Persistent action of cow rumen microorganisms in enhancing biodegradation of wheat straw by rumen fermentation
| Autor: | Junwei Wen, Bao-Shan Xing, Xiaochang C. Wang, Sifan Cao, Honglin Yuan, Kaidi Zhang, Qian Li, Yule Han |
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| Rok vydání: | 2019 |
| Předmět: |
animal structures
Environmental Engineering Rumen 010504 meteorology & atmospheric sciences Microorganism 010501 environmental sciences 01 natural sciences Lignin chemistry.chemical_compound Environmental Chemistry Animals Food science Cellulose Waste Management and Disposal Triticum 0105 earth and related environmental sciences biology Chemistry food and beverages Biodegradation biology.organism_classification Fatty Acids Volatile Pollution Methanobrevibacter Anaerobic digestion Biodegradation Environmental Fermentation Cattle Female Bacteria |
| Zdroj: | The Science of the total environment. 715 |
| ISSN: | 1879-1026 |
| Popis: | Rumen fermentation is known to be effective for lignocellulosic-wastes biodegradation to certain extent but it is still unclear if there exists a termination of the microorganisms' action to further degrade the bio-refractory fractions. In order to illuminate the related microbiological characteristics, experiments were conducted in a prolonged duration of rumen fermentation of mechanically ruptured wheat straw, with inoculation of cow rumen microorganisms in vitro. Although the organic wastes could not be biodegraded quickly, continuous conversion of the lignocellulosic contents to volatile fatty acids and biogas proceeded in the duration of more than three months, resulting in 96-97% cellulose and hemicellulose decomposition, and 42% lignin decomposition. X-ray diffraction and Fourier transform infrared spectroscopy further demonstrated the characteristics of lignocellulosic structure decomposition. Under the actions of cow rumen microorganisms, stable pH was maintained in the fermentation liquid, along with a steady NH4+-N, volatile fatty acids accumulation, and a large buffering ability. It was identified by enzyme analysis and Illumina MiSeq sequencing that the rich core lignocellulolytic enzymes secreted by the abundant and diverse rumen bacteria and fungi contributed to the persistent degradation of lignocellulosic wastes. Members of the Clostridiales order and Basidiomycota phylum were found to be the dominant lignocellulolytic bacteria and fungi, respectively. It could thus be inferred that the main lignocellulose degradation processes were a series of catalytic reactions under the actions of lignocellulolytic enzymes secreted from bacteria and fungi. The dominant hydrogenotrophic methanogens (Methanomassiliicoccus, Methanobrevibacter, Methanosphaera, and Methanoculleus) in the rumen could also assist CH4 production if the rumen fermentation was followed with anaerobic digestion. |
| Databáze: | OpenAIRE |
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