Microbial Valorization of Lignin to Bioplastic by Genome-Reduced Pseudomonas putida

Abstract

As the most abundant natural aromatic resource, lignin valorization will contribute to a feasible biobased economy. Recently, biological lignin valorization has been advocated since ligninolytic microbes possess proficient funneling pathways of lignin to valuable products. In the present study, the potential to convert an actual lignin stream into polyhydroxyalkanoates (PHAs) had been evaluated using ligninolytic genome-reduced Pseudomonas putida. The results showed that the genome-reduced P. putida can grow well on an actual lignin stream to successfully yield a high PHA content and titer. The designed fermentation strategy almost eliminated the substrate effects of lignin on PHA accumulation. Employing a fed-batch strategy produced the comparable PHA contents and titers of 0.35 g/g dried cells and 1.4 g/L, respectively. The molecular mechanism analysis unveiled that P. putida consumed more small and hydrophilic lignin molecules to stimulate cell growth and PHA accumulation. Overall, the genome-reduced P. putida exhibited a superior capacity of lignin bioconversion and promote PHA accumulation, providing a promising route for sustainable lignin valorization.

Valorizing Lignin and Coprecursors into Homogeneous Polyhydroxyalkanoates by Engineered Pseudomonas putida

“…Previous study also showed that the PHA accumulation of the engineered P. putida could be affected at higher lignin concentration. ,, …”

“…Previous study also showed that the PHA accumulation of the engineered P. putida could be affected at higher lignin concentration. 6,26,28 3HD was identified as the primary component in PHA when lignin hydrolysate was used as the sole carbon source. P. putida KT2440 cultivated on the sole APL substrate also successfully synthesized PHA containing mainly 55% 3HD.…”

“…6 The trichloromethane layer was filtered using a 0.22 μm PTFE membrane for subsequent GC-MS analysis. 28 2.5. Analysis Methods.…”

Optimized pulse‐feeding fed‐batch fermentation for enhanced lignin to polyhydroxyalkanoate transformation

“…Polyhydroxyalkanoates (PHA) are one of potential bioproducts that can be produced from lignin or lignin derivatives via microbial fermentation 6,7 . PHA are bio‐polyesters, naturally evolved as energy storage compound by selected group of microbes 8 .…”

“…[3][4][5] Polyhydroxyalkanoates (PHA) are one of potential bioproducts that can be produced from lignin or lignin derivatives via microbial fermentation. 6,7 PHA are bio-polyesters, naturally evolved as energy storage compound by selected group of microbes. 8 The bioplastics are viewed as environmental-friendly, a key material to replace fossilbased plastics, and can be applied among a multitude of diverse materials ranging from packaging to high performance med-tech applications.…”