Optimization of laccase from Lysinibacillus boronitolerans using response surface methodology

The screening of thirty two bacterial isolates collected from dye contaminated soil for laccase production revealed the high laccase production potential of the isolate K14. The laccase-producing bacterial strains were tested with guaiacol as a substrate. The bacterial isolate was identified as Lysinibacillus boronitolerans. To optimize a low-cost medium for laccase synthesis, the following parameters were used: temperature (37 degrees C), pH (7), inoculum (1%), incubation period (5 days). The media's efficiency for laccase production was statistically evaluated. An artificial neural network predicted optimal laccase production in the response surface model (RSM), with a net regression value of 0.98. The optimal media conditions for laccase production were as follows: carbon source (glucose 2%), nitrogen source (peptone 2%), inducer (copper sulfate 0.4 mM), pH (8), temperature (35 degrees C), inoculum size (1.5%) and duration (2 days). The minimal laccase production in the response surface model was 7.34 U/mL and the maximal laccase production was 12.23 U/mL on the 2nd day.