-adipogenic effects through the inhibition of adipocyte differentiation, partly via suppression of the C/EBPα-, SREBP-1c- and PPARγ-dependent pathways. © 2012 Society of Chemical Industry.

Kwon E.-Y.,Chungbuk National University | Kim K.M.,DMJ Biotech Corporation | Kim M.K.,DMJ Biotech Corporation | Lee I.Y.,DMJ Biotech Corporation | Kim B.S.,Chungbuk National University
Bioprocess and Biosystems Engineering | Year: 2011

Bacillus subtilis was cultivated to high cell density for nattokinase production by pH-stat fed-batch culture. A concentrated mixture solution of glucose and peptone was automatically added by acid-supplying pump when culture pH rose above high limit. Effect of the ratio of glucose to peptone in feeding solution was investigated on cell growth and nattokinase production by changing the ratio from 0.2 to 5 g glucose/g peptone. The highest cell concentration was 77 g/L when the ratio was 0.2 g glucose/ g peptone. Cell concentration decreased with increasing the ratio of glucose to peptone in feeding solution, while the optimum condition existed for nattokinase production. The highest nattokinase activity was 14,500 unit/mL at a ratio of 0.33 g glucose/g peptone, which was 4.3 times higher than that in batch culture. © Springer-Verlag 2011.

Cho Y.-H.,Chungbuk National University | Song J.Y.,Chungbuk National University | Kim K.M.,DMJ Biotech Corporation | Kim M.K.,DMJ Biotech Corporation | And 6 more authors.
New Biotechnology | Year: 2010

Nattokinase was produced by batch and fed-batch culture of Bacillus subtilis in flask and fermentor. Effect of supplementing complex media (peptone, yeast extract, or tryptone) was investigated on the production of nattokinase. In flask culture, the highest cell growth and nattokinase activity were obtained with 50. g/L of peptone supplementation. In this condition, nattokinase activity was 630. unit/ml at 12. h. In batch culture of B. subtilis in fermentor, the highest nattokinase activity of 3400. unit/ml was obtained at 10. h with 50. g/L of peptone supplementation. From the batch kinetics data, it was shown that nattokinase production was growth-associated and culture should be harvested before stationary phase for maximum nattokinase production. In fed-batch culture of B. subtilis using pH-stat feeding strategy, cell growth (optical density monitored at 600. nm) increased to ca. 100 at 22. h, which was 2.5 times higher than that in batch culture. The highest nattokinase activity was 7100. unit/ml at 19. h, which was also 2.1 times higher than that in batch culture. © 2010 Elsevier B.V.

Discover hidden collaborations