| 1. |
- Kim, Chang Joon, et al.
(författare)
-
발리올아민의 UV 분석방법 (A method for analysis by UV detector of valiolamine)
- 2011
-
Patent (populärvet., debatt m.m.)abstract
- A UV analysis method of valiolamine is provided to maximize detection sensitivity of valiolamine by making valiolamine to phenylisocyanate, and to enable accurate and quick HPLC analysis. CONSTITUTION: A UV analysis method of valiolamine comprises the steps of: deriving valiolamine in a microbial culture medium with a chromophore reagent to increase the detection sensitivity; and analyzing the valiolamine with increased detection sensitivity with a high performance liquid chromatography(HPLC)/UV detector. The microbial culture medium uses at least one of (i) glucose 50 g/L, soybean flour 36 g/L, peptone 5 g/L, CaCO3 4 g/L; (ii) glucose 20 g/L, corn starch 40 g/L, corn steep liquor 20 g/L, corn gluten meal 40 g/L, NH4Cl 5 g/L, NaCl 15 g/L, CaCO3 15 g/L; or (iii) glucose 10 g/L, soluble starch 50 g/L, peptone 15 g/L, corn gluten powder 30 g/L, NaCl 5 g/L, CaCO3 10 g/L. COPYRIGHT KIPO 2010
|
|
| 2. |
- Li, He, et al.
(författare)
-
Enhanced production of trehalose in Escherichia coli by homologous expression of otsBA in the presence of the trehalase inhibitor, validamycin A, at high osmolarity
- 2012
-
Ingår i: Journal of Bioscience and Bioengineering. - : Elsevier. - 1389-1723 .- 1347-4421. ; 113:2, s. 224-232
-
Tidskriftsartikel (refereegranskat)abstract
- Trehalose production in Escherichia coli DH5α was explored by overexpressing otsBA operon encoding trehalose-6-phosphate synthase and trehalose-6-phosphate phosphatase. Production and subsequent degradation of trehalose resulted in low production of trehalose in engineered cells overexpressing otsBA, which was primarily due to the concomitant expression of endogenous trehalase. Through an in vitro enzyme assay and flask cultures of engineered cells, trehalase expression was shown to be directly related to the expression of otsBA rather than osmotic stress. Validamycin A effectively inhibited E. coli trehalase and the intracellular accumulation of trehalose was markedly enhanced in the presence of validamycin A at an optimal concentration in the medium. The trehalose production was further increased upon growth in a hypertonic medium in the presence of validamycin A, with most trehalose accumulating as an intracellular product. The highest titer was obtained when otsBA expression was induced by a medium-copy vector, ptrc99A, with 0.5mM of isopropyl β-d-1-thiogalactopyranoside. Trehalose titer was 1.7 g/L in controlled bioreactor cultures using synthetic M9 medium supplemented with 40 g/L glycerol, 0.1mM validamycin A, and 300 mM NaCl.
|
|
