Isolation and properties of fungal β-glucosidases

Abstract

Using chromatography on different matrixes, three beta-glucosidases (120, 116, and 70 kDa) were isolated from enzymatic complexes of the mycelial fungi Aspergillus japonicus, Penicillium verruculosum, and Trichoderma reesei, respectively. The enzymes were identified by MALDI-TOF mass-spectrometry. Substrate specificity, kinetic parameters for hydrolysis of specific substrates, ability to catalyze the transglucosidation reaction, dependence of the enzymatic activity on pH and temperature, stability of the enzymes at different temperatures, adsorption ability on insoluble cellulose, and the influence of glucose on catalytic properties of the enzymes were investigated. According to the substrate specificity, the enzymes were shown to belong to two groups: i) beta-glucosidase of A. japonicus exhibiting high specific activity to the low molecular weight substrates cellobiose and pNPG (the specific activity towards cellobiose was higher than towards pNPG) and low activity towards polysaccharide substrates (beta-glucan from barley and laminarin); ii) beta-glucosidases from P. verruculosum and T. reesei exhibiting relatively high activity to polysaccharide substrates and lower activity to low molecular weight substrates (activity to cellobiose was lower than to pNPG).

Biochemical Characterization and Crystal Structures of a Fungal Family 3 β-Glucosidase, Cel3A from Hypocrea jecorina

“…HjCel3A Has a Broad Substrate Specificity-It has been shown that HjCel3A is able to hydrolyze cellooligosaccharides of DP2 to DP6 as well as various ␤-linked glucobioses (56). In this study, the kinetic parameters of HjCel3A have been determined in more detail using the chromogenic substrate CNPG, glucosyl disaccharides, and cellooligosaccharides (cellotriose and cellotetraose).…”

Sugarcane bagasse as a source of carbon for enzyme production by filamentous fungi1

“…The same pattern was registered in this study, indicating a greater saccharification of cellulose by A. japonicus. The characteristics of the β-glucosidase produced by A. japonicus have been previously assessed for a potential use in biomass saccharification (Korotkova et al 2009). Pasin et al (2014) reported high levels of amylase activity in A. japonicus when cultivated in different agro-industrial residues.…”

Aspergillus niger β-Glucosidase Has a Cellulase-like Tadpole Molecular Shape

“…In addition, the ␤-glucosidase activity can synergistically optimize the action of other cellulolytic enzymes, increasing the yield of the final product and decreasing the concentration of cellobiose, which is a strong inhibitor of the cellulolytic complex, especially of cello-biohydrolases, in the reaction mixture (2). Commercially available cellulase preparations are often supplemented with fungal ␤-D-glucosidases to increase the cellulolytic efficiency on pretreated biomass (3).…”

“…Six of the enzymes are from bacteria as follows: ␤-N-acetylhexosaminidase from Vibrio cholerae (NagZ), PDB 2 code 1TR9 3 ; exo-1,3-1,4-␤-glucanase (ExoP) from Pseudoalteromonas sp. BB1, PDB code 3F93 (7); ␤-N-acetylglucosaminidase (StNagZ) from Salmonella typhimurium, PDB code 4GVF (8); macrolide ␤-glycosidase/␤-glucosidase (SvDesR) from Streptomyces venezuelae, PDB code 4I3G (9); ␤-N-acetylglucosaminidase from Bacillus subtilis (YbbD), PDB code 3BMX (10); and a ␤-glucosidase from Thermotoga neapolitana (TnBgl3B), PDB code 2X40 (11); four are eukaryotic enzymes, exo-␤-1,3-1,4-glucanase (ExoI) from Hordeum vulgare subsp.…”