A pH-stable laccase from alkali-tolerant γ-proteobacterium JB: Purification, characterization and indigo carmine degradation

Singh, Gursharan; Capalash, Neena; Goel, Rajesh Kumar; Sharma, Prince

doi:10.1016/j.enzmictec.2007.07.001

Cited by 115 publications

(86 citation statements)

References 33 publications

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“…This process leads to the formation of non-toxic end products including carbon dioxide, ammonium and sulfates. Singh et al (2007) suggested another mechanism in which 4-aminobenzensulfonate was first oxidized into catechol-4-sulfonate by a strain of Hydrogenophaga intermedia, after which this metabolite was further utilized by an Agrobacterium radiobacter strain S 2 most likely through 3,4-dioxygenase I and 3,4-dioxygenase II enzymes. Laccases also oxidize aromatic amines such as anilines and phenols, in the presence of oxygen (Bollag, 1992;Chivukula & Renganahathan, 1995;Hoff et al, 1985).…”

Section: Biodegradation Via Oxidative Processesmentioning

confidence: 99%

“…Normally, laccase mediators are good substrates for laccase, stable in oxidized and reduced form and have no inhibitory effect upon enzyme activity (Gonzalez et al, 2009). Relatively few bacterial laccases have been studied with respect to their ability to degrade azo dyes (Pereira et al, 2009;Singh et al, 2007). However, laccases produced by Streptomyces are reported to be effective for the decolorization of textile dyes (Dube et al, 2008;Lu et al, 2013;Molina-Guijarro et al, 2009).…”

Section: Oxidative Enzymesmentioning

confidence: 99%

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Bacterial diversity and composition in major fresh produce growing soils affected by physiochemical properties and geographic locations

Ibekwe

Yang

et al. 2016

Science of The Total Environment

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Azo dyes and their intermediate degradation products are common contaminants of soil and groundwater in developing countries where textile and leather dye products are produced. The toxicity of azo dyes is primarily associated with their molecular structure, substitution groups and reactivity. To avoid contamination of natural resources and to minimize risk to human health, this wastewater requires treatment in an environmentally safe manner. This manuscript critically reviews biological treatment systems and the role of bacterial reductive and oxidative enzymes/processes in the bioremediation of dye-polluted wastewaters. Many studies have shown that a variety of culturable bacteria have efficient enzymatic systems that can carry out complete mineralization of dye chemicals and their metabolites (aromatic compounds) over a wide range of environmental conditions. Complete mineralization of azo dyes generally involves a two-step process requiring initial anaerobic treatment for decolorization, followed by an oxidative process that results in degradation of the toxic intermediates that are formed during the first step. Molecular studies have revealed that the first reductive process can be carried out by two classes of enzymes involving flavin-dependent and flavin-free azoreductases under anaerobic or low oxygen conditions. The second step that is carried out by oxidative enzymes that primarily involves broad specificity peroxidases, laccases and tyrosinases. This review focuses, in particular, on the characterization of these enzymes with respect to their enzyme kinetics and the environmental conditions that are necessary for bioreactor systems to treat azo dyes contained in wastewater.

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Section: Biodegradation Via Oxidative Processesmentioning

confidence: 99%

Section: Oxidative Enzymesmentioning

confidence: 99%

Bacterial diversity and composition in major fresh produce growing soils affected by physiochemical properties and geographic locations

Ibekwe

Yang

et al. 2016

Science of The Total Environment

View full text Add to dashboard Cite

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“…Purifi cation of laccase. Laccase was purifi ed to homogeneity by ammonium sulphate precipitation, DE-AE-Sepharose cation exchange chromatography and preparative Native-PAGE as described previously (Singh et al, 2007).…”

Section: Methodsmentioning

confidence: 99%

“…Laccases raised great interest because of the non-specifi c reactions they catalyze. They have been extensively used for transformation of aromatic compounds such as dyes, aromatic pollutants or in wastewater treatments (Singh et al, 2007). The laccase mediator system (LMS) has already found practical applications such as the Lignozym ® -process for biobleaching of pulp.…”

Section: Introductionmentioning

confidence: 99%

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Performance of an alkalophilic and halotolerant laccase from γ-proteobacterium JB in the presence of industrial pollutants

Singh

Sharma

Capalash

2009

J. Gen. Appl. Microbiol.

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An alkalophilic and halotolerant laccase from γ-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 ~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.

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Purification and Characterization of Multicopper Oxidases for Enzyme Electrodes

Eby

Johnson²

2014

Enzymatic Fuel Cells

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A pH-stable laccase from alkali-tolerant γ-proteobacterium JB: Purification, characterization and indigo carmine degradation

Cited by 115 publications

References 33 publications

Bacterial diversity and composition in major fresh produce growing soils affected by physiochemical properties and geographic locations

Bacterial diversity and composition in major fresh produce growing soils affected by physiochemical properties and geographic locations

Performance of an alkalophilic and halotolerant laccase from γ-proteobacterium JB in the presence of industrial pollutants

Purification and Characterization of Multicopper Oxidases for Enzyme Electrodes

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