Insight into Enzymatic Degradation of Corn, Wheat, and Soybean Cell Wall Cellulose Using Quantitative Secretome Analysis of Aspergillus fumigatus.
Lignocelluloses contained in animal forage cannot be digested by pigs or poultry with 100% efficiency. On contrary, Aspergillus fumigatus, a saprophytic filamentous fungus, is known to harbor 263 glycoside hydrolase encoding genes, suggesting that A. fumigatus is an efficient lignocellulose degrader. Hence the present study uses corn, wheat, or soybean as a sole carbon source to culture A. fumigatus under animal physiological condition to understand how cellulolytic enzymes work together to achieve an efficient degradation of lignocellulose. Our results showed that A. fumigatus produced different sets of enzymes to degrade lignocelluloses derived from corn, wheat, or soybean cell wall. In addition, the cellulolytic enzymes produced by A. fumigatus were stable under acidic condition or at higher temperatures. Using isobaric tags for a relative and absolute quantification (iTRAQ) approach, a total of ∼600 extracellular proteins were identified and quantified, in which ∼50 proteins were involved in lignocellulolysis, including cellulases, hemicellulases, lignin-degrading enzymes, and some hypothetical proteins. Data are available via ProteomeXchange with identifier PXD004670. On the basis of quantitative iTRAQ results, 14 genes were selected for further confirmation by RT-PCR. Taken together, our results indicated that the expression and regulation of lignocellulolytic proteins in the secretome of A. fumigatus were dependent on both nature and complexity of cellulose, thus suggesting that a different enzyme system is required for degradation of different lignocelluloses derived from plant cells. Although A. fumigatus is a pathogenic fungus and cannot be directly used as an enzyme source, as an efficient lignocellulose degrader its strategy to synergistically degrade various lignocelluloses with different enzymes can be used to design enzyme combination for optimal digestion and absorption of corn, wheat, or soybean that are used as forage of pig and poultry.
State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences , Beijing 100101, China.|University of Chinese Academy of Sciences , Beijing 100101, China.|Himalayan Environment Research Institute (HERI) , Bouddha-6, Kathmandu, Nepal.
Prakriti
P
Sharma Ghimire
State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences , Beijing 100101, China.
Haomiao
H
Ouyang
State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences , Beijing 100101, China.
Qian
Q
Wang
State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences , Beijing 100101, China.
Yuanming
Y
Luo
Feed Research Institute, Chinese Academy of Agricultural Sciences , Beijing 100081, China.
Bo
B
Shi
State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences , Beijing 100101, China.
Jinghua
J
Yang
State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences , Beijing 100101, China.
Yang
Y
Lü
State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences , Beijing 100101, China.|University of Chinese Academy of Sciences , Beijing 100101, China.
Cheng
C
Jin
D000821:Animal Feed; D001232:Aspergillus fumigatus / Q000201:enzymology*; D006026:Glycoside Hydrolases / Q000235:genetics / Q000378:metabolism; D008031:Lignin / Q000378:metabolism*; D013025:Glycine max / Q000378:metabolism; D014908:Triticum / Q000378:metabolism; D003313:Zea mays / Q000378:metabolism
C036909:lignocellulose; D008031:Lignin; D006026:Glycoside Hydrolases
Aspergillus fumigatus; forage; iTRAQ; lignocellulolytic proteins; lignocelluloses; secretome