Effects of Gallic Acid on Fermentation Parameters, Protein Fraction, and Bacterial Community of Whole Plant Soybean Silage

Cheng Wang; Mingyang Zheng; Shuo Wu; Xuan Zou; Xiaoyang Chen; Liangfa Ge; Qing Zhang

doi:10.3389/fmicb.2021.662966

Effects of Gallic Acid on Fermentation Parameters, Protein Fraction, and Bacterial Community of Whole Plant Soybean Silage

Front Microbiol. 2021 May 17:12:662966. doi: 10.3389/fmicb.2021.662966. eCollection 2021.

Authors

Cheng Wang^{1

2

3}, Mingyang Zheng^{1

2

3}, Shuo Wu^{1

2

3}, Xuan Zou^{1

2

3}, Xiaoyang Chen^{1

2

3}, Liangfa Ge³, Qing Zhang^{1

2

3}

Affiliations

¹ College of Forestry and Landscape Architecture, Guangdong Province Research Center of Woody Forage Engineering Technology, Guangdong Research and Development Center of Modern Agriculture (Woody Forage) Industrial Technology, South China Agricultural University, Guangzhou, China.
² Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China.
³ College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China.

Abstract

Whole plant soybean (WPS) is a kind of legume resource with characteristics of high nutrition, large biomass, and wide distribution. In the present study, we have investigated the feasibility and effects of gallic acid (GA) on WPS silage quality, nitrogen distribution, tannin content, and bacterial community. The 0.5 and 1% (fresh matter basis) GA were added into WPS for dynamic ensiling (days 3, 7, 14, and 30, respectively). The results showed that the WPS silage with GA addition significantly decreased pH value (6.16-5.38 at ensiling day 30), coliform bacteria count and butyric acid (65.3-62.0 g/kg dry matter at ensiling day 30), and amino nitrogen contents (259-88.2 g/kg total nitrogen at ensiling day 30) and promoted lactic acid (9.62-31.5 g/kg dry matter at ensiling day 30), acetic acid (24.1-85.6 g/kg dry matter at ensiling day 30), and tannin (total phenol and hydrolyzable tannin) contents. Additionally, the GA addition also contributed to the change of bacterial community, where Firmicutes and Lactobacillus were most abundant on phylum and genus levels, respectively. The above results suggested that GA additive applied in WPS silage was an effective strategy to protect nutrition and improve fermentation quality, and the 1% GA addition showed a better effect.

Keywords: bacterial community; fermentation quality; gallic acid; protein fraction; whole plant soybean.