Preservation of Pasteurella piscicida by L-drying or gelatin-disk drying method.

概要

論文の詳細を見る
This report describes the survival and pathogenicity of Pasteurella piscicida strain 5866, a pathogen of yellowtail Seriola quinqueradiata, preserved by L-drying or gelatin-disk drying method. For L-drying storage, drying media with serum base were assessed. Harvested cells were suspended in drying media and stored at 15°C after drying in a vacuum from the liquid state. For the gelatin-disk drying method, harvested cells were suspended in melted 10% Bacto-gelatin containing 1% Bacto-peptone, 0.5% Bacto beef extract, 0.5% NaCl and 0.25% ascorbic acid. Small quantities were dried over P2O5 in a vacuum and stored at 15°C after drying. For assesment of pathogenicity, juveniles of yellowtail were infected by waterborne infection in sea water. Results of L-drying storage experiments showed mist desiccans with 0.5% NaCl was the most effective drying medium with high survival for 6 months after preservation. The mist desiccans contained 3 parts calf serum and 1part nutrient broth with 7.5% galactose. In gelatin-disk drying storage, recovery was low immediately after drying but no further descrease was found after a 6 month-storage. In both preservation methods, pathogenicity was well maintained for 6 months.