Abstract:In order to evaluate the degradation abilities of two filamentous fungi on wheat bran and the difference in their abilities to release phenolic acid, the changes in the contents of total phenols and nine phenolic acid components were monitored at different time. Based on the activities of ferulic acid esterase and xylanase, the surface structure of wheat bran was examined via electron microscopy, and Aspergillus niger and Aspergillus clavatus were comprehensively evaluated. After seven days of fermentation with Aspergillus niger, the ferulic acid content reached 416.56 μg/g wheat bran, and the gallic acid content increased from 7.71 μg/g wheat bran to 105.77 μg/g wheat bran. The ferulic acid content in the fermentation by Aspergillus clavatus increased to 200.81 μg/g wheat bran. The malic acid, gallic acid, p-hydroxybenzoic acid, and coumaric acid contents increased to 88.4 μg/g wheat bran, 60.38 μg/g wheat bran, 55.56 μg/g wheat bran, and 52.93 μg/g wheat bran from 14.74 μg/g wheat bran, 7.71 μg/g wheat bran, 8.57 μg/g wheat bran, and 5.62 μg/g wheat bran, respectively. Compared with Aspergillus clavatus, Aspergillus niger exhibited significantly higher abilities to degrade wheat bran and release ferulic acid and gallic acid, but a slightly weaker ability to release malic acid. The electron microscopy results showed that the degradation ability of Aspergillus niger was better than that of Aspergillus clavatus.
