title: Magnetic cross-linked enzyme aggregates (CLEAs): a novel concept towards carrier free immobilization of lignocellulolytic enzymes.
abstract: The enzymatic conversion of lignocellulosic biomass into biofuels has been identified as an excellent strategy to generate clean energy. However, the current process is cost-intensive as an effective immobilization approach to reuse the enzyme(s) has been a major challenge. The present study introduces the concept and application of novel magnetic cross-linked enzyme aggregates (mag-CLEAs). Both mag-CLEAs and calcium-mag-CLEAs (Ca-mag-CLEAs) exhibited a 1.35 fold higher xylanase activity compared to the free enzyme and retained more than 80.0% and 90.0% activity, respectively, after 136h of incubation at 50°C, compared to 50% activity retained by CLEAs. A 7.4 and 9.0 fold higher sugar release from lime-pretreated and NH4OH pre-treated sugar bagasse, respectively, was achieved with Ca-mag-CLEAs compared to the free enzymes. The present study promotes the successful application of mag-CLEAs and Ca-mag-CLEAs as carrier free immobilized enzymes for the effective hydrolysis of lignocellulolytic biomass and associated biofuel feedstocks.
authors.affiliation: Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, Grahamstown 6140, South Africa.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Bhattacharya
authors.affiliation: Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, Grahamstown 6140, South Africa. Electronic address: b.pletschke@ru.ac.za.
authors.forename: Brett I
authors.initials: BI
authors.lastname: Pletschke
mesh_terms: D000115:Acetylesterase / Q000737:chemistry / Q000378:metabolism; D001407:Bacillus / Q000201:enzymology; D056804:Biofuels; D018533:Biomass; D044602:Cellulases / Q000737:chemistry* / Q000378:metabolism*; D002482:Cellulose; D003432:Cross-Linking Reagents; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry / Q000378:metabolism; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D052203:Ferrosoferric Oxide / Q000737:chemistry; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000378:metabolism; D007501:Iron / Q000378:metabolism; D008031:Lignin / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D012821:Silanes / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014995:Xylosidases / Q000737:chemistry / Q000378:metabolism; D001616:beta-Galactosidase / Q000737:chemistry / Q000378:metabolism
chemical_list: D056804:Biofuels; D003432:Cross-Linking Reagents; D004800:Enzymes, Immobilized; D012821:Silanes; C036909:lignocellulose; D002482:Cellulose; D008031:Lignin; C027433:bagasse; D007501:Iron; D000115:Acetylesterase; C081851:acetylxylan esterase; D044602:Cellulases; D006026:Glycoside Hydrolases; D014995:Xylosidases; D001616:beta-Galactosidase; C026579:exo-1,4-beta-D-xylosidase; C019713:alpha-N-arabinofuranosidase; D043364:Endo-1,4-beta Xylanases; D052203:Ferrosoferric Oxide
keywords: Calcium-magnetite-cross-linked enzyme aggregates; Carrier free immobilization; Magnetite-cross-linked enzyme aggregates; Thermostable xylanases