ISSN:
1750-3841
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Two morphologically distinct isolates of L. bulgaricus 1243 (designated F and O), were examined for stability during freezing and freeze-diying following growth in a nutrient broth medium supplemented with varying concentrations of calcium. While cellular morphology did not influence survival during −20°C frozen storage, calcium prevented freezing death in both isolates. Maximum survival occurred at calcium concentrations ranging between 5.4 × 10−3 and 6.7 × 10−3M. Calcium supplemented L. bulgaricus 1243-F displayed a five-fold decline in viable count (3.2 × 108 to 6.1 × 107) due to −20°C freezing, compared with cells propagated in broth without calcium, which declined 200-fold (1.7 × 108 to 6.3 × 105). Mg++ and Mn++ salts failed to exert protective effects. Calcium was ineffective in preventing freeze-injury, since cells displayed decreased acid production in milk following −20°C storage.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2621.1983.tb14896.x
Permalink