The depletion of fossil fuels and rise in their global energy consumption and demand have had a major impact on the stability of the ecosystem and highlighted the need for efficient, sustainable, and renewable alternative sources of energy. Lignocellulosic biomass-based biofuels are highly advantageous due to their enormous supply in nature. Enzymatic bioconversion of lignocellulose polysaccharides into monomeric sugars has a higher efficiency than traditional chemical modes of action. Fungal-mediated ligninolytic enzymes offer even greater advantages in the bioconversion of lignocelluloses into simple sugars due to their thermostability, activity across a wide range of pH values, high specificity, and minimal by-products. This review, based on recent developments in the field of fungal-derived ligninolytic enzymes, discusses their mechanisms of action along with their production and the modes of bioprocesses involved as well as different techniques, such as heterologous gene expression, mutagenesis, and co-culturing, that enhance production and improve catalytic and stability properties.

Biofuels: Production of fungal-mediated ligninolytic enzymes and the modes of bioprocesses utilizing agro-based residues

Catalytic properties of cellulases and hemicellulases produced by Lichtheimia ramosa: Potential for sugarcane bagasse saccharification

Penicillium roqueforti ATCC 10110 was cultivated in rice husk residue, to produce a multienzymatic extract, which was characterised for its potential biotechnological applications. Optimisation of the fermentation conditions for the xylanase activity production (U/g) was evaluated by using a Doehlert-type experimental design. The optimum xylanase activity (at 32 °C/82 h), was 1.04 U/g, which represented a deviation of 3% from the theoretically optimised value predicted by the quadratic model (R2 = 0.92). The optimum conditions were observed at pH 7.0 and 35 °C. The xylanase activity was favoured, particularly, by the presence (1 M) of Co2+ and Cu2+ and the kinetic constants were determined (K
 m
  = 7.22 mg/ml and v
 max
  = 3.29 U/g). For the endoglucanase activity, it was not possible to adjust a quadratic model but maximal activities (2.37 ± 0.01 U/g) were obtained at 32 °C for 72 h. For this enzyme, the optimum conditions were pH 4.8 and 50 °C. Also, Co2+, Cu2+, acetone, ethanol and isopropanol increased the endoglucanase activity. The substrate rice husk, without any additives, permitted the acquisition of xylanases and endoglucanases similar to those obtained from synthetic substrates, justifying its application as a substrate for solid-state fermentations.

Production and Characterisation of Xylanase and Endoglucanases Produced by Penicillium roqueforti ATCC 10110 Through the Solid-State Fermentation of Rice Husk Residue

Cellulose is the most abundant biomaterial derived from the living organisms on the earth; plant is the major contributor to the cellulose pool present in the biosphere. Cellulose is used in variety of applications ranging from nanomaterials to biofuel production. For biofuel production, cellulose has first to be broken-down into its building blocks; β-D-glucosyl unit which subsequently can be fermented to different product such as ethanol, acetic acids, among others. Cellulase is the enzymatic system, which degrades cellulose chains to glucose monomers. Cellulase is a group of three enzymes endoglucanase, exoglucanases and β-glucosidases which act together to hydrolyze cellulose to glucose units. Cellulases are found in bacteria, fungi, plants, and some animals. Fungi are the preferred source of cellulase for industrial applications since they secrete large quantities of cellulase to culture medium. Despite a remarkable number of fungi found to produce cellulase enzymes, few have been extensively investigated because they produce large quantities of these enzymes extracellularly. In this mini-review, the production of cellulase from fungi and the parameters affecting cellulase production are discussed briefly on light of recent publications. Furthermore, potential applications of cellulase enzymes are highlighted.  Article DOI:  https://dx.doi.org/10.20319/lijhls.2018.41.1936 This work is licensed under the Creative Commons Attribution-Non-commercial 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.

Fungal cellulase; production and applications: minireview

Thermostable cellulose saccharifying microbial enzymes: Characteristics, recent advances and biotechnological applications

This work reports endoglucanase and beta-glucosidase production by the thermophilic fungus Myceliophthora heterothallica in solid-state (SSC) and submerged (SmC) cultivation. Wheat bran and sugarcane bagasse were used for SSC and cardboard for SmC. Highest endoglucanase production in SSC occurred after 192 hours: 1,170.6 ± 0.8 U/g, and in SmC after 168 hours: 2,642 ± 561 U/g. The endoglucanases and beta-glucosidases produced by both cultivation systems showed slight differences concerning their optimal pH and temperature. The number of endoglucanases was also different: six isoforms in SSC and ten in SmC. Endoglucanase activity remained above 50% after incubation between pH 3.0 and 9.0 for 24 h for both cultivation systems. The effect of several chemicals displayed variation between SSC and SmC isoenzymes. Manganese activated the enzymes from SmC but inhibited those from SSC. For β-glucosidases, maximum production on SmC was 244 ± 48 U/g after 168 hours using cardboard as carbon source. In SSC maximum production reached 10.9 ± 0.3 U/g after 240 h with 1 : 1 wheat bran and sugarcane bagasse. Manganese exerted a significant activation on SSC β-glucosidases, and glucose inhibited the enzymes from both cultivation systems. FeCl3 exerted the strongest inhibition for endoglucanases and β-glucosidases.

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Effect of pH, Temperature, and Chemicals on the Endoglucanases and β-Glucosidases from the Thermophilic Fungus Myceliophthora heterothallica F.2.1.4. Obtained by Solid-State and Submerged Cultivation

Vanessa De Cï¿½ssia Teixeira Da Silva

Papers

Effect of pH, Temperature, and Chemicals on the Endoglucanases and β-Glucosidases from the Thermophilic Fungus Myceliophthora heterothallica F.2.1.4. Obtained by Solid-State and Submerged Cultivation