Ensilage and Secondary Fermentation of Maize Stalk and Their Effect on Methane Production and Microbial Community Dynamics in Anaerobic Digestion
Abstract
1. Introduction
2. Materials and Methods
2.1. Experimental Design
2.2. Harvest and Ensilage of Maize Stalks
2.3. Secondary Fermentation of Maize Stalks
2.4. Anaerobic Digestion of Maize Stalks
2.5. Kinetic Model Fitting of Organic Dry Matter (ODM) Loss and Methane Yield Loss During Secondary Fermentation
2.6. Chemical Analysis
2.7. Microbial Analysis of Maize Stalks
2.7.1. Hydrolytic Enzyme Activity Determination
2.7.2. Microbial Enumeration
2.8. Microbial Analysis of Anaerobic Digestion (AD) Samples
2.8.1. Quantitative Real-Time Polymerase Chain Reaction of Bacteria in Anaerobic Digestion (AD)
2.8.2. High-Throughput Sequencing Analysis
2.8.3. Hydrolytic Enzyme Activity Determination
2.9. Data Analysis
3. Results and Discussion
3.1. Ensilage and Secondary Fermentation of Maize Stalk
3.1.1. Characteristic Changes in Maize Stalk During Ensiling
3.1.2. Characteristic Changes, Microbial Dynamics, and Organic Dry Matter (ODM) Loss of Silage During Air Exposure
3.2. Effect of Ensiling and Air Exposure on Methane Production
3.2.1. Fermentation Dynamics in Anaerobic Digestion (AD) of Maize Stalks
3.2.2. Methane Yield Potential of Maize Stalks During Ensiling and Air Exposure
3.2.3. Quantitative Polymerase Chain Reaction of Bacteria in Anaerobic Digestion (AD) of Maize Stalks
3.2.4. Metagenomic Analysis of Bacterial Community in Anaerobic Digestion (AD) of Maize Stalks Following Ensilage and Air Exposure
3.2.5. Methane Yield Loss of Maize Stalks During Ensiling and Air Exposure
4. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
Abbreviation
AT | ambient temperature |
AD | anaerobic digestion |
ADF | acid detergent fiber |
ADL | acid detergent lignin |
CMC | carboxymethyl cellulose |
CMCase | carboxymethyl cellulase |
CMs | cellulolytic microbes |
CP | crude protein |
DM | dry matter |
FM | fresh maize stalk |
MY | methane yield |
NDF | neutral detergent fiber |
ODM | organic dry matter |
OTUs | operational taxonomic units |
sCOD | soluble chemical oxygen demand |
SF | secondary fermentation |
SMY | specific methane yield |
VFAs | volatile fatty acids |
WSCs | water-soluble carbohydrates |
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Items | FM | S0 | S2 | S3 | S7 | S12 | S22 | S40 |
---|---|---|---|---|---|---|---|---|
DM (g/kg) | 301.0 ± 1.1 | 305.1 ± 10.3 | 299.4 ± 12.3 | 286.4 ± 0.8 | 266.3 ± 13.2 | 249.7 ± 12.1 | 251.2 ± 2.8 | 457.0 ± 4.8 |
ODM (g/kg) | 276.6 ± 1.5 | 279.3 ± 11.4 | 274.0 ± 11.8 | 260.2 ± 1.0 | 240.2 ± 12.1 | 222.8 ± 11.0 | 220.9 ± 3.2 | 400.2 ± 5.7 |
Ash (g/kg) | 24.7 ± 0.8 | 25.7 ± 0.1 | 25.4 ± 0.1 | 26.2 ± 0.1 | 26.1 ± 0.4 | 26.9 ± 0.2 | 30.3 ± 0.2 | 56.8 ± 0.3 |
NDF (%DM) | 65.45 ± 0.65 | 64.59 ± 0.91 | 65.52 ± 2.10 | 70.22 ± 0.92 | 76.04 ± 1.04 | 73.27 ± 1.29 | 74.61 ± 1.64 | 62.33 ± 2.45 |
ADL (%DM) | 3.69 ± 0.78 | 6.19 ± 0.56 | 5.78 ± 0.80 | 5.00 ± 0.80 | 7.73 ± 0.97 | 7.51 ± 0.58 | 5.65 ± 1.65 | 5.12 ± 1.37 |
