Characterization and properties of intracellular proteins after cold acclimation of the ice-nucleating bacterium Pantoea agglomerans (Erwinia herbicola) IFO12686

The ice-nucleating bacterium Pantoea agglomerans (Erwina herbicola) IF012686 (INA(+)) responds to a decrease in temperature by the induction of proteins. The pattern of protein bands from strain IF012686 following a shift in temperature From 30 to 12 degreesC could be divided into four major groups: (1) increasing protein bands. (2) decreasing protein bands. (3) increasing-decreasing protein bands, and (4) almost constant protein bands. We identified a cryoprotective function in the increasing protein band round in strain IF012686. The increasing protein bands that followed a reduction in temperature were considered to have an important role in cold acclimation or adaptation. We showed that these proteins possessed cryoprotective activity when tested against the freeze-labile enzyme lactate dehydrogenase. The strain IF012686 had greater cryotolerance than Pa. agglomerans IAM1595 (INA ). and the degree of cryotolerance was increased by cold acclimation. (C) 2000 Academic Press.