Abstract
The optimization of laccase production by Agaricus bisporus CU13 under submerged fermentation conditions was conducted via response surface methodology. Incubation period, cultivation pH value, carbon sources, and nitrogen sources parameters were studied using 2, 2 '-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) as substrate for laccase activity evaluation. Response surface methodology (RSM) was used to optimize the fermentation medium composition through studying the major effective factors resulted from the one factor per time study as follows: pH values (pH 5.0-9.0), soluble starch concentration (7.5-17.5 g/L), yeast extract concentration (2.5-12.5 g/L), and incubation time (15-35 days). Central composite design (CCD) revealed that the pH value of 6.99, 15 g/L soluble starch, and 5.52 g/L yeast extract were the optimum values for laccase production after 24 days of incubation at 28 degrees C. The optimization statistics leads to the improvement of laccase activity by 156% in comparison with pre-optimization values, which reveals the efficiency of the proposed model. A. bisporus CU13 laccase was evaluated as a green alternative in dyes decolorization, where it was able to decolorize Acid Green 27 dye with decolorization percentage range of 73 to 51% at concentrations range of 25 to 200 mgL(-1) after 30 min.