CP (%DM) | 5.35 ± 0.02 | 5.45 ± 0.02 | 5.62 ± 0.06 | 5.82 ± 0.21 | 5.87 ± 0.20 | 5.28 ± 1.31 | 5.27 ± 1.14 | 4.39 ± 0.05 |
WSC (%DM) | 16.00 ± 0.21 | 1.30 ± 0.10 | 1.19 ± 0.11 | 1.50 ± 0.15 | 1.11 ± 0.10 | 0.78 ± 0.13 | 1.12 ± 0.05 | 1.08 ± 0.03 |
sCOD (%DM) | 36.04 ± 1.43 | 27.53 ± 0.39 | 26.13 ± 2.66 | 18.26 ± 8.19 | 11.08 ± 0.31 | 8.10 ± 0.42 | 12.39 ± 0.34 | 15.16 ± 0.26 |
NH3-N (‰DM) | 0.30 ± 0.03 | 0.94 ± 0.01 | 0.38 ± 0.00 | 0.24 ± 0.00 | 0.35 ± 0.00 | 0.39 ± 0.01 | 0.11 ± 0.00 | 0.05 ± 0.01 |
Nitrate-N (‰DM) | 0.41 ± 0.02 | 0.11 ± 0.00 | 0.11 ± 0.00 | 0.20 ± 0.00 | 0.21 ± 0.00 | 0.24 ± 0.00 | 0.22 ± 0.00 | 0.20 ± 0.00 |
ODMR (%) | NA | 97.06 | 94.18 | 87.84 | 81.15 | 72.98 | 65.24 | 62.95 |
Items | FM | S0 | S2 | S3 | S7 | S12 | S22 | S40 |
---|---|---|---|---|---|---|---|---|
Formic acid (%DM) | 0.05 ± 0.01 | --- | --- | --- | --- | 0.11 ± 0.00 | 0.14 ± 0.01 | 0.13 ± 0.00 |
Lactic acid (%DM) | --- | 11.91 ± 0.11 | 10.84 ± 0.02 | 3.94 ± 0.01 | 0.80 ± 0.12 | 0.59 ± 0.02 | 0.93 ± 0.01 | 0.00 ± 0.00 |
Acetic acid (%DM) | 1.68 ± 0.01 | 3.24 ± 0.02 | 1.94 ± 0.00 | 0.50 ± 0.00 | 0.57 ± 0.00 | 1.02 ± 0.00 | 0.85 ± 0.01 | 1.04 ± 0.01 |
Propionic acid (%DM) | 0.53 ± 0.01 | 0.15 ± 0.00 | 0.07 ± 0.00 | 0.32 ± 0.01 | 0.33 ± 0.00 | 0.40 ± 0.00 | --- | 0.07 ± 0.01 |
Ethanol (%DM) | 0.02 | --- | --- | --- | --- | --- | --- | --- |
Maize Stalk | Specific Methane Yield (lN/kg ODMadded) | Methane Yield (lN/kg DMorigin) | Methane Yield Recovery (%) |
---|---|---|---|
FM | 370.18 a ± 2.09 | NA | NA |
S0 | 359.59 b ± 3.11 | 349.01 ± 3.02 | 94.28 |
S2 | 362.99 ab ± 3.78 | 341.86 ± 3.56 | 92.35 |
S3 | 355.23 b ± 2.82 | 312.05 ± 2.48 | 84.30 |
S7 | 307.87 d ± 3.34 | 249.85 ± 2.71 | 67.49 |
S12 | 325.67 c ± 6.24 | 237.68 ± 4.55 | 64.21 |
S22 | 274.36 e ± 5.01 | 179.00 ± 3.27 | 48.35 |
S40 | 245.07 f ± 3.74 | 154.27 ± 2.35 | 41.68 |
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Zhang, H.; Yan, P.; Qin, Z.; Zhao, X.; Yuan, X.; Cui, Z.; Wu, J. Ensilage and Secondary Fermentation of Maize Stalk and Their Effect on Methane Production and Microbial Community Dynamics in Anaerobic Digestion. Fermentation 2025, 11, 309. https://doi.org/10.3390/fermentation11060309
Zhang H, Yan P, Qin Z, Zhao X, Yuan X, Cui Z, Wu J. Ensilage and Secondary Fermentation of Maize Stalk and Their Effect on Methane Production and Microbial Community Dynamics in Anaerobic Digestion. Fermentation. 2025; 11(6):309. https://doi.org/10.3390/fermentation11060309
Chicago/Turabian StyleZhang, Huan, Puxiang Yan, Ziyao Qin, Xiaoling Zhao, Xufeng Yuan, Zongjun Cui, and Jingwei Wu. 2025. "Ensilage and Secondary Fermentation of Maize Stalk and Their Effect on Methane Production and Microbial Community Dynamics in Anaerobic Digestion" Fermentation 11, no. 6: 309. https://doi.org/10.3390/fermentation11060309
APA StyleZhang, H., Yan, P., Qin, Z., Zhao, X., Yuan, X., Cui, Z., & Wu, J. (2025). Ensilage and Secondary Fermentation of Maize Stalk and Their Effect on Methane Production and Microbial Community Dynamics in Anaerobic Digestion. Fermentation, 11(6), 309. https://doi.org/10.3390/fermentation11060309