The Effect Of Chemotaxis On The Swarming Ability Of Bacillus Subtilis: Critical Effect Of Glutamic Acid And Lysine
Lina Hamouche, Soumaya Laalami, Ghayas Lakkis, Ahmad Kobaissi, Ali Chokr, Harald Putzer, Kassem Hamze
Index Terms: Bacillus subtilis, swarming, chemotaxis, single cell expression, flagellin, glutamic acid, lysine.
Abstract: Bacterial cells differentiation constitutes an appropriate and efficient way to respond to an ever-changing environment. Bacillus subtilis are no different, where in some conditions planktonic cells differentiate into highly motile swarmer cells. The hyperflagellated swarmer cells, located usually at the colony edge, move in a cooperative manner in order to reconnoiter new sites for colonization, this movement is called “swarming”. The chemotaxis proteins take a part of several factors playing an essential role in swarmer differentiation, hence migration therefore we assumed a connection between chemotaxis and swarming profile of B. subtilis. To this end, we examined the effect of amino acids (chemoattractants), glutamic acid and lysine, deprivation on the capability of swarming. Here we show that deprivation of synthetic B-media from glutamic acid result on attenuated defective and random swarming pattern; deprivation of lysine lead to an almost normal swarming pattern, meanwhile double deprivation of both amino acids result in important reduction of swarming capability. Moreover, we developed a method to screen the chemotaxis clearly using swarm plates with concentration gradient. Using this approach, we found that B. subtilis manage to swarm completely toward glutamic acid and didn’t swarm toward medium lacking this amino acid; meanwhile the bacteria manage to swarm in all sides of plates with concentration gradient of lysine. Furthermore, our results indicate that these two chemoattractants can reduce the motility by modulating the expression of hag gene. The absence of glutamic acid and lysine decrease the expression of hag during swarming, respectively for 36% and 15%.
 J. Adler, “Chemotaxis in bacteria,” Science Vol. 153, pp. 708-716, 1966.
 S.I. Aizawa, I.B. Zhulin, L. Márquez-Magana and G.W. Ordal, “Chemotaxis and motility”, p. 437-452. In A.L. Sonenshein, J. A. Hoch, and R. Losick (ed.), Bacillus subtilis and its closest relatives: from genes to cells. ASM Press, Washington, D.C, 2002.
 H. Antelmann, S. Engelmann, R. Schmid, A. Sorokin, A. Lapidus and M. Hecker, ” Expression of a stress- and starvation-induced dps/pexB-homologous gene is controlled by the alternative sigma factor sigmaB in Bacillus subtilis,” J. Bacteriol. Vol. 179, pp. 7251–7256, 1997.
 M. Burkart, A. Toguchi and R.M. Harshey, “The chemotaxis system, but not chemotaxis, is essential for swarming motility in Escherichia coli,” Proc. Natl. Acad. Sci. Vol. 95, pp. 2568–2573, 1998.
 N.C. Darnton, L. Turner, S. Rojevsky and H.C. Berg, “Dynamics of bacterial swarming” Biophys J. Vol. 98, pp. 2082–2090, 2010.
 D. Debois, K. Hamze, V. Guérineau, J.P. Le Caër, I.B. Holland, P. Lopes, J. Ouazzani, S.J. Séror, A. Brunelle and O. Laprévote, “In situ localisation and quantification of surfactins in a Bacillus subtilis swarming community by imaging mass spectrometry,” Proteomics. Vol. 8, pp. 3682–3691, 2008.
 J.J. Falke and G.L. Hazelbauer, “Transmembrane signaling in bacterial chemoreceptors,” Trends Biochem. Sci. Vol. 26, pp. 257–265, 2001.
 G.M. Fraser and C. Hughes, “Swarming motility,” Curr. Opin. Microbiol. Vol. 2, pp. 630-635, 1999.
 K. Fredrick and J.D. Helmann, “FlgM is a primary regulator of sigma D activity, and its absence restores motility to a sinR mutant,” J. Bacteriol. Vol. 178, pp. 7010–7013, 1996.
 L.F. Garrity and G.W. Ordal, “Activation of the CheA kinase by asparagine in Bacillus subtilis chemotaxis,” Microbiology. Vol. 143, pp. 2945– 2951, 1997.
 G.D. Glekas, J.R. Cates, T.M. Cohen, C.V. Rao CV and G.W. Ordal, “Site-specific methylation in Bacillus subtilis chemotaxis: effect of covalent modifications to the chemotaxis receptor McpB,” Microbiology, Vol. 157, pp. 56-65, 2011.
