Biotransformation of toxic lignin and aromatic compounds of lignocellulosic feedstock into eco-friendly biopolymers by Pseudomonas putida KT2440

Lignin and its derivatives are the most neglected compounds in bio-processing industry due to their toxic and recalcitrant nature. Considering this, the present study aimed at valorizing these toxic compounds by employing Pseudomonas putida KT2440. Acclimatization resulted in improved tolerance with considerable lag phase reduction and aromatics degradation. Glucose as co-substrate enhanced growth and degradation in the toxic environment. The strain was able to degrade 30 % (1.60 g.L- 1) lignin, 45 mM benzoate, 40 mM p-coumarate, 35 mM ferulate, 10 mM phenol, 10 mM pyrocatechol and 8 mM aromatics mixture. The strain synthesized bio-polymers using these compounds under feast and famine conditions. Characterization using GC-MS, FT-IR, H1 NMR revealed them to be Polyhydroxyalkanoate (PHA) heteropolymers. All the analyzed PHAs contained ver-satile monomers with Hexadecanoic acid being the major one. This is a novel attempt towards lignin and aro-matics degradation coupled with biopolymers synthesis without any genetic manipulation of the strain.

Automated summary

This study successfully utilized Pseudomonas putida KT2440 to valorize lignin and its derivatives, and synthesized bio-polymers without any genetic manipulation.