Assessment strategy for bacterial lignin depolymerization: Kraft lignin and synthetic lignin bioconversion with Pseudomonas putida. (September 2021)

• Record Type: Journal Article
• Authors: Rouches, E.; Gómez-Alvarez, H.; Majira, A.; Martín-Moldes, Z.; Nogales, J.; Díaz, E.; Bugg, T.D.H.; Baumberger, S.
• Is Part Of: Bioresource technology reports. Volume 15(2021)
• Publication Date: 2021-09
• Subjects: Bacterial conversion -- Depolymerization -- HPSEC -- Lignin -- Phenolic metabolites; Biomass energy -- Periodicals; Biotransformation (Metabolism) -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Waste products as fuel -- Periodicals; Waste products as fuel; Organic wastes; Factory and trade waste; Biotransformation (Metabolism); Biomass energy; Agricultural wastes; Periodicals; Electronic journals; 662.88
• DOI: 10.1016/j.biteb.2021.100742
• Languages: English
• ISSNs: 2589-014X

Abstract

Abstract: In order to better understand bacterial depolymerization of lignin, a new analytical approach was proposed using Pseudomonas putida KT2440 as delignifying bacterium and Escherichia coli as non-delignifying control. Two different types of lignins, technical Kraft lignin and synthetic dehydrogenopolymer (DHP), were submitted to a bioconversion kinetic study over 7 days. The concomitant analysis of the supernatant acid-precipitable lignin fraction and water-soluble extractives by high-performance size-exclusion chromatography (HPSEC) and gas chromatography – mass spectrometry (GC–MS) highlighted the specific action of P. putida towards these substrates, with the transitory formation of phenolic metabolites (dihydroferulic acid for Kraft lignins and dimers for DHP) and the prevention of Kraft lignin self-assemblying. In both cases lignin apparent depolymerization followed by repolymerization was observed. The analysis of the bacterial pellets indicated the time-increasing content of lignins associated to bacterial cells, which could account for the apparent structural changes observed with E. coli in the supernatant. Graphical abstract: Unlabelled Image Highlights: Incubation with P. putida KT2440 prevented self-polymerization of Kraft lignin. Apparent DHP depolymerization took place during incubation with P. putida KT2440. P. putida KT2440 metabolized phenolic monomers during the first 24 h incubation. Dihydroferulic acid was transitory formed by lignin treatment with P. putida KT244. Lignin was found associated to non-delignifying E. coli bacterium after incubation.