Optimization of media for beta-fructofuranosidase production by Aspergillus niger in submerged and solid state fermentation

The kinetics of beta -fructofuranosidase (Ffase) production by Aspergillus niger in submerged (SmF) and solid-state fermentation (SSF) systems was inv estigated. The maximum productivity of Ffase (81.8 U/litre/h) was obtained in SSF for 72 h while it was 18.3 U/litre/h in SmF for 120 h. The productiv ity of extra cellular Ffase produced in SSF was five-fold higher than in Sm F. Optimization of fermentation medium for Ffase production was carried out using De Meo's fractional factorial design with seven components such as ( NH4)(2)SO4, KH2PO4, FeSO4, MgSO4 . 7H(2)O, sucrose, area and yeast extract. The media designed for SmF after two steps of optimization supported the g rowth of A. niger and higher productivity of Ffase (58.3 U/litre/h) than wi th the medium before optimization. The optimized medium of SmF when used in SSF, did not improve the Ffase productivity and therefore the medium for S SF was optimized independent of SmF. After two optimization steps, the medi a was defined for SSF which supported the growth and high level of Ffase pr oductivity (149.1 U/litre/h) in SSF compared to the medium before optimizat ion (81.8 U/litre/h) and optimized medium for SmF (58.3 U/litre/h), The res ults suggested that the optimized media for SmF and SSF for the production of Ffase have to be different. (C) 2001 Elsevier Science Ltd. All rights re served.