Calcium carbonate mediates higher lignin peroxidase activity in the culture supernatant of Streptomyces viridosporus T7A

Lignin peroxidase (LiP) production has been extensively studied due to the potential use of this enzyme in environmental pollution control. Important aspects of the production of the enzyme by S. viridosponls T7A which have b een studied include the improvement of yield and enzyme stabilization. In e xperiments performed in agitated flasks containing culture media composed o f yeast extract as the source of nitrogen, mineral salts and different carb on sources, the use of glucose resulted in the highest values for LiP activ ity (350 U/L), specific LIP activity (450 U/g) and productivity (7 U/L/h). As the profile obtained with glucose-containing medium suggested enzyme ins tability, the effect of calcium carbonate was evaluated. The addition of Ca CO3 in two different concentrations, 0.5% and 5.0%, resulted in higher valu es of maximum Lip activity, 600 and 900 U/L, respectively The presence of t his salt also anticipated enzyme activity peaks and allowed the detection o f higher enzyme activities in the extracellular medium for longer periods o f time. These results indicate a positive effect of calcium carbonate on Li P production, which is extremely relevant for industrial processes.