title: [Ultrastructure of resting cells of some non-spore-forming bacteria].
abstract: Using electron microscopy (ultrathin sections and freeze-fractures), we investigated the ultrastructure of the resting cells formed in the cultures of Micrococcus luteus, Arthrobacter globiformis, and Pseudomonas aurantiaca under conditions of prolonged incubation (up to 9 months). These resting cells included cyst-like forms that were characterized by complex cell structure and the following ultrastructural properties: (i) a thickened or multiprofiled cell wall (CW), typically made up of a layer of the preexisting CW and one to three de novo synthesized murein layers; (ii) a thick, structurally differentiated capsule; (iii) presence of large intramembrane particles (d = 180-270 A), occurring both on the PF and EF sides of the membrane fractures of M. luteus and A. globiformis; (iv) a peculiar structure of the cytoplasm, which was either fine-grained or lumpy (coarse-grained) in different parts of the cell population; and (v) a condensed nucleoid. Intense formation of cyst-like cells occurred in aged (2- to 9-month-old) bacterial cultures grown on diluted complex media or on nitrogen-, carbon-, and phosphorus-limited synthetic media, as well as in suspensions of cells incubated in media with sodium silicate. The general morphological properties, ultrastructural organization, and physiological features of cyst-like cells formed during the developmental cycle suggest that constitutive dormancy is characteristic of non-spore-forming bacteria.
authors.forename: N E
authors.initials: NE
authors.lastname: Suzina
authors.forename: A L
authors.initials: AL
authors.lastname: Muliukin
authors.forename: A N
authors.initials: AN
authors.lastname: Kozlova
authors.forename: A P
authors.initials: AP
authors.lastname: Shorokhova
authors.forename: V V
authors.initials: VV
authors.lastname: Dmitriev
authors.forename: E S
authors.initials: ES
authors.lastname: Barinova
authors.forename: O N
authors.initials: ON
authors.lastname: Mokhova
authors.forename: G I
authors.initials: GI
authors.lastname: El'-Registan
authors.forename: V I
authors.initials: VI
authors.lastname: Duda
mesh_terms: D001173:Arthrobacter / Q000254:growth & development / Q000648:ultrastructure*; D002244:Carbon; D002473:Cell Wall / Q000648:ultrastructure; D020285:Cryoelectron Microscopy; D003470:Culture Media; D016982:Micrococcus luteus / Q000254:growth & development / Q000648:ultrastructure*; D009584:Nitrogen; D010457:Peptidoglycan / Q000648:ultrastructure; D011549:Pseudomonas / Q000648:ultrastructure*; D017640:Silicates
chemical_list: D003470:Culture Media; D010457:Peptidoglycan; D017640:Silicates; D002244:Carbon; C005691:sodium silicate; D009584:Nitrogen