Enhancement of Environmental Hazard Degradation in the Presence of Lignin: a Proteomics Study

Abstract

Proteomics studies of fungal systems have progressed dramatically based on the availability of more fungal genome sequences in recent years. Different proteomics strategies have been applied toward characterization of fungal proteome and revealed important gene functions and proteome dynamics. Presented here is the application of shot-gun proteomic technology to study the bio-remediation of environmental hazards by white-rot fungus. Lignin, a naturally abundant component of the plant biomass, is discovered to promote the degradation of Azo dye by white-rot fungus Irpex lacteus CD2 in the lignin/dye/fungus system. Shotgun proteomics technique was used to understand degradation mechanism at the protein level for the lignin/dye/fungus system. Our proteomics study can identify about two thousand proteins (one third of the predicted white-rot fungal proteome) in a single experiment, as one of the most powerful proteomics platforms to study the fungal system to date. The study shows a significant enrichment of oxidoreduction functional category under the dye/lignin combined treatment. An in vitro validation is performed and supports our hypothesis that the synergy of Fenton reaction and manganese peroxidase might play an important role in DR5B dye degradation. The results could guide the development of effective bioremediation strategies and efficient lignocellulosic biomass conversion.

Synergistic Improvement of Carbohydrate and Lignin Processability by Biomimicking Biomass Processing

“…During the lignin biodegradation process (Rouches et al, 2016;Qin et al, 2018), white-rot fungi produce multiple types of reactive radicals by both enzymes and Fenton reaction reagents, as well as organic acid, such as oxalic acid to efficiently disrupt the lignocellulose matrix (Rudakiya and Gupte, 2017;Kameshwar and Qin, 2018). The integration of reactive radicals and organic acid can be exploited to establish a new process for lignocellulosic biomass conversion (Sun et al, 2016(Sun et al, , 2017. The previous pretreatment, by mimicking the Fenton reaction, was designed to focus on the enzymatic hydrolysis performance of the lignocellulosic biomass (Jung et al, 2015), while the lignin processibility was not discussed.…”

Analysis of decolorization potential of Myrothecium roridum in the light of its secretome and toxicological studies

“…The enzymatic degradation of dyes was generally enhanced in the solutions with pH 4–8. Recently, laccase from Myrothecium verrucaria MD-R-16 demonstrated the decolorization of Methyl Red by more than 60% in the pH range of 4.5–6.5, with the maximum (80%) at pH 5.5 (Sun et al 2017). As a general trend, most of the laccases of fungal origins maximally work at slightly acidic and neutral pH.…”

Lytic polysaccharide monooxygenases promote oxidative cleavage of lignin and lignin–carbohydrate complexes during fungal degradation of lignocellulose

“…In addition, the expression pattern of LPMO (AA9) proteins seemed to show a good correlation with lignin and LCC degradation within the secretome of P. ostreatus based on the results of the structure analysis after fungal pretreatment. The HO • produced by the Fenton reaction is a non-specific oxidant that can oxidize both polysaccharides and lignin-related aromatic compounds (Martinez et al, 2009;Sun et al, 2017). Considering the decreased expression of the main LCC degradation related enzyme CE1 (Supporting Information Table S4) (Dilokpimol et al, 2016) while LCC degradation was significantly promoted in the presence of Mn 2+ , we hypothesized that the increased fungal LCC degradation may be attributed to the enhanced production of hydroxy radicals in the presence of Mn 2+ .…”