Poplar Lignin Decomposition by Gram-Negative Aerobic Bacteria

Abstract

Eleven gram-negative aerobic bacteria ( Pseudomonadaceae and Neisseriaceae ) out of 122 soil isolates were selected for their ability to assimilate poplar dioxane lignin without a cosubstrate. Dioxane lignin and milled wood lignin degradation rates ranged between 20 and 40% of initial content after 7 days in mineral medium, as determined by a loss of absorbance at 280 nm; 10 strains could degrade in situ lignin, as evidenced by the decrease of the acetyl bromide lignin content of microtome wood sections. No degradation of wood polysaccharides was detected. Lignin biodegradation by Pseudomonas 106 was confirmed by 14 CO 2 release from labeled poplar wood, although in lower yields compared with results obtained through chemical analysis based on acetyl bromide residual lignin determination.

Transformations of (14C‐lignin) cell walls of wheat by rumen microorganisms

“…(I4C-Lignin) substrates were prepared by the cut stem infusion method (Agosin et a1 1985): wheat plants were cut under the last node and batches of five stems were each fed 2 MBq phe or sin in the dark for 96 h at 25°C (Mosoni et al 1993). The lower halves of the apical internodes were ground under liquid nitrogen, treated with pronase (Odier et al 1981) and then Soxhlet extracted successively with toluene/ethanol (2 : 1 v) and ethanol to obtain the cell wall residue (CWR). This residue was treated with 1 M NaOH at 35°C for 2 h to yield the saponified residue (SR).…”

Absence of microbial mineralization of lignin in anaerobic enrichment cultures

“…[14C]lignin poplar wood preparation. L-[U-14C]phenylalanine was used as a precursor of lignin biosynthesis to feed poplar twigs (Populus euramericana Dode cultivar I214) by using the cut stem technique as described previously (30). The stems were allowed to metabolize for 72 h under continuous light, after which the xylem was collected.…”

Microbial delignification and hydrolysis of lignocellulosic biomass to enhance biofuel production: an overview and future prospect

“…showed up to 52% of lignin degradation within 30 days on poplar wood (Dionisi et al 2014). On the other hand, Acinetobacter removed about 47 to 57% of lignin from poplar wood within 30 days of pretreatment (Odier et al 1981;Dionisi et al 2014). This is the maximum lignin removal reported so far by using bacteria.…”