title: Performance of an alkalophilic and halotolerant laccase from gamma-proteobacterium JB in the presence of industrial pollutants.
abstract: An alkalophilic and halotolerant laccase from gamma-proteobacterium JB catalyzed in high concentrations of organic solvents and various salts. The enzyme retained 80-100% activity in 10% concentration of dimethylsulfoxide (DMSO), ethanol, acetone or methanol; 100, 85 and 50% activity in 20 mM MgCl(2), 5.0 mM MnCl(2) and 0.1 mM CuCl(2); 140, 120 and 110% activity in 5.0 mM MnSO(4), 10 mM MgSO(4) and 1mM CaSO(4), respectively. Sodium halides inhibited the enzyme in the order: F(-)> Br(-)> I(-)> Cl(-). In 0.5 M NaCl, pH 6.0, laccase was approximately 60% active. Decolorization of indigo carmine by laccase at pH 9.0 was not inhibited even in the presence of 0.5 M NaCl. Release of chromophoric, reducing and hydrophobic compounds during biobleaching of straw rich-soda pulp by laccase was not inhibited when the enzyme was applied in the presence of 1 M NaCl at pH 8.0. Laccase retained 50% residual activity even when incubated with 5% calcium hypochlorite for 30 min.
authors.affiliation: Department of Microbiology, Panjab University, Chandigarh, India.
authors.forename: Gursharan
authors.initials: G
authors.lastname: Singh
authors.forename: Prince
authors.initials: P
authors.lastname: Sharma
authors.forename: Neena
authors.initials: N
authors.lastname: Capalash
mesh_terms: D017610:Calcium Compounds / Q000378:metabolism; D004795:Enzyme Stability; D020563:Gammaproteobacteria / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D007203:Indigo Carmine / Q000378:metabolism; D007220:Industrial Waste; D042845:Laccase / Q000502:physiology*; D008031:Lignin / Q000378:metabolism; D055049:Salt Tolerance; D012965:Sodium Chloride / Q000378:metabolism; D013431:Sulfates / Q000378:metabolism
chemical_list: D017610:Calcium Compounds; D007220:Industrial Waste; D013431:Sulfates; C004488:calcium hypochlorite; D012965:Sodium Chloride; D008031:Lignin; D007203:Indigo Carmine; D042845:Laccase