METHYLXANTHINES AS INDUCERS OF PECTIN LYASE IN PENICILLIUM-GRISEOROSEUM CULTURED ON SUCROSE

Pectin lyase (PL) from Penicillium griseoroseum can be induced by xant hine, theobromine, theophylline and especially by caffeine and hypoxan thine (5 mmol l(-1) With 0.01% Beast extract (YE)). For caffeine and h ypoxanthine, PL activity was, respectively, 5.2 and 3.7 times higher t han with YE alone. The simultaneous addition of caffeine or hypoxanthi ne (5 mmol l(-1)) and YE (0.1%) had a synergistic effect on PL activit y as compared to the addition of these substances alone (0.2% YE; 10 m mol l(-1) caffeine; 10 mmol l(-1) hypoxanthine). Increasing caffeine c oncentrations (0-10 mmol l(-1)) for a constant YE, content of 0.01%, r esulted in an increase in PL activity and a decrease in mycelial mass. For a constant caffeine concentration (5 mmol l(-1)) and increasing Y E contents (0-0.2%), a higher PL activity and mycelial mass were detec ted. The addition of caffeine (10 mmol l(-1)) at the beginning of incu bation increased PL activity and decreased mycelial mass, while caffei ne added after 12 and 24 h resulted in decreases in PL activity and in creases in mycelial mass. The results presented here indicate that met hylxanthines, especially caffeine, can induce PL in P. griseoroseum.