Gelatin-Disk Method for Preservation of Campylobacter jejuni and Campylobacter coli

Abstract

The gelatin-disk method was applied for the preservation of Campylobacter. This method was obviously superior to the conventional method such as the freeze-drying method. Especially, the recovery of viable organisms was excellent when the organisms were preserved in the disk that was prepared by mixing 5 volumes of a 10% sucrose solution added with 3% skin milk, 1 volume of a 5% ascorbic acid solution and 5 volumes of a 20% gelatin solution. The reduction rates of viable organisms of Campylobacter jejuni (C. jejuni) and Campylobacter coli (C. coli) immediately after making the disks were less than 3 and 1 log CFU/disk, respectively.
The viable organisms were recovered 3 weeks after the preservation at 10°C, even at 35°C in the case of C. coli. The recovery rate increased further when the dissolving broth containing a 5×10^-3M magnesium sulfate was used in comparison with the dissolvent without magnesium sulfate.