Expression of CspA and GST by an Antarctic psychrophilic bacterium Colwellia sp. NJ341 at near-freezing temperature

Summary A psychrotrophic bacterium Colwellia sp. NJ341 from Antarctic sea ice could grow at −5 and 22 °C, and the extent of cellular protein content and growth were greater at low temperatures (0–10 °C) than at higher temperatures. SDS-PAGE analysis demonstrated the presence of a 7 kDa cold-shock protein. The further result of two-dimensional electrophoresis (2-DE) showed that two proteins a and c were newly synthesized at near-freezing temperatures. With matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS) analysis, proteins a and c were identified as glutathione S-transferase (GST) and cold-shock protein A (CspA), respectively, which were involved in cold-adaptation at near-freezing temperature in an Antarctic psychrophilic bacterium Colwellia sp. NJ341.