Skip to main content

Table 1 Strategies for engineering redox homeostasis and its effects on alcohols production

From: Engineering redox homeostasis to develop efficient alcohol-producing microbial cell factories

Strategy Specific approach Target product Main effects Ref.
Titer Yield Productivity
Improving the availability of cofactors
 Fine-tuning of NAD(P)H-dependent gene Fine-tuining of yjhG and mdlC 1,2,4-Butanetriol Increased by 71.4% NR NR [4]
Fine-tuning of adhE2 Butanol Increased from 15 to 18.3 g/L NR NR [31]
 Blocking NADH-competing pathways Knock out ldh 1,2-Propanediol Increased from 1.08 to 1.30 g/L anaerobically, from 1.10 to 1.40 g/L microaerobically Increased by 43% anaerobically, by 67% microaerobically NR [19]
Knock out aldA 1,3-Propanediol Increased from 698.6 to 927.6 mM Increased from 0.355 to 0.699 mol/mol Increased by 33% [34]
Knock out adh, ldh and frd Butanol Increased from 141 to 274 mg/L NR NR [20]
Knock out mdh 1,4-Butanediol Increased from ~3 to ~8 mM NR NR [37]
 Increasing total NAD level Overexpress pncB Ethanol Increased from 11.50 to 28.58 mM NR NR [40]
 Introducing NAD(P)H regeneration systems Overexpress fdh1 Ethanol Increased from ~15 to ~175 mM NR NR [21]
Overexpress fdh1 Ethanol Increased from 52.20 to 117.77 mM Increased from 0.72 to 1.33 mol/mol NR [22]
Overexpress fdh 1,3-Propanediol NR Increased by 17.3% NR [45]
Overexpress fdh 2,3-Butanediol Increased from 16.1 to 17.8 g/L Increased from 82.5 to 91.8% Increased by 33% [46]
Activate pyruvate dehydrogenase, fine-tune express fdh1 Butanol Increased from 5.02 to 6.8 g/L NR Increased by 136% [35]
Overexpress GDP1 Ethanol Increased from 90 to 100 mM Increased from 18 to 41% NR [49]
Electrically regenerate NADH Isobutanol Produced 846 mg/L NR NR [53]
Electrically regenerate NADPH Isopropanol Produced 216 mg/L NR NR [55]
Manipulating affinity of redox enzymes for NAD(P)H
 Switching the affinity from one type to another Mutate XR (NADPH to NADH) Ethanol NR Increased from 0.24 to 0.34 g/g NR [63]
Mutate XR (NADPH to NADH) Ethanol Increased from 16.7 to 25.3 g/L Increased from 0.33 to 0.38 g/g NR [65]
Introduce NADPH-preferring enzymes in Synechococcus Butanol Increased from 6.4 to 29.9 mg/L NR NR [67]
Replace bcd-etfAB with ter Butanol Increased from 0.1 to 1.8 g/L NR NR [48]
 Improving affinity for NAD(P)H Introduce alcohol dehydrogenase II and pyruvate decarboxylase genes from Z. mobilis Ethanol Increased from 18 to 750 mM NR NR [18]
Increase affinities of IlvC and AdhA for NADH Isobutanol Increased from 1 to 13.4 g/L Increased from 53 to 100% of the theoretical yield Increased by 38–88% [75]
Globally engineering cellular redox balance
  Manipulating respiratory levels Knock out ubiCA and supply coenzyme Q1 Ethanol NR Increased from 0.48 to 0.80 mol/mol aerobically NR [78]
 Introducing glutathione Overexpress gshAB Butanol Increased from 10.8 to 14.8 g/L NR NR [84]
 Engineering redox-sensitive transcription factor Rex Inactivate rex Ethanol, Butanol Increased from ~20 to ~120 mM and increased from 60 to 120 mM, respectively NR NR [87]
  1. NR not reported