title: Release of cell-free ice nuclei from Halomonas elongata expressing the ice nucleation gene inaZ of Pseudomonas syringae.
abstract: Release of ice nuclei in the growth medium of recombinant Halomonas elongata cells expressing the inaZ gene of Pseudomonas syringae was studied in an attempt to produce cell-free active ice nuclei for biotechnological applications. Cell-free ice nuclei were not retained by cellulose acetate filters of 0.2 microm pore size. Highest activity of cell-free ice nuclei was obtained when cells were grown in low salinity (0.5-5% NaCl, w/v). Freezing temperature threshold, estimated to be below -7 degrees C indicating class C nuclei, was not affected by medium salinity. Their density, as estimated by Percoll density centrifugation, was 1.018 +/- 0.002 gml(-1) and they were found to be free of lipids. Ice nuclei are released in the growth medium of recombinant H. elongata cells probably because of inefficient anchoring of the ice-nucleation protein aggregates in the outer membrane. The ice+ recombinant H. elongata cells could be useful for future use as a source of active cell-free ice nucleation protein.
authors: Department of Chemistry, University of Ioannina, Greece.
authors: G
authors: G
authors: Tegos
authors: C
authors: C
authors: Vargas
authors: A
authors: A
authors: Perysinakis
authors: A I
authors: AI
authors: Koukkou
authors: A
authors: A
authors: Christogianni
authors: J J
authors: JJ
authors: Nieto
authors: A
authors: A
authors: Ventosa
authors: C
authors: C
authors: Drainas
mesh_terms: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics*; D003001:Cloning, Molecular; D003470:Culture Media; D005615:Freezing; D020632:Halomonas / Q000235:genetics* / Q000254:growth & development; D015151:Immunoblotting; D011549:Pseudomonas / Q000235:genetics*; D011994:Recombinant Proteins / Q000096:biosynthesis; D012965:Sodium Chloride
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D003470:Culture Media; D011994:Recombinant Proteins; C063113:ice nucleation protein; D012965:Sodium Chloride