Flavin-containing monooxygenases (FMOs) have been identified from a variety of organisms. Our previous studies found that recombinant E. coli cells harboring fmo gene from Methylophaga aminisulfidivorans MPT produced indigo (920 mg/L) and indirubin (≤5 mg/L) in a 5 L fermentor containing tryptophan medium (2g/L tryptophan, 10g/L NaCl and 5g/L yeast extract). Interestingly, indirubin production greatly increased when cysteine was added to the tryptophan medium. Although growth of the recombinant E. coli harboring fmo gene was inhibited by cysteine, protein expression level and activity of FMO were not influenced. The optimum culture conditions for indirubin production in tryptophan medium were as follows: 2 g/L tryptophan, 5 g/L yeast extract, 10 g/L NaCl, 3 mM cysteine, pH 8.0 and at 30℃. Under these conditions, recombinant E. coli cells produced 223.6 mg/L of indirubin. In order to investigate the proteins involved in indirubin production in E. coli, proteomic analysis was performed using two-dimensional gel electrophoresis in conjunction with MALDI-TOF mass spectrometry. The analysis showed that the expression levels of 66 proteins were varied quantitatively with statistical significance under the optimum indirubin production condition. Through classification of physiological functions from Matrix Science Database analysis, nine proteins, which maybe involved in tryptophan synthesis and biofilm formation, were identified. Carrageenans are classified according to the number and the position of sulfate ester groups. They are made up of linear chains of galactose. The κ-carrageenase CgkA from Pseudoalteromonas carrageenovora is a hydrolase involved in the degradation of carrageenan. In this study, we expressed recombinant scaffolding protein mini-CbpA from Clostridium cellulovorans in Escherichia coli. To assemble the carrageenan-degrading complex via cohesin-dockerin interaction, a chimeric carrageenase cCgkA was constructed to containing the catalytic domain of CgkA fused with a dockerin domain of C. cellulovorans EngB. The resulting hydrolysis complex could degrade carrageenan efficiently with synergic effect of carrageenan-degrading enzyme activities. This is the first report on the formation of carrageenan-degrading complex using the cohesin-dockerin interaction system. The enhancement of carrageenan-degrading complex activities will lead to the commercial production of useful products from agar biomass at low costs. [This Study was supported by Technology Development Program for Agriculture and Forestry, Ministry for Agriculture, Forestry and Fisheries, Republic of Korea(No. 309016-5)] A capnophilic rumen bacteria, Actinobacillus succinogenes can produce high level of succinic acid as a major fermentation end product. Succinic acid is a four-carbon dicarboxylic acid, produced as an intermediate of the tricarboxylic acid cycle and can be used to produce various industrially useful chemicals like 1,4-butandiol and tetrahydrofuran, as well as biodegradable polymers. During the anaerobic fermentation, the carbon dioxide availability is a key factor determining the succinic acid productivity. In this study, to incr ... 전체 초록 보기