Increase in the Activity of alpha-amylase Produced by Aspergillus oryzae in Dried Unripe Apple Pulp Culture on Addition of NaNO3 and MgSO4

摘要

Unripe apples contain large quantities of starch and represent an unused organic resource. Starch hydrolysis in unripe apples may provide an effective method to utilize this resource as a food material. Aspergillus oryzae can be grown using unripe apples. However, the activity level of alpha-amylase produced by A. oryzae grown in dried unripe apple pulp remains unconfirmed. Therefore, we here examined various culture conditions that might increase this alpha-amylase activity. Our results suggested that for culturing A. oryzae in dried unripe apple pulp using the shaking culture method, the addition of NaNO3 and MgSO4 center dot 7H(2)o as nitrogen and magnesium and/or sulfur sources, respectively, was essential. Thus, alpha-amylase production by A. oryzae required high oxygen levels and additional nitrogen and magnesium and/or sulfur sources, both of which occur in low quantities in dried unripe apple pulp.