Vandana et al.

growth and morphology of microorganisms, they are sensitive to the concentration

of hydrogen ion present in the medium. The optimal value of pH varies according

to the substrate because different substrate causes different reaction for laccases.

Since each substrate supported a particular pH for maximum enzyme secretion

and the enzyme instability at very high or very low pH.

Fig: 2 Effect of pH on laccase activity

Effect of incubation timeon laccase activity

Laccase activity was observed maximumat 120 h (0.0842 U/ml) (Fig: 3).The

present study is in contrast with the finding of Sivakumar et al., (2010) in which

effect of incubation time on laccase activity was studied and highest activity was

observed on 10th day of incubation with Ganoderma sp. The similar kind of study

was conducted by Desai et al., (2011) in which highest activity by fungi was

Fig: 3 Effect of incubation time on laccase activity

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