Ferulic Acid Esterase-Producing Inoculant Improves Fiber Degradation and Modulates Microbial Diversity in Corn Bran Silage and Whole-Plant Corn Silage

Ferulic acid esterase (FAE) catalyzes the hydrolysis of the feruloyl ester bond in lignocellulose, exposing cellulose. The objective of this research was to examine the impacts of Bacillus amyloliquefaciens A30 producing FAE on the fermentation quality, fiber degradation, enzyme activity and microbial diversity of corn bran silage and whole-plant corn silage. The experimental treatments were as follows: control (CK), cellulase (CEL), strain A30 (A30) and CEL + A30. Corn bran and whole-plant corn were ensiled for 14 d and 60 d, respectively. The results showed that all additive treatments effectively reduced the pH, neutral detergent fiber, acid detergent fiber and cellulose contents of both corn bran silage and whole-plant corn silage in comparison with control, with CEL + A30 group performing the best effects. Meanwhile, higher FAE activity was detected in A30 and CEL + A30 groups during ensiling. Furthermore, the supplementation of A30 increased the degradation ratio of NDF, ADF, ADL, and cellulose of corn bran silage and whole-plant corn silage. Additionally, treatments with A30 and CEL + A30 increased the abundance of Lactobacillus, and reduced the proportion of pathogenic genera, including Acinetobacter, Enterobacter, and Sphingobacterium. In conclusion, the application of A30 may effectively promote fiber degradation and the stability of microecological system for corn silage.