INFLUENCE OF FERMENTATION TIME AND TEMPERATURE IN THE PRODUCTION OF CHITINASES BY METARHIZIUM ANISOPLIAE CG374

Emerson Santos (UNESP); Natália Moreira Barbosa (UNESP); Renata Cunha Carvalho (UNESP); Rosemeire Cristina Linhari Rodrigues Pietro (UNESP)

The use and production of enzyme have become one of the areas of great interest of the biotechnological industry. The enzymes produced by microorganisms in fermentation processes have been widely searched and used in the world. Chitin is a biopolymer found in the cuticles of insects and crustaceans and in cell walls of fungi. The enzymes responsible for hydrolysis of chitin are chitinases (EC 3.2.1.14) involved in a variety of biological functions such as defense, digestion of nutrients, morphogenesis and pathogenesis. Several strains of Metarhizium anisopliae have been extensively evaluated for its ability chitinolytic. This work evaluated the influence of temperature and time in the fermentation process to obtain chitinases by M. anisopliae CG374. This strain from the CCFE / EMBRAPA was isolated from soil and selected among others, in a previous study, as the best producer of chitinases. Were inoculated 1.0 x 10⁷ spores / ml in 100 ml of liquid culture medium containing chitin of crustaceans as enzyme inducer. Fermentation occurred in the orbital shaker for 10 days at 180 rpm, at temperatures of 25, 28 and 30º C. The activity of chitinases and the concentration of proteins were determined using the methods described in literature. The results showed that the temperature of 28º C was the ideal for the production of chitinases giving a specific activity of approximately 2.0 and 4.0 respectively to the production of 25 and 30º C ones. This result is possibly related to the fact that the strain was isolated from soil in Brazilian hot regions. As to the time, the results indicated that after 120 hours of fermentation, the specific activity was 1.2 times higher than after 96 hours and 1.7 times higher than after 48 hours. The results obtained in the work are of great importance because of the strain CG374 has not been studied previously for this purpose.