초록 ▼

A concentrated bacterial culture, capable of being cooled to temperatures as low as about -40°C. for storage without rapid freezing and with minimum damage to the bacterial cells, is prepared by diluting a conventionally prepared concentrated cell paste with a liquid anti-freeze agent containing one

A concentrated bacterial culture, capable of being cooled to temperatures as low as about -40°C. for storage without rapid freezing and with minimum damage to the bacterial cells, is prepared by diluting a conventionally prepared concentrated cell paste with a liquid anti-freeze agent containing one or more water freezing point depressants which are water-soluble, are non-injurious to the bacteria, and do not form crystals when cooled to a predetermined temperature within the range of about 5 to about -40°C. The amount of the freezing point depressant(s) is sufficient to prevent formation of ice crystals from the water present in the diluted product when cooled to the predetermined temperature. The culture, which does not become hard or crystalline upon being cooled to temperatures as low as -40°C., can be warmed to a temperature convenient for sampling, assaying and blending and then re-cooled to a cold storage temperature without an appreciable reduction in viability.

대표청구항 ▼

In a process for preparing a concentrated bacterial culture which can be cooled to a subfreezing temperature for preserving the viability of the bacteria for an extended time including the steps of inoculating an aqueous bacterial nutrient medium with a culture of the bacteria, incubating the inocul

In a process for preparing a concentrated bacterial culture which can be cooled to a subfreezing temperature for preserving the viability of the bacteria for an extended time including the steps of inoculating an aqueous bacterial nutrient medium with a culture of the bacteria, incubating the inoculated medium under suitable conditions to obtain a desired yield of bacterial cells, and concentrating the medium to obtain a concentrated bacterial paste containing water, the improvement comprising admixing with said paste a liquid anti-freeze agent containing at least one water freezing point depressant which is water-soluble, is non-injurious to the bacteria, and does not form crystals when cooled to a predetermined temperature within the range of about 5°to about -40°C., the amount of said water freezing depressant in said anti-freeze agent being sufficient to prevent formation of ice crystals from the water present in the resultant mixture when the resultant mixture is cooled to said predetermined temperature.