Fiber degradation potential of natural co-cultures of Neocallimastix frontalis and Methanobrevibacter ruminantium isolated from yaks (Bos grunniens) grazing on the Qinghai Tibetan Plateau
| Autor: | Rui-Fang Shi, Hui Yang, Hong-Jian Yang, Qian-Hong Ye, Ruijun Long, Ya-Qin Wei, Xi-Hui Shen, Jun-Guo Du, Zhi-Ye Wang, Xiao-Jin Qi |
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| Rok vydání: | 2015 |
| Předmět: |
0301 basic medicine
Dietary Fiber animal structures Rumen 030106 microbiology Methanobrevibacter Poaceae Microbiology Esterase Neocallimastix 03 medical and health sciences RNA Ribosomal 16S Botany Animals Dry matter Food science Anaerobiosis Lactic Acid Acetic Acid Endo-1 4-beta Xylanases biology Ethanol Esterases Sequence Analysis DNA Straw biology.organism_classification Methanogen Coculture Techniques Gastrointestinal Microbiome 030104 developmental biology Infectious Diseases Xylanase Cattle |
| Zdroj: | Anaerobe. 39 |
| ISSN: | 1095-8274 |
| Popis: | Several natural anaerobic fungus-methanogen co-cultures have been isolated from rumen and feces source of herbivores with strong fiber degrading ability. In this study, we isolated 7 Neocallimastix with methanogen co-cultures from the rumen of yaks grazing on the Qinghai Tibetan Plateau. Based on morphological characteristics and internal transcribed spacer 1 sequences (ITS1), all the fungi were identified as Neocallimastix frontalis. The co-cultures were confirmed as the one fungus - one methanogen pattern by the PCR-denatured gradient gel electrophoresis (DGGE) assay. All the methanogens were identified as Methanobrevibacter ruminantium by 16s rRNA gene sequencing. We investigated the biodegrading capacity of the co-culture (N. frontalis + M. ruminantium) Yaktz1 on wheat straw, corn stalk and rice straw in a 7 days-incubation. The in vitro dry matter digestibility (IVDMD), acid detergent fiber digestibility (ADFD) and neural detergent fiber digestibility (NDFD) values of the substrates in the co-culture were significantly higher than those in the mono-culture N. frontalis Yaktz1. The co-culture exhibited high polysaccharide hydrolase (xylanase and FPase) and esterase activities. The xylanase in the co-culture reached the highest activity of 12500 mU/ml on wheat straw at the day 3 of the incubation. At the end of the incubation, 3.00 mmol-3.29 mmol/g dry matter of methane were produced by the co-culture. The co-culture also produced high level of acetate (40.00 mM-45.98 mM) as the end-product during the biodegradation. Interestingly, the N. frontalis Yaktz1 mono-culture produced large amount of lactate (8.27 mM-11.60 mM) and ethanol (163.11 mM-242.14 mM), many times more than those recorded in the previously reported anaerobic fungi. Our data suggests that the (N. frontalis + M. ruminantium) Yaktz1 co-culture and the N. frontalis Yaktz1 mono-culture both have great potentials for different industrial use. |
| Databáze: | OpenAIRE |
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