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Isolation and biochemical characterization of laccase and tyrosinase activities in a novel melanogenic soil bacterium

Paper ID Volume ID Publish Year Pages File Format Full-Text
18462 42724 2006 8 PDF Available
Title
Isolation and biochemical characterization of laccase and tyrosinase activities in a novel melanogenic soil bacterium
Abstract

Bacterial polyphenol oxidases (PPOs) with a high oxidizing capacity for a wide range of substrates could make their applications in phenolic biotransformation, food processing, cosmetics, and textile industry. We have isolated a melanogenic soil bacterium by differential screening of a number of strains which were isolated from the Iranian microflora. The taxonomic characterization of this strain indicates that it belongs to the genus Bacillus (HR03), and has the ability to produce all types of PPOs; cresolase (EC 1.14.18.1), cathecolase (EC.1.10.3.1), and laccase (EC 1.10.3.2). We studied the tyrosinase activity using l-tyrosine and l-dopa as substrates and the laccase activity with specific substrates such as syringaldazine and 2,6-dimethoxyphenol. The optimum pH and temperature, obtained for all types of polyphenol oxidases, were at about pH 5.5 and 55 °C, respectively. Tyrosinase-like enzyme of this strain shows a lag period in its tyrosine hydroxylase activity that could be avoided by the addition of small amounts of l-dopa and sodium dodecyl sulfate (SDS). In addition, tyrosinase and laccase were activated by SDS below the critical micelle concentration and were inhibited by 1 mM EDTA. We tested the resistance of melanized-cells against UVA, UVC and H2O2. Results show that melanin protects strain HR03 against UV lights and the oxidant.

Keywords
Polyphenol oxidases; Tyrosinase; Laccase; Biochemical characterization; Bacillus sp.; UV resistance
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Isolation and biochemical characterization of laccase and tyrosinase activities in a novel melanogenic soil bacterium
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Publisher
Database: Elsevier - ScienceDirect
Journal: Enzyme and Microbial Technology - Volume 39, Issue 7, 3 November 2006, Pages 1409–1416
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us