 K. Hamze, D. Julkowska, S. Autret, K. Hinc, K. Nagorska, A. Sekowska, I.B. Holland and S.J. Séror, “Identification of genes required for different stages of dendritic swarming in Bacillus subtilis, with a novel role for phrC,” Microbiology, Vol. 155, pp. 398–412, 2009.
 K. Hamze, S. Autret, K. Hinc, S. Laalami, D. Julkowska, R. Briandet, M. Renault, C. Absalon, I.B. Holland, H. Putzer and S.J. Séror, “Single-cell analysis in situ in a Bacillus subtilis swarming community identifies distinct spatially separated subpopulations differentially expressing hag (flagellin), including specialized swarmers,” Microbiology, Vol. 157, pp. 2456–2469, 2011.
 D.W. Hanlon and G.W. Ordal, “Cloning and characterization of genes encoding methyl-accepting chemotaxis proteins in Bacillus subtilis,” J. Biol. Chem. Vol. 269, pp. 14038–14046, 1994.
 R.M. Harshey, “Bacterial motility on a surface: many ways to a common goal,” Annu. Rev. Microbiology. Vol. 57, pp. 249–273, 2003.
 D. Julkowska, M. Obuchowski, I.B. Holland and S.J. Séror, “Branched swarming patterns on a synthetic medium formed by wild-type Bacillus subtilis strain 3610: detection of different cellular morphologies and constellations of cells as the complex architecture develops,” Microbiology, Vol. 150, pp. 1839-1849, 2004.
 D. Julkowska, M. Obuchowski, I.B. Holland and S.J. Séror, “Comparative Analysis of the Development of Swarming Communities of Bacillus subtilis 168 and a Natural Wild Type,” J. Bacteriol. Vol. 187, pp. 65-76, 2005.
 W.U. Kang, H.E. Walukiewicz, G.D. Glekas, G.W. Ordal and C.V. Rao, “Attractant Binding Induces Distinct Structural Changes to the Polar and Lateral Signaling Clusters in Bacillus subtilis Chemotaxis,” J. Biol. Chem. Vol. 286, pp. 2587-2595, 2010.
 D.B. Kearns and R. Losick, “Swarming motility in undomesticated Bacillus subtilis,” Mol. Microbiol. Vol. 49, pp. 581–590, 2003.
 D.B. Kearns, F.R. Chu and R. Losick, “Genes governing swarming in Bacillus subtilis and evidence for a phase variation mechanism controlling surface motility,” Mol. Microbiol. Vol. 52, pp. 357–369, 2004.
 J.R. Kirby, M.M. Saulmon, C.J. Kristich and G.W. Ordal, “CheY dependent methylation of the asparagine receptor, McpB, during chemotaxis in Bacillus subtilis,” J. Biol. Chem. Vol. 274, pp. 11092-11100, 1999.
 C.J. Kristich, G.D. Glekas and G.W. Ordal, “The conserved cytoplasmic module of the transmembrane chemoreceptor McpC mediates carbohydrate chemotaxis in Bacillus subtilis,” Mol. Microbiol. Vol. 47, pp. 1353-1366, 2003.
 S. Mariconda, Q. Wang and R.M. Harshey, “A mechanical role for the chemotaxis system in swarming motility,” Mol. Microbiol. Vol. 60, pp. 1590–1602, 2006.
 J. Müller, S. Schiel, G.W. Ordal and H.H. Saxild, “Functional and genetic characterization of rncpC, which encodes a third methyl-accepting chemotaxis protein in Bacillus subtilis,” Microbiobgy, Vol. 143, pp. 3231-3240, 1997.
 F. Peypoux, J.M. Bonmatin and J. Wallach, “Recent trends in the biochemistry of surfactin,” Appl. Microbiol. Biotechnol. Vol. 51, pp. 553–563, 1999.
 C.V. Rao, G.D. Glekas and G.W. Ordal, “The three adaptation systems of Bacillus subtilis chemotaxis,” Trends Microbiol. Vol. 16, pp. 480-487, 2008.
 A.L. Sonenshein, “Krebs citric acid cycle,” pp. 151–162 In A.L. Sonenshein, J.A. Hoch and R. Losick, editors. (ed.), Bacillus subtilis and its closest relatives: from genes to cells. ASM Press, Washington, DC, 2002.
 M.A. Zimmer, J. Tiu, M.A. Collins and G.W. Ordal, “Selective Methylation Changes on the Bacillus subtilis Chemotaxis Receptor McpB Promote Adaptation,” J. Biol. Chem. Vol. 275, pp. 24264–24272, 2000.