Fingerprints of partial oxidation of biogenic magnetite from cultivated and natural marine magnetotactic bacteria using synchrotron radiation

Autor(es)

Rodelli, D. ^[1] ; Jovane, L. ^[1] ; Roberts, A. P. ^[2] ; Cypriano, J. ^[3] ; Abreu, F. ^[3] ; Lins, U. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Oceanog, BR-05508120 Sao Paulo - Brazil

^[2] Australian Natl Univ, Res Sch Earth Sci, Canberra, ACT 2601 - Australia

^[3] Unv Fed Rio de Janeiro, Inst Microbiol Paulo de Goes, BR-21941902 Rio De Janeiro - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ENVIRONMENTAL MICROBIOLOGY REPORTS; v. 10, n. 3, p. 337-343, JUN 2018.
• Citações Web of Science: 4

Resumo

Magnetotactic bacteria are a multi-phyletic group of bacteria that synthesize membrane-bound magnetic minerals. Understanding the preservation of these minerals in various environments (e.g., with varying oxygen concentrations and iron supply) is important for understanding their role as carriers of primary magnetizations in sediments and sedimentary rocks. Here we present X-ray near edge structure (XANES) spectra for Fe in magnetotactic bacteria samples from recent sediments to assess surface oxidation and crystal structure changes in bacterial magnetite during early burial. Our results are compared with a XANES spectrum of cultivated Magnetofaba australis samples, and with magnetic properties, and indicate that oxidation of magnetite to maghemite increases with depth in the sediment due to longer exposure tomolecular oxygen. These results are relevant tounderstanding magnetic signatures carried by magnetofossils in oxic sediments and sedimentary rocks of different ages. (AU)

• Processo FAPESP: 11/22018-3 - Avaliação da produtividade primária marinha através do estudo das bactérias magnetotáticas em sedimentos
• Beneficiário: Luigi Jovane
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Jovens Pesquisadores
• Processo FAPESP: 12/21212-3 - Paleoclimatologia e paleoceanografia entre o Eoceno médio -Oligoceno usando o paleomagnetismo
• Beneficiário: Daniel Rodelli
• Modalidade de apoio: Bolsas no Brasil - Doutorado