Vandana et al.

extends in biosensors also (Grac et al., 2002; Duran and Eposito, 2000)labelling in

immunoassays, drug analysis, clarification of juices and wines, design of laccase

fungicidal and bactericidal preparations (Jahansen, 1996).

Other organic compounds, such as nitroso compounds ortriphenylamine and

phenothiazine derivates (i.e. promazine, phenothiazine- 10-propionic acid or

2-nitro-1-naftol-4-sulfonic acid), have been tested as laccase mediators for the

oxidation of lignin dimers, kraft paper pulp or textile dyes (Bourbonnais et al.,

1997a; Camarero et al., 2005; Fabbrini et al., 2002; Paice et al., 1997). More

recently, phenylpyrazolones have been demonstrated to mediate the oxidation

of veratryl alcohol or xenobiotics by laccase (Shleev et al., 2003; Shleev et al.,

2004). On the other hand, metal ions, such as Mn2+ could act as laccase mediators

when they are oxidized by the enzyme (Muñoz et al., 1997). In addition, metallic

complexes, the so-called polyoxometalates, have been described as laccase

mediators for the degradation of lignin (Gamelas et al., 2005; Gamelas et al.,

2007). The versatility of laccase-mediator systems for oxidative transformation

of aromatic compounds is evidenced by the variety of possible applications such

as: delignification and bleaching of paper pulp decolorization of industrial dyes or

detoxification of pollutants (Bajpai, 2004; Barreca et al., 2004; Claus et al., 2002;

Husain and Husain, 2008; Morozova et al., 2007a).

Material and Methods

Optimization of culture conditions for enzyme production (Ding et al., 2012)

This was done by varying culture conditions that effect laccase production to

determine the optimum conditions for the production of laccase from Pseudomonas

aeruginosa . Production medium (Dipotassium hydrogen phosphate-2.75g,

Potassium hydrogen phosphate-2.25g, Ammonium sulfate-1.00g, Magnesium

Chloride-0.20g, Sodim Chloride-0.10g, Ferric Chloride-0.02g, Calcium Chloride-

0.01g, Distilled water-1000ml, pH-7.0) was used for analysis.

Effect of temperature

Effect of temperature on laccase production was studied. The production medium

was inoculated with 1 ml culture of Aspergillus niger and incubated at different

temperatures viz. 20, 30, 40 and 50ºC for 7 days with pH 5.6.

Effect of pH

The effect of pH on laccase production was carried out by incubating the flasks

containing 100 ml of production media was inoculated with 1 ml of culture

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International Journal of Bioinformatics and Biological Sciences : v.2 n.3&4. Dec. 2014