Purification and biochemical characterization of a new thermostable laccase from Enterococcus faecium A2 by a three-phase partitioning method and investigation of its decolorization potential.
Arch Microbiol 2022;
204:533. [PMID:
35906438 DOI:
10.1007/s00203-022-03054-x]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 06/02/2022] [Accepted: 06/03/2022] [Indexed: 11/02/2022]
Abstract
Three-phase partitioning (TPP) is a simple, fast, cost-effective, and highly efficient process that can be used in the purification of laccases. In this study, microorganisms with laccase activity were isolated from water samples collected from the Agri-Diyadin hot spring. The isolate with the highest laccase activity was found to be the A2 strain. As a result of molecular (16S rRNA sequence) and conventional (morphological, biochemical, and physiological) analyses, it was determined that the A2 isolate was 99% similar to Enterococcus faecium (Genbank number: MH424896). The laccase was purified to 4.9-fold with 110% recovery using the TPP. The molecular mass of the enzyme was found by SDS-PAGE to be 50.11 kDa. Optimum pH 6.0 and optimum temperature for laccase were determined as 80 °C. The laccase exhibited pH stability over a wide range (pH 3.0-9.0) and a high thermostability, retaining over 90% of its activity after 1 h of incubation at 20-90 °C. The laccase exhibited high thermostability, with a heat inactivation half-life of approximately 24 h at 80 °C. The enzyme remained highly stable in the presence of surfactants and increased its activity in the presence of organic solvents, Cr2+, Cu2+, and Ag+ metal ions. The Km, Vmax, kcat, and kcat/Km values of laccase for 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) substrate were 0.68 mM, 5.29 μmol mL-1 min-1, 110.2 s-1, and 162.1 s-1 mM-1, respectively.
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