03123naa a2200373 a 450000100080000000500110000800800410001902400430006010000160010324501630011926000090028252019710029165000220226265000120228465000290229665000100232565300330233565300200236865300200238865300260240865300260243470000200246070000160248070000240249670000200252070000240254070000250256470000160258970000160260570000180262170000230263970000190266277300680268121441302022-06-20       2022    bl uuuu     u00u1 u    #d7 ahttps://doi.org/10.1111/lam.136382DOI1 aETTO, R. M.  aInfluence of environmental factors on the tropical peatlands diazotrophic communities from the Southern Brazilian Atlantic Rain Forest.h[electronic resource]  c2022  aThe tropical peatlands of southern Brazil are essential for the maintenance ofthe Atlantic Rain Forest, one of the 25 hotspots of biodiversity in the world.Although diazotrophic micro-organisms are essential for the maintenance ofthis nitrogen limited ecosystem, so far studies have focused only on micro-organisms involved in the carbon cycle. In this work, peat samples werecollected from three tropical peatland regions during dry and rainy seasonsand their chemical and microbial characteristics were evaluated. Our resultsshowed that the structure of the diazotrophic communities in the Braziliantropical peatlands differs in the evaluated seasons. The abundance of the genusBradyrhizobiumshowed to be affected by rainfall and peat pH. Despite theshifts of the nitrogen-fixing population in the tropical peatland caused byseasonality it showed to be constantly dominated bya-Proteobacteria followedbyCyanobacteria. In addition, more than 50% ofnifHgene sequences have notbeen classified, indicating the necessity for more studies in tropical peatland,since the reduction of N supply in the peatlands stimulates the recalcitrantorganic  matter  decomposition  performed  by  peatland  micro-organisms,influencing the C stock.  This manuscript reports the first ecological study of tropical peat-lands diazotrophic communities from the Brazilian Atlantic Rain Forest, one of the world?s largestbiodiversity hotspots. Based on culturing and culture-independent approaches, our results showed alter-ations in the structure of the diazotrophic communities in different seasons. The genusBradyrhizobiumabundance was affected by rainfall and peat pH. In addition, the great number of unclassifiednitrogen-fixing bacteria indicated the need for additional studies to guide future mitigation actions,since the reduction of N supply in the peatlands stimulates the recalcitrant organic matter decomposi-tion performed by peatland micro-organisms, influencing the C stock.  aMicrobial ecology  aCarbono  aFixação de Nitrogênio  aTurfa  aBiological nitrogen fixation  aCommunity level  aMata Atlântica  aOmbrotrophic peatland  aSubstrate utilization1 aJESUS, E. da C.1 aCRUZ, L. M.1 aSCHNEIDER, B. S. F.1 aTOMACHEWSKI, D.1 aURREA-VALENCIA , S.1 aGONÇALVES, D. R. P.1 aGALVÃO, F.1 aAYUB, R. A.1 aCURCIO, G. R.1 aSTEFFENS, M. B. R.1 aGALVÃO, C. W.  tLetters in Applied Microbiologygv. 74, n. 4, p. 543-554, 2022.