Spore-forming Serratia marcescens subsp. sakuensis subsp. nov., isolated from a domestic wastewater treatment tank

1 Ecological and Toxicological Laboratory, Department of Bioscience and Biotechnology, Faculty of Agriculture, Shinshu University (United Graduate School of Agriculture, Gifu University), 8304 Minamiminowa, Kamiina, Nagano 399-4598, Japan 2 UltraStructure Research Laboratories Ltd, Tochiku, Yokohama 224-0007, Japan Correspondence Ryozo Iriye kn53278{at}gipmc.shinshu-u.ac.jp A strain (KRED T ) that formed endospores and produced the pigment prodigiosin was isolated from activated sludge. The presence of spores in cells of strain KRED T was evident upon electron microscopy examination, heat treatment and the detection of dipicolinic acid in the cells. Biochemical characteristics, and 16S rDNA sequence and DNA–DNA homology data identified strain KRED T as Serratia marcescens . The major respiratory quinone of strain KRED T was found to be ubiquinone Q-8. The formation of endospores by Gram-negative bacteria has not been observed previously, and has never been reported in any species of Serratia . Here, it is shown that strain KRED T (JCM 11315 T =CIP 107489 T ) represents a novel subspecies of S. marcescens , for which the name Serratia marcescens subsp. sakuensis is proposed. Abbreviations: DPA, dipicolinic acid (pyridine-26-dicarboxylic acid); t R , retention time Published online ahead of print on 18 October 2002 as DOI 10.1099/ijs.0.02158-0. The DDBJ accession number for the 16S rRNA gene sequence of Serratia marcescens subsp. sakuensis KRED T is AB061685. Present address: Fujiclean Engineering Company Ltd, Chigusa, Nagoya 464, Japan.