食品科学 ›› 2013, Vol. 34 ›› Issue (11): 157-162.doi: 10.7506/spkx1002-6630-201311035

• 基础研究 • 上一篇    下一篇

钝齿棒杆菌产乳酸与琥珀酸的代谢调控

陈小举,姜绍通*,李兴江,潘丽军   

  1. 合肥工业大学农产品加工研究院,生物与食品工程学院,安徽 合肥 230009
  • 收稿日期:2012-02-11 修回日期:2013-03-19 出版日期:2013-06-15 发布日期:2013-06-03
  • 通讯作者: 陈小举 E-mail:hongyijianke888@163.com
  • 基金资助:

    小麦麸皮发酵产琥珀酸放线杆菌的代谢调控研究;基于能量平衡机制的玉米芯水解糖发酵产丁二酸杆菌代谢途径研究

Metabolic Regulation of Succinic Acid and Lactic Acid Production by Corynebacterium crenatum

CHEN Xiao-ju,JIANG Shao-tong*,LI Xing-jiang,PAN Li-jun   

  1. School of Biotechnology and Food Engineering, Institute of Agricultural Products Processing Technology, Hefei University of Technology, Hefei 230009, China
  • Received:2012-02-11 Revised:2013-03-19 Online:2013-06-15 Published:2013-06-03

摘要:

为实现利用钝齿棒杆菌厌氧发酵联产乳酸和琥珀酸,在代谢通量计算的基础上,利用NaHCO3对钝齿棒杆菌厌氧发酵产乳酸与琥珀酸进行调控。NaHCO3浓度由0mmol/L增加到100mmol/L时,葡萄糖的消耗速率达到了69.14mmol/(L·h),增加了130%,乳酸累积浓度也由184.10mmol/L上升到400.92mmol/L。NaHCO3浓度为200mmol/L时,琥珀酸累积浓度达到128.05mmol/L,是NaHCO3为0mmol/L时的9.2倍。乳酸和琥珀酸的总酸产量为1.9mol/mol。酶活分析表明,NaHCO3对磷酸烯醇式丙酮酸羧化酶(PEPC)有激活作用。NaHCO3浓度为100mmol/L时,PEPC酶活力上升到1.242U/mg,使磷酸烯醇式丙酮酸(PEP)流向C4途径的碳流量增加2倍。代谢通量分析表明C4途径是钝齿棒杆菌产琥珀酸的主要途径,经由C4途径产生的琥珀酸占整个琥珀酸产量的96%。研究结果表明加入NaHCO3能调节乳酸和琥珀酸的产量,为利用钝齿棒杆菌厌氧发酵联产乳酸和琥珀酸提供了数据支持。

关键词: 钝齿棒杆菌, 代谢通量, 琥珀酸, 乳酸, 碳酸氢钠

Abstract:

In order to improve the production of lactic acid and succinic acid by C. crenatum, the effect of sodium
bicarbonate on the yield of succinic acid and lactic acid was investigated. Sodium bicarbonate had a significant effect on
glucose consumption rate and organic acid production rate of C. crenatum under oxygen deprivation. With the addition
of 100 mmol/L of sodium bicarbonate, the glucose consumption rate increased by 130%, reaching 69.14 mmol/(L•h),
and the lactic acid accumulation showed an increase from 184.10 mmol/L to 400.92 mmol/L. When the concentration
of added sodium bicarbonate reached 200 mmol/L, the concentration of accumulated succinic acid was 128.05 mmol/L,
which indicated a 9.2-fold increase compared to no addition of sodium bicarbonate, and the total yield of lactic acid and
succinic acid was 1.9 mol/mol. Further analysis showed that sodium bicarbonate activated phosphoenolpyruvate carboxylase
(PEPC) in C. crenatum. PEPC activity increased from 0.956 U/mg to 1.242 U/mg in the presence of 100 mmol/L of sodium
bicarbonate. The flux from phosphoenolpyruvate (PEP) to oxaloacetate increased 3 times and the flux from PEP to pyruvate
decreased 18.9%. Metabolic flux analysis indicated that 96% of succinic acid was produced through the C4 pathway. The
results of this study indicate lactic acid and succinic acid can be produced by C. crenatum under oxygen deprivation even
though their proliferation is arrested.

Key words: Corynebacterium crenatum, metabolic flux analysis, succinic acid, lactic acid, sodium bicarbonate

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