Empedobacter stercoris sp. nov., isolated from an input sample of a biogas plant

Abstract

Two Gram-stain-negative, rod-shaped bacteria, strains 990B6_12ER2AT and 994B6_12ER2A, were isolated during microbiological analysis of a mixed manure sample which was used as input material for a German biogas plant. Phylogenetic identification based on nearly full-length 16S rRNA gene sequences placed the isolates into the family Flavobacteriaceae within the phylum Bacteroidetes. Strains 990B6_12ER2AT and 994B6_12ER2A shared identical 16S rRNA gene sequences and showed highest 16S rRNA gene sequence similarity to the type strains of Empedobacter falsenii (97.3 %) and Empedobacter brevis (96.8 %). The major cellular fatty acids of strains 990B6_12ER2AT and 994B6_12ER2A were iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and iso-C17 : 0 3-OH. The polyamine pattern contained predominantly sym-homospermidine and the quinone system was menaquinone MK-6. Major polar lipids were phosphatidylethanolamine, one unidentified aminolipid and one unidentified polar lipid not containing an amino residue, a phosphate residue or a sugar moiety. In addition, moderate to minor amounts of several unidentified lipids were detected. The DNA G+C content was 31.7 and 29.0 mol%, for strains 990B6_12ER2AT and 994B6_12ER2A, respectively. On the basis of phylogenetic, chemotaxonomic and physiological analysis we propose a novel species of the genus Empedobacter, Empedobacter stercoris sp. nov. (type strain 990B6_12ER2AT = CIP 110833T = LMG 28501T).