文献类型：期刊文献

英文题名：Metabolic flux analysis of the central carbon metabolism of the industrial vitamin B12 producing strain Pseudomonas denitrificans using 13C-labeled glucose

作者：Wang, Ze-Jian[1]; Wang, Ping[2]; Liu, Yu-Wei[1]; Zhang, Yi-Ming[3]; Chu, Ju[1]; Huang, Ming-zhi[1]; Zhuang, Ying-Ping[1]; Zhang, Si-Liang[1]

机构：[1] State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China; [2] Microbiology Laboratory of Hebei Medical University, Shijiazhuang, China; [3] Department of Chemical and Biological Engineering, Chalmers University of Technology, Kemiv?gen 10, SE-412 96 G?teborg, Sweden

年份：2012

卷号：43

期号：2

起止页码：181

外文期刊名：Journal of the Taiwan Institute of Chemical Engineers

收录：EI(收录号：20120814791147)

语种：英文

外文关键词：Bacteria - Cultivation - Physiology - Carbon - Oxygen supply - Amino acids - Metabolism

摘要：The network topology and metabolic fluxes of central carbon metabolism in the industrial vitamin B12 producing strain Pseudomonas denitrificans were characterized under oxygen limiting levels. Cultivations were carried out with 100% [1-13C] or 20% [U-13C] glucose as substrates under different oxygen supply conditions. The labeling patterns of the proteinogenic amino acids of exponentially growing cells were used to accurately estimate the fluxes in the central carbon metabolism of P. denitrificans. Metabolic flux analysis showed that glucose was mostly catabolized by the Entner-Doudoroff and pentose phosphate pathways. Up to 33% of glucose was consumed via the PP pathway under high specific oxygen uptake rate (SOUR) conditions. This amount was 77.9% higher than that under low oxygen uptake conditions. Quantitative evidence was also found for reversible serine hydroxymethyl transferase and threonine aldolase activities. Metabolic flux and cofactor analyses further showed that higher SOUR accelerated the supply of precursors and methyl groups. SOUR also provided more NADPH for higher vitamin B12 production under the same glucose consumption. ? 2012.