Bioremediation of lignosulphonates by lignin-degrading basidiomycetous fungi

Trametes versicolor in lignocellulose-based bioeconomy: State of the art, challenges and opportunities

Although Trametes versicolor is one of the most investigated white-rot fungi, the industrial application of this fungus and its metabolites is still far from reaching its full potential. This review aims to highlight the opportunities and challenges for the industrial use of T. versicolor according to the principles of circular bioeconomy. The use of this fungus can contribute significantly to the success of efforts to valorize lignocellulosic waste biomass and industrial lignocellulosic byproducts. Various techniques of T. versicolor cultivation for enzyme production, food and feed production, wastewater treatment, and biofuel production are listed and critically evaluated, highlighting bottlenecks and future perspectives. Applications of T. versicolor crude laccase extracts in wastewater treatment, removal of lignin from lignocellulose, and in various biotransformations are analyzed separately.

Trends in predictive biodegradation for sustainable mitigation of environmental pollutants: Recent progress and future outlook

The feasibility of in-silico techniques, together with the computational framework, has been applied to predictive bioremediation aiming to clean-up contaminants, toxicity evaluation, and possibilities for the degradation of complex recalcitrant compounds. Emerging contaminants from different industries have posed a significant hazard to the environment and public health. Given current bioremediation strategies, it is often a failure or inadequate for sustainable mitigation of hazardous pollutants. However, clear-cut vital information about biodegradation is quite incomplete from a conventional remediation techniques perspective. Lacking complete information on bio-transformed compounds leads to seeking alternative methods. Only scarce information about the transformed products and toxicity profile is available in the published literature. To fulfill this literature gap, various computational or in-silico technologies have emerged as alternating techniques, which are being recognized as in-silico approaches for bioremediation. Molecular docking, molecular dynamics simulation, and biodegradation pathways predictions are the vital part of predictive biodegradation, including the Quantitative Structure-Activity Relationship (QSAR), Quantitative structure-biodegradation relationship (QSBR) model system. Furthermore, machine learning (ML), artificial neural network (ANN), genetic algorithm (GA) based programs offer simultaneous biodegradation prediction along with toxicity and environmental fate prediction. Herein, we spotlight the feasibility of in-silico remediation approaches for various persistent, recalcitrant contaminants while traditional bioremediation fails to mitigate such pollutants. Such could be addressed by exploiting described model systems and algorithm-based programs. Furthermore, recent advances in QSAR modeling, algorithm, and dedicated biodegradation prediction system have been summarized with unique attributes.

Lignosulfonates as Fire Retardants in Wood Flour-Based Particleboards

Wood flour particleboards (WFP), like other wood-based items, require the addition of fire retardants (FRs) to reduce their high flammability. In this work, a waste lignosulfonate (CaLS) from paper mill is used as a low-cost FR to reduce WFP flammability. CaLS is purified by dialysis and the dialysed lignosulfonate (LD) is used, alone or combined with ammonium polyphosphate (APP), as a FR additive in the preparation of urea-formaldehyde WFP. The fire behaviour of the modified WFPs is studied by cone calorimetry. The use of 15 wt.% LD reduces the peak of heat release rate (HRR) and total smoke production by 25%, also increasing char formation. HRR peak is further reduced up to 40%, if APP is introduced in the formulation. This work discloses a viable and cost-effective strategy for improving the fire retardancy performance of WFP by partial replacement of a commercial FR with a fully renewable additive, isolated through a green and cost-effective process.

Depolymerization of lignosulfonates by submerged cultures of the basidiomycete Irpex consors and cloning of a putative versatile peroxidase

Lignosulfonates are abundantly available byproducts of the paper and pulping industry, and they therefore represent a promising feedstock for new sustainable processes. For industrial applications of lignosulfonates, their molecular weight distribution is a critical factor. In order to decrease the average molecular weight of lignosulfonates, Seventeen basidiomycetes were screened for their capability to depolymerize lignosulfonates from spent sulfite liquor (SSL) in surface and liquid cultures. Five basidiomycetes polymerized the lignosulfonates under the selected conditions. Only Irpex consors was found to efficiently degrade calcium lignosulfonates when SSL (0.5%, w/w) was used as the sole carbon and nitrogen source. The average molecular weight of the lignosulfonates was reduced from ∼26 to ∼4 kDa as determined by size exclusion chromatography (SEC) within two weeks. Various extracellular enzyme activities of I. consors were determined over the culture period. High peroxidase activities were correlating with a high degradation rate and the culture was harvested at the day of highest peroxidase activity. A putative versatile peroxidase was isolated by fast protein liquid chromatography (FPLC) and its encoding cDNA was cloned.

Decolorization of ammonium lignosulfonate with H(2)O(2)/Cu(II) heterogeneous catalyst

The potential of ammonium lignosulfonate (ALS) decolorization and degradation in aqueous solution was studied in a heterogeneous system using hydrogen peroxide and a Cu (II)-chelating ion exchanger. This was based on acrylic copolymers functionalized with N,N dimethylamino propylamine (DMAPA) as a catalyst. In order to optimize the efficiency of the system, the influence of such process parameters like H(2)O(2) concentration, pH, contact time, temperature, ALS concentration and catalyst amount were evaluated. The apparent rate constant of decolorization calculated from the absorbance data indicates that the process profiles follow pseudo-first order kinetics. Lignosulfonate degradation was furthermore studied by FTIR spectroscopy, thermogravimetric analysis and determination in phenolic compounds. The catalyst stability and reusability have also been investigated. Our experimental results clearly indicate that, under optimum conditions, the ammonium lignosulfonate solutions exhibit a total bleaching associated with degradation and significant mineralization to CO(2).