Identification of a compound in chamaecyparis taiwanensis inhibiting the ice-nucleating activity of pseudomonas fluorescens kuin-1

Abstract

Inactivation of the ice-nucleating activity of Pseudomonas fluorescens KUIN-1 by compounds in the leaves from coniferous trees were investigated, and the inactivated material was identified. Intact cells of the strain KUIN-1 and the acetone or methanol extracts of leaves of various coniferous trees were allowed to react for 30 min at 18°C. Antinucleation compounds were obtained from Chamaecyparis taiwanensis. When the acetone extract from the leaves of coniferous trees was added to the cell suspension (about 106 cells/ml) in 50 mM potassium phosphate buffer (pH 7.0), the ice nucleating temperature, T50, was significantly decreased (T50