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US 4,226,940 AGranted
Non-frozen concentrated bacterial cultures
AssigneeGreat Lakes Biochemical Co., Inc.
InventorArnold B. Storrs
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AssigneeGreat Lakes Biochemical Co., Inc.
InventorArnold B. Storrs
Estimating the term…
A concentrated bacterial culture, capable of being cooled to temperatures as low as about -40.degree. 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.degree. 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.degree. 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.
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
A concentrated bacterial culture comprising live bacterial cells containing an anti-freeze agent including 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.degree. to about -40.degree. C., the amount of said water freezing point depressant in said anti-freeze agent being sufficient to prevent formation of ice crystals from the water present in said culture when cooled to said predetermined temperature.
Dependencies are inferred from the claim text.