Crystalline-gel-molten phase transitions of water in calcium dipicolinate (Ca-DPA)

POSTER

Abstract

The heat resistance of bacterial spores directly correlates to the protoplast dehydration and presence of dipicolinic acid (DPA) and its associated metal salts at the core. Bacteria's structural integrity in moist heat conferred by high concentration of DPA and calcium DPA salts depends on the properties are additional water molecules and temperature. In our reactive MD simulations, we characterize different possible phases and the transport properties of water molecules. We observed solid-gel and gel-liquid phase transitions of the hydrated Ca-DPA system. These simulations reveal monotonically decreasing solid-gel-liquid transition temperatures with increasing cell hydration, reflecting the experimental trend of moist-heat resistance of bacterial spores. We also observed that the calcification of bacterial spores further increases the transition temperatures.

Authors

  • Subodh C. Tiwari

    University of Southern California, CACS, USC

  • Ankit Mishra

    University of Southern California, CACS, USC

  • Chunyang Sheng

    University of Southern California

  • Pankaj Rajak

    Univ of Southern California, University of Southern California

  • Rajiv Kalia

    Univ of Southern California, CACS Mork Family Department of Chemical Engineering and Material Science, Department of Physics, University of Southern California, University of Southern California, CACS, Dept. of Physics & Astronomy, Dept. of Chemical Engineering & Materials Science, Dept. of Computer Science, University of Southern California, CACS, Department of Physics and Astronomy, Department of Chemical Engineering and Materials Science, Collaboratory of Advanced Computing and Simulations Department of Physics and Astronomy,University of Southern California

  • Aiichiro Nakano

    Univ of Southern California, CACS Mork Family Department of Chemical Engineering and Material Science, Department of Physics, University of Southern California, University of Southern California, CACS, Dept. of Physics & Astronomy, Dept. of Chemical Engineering & Materials Science, Dept. of Computer Science, University of Southern California, CACS, Department of Physics and Astronomy, Department of Chemical Engineering and Materials Science, Collaboratory of Advanced Computing and Simulations Department of Physics and Astronomy,University of Southern California

  • Priya Vashishta

    Univ of Southern California, CACS Mork Family Department of Chemical Engineering and Material Science, Department of Physics, University of Southern California, University of Southern California, CACS, Dept. of Physics & Astronomy, Dept. of Chemical Engineering & Materials Science, Dept. of Computer Science, University of Southern California, CACS, Depts. of Physics & Astronomy, Computer Science, and Chemical Engg. & Material Science, USC, CACS, Department of Physics and Astronomy, Department of Chemical Engineering and Materials Science, Collaboratory of Advanced Computing and Simulations Department of Physics and Astronomy,University of Southern California, CACS, Depts. of Physics & Astronomy, Computer Science, and Chemical Engg. and Material Science, USC