Two-stage pH control strategy based on the pH preference of acetoin reductase regulates acetoin and 2,3-butanediol distribution in Bacillus subtilis

PLoS One. 2014 Mar 7;9(3):e91187. doi: 10.1371/journal.pone.0091187. eCollection 2014.

Abstract

Acetoin reductase/2,3-butanediol dehydrogenase (AR/BDH), which catalyzes the interconversion between acetoin and 2,3-butanediol, plays an important role in distribution of the products pools. This work characterized the Bacillus subtilis AR/BDH for the first time. The enzyme showed very different pH preferences of pH 6.5 for reduction and pH 8.5 for oxidation. Based on these above results, a two-stage pH control strategy was optimized for acetoin production, in which the pH was controlled at 6.5 for quickly converting glucose to acetoin and 2,3-butanediol, and then 8.0 for reversely transforming 2,3-butanediol to acetoin. By over-expression of AR/BDH in the wild-type B. subtilis JNA 3-10 and applying fed-batch fermentation based on the two-stage pH control strategy, acetoin yield of B. subtilis was improved to a new record of 73.6 g/l, with the productivity of 0.77 g/(l · h). The molar yield of acetoin was improved from 57.5% to 83.5% and the ratio of acetoin/2,3-butanediol was switched from 2.7:1 to 18.0:1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetoin / metabolism*
  • Alcohol Oxidoreductases / antagonists & inhibitors
  • Alcohol Oxidoreductases / isolation & purification
  • Alcohol Oxidoreductases / metabolism*
  • Animals
  • Bacillus subtilis / drug effects
  • Bacillus subtilis / enzymology
  • Bacillus subtilis / metabolism*
  • Bioreactors / microbiology
  • Butylene Glycols / metabolism*
  • Cattle
  • Edetic Acid / pharmacology
  • Electrophoresis, Polyacrylamide Gel
  • Enzyme Inhibitors / pharmacology
  • Fermentation / drug effects
  • Hydrogen-Ion Concentration
  • Ions
  • Kinetics
  • Metabolic Networks and Pathways / drug effects
  • Metals / pharmacology
  • Serum Albumin, Bovine / metabolism
  • Substrate Specificity / drug effects
  • Temperature
  • Time Factors

Substances

  • Butylene Glycols
  • Enzyme Inhibitors
  • Ions
  • Metals
  • Serum Albumin, Bovine
  • 2,3-butylene glycol
  • Edetic Acid
  • Acetoin
  • Alcohol Oxidoreductases
  • butanediol dehydrogenase

Grants and funding

This work was supported by the Program for New Century Excellent Talents in University (NCET-10-0459), the National Basic Research Program of China (973 Program) (2012CB725202), the National Natural Science Foundation of China (21276110), the Research Project of Chinese Ministry of Education (No.113033A), the Fundamental Research Funds for the Central Universities (JUSRP51306A and JUSRP21121), the 111 Project (111-2-06) and a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institution. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.