Study of Production and Characterization of Laccase Enzyme from Klebsiellapneumoniae K7 Isolate

Abstract

Sixty four local isolated of Klebsiella spp. have been isolated from environment samples (soil and water).
These isolates were identified and diagnosis according to phenotype and biochemical tests. These isolates
were subjected to primary and secondary screening, to select the isolate with the highest laccase activity.
Fifteen isolates chosen from primary screening for screening their enzyme activity in secondary screening.
It has been found the Klebsiella(K7) has the highest productivity of the enzyme (12 Unit/ml).Klebsiella(K7)
isolate was diagnosis by Vitak 2 system, it was identified asK. pneumonia. The laccase purified was
characterization, the experiments showed that: The molecular weight of laccase was 120KD and the optimum
pH for the purified laccase activity was 4.5 and forstability was 6.5. the optimum temperature for enzyme
activity was 40oC,the enzyme showed that laccase lost 22, 23 and 20% of its initial activity at 20, 25 and
35°C, respectively.