Isolation, identification and fibrolytic characteristics of rumen fungi grown with indigenous methanogen from yaks (Bos grunniens) grazing on the Qinghai‐Tibetan Plateau

• Published in: Journal of applied microbiology Vol. 120; no. 3; pp. 571 - 587
• Main Authors: Wei, Y.‐Q, Yang, H.‐J, Luan, Y, Long, R.‐J, Wu, Y.‐J, Wang, Z.‐Y
• Format: Journal Article
• Language: English
• Published: England Published for the Society for Applied Bacteriology by Blackwell Science 01-03-2016; Oxford University Press
• Subjects: acetates; anaerobic fungi; Animals; Biodegradation; Bos grunniens; Cattle - metabolism; Cattle - microbiology; Cellulase - metabolism; Cellulose - metabolism; coculture; co‐culture; Dietary Fiber - metabolism; digestibility; Digestion; endo-1,4-beta-glucanase; ferulic acid; feruloyl esterase; Fungal Proteins - metabolism; Fungi; Fungi - classification; Fungi - genetics; Fungi - isolation & purification; Fungi - metabolism; grazing; in vitro studies; industry; internal transcribed spacers; lignocellulose; Methane; Methane - metabolism; Methanobrevibacter; Methanobrevibacter ruminantium; methanogen; methanogens; Microbiology; Molecular Sequence Data; Neocallimastix; Neocallimastix frontalis; Orpinomyces; p-coumaric acid; Phylogeny; Piromyces; ribosomal RNA; rumen; Rumen - metabolism; Rumen - microbiology; rumen fungi; sequence analysis; Tibet; Triticum aestivum; wheat straw; xylanases; yak; yaks; China; yak; co-culture; anaerobic fungi; rumen; methanogen
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1111/jam.13035

AIM: To obtain co‐cultures of anaerobic fungi and their indigenously associated methanogens from the rumen of yaks grazing on the Qinghai‐Tibetan Plateau and investigate their morphology features and ability to degrade lignocellulose. METHODS AND RESULTS: Twenty fungus‐methanogen co‐cultures were obtained by Hungate roll‐tube technique. The fungi were identified as Orpinomyces, Neocallimastix and Piromyces genera based on the morphological characteristics and internal transcribed spacer 1 sequences analysis. All methanogens were identified as Methanobrevibacter sp. by 16S rRNA gene sequencing. There were four types of co‐cultures: Neocallimastix with Methanobrevibacter ruminantium, Orpinomyces with M. ruminantium, Orpinomyces with Methanobrevibacter millerae and Piromyces with M. ruminantium among 20 co‐cultures. In vitro studies with wheat straw as substrate showed that the Neocallimastix with M. ruminantium co‐cultures and Piromyces with M. ruminantium co‐cultures exhibited higher xylanase, filter paper cellulase (FPase), ferulic acid esterase, acetyl esterase activities, in vitro dry matter digestibility, gas, CH₄, acetate production, ferulic acid and p‐coumaric acid releases. The Neocallimastix frontalis Yak16 with M. ruminantium co‐culture presented the strongest lignocellulose degradation ability among 20 co‐cultures. CONCLUSIONS: Twenty fungus‐methanogen co‐cultures were obtained from the rumen of grazing yaks. The N. frontalis with M. ruminantium co‐cultures were highly effective combination for developing a fermentative system that bioconverts lignocellulose to high activity fibre‐degrading enzyme, CH₄ and acetate. SIGNIFICANCE AND IMPACT OF THE STUDY: The N. frontalis with M. ruminantium co‐cultures from yaks grazing on the Qinghai‐Tibetan Plateau present great potential in lignocellulose biodegradation industry.