Pleurotus ostreatuslaccase recovery from residual compost using aqueous two-phase systems

Abstract

BACKGROUND: Multiple aqueous two‐phase systems (ATPS) were evaluated for the partial purification of laccase from a crude aqueous extract. The laccase extract was obtained from residual compost, generated from the production of the edible mushroom Pleurotus ostreatus. A total of 59 ATPS were evaluated; 16 systems using poly (ethylene glycol) (PEG) and phosphates, 20 systems using UCON (ethylene oxide/propylene oxide copolymer) and different salts, and 23 polymer–polymer systems (Ficoll, Dextran and PEG). RESULTS: Protein partitioning was not achieved with the PEG–phosphate systems. ATPS composed of UCON and salts presented great potential for laccase recovery, with up to 95.12 ± 5.27, 96.05 ± 4.99 and 98.31 ± 3.58% recovery, and purification factors of 5.02, 4.14 and 9.97 for the UCON‐NaH₂PO₄ , UCON‐NaSO₄, and UCON‐(NH₄)₂SO₄ systems, respectively. The PEG 10 000/Dextran 10 000 and the PEG 10 000/Dextran 100 000 polymer–polymer systems proved to have potential, presenting purification factors as high as 5.78 and 6.56, respectively. CONCLUSION: The laccase analyzed in this study had a molecular weight of approximately 30 kDa, and thus, is the smallest laccase yet to be reported for P. ostreatus. ATPS represent an attractive alternative for the efficient recovery of laccase from residual compost generated after P. ostreatus production. © 2016 Society of Chemical Industry