title: A unique intracellular compartment formed during the oligotrophic growth of Rhodococcus erythropolis N9T-4.
abstract: Rhodococcus erythropolis N9T-4, isolated from stored crude oil, shows extremely oligotrophic features and can grow on a basal medium without any additional carbon, nitrogen, sulfur, and energy sources, but requires CO2for its oligotrophic growth. Transmission electron microscopic observation showed that a relatively large and spherical compartment was observed in a N9T-4 cell grown under oligotrophic conditions. In most cases, only one compartment was observed per cell, but in some cases, it was localized at each pole of the cell, suggesting that it divides at cell division. We termed this unique bacterial compartment an oligobody. The oligobody was not observed or very rarely observed in small sizes under nutrient rich conditions, whereas additional carbon sources did not affect oligobody formation. Energy dispersive X-ray spectroscopy analysis revealed remarkable peaks corresponding to phosphorus and potassium in the oligobody. The oligobodies in N9T-4 cells could be stained by Toluidine blue, suggesting that the oligobody is composed of inorganic polyphosphate and is a type of acidocalcisome. Two genes-encoding polyphosphate kinases, ppk1 and ppk2, were found in the N9T-4 genome: ppk1 disruption caused a negative effect on the formation of the oligobody. Although it was suggested that the oligobody plays an important role for the oligotrophic growth, both ppk-deleted mutants showed the same level of oligotrophic growth as the wild-type strain.
authors.affiliation: Department of Engineering, Graduate School of Integrated Science and Technology, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, 432-8561, Japan. yoshida.nobuyuki@shizuoka.ac.jp.|Department of Applied Chemistry and Biochemical Engineering, Faculty of Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, 432-8561, Japan. yoshida.nobuyuki@shizuoka.ac.jp.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Yoshida
authors.affiliation: Department of Engineering, Graduate School of Integrated Science and Technology, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, 432-8561, Japan.|The Institute of Enology and Viticulture, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1-13-1 Kitashin, Kofu, Yamanashi, 400-0005, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Yano
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Kedo
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Fujiyoshi
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan.
authors.forename: Rina
authors.initials: R
authors.lastname: Nagai
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan.|Department of Biotechnology, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, 2-1, Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Megumi
authors.initials: M
authors.lastname: Iwano
authors.affiliation: Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, 7-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Taguchi
authors.affiliation: Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, 7-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Nishida
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takagi
mesh_terms: D003470:Culture Media / Q000737:chemistry*; D003593:Cytoplasm / Q000737:chemistry / Q000648:ultrastructure*; D017353:Gene Deletion; D046529:Microscopy, Electron, Transmission; D010758:Phosphorus / Q000032:analysis; D017856:Phosphotransferases (Phosphate Group Acceptor) / Q000235:genetics / Q000378:metabolism; D011188:Potassium / Q000032:analysis; D012240:Rhodococcus / Q000737:chemistry / Q000254:growth & development* / Q000378:metabolism / Q000648:ultrastructure*; D013052:Spectrometry, X-Ray Emission; D013194:Staining and Labeling
chemical_list: D003470:Culture Media; D010758:Phosphorus; D017856:Phosphotransferases (Phosphate Group Acceptor); C022424:polyphosphate kinase; D011188:Potassium
keywords: Bacterial compartment; Inorganic polyphosphate; Oligobody; Oligotroph; Rhodococcus erythropolis N9T-4