Kinetic modelling of laccase mediated delignification of Lantana camara

Cellulose / waste Cu2+-activated carbon composite: A sustainable and green material for boosting laccase activity and degradation of bisphenol A in wastewater

Low enzyme activity is one of the disadvantages of immobilized laccase. In this study, waste Cu2+-loaded activated carbon (Cu-AC) was successfully used in preparing a novel composite support，cellulose / Cu2+-loaded activated carbon beads (C / Cu-AC)， and effectively boosted immobilized laccase activity. To achieve optimum conditions for immobilization of laccase, the immobilization time, pH and laccase concentration were examined. The highest immobilized laccase activity (34.21 U/g) was achieved under optimum conditions (T = 4 h, pH = 4, C = 5 g/L), which was increased by 35.86 % compared to control. In addition, the immobilized laccase showed an outstanding performance in thermostability and reusability compared to free laccase. Moreover, the degradation of BPA by immobilized laccase was carried out, and the optimum degradation conditions were explored. Under such conditions: concentration of BPA was 75 mg / L and pH = 4, t = 1 h, T = 50 °C，the removal yield of BPA reached a maximum of 79.88 %. Therefore, the utilization of waste Cu-CA is a powerful method to boost immobilized laccase activity and creating a new way to high value treatment of waste Cu-CA.

Jute sticks biomass delignification through laccase-mediator system for enhanced saccharification and sustainable release of fermentable sugar

Jute sticks obtained after the extraction of jute fiber are an excellent biomass feedstock with a significant amount of carbohydrates that makes it an attractive resource for sustainable energy generation. However, the high lignin content in the jute stick hinders the cellulosic component of the cell wall from enzymatic hydrolysis.This work demonstrates the lignin degradation of jute stick biomass by Trametes maxima laccase in the presence of mediator Hydroxybenzotriazole and improvement in its subsequent saccharification. Lignin component in jute stick is reduced by 21.8% in a single reaction treatment with laccase-mediator compared to the untreated jute stick sample used as control. The yield of fermentable sugar is increased by 19.5% that verifies enhanced saccharification after lignin removal. Delignification of jute stick was corroborated through different analytical techniques. The Pyrolysis gas chromatography/mass spectrometry results further confirms abundance of S lignin unit in the jute stick compared to the H and G unit and modification in lignin polymer as a change in the syringyl-to-guaiacyl ratio. Hence, this work demonstrates that jute stick can be effectively delignified using biocatalyst-mediator system and utilized as biomass source, thus contributing in circular bio-economy through waste valorization.

In silico optimization of enzyme mediated debittering of Assam lemon: biochemical and sensory evaluation studies

Commercialization of citrus fruit juice is always hindered by the bitterness development in juice when stored for a significant period of time. In order to debitter citrus juice, an attempt has been taken up by treating the juice with tannase. Central Composite Design (CCD) based Response Surface Methodology (RSM) has been implemented to evaluate and optimize the effect of underlying process parameters viz., enzyme volume, temperature, incubation time and enzyme titre on debittering effect of Assam lemon juice. The significance of parameters and their interaction were assessed by analysis of variance at 95% level of confidence. Optimization study reveals that the maximum debittering (40.12 ± 0.02%) of Assam lemon juice takes place at ambient temperature (37 °C) within an incubation time of 2 h and 1.12% (v/v) enzyme volume while 30 IU/ml enzyme activity. Moreover, percentage contribution of the underlying process parameters demonstrate that the enzyme volume and enzyme titre as first and second most significant contributors in process of debittering. As part of validating the above results, experimental debittering has been performed and compared with predicted debittering percentage which showed a high coefficient value (0.971) which ensures the effectiveness of the proposed model. Biochemical analysis of the treated juice reveals improved antioxidant property after enzymatic treatment by 15.30%. Total sugar and reducing sugar content has also been enhanced by 1.38 and 1.49 folds, respectively, after enzymatic treatment of juice. Furthermore, no alteration in the elemental composition of the treated juice ensure that the quality of the final juice is retained with the enzyme applications. Sensory analysis based on nine-point Hedonic scale advocates the best organoleptic property in 1% (v/v) enzyme treated juice.

Microcrystalline Cellulose Based on Cellulose Containing Raw Material Modified by Steam Explosion Treatment

Today’s methods for producing powdered celluloses, in particular microcrystalline cellulose (MCC), from various plant raw materials, while applying new highly efficient methods for the isolation of cellulose are of a great interest. One of these methods is the production of MCC from lignocellulosic material activated by steam explosion treatment. The material obtained by this method from wood has a high reactivity, low content of residual lignin, a high specific surface, which allows to subject it successfully and efficiently to accelerated delignification or hydrolytic breakdown (degradation). This ability of the lignocellulosic material, activated by steam explosion, is the basis of this study, which provides the results of an experimental evaluation of the component and dispersion analysis of MCC, obtained from this material.

Firefly-like Water Splitting Cells Based on FRET Phenomena with Ultrahigh Performance over 12

A firefly-like chemiluminescence reaction was utilized in a ZrO₂ nanoparticle matrix of water splitting cells, where the chlorophyll of Lantana camara was used as the major photosensitizer to excite electrons to the conduction band of ZrO₂. The fluorescence resonance energy transfer (FRET) was induced by rubrene, a firefly-like chemiluminescence molecule, and Lantana camara chlorophyll combined with 9,10-diphenylanthracene. The ZrO₂ nanoparticle film coated by the chlorophyll of Lantana camara and 9,10-diphenylanthracene under chemiluminescence irradiation in 1 M KHCO₃ water solution demonstrated the highest photocurrent density (88.1 A/m²) and the highest water splitting efficiency (12.77%).