Adaptive Reactions of Mycoplasmas In Vitro: “Viable but Unculturable Forms” and Nanocells of Acholeplasma laidlawii
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The adaptation of Acholeplasma laidlawii to conditions unfavorable for growth has been found to be accompanied by cell transformation into special morphological structures known as ultramicroforms (nanocells). The ratio of the cells of the two morphological types in the population depended on the growth conditions. Nanocells retained viability for a long time under conditions unfavorable for growth and showed resistance to stressors. Reduction in the cell size occurred due to unequal division, which involved the loss of cytoplasmic material. A. laidlawii ultramicroforms (nanocells) were able to restore proliferative activity and to revert to their initial vegetative form; they measured less than 0.2 µm and are the smallest cells known at present. Nanocells formed in vitro under exposure to abiogenic stressors may correspond to the A. laidlawii minibodies observed in infected plants upon exposure to biogenic stressors. The transformation of A. laidlawii cells into ultramicroforms was accompanied by condensation of the nucleoid, a change in the polypeptide spectrum, and a change in the availability of rRNA operons for in vitro amplification. All these changes are indicative of reorganization of the genetic and metabolic systems of mycoplasmas.
Key wordsmycoplasmas adaptation nanoforms viable but unculturable forms
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- 1.Borkhsenius, S.N., Cheronova, O.A., Chernov, V.M., and Vonskii, M.S., Mikoplasmy (Mycoplasmas), St. Petersburg: Nauka, 2002.Google Scholar
- 2.Litvin, V.Yu., Gintsburg, A.L., Pushkareva, V.I., Romanova, Yu.M., and Boev, B.V., Epidemiologicheskie aspekty ekologii bakterii (Epidemiological Aspects of Bacterial Ecology), Moscow, 1997.Google Scholar
- 5.Golovlev, E.L., An Alternative State of Asporogenous Bacteria, Mikrobiologiya, 1998, vol. 67, pp. 725–735.Google Scholar
- 6.Vainshtein, M.B. and Kudryashova, E.B., Nannobacteria, Mikrobiologiya, 2000, vol. 69, pp. 163–174.Google Scholar
- 7.Davies, K.E., Genome Analysis, Oxford: IRL Press, 1988.Google Scholar
- 8.Weisburg, W.G., Tully, J.G., Rose, D.L., Petzel, J.P., Oyaizu, H., Yang, D., Mandelco, L., Sechrest, J., Lawrence, T.G., van Etten, J.L., Maniloff, J., and Woese, C.R., A Phylogenetic Analysis of the Mycoplasmas: Basis for Their Classification, J. Bacteriol., 1989, vol. 171, pp. 6455–6467.PubMedGoogle Scholar
- 12.Shleeva, M.O., Bagramyan, K., Telkov, M.V., Mukamolova, G.V., Young, M., Kell, D.B., and Kaprelyants, A.S., Formation and Resuscitation of “Noncultivation” Cells of Rhodococcus rhodochrous and Mycobacterium tuberculosis in Prolonged Stationary Phase, Microbiology, 2002, vol. 148, pp. 1581–1591.PubMedGoogle Scholar
- 13.Chernov, V.M., Gogolev, Yu.V., Popova, N.V., and Chernova, O.A., Genetic Variability of Mycoplasmas (Acholeplasma laidlawii) during Their Interaction with Eukaryotes (Pisum sativum), Dokl. Akad. Nauk, 1999, vol. 369, pp. 275–277.Google Scholar
- 14.Serebrennikova, L.A., Soil as a Possible Habitat of Mycoplasmas, in Materialy yubil. nauchn. konf. (Proc. of a Jubilee Sci. Conf.), Moscow, 2003.Google Scholar
- 16.Zigangirova, N.A., Barkhatova, O.I., Rakovskaya, I.V., and Gintsburg, A.L., Effect of Environmental Factors on the Expression of the Mycoplasma pneumoniae Gene That Determines Synthesis of the Adhesion Protein R1, Zh. Mikrobiol., Epidemiol., Immunobiol., 2003, no. 4, pp. 17–22.Google Scholar
- 18.Tarchevskii, I.A. and Chernov, V.M., Molecular Aspects of Phytoimmunity, Mikol. Fitopatol., 2000, vol. 34, pp. 1–10.Google Scholar