摘要
以Klebsiella pneumoniae利用葡萄糖和木糖双底物生物转化生产2,3-丁二醇和氢气过程为研究对象,对其进行代谢计量分析。分析结果显示:2,3-丁二醇和氢气相对于底物葡萄糖和木糖的质量收率依赖于还原能力NADH2氧化磷酸化的分率(δ)。当δ=27时,即在总还原能力NADH2中有27mol NADH2被氧化磷酸化,剩余部分用来产生氢气,呼吸商为14时,2,3-丁二醇和氢气的最优质量收率分别为50%和0.8%;而当δ=1,即还原能力NADH2全部被氧化磷酸化、不产生氢气,呼吸商为4时,2,3-丁二醇的质量收率为37.5%;2,3-丁二醇和氢气的质量收率与底物中葡萄糖和木糖的比值无关。而氢气的摩尔收率与底物中葡萄糖和木糖的比值相关,当底物全部是葡萄糖或木糖时,其最优摩尔收率分别为71%和60%。该分析结果为葡萄糖和木糖双底物生物转化生产2,3-丁二醇过程的实验研究奠定了理论基础。
Glucose and xylose were used as substrates cofermentated by Klebsiella pneumoniae to produce 2,3- butanediol and hydrogen, which was stoichiometricall analyzed according to energy（ATP）, reducing equivalent and mass balances. The theoretical analysied revealed that the mass yield of 2,3-butanediol and hydrogen to substrate was independent of the ratio of glucose to xylose initially added, and depended only on the molar fraction of reducing equivalent oxidized by molecular oxygen（δ）. The optimal theoretical mass yield of 2, 3-butanediol and hydrogen to substrate can reach to 0.50 g/g and 0.008 g/g respectively at the respiratory quotient value to 14, if all pyruvic acid entered into acetoin pathway instead of the others, and the molar fraction of NA2DH2 oxidized was 1/7, the residual NADH2 was used to produce hydrogen. When the reducing equivalent was completely oxidized without hydrogen production, the mass yield of 2,3-butanediol was 0. 375 g/g at the respiratory quotient to 4. The theoretical analysis can help us understand the metabolic principles further, design and control the experimental investigations better.
出处
《生物加工过程》
CAS
CSCD
2006年第3期44-50,共7页
Chinese Journal of Bioprocess Engineering
关键词
2
3-丁二醇
氢
葡萄糖
木糖
代谢计量分析
2,3-butanediol
hydrogen
glucose
xylose
stoichiometrically analysis
