Desulfuromonas palmitatis sp. nov., a marine dissimilatory Fe(III) reducer that can oxidize long-chain fatty acids

Abstract

Studies on the microorganisms living in hydrocarbon-contaminated sediments in San Diego Bay, California led to the isolation of a novel Fe(III)-reducing microorganism. This organism, designated strain SDBY1, was an obligately anaerobic, non-motile, non-flagellated, gram-negative rod. Strain SDBY1 conserves energy to support growth from the oxidation of acetate, lactate, succinate, fumarate, laurate, palmitate, or stearate. H2 was also oxidized with the reduction of Fe(III), but growth with H2 as the sole electron donor was not observed. In addition to various forms of soluble and insoluble Fe(III), strain SDBY1 also coupled growth to the reduction of fumarate, Mn(IV), or S0. Air-oxidized minus dithionite-reduced difference spectra exhibited peaks at 552.8, 523.6, and 422.8 nm, indicative of c-type cytochrome(s). Strain SDBY1 shares physiological characteristics with organisms in the genera Geobacter, Pelobacter, and Desulfuromonas. Detailed analysis of the 16S rRNA sequence indicated that strain SDBY1 should be placed in the genus Desulfuromonas. The new species name Desulfuromonas palmitatis is proposed. D. palmitatis is only the second marine organism found (after D. acetoxidans) to oxidize multicarbon organic compounds completely to carbon dioxide with Fe(III) as an electron acceptor and provides the first pure culture model for the oxidation of long-chain fatty acids coupled to Fe(III) reduction.

Genome-scale analysis of anaerobic benzoate and phenol metabolism in the hyperthermophilic archaeon Ferroglobus placidus

“…placidus medium was prepared as previously described . After autoclaving, FeCl 2 (1.3 mM), Na 2 SeO 4 (30 mg l -1 ), Na 2 WO 4 (40 mg l -1 ), APM salts (1 g l -1 MgCl 2 , 0.23 g l -1 CaCl 2 ) (Coates et al, 1995), DL vitamins (Lovley and Phillips, 1988) and all electron donors were added to the sterilized medium from anaerobic stock solutions. Cultures were incubated under N 2 :CO 2 (80:20) at 851 C in the dark.…”

Manganese: A New Emerging Contaminant in the Environment

“…Three well-studied and phylogenetically distinct manganese-oxidizing bacteria have been described: i) theProteobacterium Leptothrix discophora, isolated from a swamp; ii) the -Proteobacterium Pseudomonas putida, which is a ubiquitous freshwater and soil bacterium; iii) the Bacillus sp spores, isolated from a near-shore manganese sediment (De Schamphelaire et al, 2007). A number of related metal-reducing micro-organisms have been identified and classified as the Geobacteraceae (Caccavo et al, 1994;Coates et al, 1995Coates et al, , 2001Holmes et al, 2004;Vandieken et al, 2006). The biochemical pathways involved in Mn 2+ oxidation have not yet been completely elucidated.…”

Desulfuromonas svalbardensis sp. nov. and Desulfuromusa ferrireducens sp. nov., psychrophilic, Fe(III)-reducing bacteria isolated from Arctic sediments, Svalbard

“…Species of Desulfuromusa, Malonomonas rubra, strain 102 T and Geopsychrobacter electrodiphilus share the Reference species: 1, Desulfuromonas acetoxidans; 2, Desulfuromonas acetexigens; 3, Desulfuromonas thiophila; 4, Desulfuromonas chloroethenica; 5, Desulfuromonas palmitatis; 6, 'Desulfuromonas michiganensis'. Data for reference species were taken from Pfennig & Biebl (1976, 1997, Coates et al (1995), Krumholz (1997) and Sung et al (2003). ND, Not determined; +, substrate used for growth; 2, substrate not used for growth; (+), substrate reduced but no growth observed.…”