Low ultrasonic stimulates fermentation of riboflavin producing strain Ecemothecium ashbyii

The effect of low ultrasonic stimulation on fermentation of riboflavin producing strain Ecemothecium ashbyii was investigated. In this paper, several key biochemical parameters related to cell growth were measured. The results of the present study show that all of the given different frequency of low ultrasonic treatment could promote mycelium growth, at the same time also improve output of riboflavin, and the optimum frequency was about 24 kHz. After 24 kHz ultrasonic incontinuous treatments, the fermentation time was shortened by 36 h and productivity rate of riboflavin was increased by about 5 times compared with the control groups. (C) 2003 Elsevier Science B.V. All rights reserved.