Not just a methane source: Amazonian floodplain sediments harbour a high diversity of methanotrophs with different metabolic capabilities

Author(s)

Gontijo, Julia B. ^[1] ; Paula, Fabiana S. ^{[2, 1]} ; Venturini, Andressa M. ^[1] ; Yoshiura, Caio A. ^[1] ; Borges, Clovis D. ^[1] ; Moura, Jose Mauro S. ^[3] ; Bohannan, Brendan J. M. ^[4] ; Nusslein, Klaus ^[5] ; Mazza Rodrigues, Jorge L. ^{[6, 7]} ; Tsai, Siu M. ^[1]

Affiliation

^[1] Univ Sao Paulo, Ctr Nucl Energy Agr, Cell & Mol Biol Lab, Piracicaba - Brazil

^[2] Univ Sao Paulo, Oceanog Inst, Dept Biol Oceanog, Sao Paulo - Brazil

^[3] Fed Univ Western Para, Ctr Interdisciplinary Format, Santarem - Brazil

^[4] Univ Oregon, Inst Ecol & Evolut, Dept Biol, Eugene, OR 97403 - USA

^[5] Univ Massachusetts, Dept Microbiol, Amherst, MA 01003 - USA

^[6] Univ Calif Davis, Dept Land Air & Water Resources, Davis, CA 95616 - USA

^[7] Lawrence Berkeley Natl Lab, Environm Genom & Syst Biol Div, Berkeley, CA - USA

• Document type: Journal article
• Source: Molecular Ecology; v. 30, n. 11, p. 2560-2572, JUN 2021.
• Web of Science Citations: 1

Abstract

The Amazonian floodplain forests are dynamic ecosystems of great importance for the regional hydrological and biogeochemical cycles and function as a significant CH4 source contributing to the global carbon balance. Unique geochemical factors may drive the microbial community composition and, consequently, affect CH4 emissions across floodplain areas. Here, we report the in situ composition of CH4 cycling microbial communities in Amazonian floodplain sediments. We considered how abiotic factors may affect the microbial community composition and, more specifically, CH4 cycling groups. We collected sediment samples during wet and dry seasons from three different types of floodplain forests, along with upland forest soil samples, from the Eastern Amazon, Brazil. We used high-resolution sequencing of archaeal and bacterial 16S rRNA genes combined with real-time PCR to quantify Archaea and Bacteria, as well as key functional genes indicative of the presence of methanogenic (mcrA) and methanotrophic (pmoA) microorganisms. Methanogens were found to be present in high abundance in floodplain sediments, and they seem to resist the dramatic environmental changes between flooded and nonflooded conditions. Methanotrophs known to use different pathways to oxidise CH4 were detected, including anaerobic archaeal and bacterial taxa, indicating that a wide metabolic diversity may be harboured in this highly variable environment. The floodplain environmental variability, which is affected by the river origin, drives not only the sediment chemistry but also the composition of the microbial communities. These environmental changes seem also to affect the pools of methanotrophs occupying distinct niches. Understanding these shifts in the methanotrophic communities could improve our comprehension of the CH4 emissions in the region. (AU)

• FAPESP's process: 14/50320-4 - Dimensions US-BIOTA - São Paulo: collaborative research: integrating dimensions of microbial biodiversity across land use change in tropical forests
• Grantee: Tsai Siu Mui
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants
• FAPESP's process: 17/26138-0 - Taxonomic and functional evaluations of microbial community involved in methane cycling of Brazilian Amazon soils
• Grantee: Fabiana da Silva Paula
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 18/14974-0 - Dynamics of methane and sulfur microbial communities in Amazonian soils
• Grantee: Júlia Brandão Gontijo
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 17/09643-2 - Soil microbial communities in forest-to-pasture conversion: a multi-omics approach
• Grantee: Andressa Monteiro Venturini
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 15/13546-7 - Microbial community resilience capacity assessed by metagenomics and metatranscriptomics in Amazon forest and pasture soils
• Grantee: Andressa Monteiro Venturini
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 19/25931-3 - Taxonomic and functional depiction of the microbial community involved in methane transformations in soils of the Brazilian Amazonia
• Grantee: Andressa Monteiro Venturini
• Support Opportunities: Scholarships in Brazil - Post-Doctoral