Screening and identification of lignin-degrading bacteria in termite gut and the construction of LiP-expressing recombinant Lactococcus lactis

Recent advances in lignin valorization with bacterial cultures: microorganisms, metabolic pathways, and bio-products

“…Wood-eating termites play an important role in natural carbon cycle and most lignocellulosic materials are digested in termite hindgut [20]. Thus, the termite gut is a rich source for the isolation of lignin-degrading bacteria and some bacteria responsible for lignin degradation were isolated successfully [21, 22]. In addition, some endophytes can decompose plant residues rapidly when the plants die due to its lignocellulose degradation ability, and endophytic bacteria were also isolated for lignin degradation [23].…”

“…The commonly used dyes for lignin-degrading bacteria screening include Azure B, Toluidene Blue O, Methylene Blue, Malachite Green, Remazol Brilliant Blue R, indulin AT, etc. [21, 26, 28, 31–33].…”

“…PT01 (DSM 29581)Forest surface soilPrimary screening with kraft lignin as the sole carbon source; secondary screening by determining the decolorization of Remazol Brilliant Blue R as indicatorPossess dye decolorization ability on Azure B, Methylene blue, Remazol Brilliant Blue R; Can catabolize syringaldehyde, syringic acid, vanillin, vanillic acid, vanillyl alcohol, guaiacol, veratyl alcohol, and biphenyl[32] Enterobacter sp. PY12Termites gutsPrimary screening with lignin as the sole carbon source; secondary screening by determining the decolorization of Azure-BPossess high lignin peroxides activity; possess dye decolorization ability on Congo red, Neutral red, Azure-B, Malachite green, and Methylene blue[21] Trabulsiella sp. IIPTG13Termite gutsUse guaiacylglycerol- β -guaiacyl ether as the sole carbon sourceCan degrade lignin to organic acids and some low-molecular weight aromatics[22] Pantoea sp.…”

Bioprospecting Microbial Diversity for Lignin Valorization: Dry and Wet Screening Methods

“…The qualitative detection of lignin-degrading bacteria and fungi are generally performed using natural substrates that resemble the lignin structure (Figure 3; Table 1). The most common practice is to use aromatic dyes such as azure B, Remazol Marine Blue, toluidine blue, methylene blue, malachite green, Remazol Brilliant Blue R and indulin AT as carbon sources in the growth medium and to monitor the modification in the color from the degradation by the oxidative enzymes produced by the microorganisms (Figure 3; Raj et al, 2007;Nozaki et al, 2008;Zhou et al, 2017;Xu et al, 2019). In liquid media, the degradation of methylene blue, toluidine blue, and malachite green dyes can be quantified by measuring the optical density of the sample at a wavelength of 620 nm using a spectrophotometer.…”

“…This methodology was successfully used to retrieve Bacillus sp. (Raj et al, 2007), basidiomycetes fungi (Nozaki et al, 2008), actinobacteria, Klebsiella pneumoniae (Xu R. et al, 2018), Pseudomonas putida and Ochrobactrum tritici presenting lignin-degrading activity in soils, leaf mold samples, and termite guts (Zhou et al, 2017).…”