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Indigenously associated methanogens intensified the metabolism in hydrogenosomes of anaerobic fungi with xylose as substrate
Author(s) -
Li Yuanfei,
Jin Wei,
Mu Chunlong,
Cheng Yanfen,
Zhu Weiyun
Publication year - 2017
Publication title -
journal of basic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0233-111X
DOI - 10.1002/jobm.201700132
Subject(s) - formate , fermentation , mixed acid fermentation , anaerobic exercise , xylose , biochemistry , metabolism , monoculture , xylose metabolism , biology , food science , chemistry , bacteria , lactic acid fermentation , lactic acid , physiology , genetics , agronomy , catalysis
Anaerobic fungi are potent lignocellulose degraders, but have not yet been exploited in this capacity, largely owing to their poor metabolic characterization. In the current study, a time course of fermentation was conducted to study the effect of the co‐cultured methanogens on xylose metabolism by anaerobic fungi. The fermentation end‐products from anaerobic fungal monoculture were H 2 (6.7 ml), CO 2 (65.7 ml), formate (17.90 mM), acetate (9.00 mM), lactate (11.89 mM), ethanol, and malate after 96 h fermentation. Compared to the monoculture, the end‐products of co‐culture shifted to more CO 2 (71.8 ml) and acetate (15.20 mM), methane (14.9 ml), less lactate (5.28 mM), and hardly detectable formate and H 2 at the end of fermentation. After 48 h, accumulated formate was remarkably consumed by co‐cultured methanogens, accompanied by significantly increased acetate, CO 2 and pH, and decreased lactate and malate. Xylose utilization, in both cultures, was similar during fermentation. However, the relative flux of carbon in hydrogenosomes in the co‐culture was higher than that in the monoculture. In conclusion, the co‐culture with methanogens enhanced “energy yields” of anaerobic fungi by removing the accumulated formate, decreased the metabolism in cytosol, for example, the lactate pathway, and increased the metabolism in hydrogenosomes, for example, the acetate pathway.