Identification of a novel ice-nucleating bacterium of Antarctic origin and its ice nucleation properties.
A novel ice-nucleating bacterium (INB) was isolated from Ross Island, Antarctica. INBs could be isolated more frequently than was generally thought. INB strain IN-74 was found in the white colony group. Strain IN-74 was identified from its taxonomic characteristics as a novel INB, Pseudomonas antarctica IN-74. When strain IN-74 was cultured aerobically in a medium consisting of the ice-nucleating broth (pH 7.0) for 6 days at 4 degrees C, the ice-nucleating activity of strain IN-74 cells was obtained. Strain IN-74 cells produced ice nuclei only at extremely low growth temperatures. The nuclei appeared to be less thermolabile than those of INB Pseudomonas fluorescens KUIN-1. The freezing difference spectra in D2O and H2O at ice-nucleating temperature for strain IN-74 cells and conventional INBs (Pseudomonas fluorescens KUIN-1, Pseudomonas viridiflava KUIN-2, and Pseudomonas syringae C-9) exhibited different curves.
Obata
H
H
Faculty of Engineering, High Technology Research Center, Kansai University, 3-3-35 Yamatecho, Suita-shi, Osaka, 564-8680, Japan.
Muryoi
N
N
Kawahara
H
H
Yamade
K
K
Nishikawa
J
J
D000864:Antarctic Regions; D001419:Bacteria / Q000302:isolation & purification* / Q000378:metabolism* / Q000648:ultrastructure; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D003081:Cold Climate; D017666:Deuterium Oxide; D005615:Freezing; D007053:Ice; D007202:Indicators and Reagents; D008854:Microscopy, Electron; D011489:Protein Denaturation; D011549:Pseudomonas / Q000378:metabolism; D011551:Pseudomonas fluorescens / Q000378:metabolism; D014867:Water
D001425:Bacterial Outer Membrane Proteins; D007053:Ice; D007202:Indicators and Reagents; C063113:ice nucleation protein; D014867:Water; D017666:Deuterium Oxide