Theresa Winter

Publications (4)17.47 Total impact

• Article: Characterization of the global impact of low temperature gas plasma on vegetative microorganisms.

  Theresa Winter, Jörn Winter, Martin Polak, Kathrin Kusch, Ulrike Mäder, Rabea Sietmann, Jörg Ehlbeck, Sacha van Hijum, Klaus-Dieter Weltmann, Michael Hecker, Harald Kusch
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  ABSTRACT: Plasma medicine and also decontamination of bacteria with physical plasmas is a promising new field of life science with huge interest especially for medical applications. Despite numerous successful applications of low temperature gas plasmas in medicine and decontamination, the fundamental nature of the interactions between plasma and microorganisms is to a large extent unknown. A detailed knowledge of these interactions is essential for the development of new as well as for the enhancement of established plasma-treatment procedures. In the present work we introduce for the first time a growth chamber system suitable for low temperature gas plasma treatment of bacteria in liquid medium. We have coupled the use of this apparatus to a combined proteomic and transcriptomic analyses to investigate the specific stress response of Bacillus subtilis 168 cells to treatment with argon plasma. The treatment with three different discharge voltages revealed not only effects on growth, but also clear evidence of cellular stress responses. B. subtilis suffered severe cell wall stress, which was made visible also by electron microscopy, DNA damages and oxidative stress as a result of exposure to plasma. These biological findings were supported by the detection of reactive plasma species by OES measurements.
  Proteomics 09/2011; 11(17):3518-30. · 4.43 Impact Factor
• Source

  Available from: Rene van der Ploeg

  Article: Environmental salinity determines the specificity and need for Tat-dependent secretion of the YwbN protein in Bacillus subtilis.

  René van der Ploeg, Ulrike Mäder, Georg Homuth, Marc Schaffer, Emma L Denham, Carmine G Monteferrante, Marcus Miethke, Mohamed A Marahiel, Colin R Harwood, Theresa Winter, Michael Hecker, Haike Antelmann, Jan Maarten van Dijl
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  ABSTRACT: Twin-arginine protein translocation (Tat) pathways are required for transport of folded proteins across bacterial, archaeal and chloroplast membranes. Recent studies indicate that Tat has evolved into a mainstream pathway for protein secretion in certain halophilic archaea, which thrive in highly saline environments. Here, we investigated the effects of environmental salinity on Tat-dependent protein secretion by the Gram-positive soil bacterium Bacillus subtilis, which encounters widely differing salt concentrations in its natural habitats. The results show that environmental salinity determines the specificity and need for Tat-dependent secretion of the Dyp-type peroxidase YwbN in B. subtilis. Under high salinity growth conditions, at least three Tat translocase subunits, namely TatAd, TatAy and TatCy, are involved in the secretion of YwbN. Yet, a significant level of Tat-independent YwbN secretion is also observed under these conditions. When B. subtilis is grown in medium with 1% NaCl or without NaCl, the secretion of YwbN depends strictly on the previously described "minimal Tat translocase" consisting of the TatAy and TatCy subunits. Notably, in medium without NaCl, both tatAyCy and ywbN mutants display significantly reduced exponential growth rates and severe cell lysis. This is due to a critical role of secreted YwbN in the acquisition of iron under these conditions. Taken together, our findings show that environmental conditions, such as salinity, can determine the specificity and need for the secretion of a bacterial Tat substrate.
  PLoS ONE 01/2011; 6(3):e18140. · 4.09 Impact Factor
• Source

  Available from: Haike Antelmann

  Article: Synthetic effects of secG and secY2 mutations on exoproteome biogenesis in Staphylococcus aureus.

  Mark J J B Sibbald, Theresa Winter, Magdalena M van der Kooi-Pol, G Buist, E Tsompanidou, Tjibbe Bosma, Tina Schäfer, Knut Ohlsen, Michael Hecker, Haike Antelmann, Susanne Engelmann, Jan Maarten van Dijl
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  ABSTRACT: The gram-positive pathogen Staphylococcus aureus secretes various proteins into its extracellular milieu. Bioinformatics analyses have indicated that most of these proteins are directed to the canonical Sec pathway, which consists of the translocation motor SecA and a membrane-embedded channel composed of the SecY, SecE, and SecG proteins. In addition, S. aureus contains an accessory Sec2 pathway involving the SecA2 and SecY2 proteins. Here, we have addressed the roles of the nonessential channel components SecG and SecY2 in the biogenesis of the extracellular proteome of S. aureus. The results show that SecG is of major importance for protein secretion by S. aureus. Specifically, the extracellular accumulation of nine abundant exoproteins and seven cell wall-bound proteins was significantly affected in an secG mutant. No secretion defects were detected for strains with a secY2 single mutation. However, deletion of secY2 exacerbated the secretion defects of secG mutants, affecting the extracellular accumulation of one additional exoprotein and one cell wall protein. Furthermore, an secG secY2 double mutant displayed a synthetic growth defect. This might relate to a slightly elevated expression of sraP, encoding the only known substrate for the Sec2 pathway, in cells lacking SecG. Additionally, the results suggest that SecY2 can interact with the Sec1 channel, which would be consistent with the presence of a single set of secE and secG genes in S. aureus.
  Journal of bacteriology 07/2010; 192(14):3788-800. · 3.94 Impact Factor
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  Available from: Haike Antelmann

  Article: Thiol-disulphide oxidoreductase modules in the low-GC Gram-positive bacteria.

  Thijs R H M Kouwen, Annemieke van der Goot, Ronald Dorenbos, Theresa Winter, Haike Antelmann, Marie-Claire Plaisier, Wim J Quax, January Maarten van Dijl, Jean-Yves F Dubois
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  ABSTRACT: Disulphide bond formation catalysed by thiol-disulphide oxidoreductases (TDORs) is a universally conserved mechanism for stabilizing extracytoplasmic proteins. In Escherichia coli, disulphide bond formation requires a concerted action of distinct TDORs in thiol oxidation and subsequent quinone reduction. TDOR function in other bacteria has remained largely unexplored. Here we focus on TDORs of low-GC Gram-positive bacteria, in particular DsbA of Staphylococcus aureus and BdbA-D of Bacillus subtilis. Phylogenetic analyses reveal that the homologues DsbA and BdbD cluster in distinct groups typical for Staphylococcus and Bacillus species respectively. To compare the function of these TDORs, DsbA was produced in various bdb mutants of B. subtilis. Next, we assessed the ability of DsbA to sustain different TDOR-dependent processes, including heterologous secretion of E. coli PhoA, competence development and bacteriocin (sublancin 168) production. The results show that DsbA can function in all three processes. While BdbD needs a quinone oxidoreductase for activity, DsbA activity appears to depend on redox-active medium components. Unexpectedly, both quinone oxidoreductases of B. subtilis are sufficient to sustain production of sublancin. Moreover, DsbA can functionally replace these quinone oxidoreductases in sublancin production. Taken together, our unprecedented findings imply that TDOR systems of low-GC Gram-positive bacteria have a modular composition.
  Molecular Microbiology 06/2007; 64(4):984-99. · 5.01 Impact Factor