International Journal of Systematic and Evolutionary Microbiology
Published: October 16, 2014
C-DEBI Contribution Number: 315


Enrichment cultures inoculated with hydrothermally influenced nearshore sediment from Papua New Guinea led to the isolation of an arsenic-tolerant, acidophilic, facultatively aerobic bacterial strain designated PNG-April. Cells of this strain were Gram-stain-negative, rod-shaped, motile and did not form spores. Strain PNG-April grew at temperatures between 4 °C and 40 °C (optimum 30–37 °C), at pH 3.5 to 8.3 (optimum pH 5–6) and in the presence of up to 2.7 % NaCl (optimum 0–1.0 %). Both arsenate and arsenite were tolerated up to concentrations of at least 0.5 mM. Metabolism in strain PNG-April was strictly respiratory. Heterotrophic growth occurred with O or nitrate as electron acceptors, and aerobic lithoautotrophic growth was observed with thiosulfate or nitrite as electron donors. The novel isolate was capable of N-fixation. The respiratory quinones were Q-8 and Q-7. Phylogenetically, strain PNG-April belongs to the genus and shares the highest 16S rRNA gene sequence similarity with the type strains of (99.8 %), (98.8 %), (98.4 %) and (98.4 %). Differences from these related species in several physiological characteristics (lipid composition, carbohydrate utilization, enzyme profiles) and DNA–DNA hybridization suggested the isolate represents a novel species of the genus , for which we propose the name sp. nov. The type strain is PNG-April ( = DSM 28142 = LMG 28183).