title: Applications of soluble, encapsulated and cross-linked peroxidases from Sapindus mukorossi for the removal of phenolic compounds.
abstract: Peroxidases have been known to polymerize phenolic compounds and precipitate them from solution. Sapindus peroxidases (SPases) were extracted from the leaves of Sapindus mukorossi and precipitated with four volumes of chilled methanol. Soluble, encapsulated and cross-linked forms of enzymes were used for the removal of phenolic compounds (initial concentration 1.0 mM) in a stirred batch reactor. Calcium alginate beads were prepared using sodium alginate and calcium chloride at 1.5% and 5.0% (w/v), respectively. Sodium alginate and glutaraldehyde at 1.0% (w/v) and 0.8% (v/v), respectively, were optimized for cross-linking of SPases. The maximal removal of 2-chlorophenol was found in the buffers ofpH range 4-7 and at 30-60 degrees C in the presence of 1.2 mM H2O2 by soluble enzymes, but encapsulated and cross-linked enzymes worked well at pH 5 and at 50 degrees C in the presence of 0.8 mM H2O2. The optimized doses of soluble, encapsulated and cross-linked SPases were 1.2, 4.2 and 1.2 mg/mL, respectively, for the removal of phenolic compounds. Encapsulated and cross-linked enzymes showed a lower efficiency than soluble enzyme but can be reused in multiple cycles for the removal of phenolic compounds.
authors.affiliation: Department of Biotechnology, Panjab University, Chandigarh, India. jagtar@rediffmail.com
authors.forename: J
authors.initials: J
authors.lastname: Singh
authors.forename: S
authors.initials: S
authors.lastname: Sinha
authors.forename: N
authors.initials: N
authors.lastname: Batra
authors.forename: A
authors.initials: A
authors.lastname: Joshi
mesh_terms: D006863:Hydrogen-Ion Concentration; D010544:Peroxidases / Q000378:metabolism*; D019800:Phenol / Q000378:metabolism*; D032127:Sapindus / Q000201:enzymology*; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D018508:Water Purification
chemical_list: D014874:Water Pollutants, Chemical; D019800:Phenol; D010544:Peroxidases