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Table 2 Fermentative characteristics of high-moisture alfalfa silages after ensiling

From: Enhancement of lignocellulosic degradation in high-moisture alfalfa via anaerobic bioprocess of engineered Lactococcus lactis with the function of secreting cellulase

Items Additives Time (days) SEM Significance
1 6 18 60 Additives Time Additives × time
pH Control 5.80aA 4.57aB 4.39aB 5.35aA 0.059 < 0.001 < 0.001 < 0.001
EN 5.80aA 4.42abC 4.17bcD 4.62bB
HT1 4.95cB 4.42abC 4.32abC 5.22aA
HT1 + EN 5.23bA 4.40abB 4.29abcC 4.47bB
HT2 4.76dA 4.20bC 4.12cC 4.49bB
Lactic acid (g/kg DM) Control 8.67bB 40.1bA 41.1bA 16.3bB 2.914 < 0.001 < 0.001 < 0.001
EN 10.3bC 45.2abAB 56.6aA 33.8bB
HT1 16.4aC 40.3bB 49.4abA 18.3bC
HT1 + EN 16.1aC 52.5aB 50.1abB 69.0aA
HT2 17.4aD 41.9bC 58.2aB 67.1aA
Acetic acid (g/kg DM) Control 12.0aC 22.8abBC 32.4abAB 42.5bA 3.027 < 0.001 < 0.001 < 0.001
EN 12.2aC 24.8aBC 33.6aB 79.2aA
HT1 2.10bC 16.0bcBC 24.6bB 46.2bA
HT1 + EN 5.09bD 19.0abC 30.9abB 39.9bA
HT2 1.70bD 9.56cC 24.3bB 32.4bA
Propionic acid (g/kg DM) Control 0.19 0.00 0.00 5.69 1.028 0.150 0.011 0.110
EN 0.00 0.00 0.00 0.00
HT1 0.00B 0.00B 0.00B 3.79A
HT1 + EN 0.00 0.00 0.00 0.00
HT2 0.00 0.00 0.00 0.00
Butyric acid (g/kg DM) Control 0.00B 0.00B 0.59B 36.94aA 2.700 < 0.001 < 0.001 < 0.001
EN 0.00 0.00 0.00 0.00
HT1 0.00B 0.00B 0.00B 29.89aA
HT1 + EN 0.00 0.00 0.00 0.00b
HT2 0.00 0.00 0.00 0.00b
Ammonia-N (g/kg N) Control 50.2aB 103aB 113aB 246aA 11.49 < 0.001 < 0.001 < 0.001
EN 48.2abC 79.2bB 87.1bB 129bA
HT1 35.6bcB 65.8bcB 83.26bB 210abA
HT1 + EN 37.7abcD 64.7bcC 91.0bB 108bA
HT2 34.0cD 51.9cC 81.1bB 106bA
LA/AA Control 0.74 dBC 1.77bA 1.26cAB 0.38bC 0.254 < 0.001 < 0.001 < 0.001
EN 0.84dB 1.83bA 1.68bcAB 0.44bC
HT1 7.84bA 2.64bB 2.04abBC 0.43bC
HT1 + EN 3.16cA 2.81bA 1.65bcB 1.75aB
HT2 10.33 aA 4.40 aB 2.39 aC 2.08aC
V-score Control 99.6abA 85.9cA 79.8bA 38.2bcB 2.519 < 0.001 < 0.001 < 0.001
EN 99.5bA 91.7bB 87.9aB 68.8abC
HT1 100aA 95.6abAB 88.8aB 36.5cC
HT1 + EN 100aA 95.4abA 88.3aB 79.7aC
HT2 100aA 99.5aA 91.7aB 83.6aC
  1. Values with different superscript lowercase letters show significant differences among treatments in the same ensiling day, values with different superscript capital letters show significant differences among ensiling days in the same treatment (P < 0.05) according to Tukey’s test
  2. Control, silage treated without additives; DM, dry matter; EN, cellulase; HT1, wild-type L. lactis subsp. lactis MG1363; HT1 + EN, combination of HT1 and EN; HT2, combination of transgenically engineered L. lactis strains HT1/pMG36e-usp45-bgl1, HT1/pMG36e-usp45-cbh2, and HT1/pMG36e-usp45-egl3; N, nitrogen; LA/AA, ratio of lactic acid to acetic acid; SEM, standard error of the means