Nuevas actividades enzimáticas acordes a las necesidades tecnológicas.

MORATA, V.I.

San Rafael

Congreso; Congreso Latinoamericano de Ingeniería y Ciencias Aplicadas (CLICAP); 2005

FCAI-UNCuyo

MICROBIAL a-AMYLASE ACTIVITY AT INTERMEDIATE TEMPERATURES (15-20ºC)   Morata de Ambrosini, V.I.1,2, Baca de Giménez2, F, Cabeza, M.S.1,2 and Oliver, G.3 1CONICET- vmorata@fcai.uncu.edu.ar 2Fac. Cs Ap a la Industria. Univ Nac Cuyo. (5600) San Rafael. Mendoza. Argentina 3CERELA, Chacabuco 145. (4000)San Miguel de Tucumán. Argentina   a-Amylases produced by mesophilic and thermophilic microorganisms are thoroughly known and have been applied to diverse technological purposes (Priest, 1977). Recently, Cheesa et al., 1999, have carried out a more detailed study on amylases from psychrophilic microorganisms, isolated from Antarctica. The results have learned that microorganisms in their natural habitat produce enzymes adapted to local temperatures, which means that they are able to function under the given conditions and can withstand possible extreme conditions (Gerday et al., 2001). The present study looked for a-amylase-producing microorganisms in their natural habitats with enzymes active at temperatures between 15 and 20°C and at the same time reasonably thermo-resistant, parameters essential for determined technological purposes. Isolation and selection of mesophilic a-amylase-producing Bacilli was carried out in a temperate area (San Rafael, Mendoza, Argentina) with an average temperature of 15-20°C as stress condition. Four strains with acceptable a-amylase activity were selected, and the highest activity producer strain was classified and identified as Bacillus circulans VM102. Production tests were carried out in a SGI SET002M SGI fermentor. Optimum growth temperature of the strain was 40°C and optimum temperature for production of a-amylase activity was 37°C. Activity was stable between 15 and 40°C, above which the enzyme became inactivated.