【作者】 于伟帅； 吴悦明； 李多川；

【机构】 山东农业大学菌物学系；

【摘要】 Lytic polysaccharide monooxygenases(LPMOs) of the auxiliary activity family 9(AA9) oxidatively degrade cellulose.It is well-known that cellulose is degraded by cellulases via hydrolysis mechanism in the termite gut.However,the existence of oxidative cleavage in cellulose degradation within the termite gut remains uncertain.In this study,we report for the first time experimental evidence that the oxidative cleavage of cellulose degradation in the termite Cryptotermes declivis gut.We identified a variety of fungi from the termite C.declivis gut through extensive analysis of isolated fungi and ITS sequencing.The majority of the fungal community was found to be composed of Ascomycota fungi.Genome sequencing revealed the presence of an AA9 LPMO(TfAA9A) in Talaromyces funiculosus isolated from the termite C.declivis gut.The expression of TfAA9A in the termite C.declivis gut was observed using RT-PCR,and its ability to oxidize cellulose was confirmed in vitro through heterologous expression in P.pastoris.Further transcriptome and proteomics analysis showed expressed genes and proteins of fungal AA9 LPMOs in the termite C.declivis gut.All the experimental data support the oxidative cleavage of cellulose in the termite C.declivis gut.This study offers a new direction for understanding the mechanism of termite cellulose degradation.更多还原

【Abstract】 Lytic polysaccharide monooxygenases(LPMOs) of the auxiliary activity family 9(AA9) oxidatively degrade cellulose.It is well-known that cellulose is degraded by cellulases via hydrolysis mechanism in the termite gut.However,the existence of oxidative cleavage in cellulose degradation within the termite gut remains uncertain.In this study,we report for the first time experimental evidence that the oxidative cleavage of cellulose degradation in the termite Cryptotermes declivis gut.We identified a variety of fungi from the termite C.declivis gut through extensive analysis of isolated fungi and ITS sequencing.The majority of the fungal community was found to be composed of Ascomycota fungi.Genome sequencing revealed the presence of an AA9 LPMO(TfAA9A) in Talaromyces funiculosus isolated from the termite C.declivis gut.The expression of TfAA9A in the termite C.declivis gut was observed using RT-PCR,and its ability to oxidize cellulose was confirmed in vitro through heterologous expression in P.pastoris.Further transcriptome and proteomics analysis showed expressed genes and proteins of fungal AA9 LPMOs in the termite C.declivis gut.All the experimental data support the oxidative cleavage of cellulose in the termite C.declivis gut.This study offers a new direction for understanding the mechanism of termite cellulose degradation.更多还原