Lignin degradation is a major process in the global carbon cycle across both terrestrial and marine ecosystems.Bathyarchaeia,which are among the most abundant microorganisms in marine sediment,have been proposed to me...Lignin degradation is a major process in the global carbon cycle across both terrestrial and marine ecosystems.Bathyarchaeia,which are among the most abundant microorganisms in marine sediment,have been proposed to mediate anaerobic lignin degradation.However,the mechanism of bathyarchaeial lignin degradation remains unclear.Here,we report an enrichment culture of Bathy-archaeia,named Candidatus Baizosediminiarchaeum ligniniphilus DL1YTT001(Ca.B.ligniniphilus),from coastal sediments that can grow with lignin as the sole organic carbon source under mesophilic anoxic conditions.Ca.B.ligniniphilus possesses and highly expresses novel methyltransferase 1(MT1,mtgB)for transferring methoxyl groups from lignin monomers to cob(I)alamin.MtgBs have no homology with known microbial methyltransferases and are present only in bathyarchaeial lineages.Heterologous expression of the mtgB gene confirmed O-demethylation activity.The mtgB genes were identified in metagenomic data sets from a wide range of coastal sediments,and they were highly expressed in coastal sediments from the East China Sea.These findings suggest that Bathyarchaeia,capable of O-demethylation via their novel and specific methyltransferases,are ubiquitous in coastal sediments.展开更多
基金supported financially by the Natural Science Foundation of China(Grants 42276139,42230401,42141003,41921006,92051116,91951209)2030 Project,Shanghai Jiao Tong University(Grant WH510244001)the National Postdoctoral Program for Innovative Talents(Grant No.BX20190204).
文摘Lignin degradation is a major process in the global carbon cycle across both terrestrial and marine ecosystems.Bathyarchaeia,which are among the most abundant microorganisms in marine sediment,have been proposed to mediate anaerobic lignin degradation.However,the mechanism of bathyarchaeial lignin degradation remains unclear.Here,we report an enrichment culture of Bathy-archaeia,named Candidatus Baizosediminiarchaeum ligniniphilus DL1YTT001(Ca.B.ligniniphilus),from coastal sediments that can grow with lignin as the sole organic carbon source under mesophilic anoxic conditions.Ca.B.ligniniphilus possesses and highly expresses novel methyltransferase 1(MT1,mtgB)for transferring methoxyl groups from lignin monomers to cob(I)alamin.MtgBs have no homology with known microbial methyltransferases and are present only in bathyarchaeial lineages.Heterologous expression of the mtgB gene confirmed O-demethylation activity.The mtgB genes were identified in metagenomic data sets from a wide range of coastal sediments,and they were highly expressed in coastal sediments from the East China Sea.These findings suggest that Bathyarchaeia,capable of O-demethylation via their novel and specific methyltransferases,are ubiquitous in coastal sediments.
