Isolation and characterization of Lignin-derived monomer degraders under acidic conditions from tropical peatland

[摘要] Tropical peatlands account for one of the largestcarbon stores in the form of organic matter due tothe accumulation of plant litter and waterloggedconditions. Recent anthropogenic disturbances,such as forest fires, agricultural conversion anddrainage, in tropical peatlands have caused a vastamount of carbon to be released into the atmosphere, and microbial activities are impacted bythese changes. A recent study showed that manyphenol- and lignin-degrading bacteria prefer alkaline and neutral pH conditions, while tropical peatland conditions are acidic, possibly changing themechanisms of the utilization of organic matter frompeat soil. The purpose of this study was to isolateand characterize phenolic compound-degradingbacteria from tropical peatlands under acidic conditions due to the lack of information on how thebiological processes of microorganisms occur in thisunique habitat. Two isolates show the capability toutilize phenolic aldehydes based on building blocksof lignin that are abundant in tropical peatlands,including hydroxyphenyl, guaiacyl and syringylunits. The identification of these isolates by 16SrDNA shows that strain S38 is similar toStenotrophomonas sp., while strain S46 is similar toBurkholderia sp. Further characterization of theseisolates shows their ability to degrade4-hydroxybenzaldehyde and vanillin into phenolicacids within 24 hours of incubation and syringaldehyde within 7 days of incubation. In conclusion,these isolated bacteria show the ability to withstandthe acidic environment of tropical peatlands andutilize lignin monomers through unknown metabolicpathways.

[学科分类] 微生物学和免疫学

[关键词] Burkholderia;Lignin-derived monomer;low pH;Stenotrophomonas;tropical peatlands