COAGULANT PROTEASE PRODUCTION BY THE FUNGUS THERMOMUCOR INDICAE
SEUDATICAE-N31 BY SUBMERGED FERMENTATION
Bruna L. da Silva, Fernanda M. Geraldes, Fernanda Beraldo, Rafaela G. Bucci, Samara C.
Murari, Eleni Gomes, Roberto da Silva. Universidade Estadual Paulista Júlio de Mesquita Filho,
Instituto de Biociências, Letras e Ciências Exatas. Rua Cristóvão Colombo, 2265, Jardim
Nazareth, 15054-000, São José do Rio Preto, SP, Brasil.
Proteases are one of the most important industrial enzymes. The protease of the thermophilic
fungus Thermomucor indicae seudaticae N31 arouses interest for cheese production given its
ability to form clots in milk similar to commercial coagulants. This enzyme has been studied
under the production on solid state fermentation (SSF), however, due to difficulties in the
process control inherent to the SSF, it became important to study the enzyme under the
submerged fermentation (SmF), which allows better control of fermentation parameters. So, it
was carried out a production of the enzyme over 144 hours of fermentation at 45 ° C and 150
rpm, with enzymatic extraction every 24 h. The ratio of coagulant activity (AC) / proteolytic
activity (PA), describing the action coagulant, was monitored. The fermentation took place in
vials containing 25 mL of saline solution (NH4)2SO4, MgSO4.7H2O, NH4NO3 (0.1%) and wheat
bran (1%). There was a peak of enzyme production at 72 h, with AC 12.39 U/mL and AP 0.04
U/mL, obtaining the ratio AC/AP 282.28. From this result we evaluated the effect of the
concentration of saline (0.1, 0.3, 0.5, 0.7 and 0.9%) on the enzyme production. The data shown
that the increase in salt concentration to 0.5% resulted in an increase in the AC/AP to 584.91
(25.67 AC U/ml) in 48 hours. These results demonstrate the feasibility of producing the enzyme
under conditions of SmF and that under these conditions the ratio CA/PA is enhanced, which is
interesting from the viewpoint of industrial application of this coagulant protease.
Acknowledgements: FAPESP, CNPq, CAPES