A halotolerant laccase from Chaetomium strain isolated from desert soil and its ability for dye decolourization.

ABSTRACT: A novel fungal laccase produced by the ascomycete Chaetomium sp. isolated from arid soil was purified and characterized and its ability to remove dyes was determined. Extracellular laccase was purified 15-fold from the crude culture to homogeneity with an overall yield of 50% using ultrafiltration and anion-exchange chromatography. The purified enzyme was found to be a monomeric protein with a molecular mass of 68 kDa, estimated by SDS-PAGE, and with an isoelectric point of 5.5. The optimal temperature and pH value for laccase activity toward 2,6-DMP were 60 °C and 3.0, respectively. It was stable at temperatures below 50 °C and at alkaline conditions. Kinetic study showed that this laccase showed higher affinity on ABTS than on 2,6-DMP. Its activity was enhanced by the presence of several metal ions such as Mg²⁺, Ca²⁺ and Zn²⁺, while it was strongly inhibited by Fe²⁺, Ag⁺ and Hg²⁺. The novel laccase also showed high, remarkable sodium chloride tolerance. Its ability to decolorize different dyes, with or without HBT (1-hydroxy-benzotriazole), as redox mediator, suggests that this protein may be useful for different industrial applications and/or bioremediation processes.

SUBMITTER: Mtibaa R 

PROVIDER: S-EPMC5602793 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature