Study of new alternatives to obtain of high concentrations of alkaline proteases from fungus Lecanicillum sp

Abstract

Biotechnological process development has made possible the obtaining of efficient and profitable products for different applications in agriculture, including biologic control of pests. In the present work, different choices were evaluated in order to increase extracellular alkaline proteases production for the fungus Lecanicillium sp. strain 3166. These enzymes showed high nematicide activity. The growing rate of microorganism and the enzyme production were evaluated at different starting pH, which proved to have influence on alkaline proteases induction. A 23 factorial design was made in order to formulate a culture media, being C/N relation and nitrogen source the most significant factors. The relation C/N=1 and soja bean flour were the most favoured. Experiences in 10 liters fermenter using batch and fed-batch culture showed an improvement in alkaline proteases production. The maxime proteolitic activities were 0,35 mg mL-1 y 0,52 mg mL-1 respectively.