Table 5 Aromatic and other chemicals from lignin degradation pathways by bacteria

p-Hydroxybenzoic acid

p-Coumaric acid

Engineered Burkholderia glumae BGR1

Delete genes encoding p-hydroxybenzoate-3-hydroxylase, benzoyl-CoA ligase; overexpress p-hydroxcinnmaoyl-CoA synthetase II

2.73 g/L

99.0% mol/mol

[69]

Pyrogallol, GA

Syringic acid

Engineered E. coli

Co-express desA, ligM and a GA decarboxylase gene

7.3 mg/L pyrogallol, 18 mg/L GA

7.3 mg pyrogallol/g syringate, 18 mg GA/g syringate

[117]

Vanillin

2.5% Wheat straw lignocellulose

R. jostii

Delete vdh gene

96 mg/L

–

[131]

Vanillin

Lignin extracted from wheat straw

Shewanella putrefaciens

Construct a microbial fuel cell system for lignin depolymerization

275 mg/L

–

[132]

Pyruvate

p-Coumaric acid

P. putida KT2440-CJ122

Choose protocatechuic acid meta-cleavage pathway for p-coumaric acid conversation

–

0.414 g/g

[135]

Lactic acid

p-Coumaric acid

P. putida KT2440-CJ122

Choose protocatechuic acid meta-cleavage pathway for p-coumaric acid conversation

–

0.411 g/g

[135]

Pyruvate

p-Coumaric acid

P. putida KT2440-CJ124

Choose protocatechuic acid ortho-cleavage pathway for p-coumaric acid conversation

–

0.019 g/g

[135]

Lactic acid

p-Coumaric acid

P. putida KT2440-CJ124

Choose protocatechuic acid ortho-cleavage pathway for p-coumaric acid conversation

–

0.145 g/g

[135]

Methane

Hydrolysis lignin

Anaerobic microorganisms

Degrade lignin by anaerobic digestion in a nylon bag

125 mL methane/g volatile solid

[136]