Botryosphaeria spp. as Producers of Laccase When Cultivated on Vegetable Oils as Sole Carbon Source: Optimizing Laccase Production by Botryosphaeria rhodina MAMB-05 on Soybean Oil

Eight vegetable oils and glycerol were examined as sole carbon source to screen nine isolates of Botryosphaeria spp. Among these, B. rhodina MAMB-05 produced highest laccase titres on all carbon sources evaluated followed by B. rhodina MMLR isolated (from orange, Citrus sp.). The influence of inorganic nitrogen (NH 4 Cl, NaNO 3 , (NH 4 ) 2 SO 4 , and NH 4 NO 3 ), organic nitrogen (yeast extract (YE), urea, peptone, and corn steep liquor) sources, inorganic phosphate (KH 2 PO 4 , Na 2 HPO 4 , NaH 2 PO 4 , K 2 HPO 4 ), as well as increasing concentrations of copper (from zero to 100 µg mL -1 ), as nutritional requirements for enhancing laccase production by B. rhodina MAMB-05 were also evaluated. Soybean oil was the only carbon source in a central composite factorialdesign (2 3 ) to optimize laccase production with the selected variables NaNO 3 , KH 2 PO 4 and copper (CuSO 4 .5H 2 O), using the response surface methodology. The optimal conditions obtained were NaNO 3 (100 g L -1 ), KH 2 PO 4 (125 g L -1 ) and 50 µg mL -1 of CuSO 4 .5H 2 O. The specific laccase activity obtained (2.95 U mg -1 ) in the validation experiments using the optimal condition for laccase production by B. rhodina MAMB-05 was in agreement with the predicted value (3.07 U mg -1 ), and demonstrated the fitness of the proposed model. DOI: http://dx.doi.org/10.17807/orbital.v10i7.1206