Amylase production by Aspergillus oryzae in a solid-state bioreactor with fed-batch operation using mussel processing wastewaters as feeding medium

作者：Torrado Ana^*; Vazquez Jose Antonio; Prieto Miguel Angel; Fucinos Pablo; Montemayor Maria Ignacia; Pastrana Lorenzo; Gonzalez Maria Pilar; Murado Miguel Angel

来源：Journal of Chemical Technology and Biotechnology, 2013, 88(2): 226-236.

DOI：10.1002/jctb.3813

• amylase production
• mussel processing wastewaters
• solid-state
• salinization
• solid-state bioreactor
• fed-batch
• Weibull equation
• SSC
• SSF

BACKGROUND: The high oxygen availability in solid-state cultures makes them especially suitable for fungal enzyme production. Glycogen-rich mussel processing wastewaters have been used successfully as substrates for amylase production by Aspegillus oryzae in solid-state cultures supported in polyurethane foam. The aim of this work was to study the fed-batch mode in a scalable solid-state bioreactor to extend the productive period and obtain high amylase production. Culture salinization due to the NaCl content of these wastewaters is the main drawback. RESULTS: Evaporation of the excess liquid added during feeding led to progressive salt accumulation. The effect of culture salinization on amylase production was analysed and mathematically modelled, and the IC50 (65.4 g L-1 of NaCl) was calculated. An optimum operation mode for this bioreactor was designed that included foam extrusion for removing the incubated medium, washing and a final recharge with fresh medium every 72 h of incubation. This procedure kept the salt concentration under IC50 and increased the amylase production from 3000 to 12 000 UE g-1. CONCLUSION: An operating mode with intermittent extrusions and washings of the support between feedings was found to be an appropriate procedure for preventing the accumulation of inhibitory compounds in fed-batch solid-state cultures.

• 出版日期2013-2