Pectin Degradation is an Important Determinant for Alfalfa Silage Fermentation through the Rescheduling of the Bacterial Community

• Main Authors: Bing Wang, Zhiqiang Sun, Zhu Yu
• Format: Article
• Language: English
• Published: MDPI AG 2020-03-01
• Series: Microorganisms
• Subjects: 16S rRNA gene; silage; pectinase; bacteria
• Online Access: https://www.mdpi.com/2076-2607/8/4/488

This study aimed to evaluate the effects of the four kinds of additives on the silage quality and the relevant bacterial community diversity by Illumina HiSeq 16S rRNA sequencing. The four kinds of additives were <i>Lactobacillus plantarum</i> (LP), organic acids including gallic acid (GA) and phenyllactic acid (PA), pectin (PEC), and enzymes including pectinase (PEE) and cellulase (CE). After 30 d of fermentation, the pH value was shown to have the lowest value in the PEE and PEC groups, followed by the PA group, and then in CE and GA groups; the highest value of pH was found in both LP and control groups. The ammonia nitrogen concentration was lower in the PEE group compared to the other groups except for the PA group. In the comparisons among the seven groups, <i>Lactobacillus</i> was higher in the LP group, <i>Paracoccus</i> was higher in the GA group, <i>Weissella</i> was higher in the PA group, <i>Leuconostoc</i> was higher in the PEC group, <i>Bacillus</i>, <i>Aeromonas</i>, and <i>Curvibacter</i> were higher in the PEE group, and <i>Coriobacteriaceae_UCG_002</i> was higher in the CE group compared to the other groups. This study proposed that the addition of PEC and PEE improved the fermentation quality of alfalfa silage compared to other additives by improving the bacterial community of <i>Leuconostoc</i>, and <i>Bacillus</i> and <i>Aeromonas</i>, respectively. Moreover, the enhanced fermentation quality of alfalfa silage by the supplementation of PEC and PEE might be attributed to other unclassified genera. This study provides an implication that pectin degradation is an important determinant for alfalfa silage fermentation through the rescheduling of bacterial community diversity.