Study on environmental factors in rhamnosidase production from Penicillium ulaiense by factorial design of experiments.

V. RAJAL; O. DOMÍNGUEZ; G. ELLENRIEDER; C. CUEVAS

Santa Fe, Argentina

Congreso; 3rd Mercosur Congress on Process System Engineering– 1st Mercosur Congress on Chemical Engineering; 2001

Penicillium ulaiense is a citrus post harvest pathogenic fungus recently described. It exhibited some hydrolase activities. a-Rhamnosidase production was studied in liquid medium with rhamnose as carbon source and inducer. An environmental factor study of P. ulaiense in the production of a-rhamnosidase was carried out by factorial design and analysis of experiments. Some growth conditions such as temperature and initial pH, and some nutritional factors such as yeast and rhamnose concentrations were studied by means of a factorial design at two levels, with four central points for error estimation. Only one response, the enzyme activity, was considered at four different times: 12, 14, 16 y 20 days. The influence of temperature, initial pH, yeast extract and rhamnose concentrations were significant. For the experimental interval studied, it was established that lower limit of temperature (26ºC), initial pH (5.5), yeast extract concentration (5 g/l), and higher rhamnose concentration (10 g/l) are the best conditions for optimum medium for enzyme production.