CHAIN LENGTH OF LEUCONOSTOC-CITROVORUM MODIFIED BY DILUTION AND SHAKING PROCEDURES OF PLATE COUNT

Strains of Leuconostoc citrovorum producing long (CAF-B; Da3) and short (9; 14) chains were grown in sterile skimmilk for 18 hr at 22 and 30 C, then shaken before and after dilution in buffered distilled water with and without glass beads. Stained preparations were examined microscopically to enumerate cells in chains of L. citrovorum. In milk cultures: a) Chains of CAF-B grown at 22 instead of 30 C resisted breakup most; the reverse was true of Da3, b) breakup of chains of Strains 9 and 14 was unrelated to incubation temperature, c) shaking three strains 50 or more times yielded chains most of which contained four or less cells, and d) chains of Strains 9 and 14 broke up most readily. Chains of some strains, when added to diluent, partially broke up before shaking. Additional shaking (50 or more times) yielded a preponderance of chains, each with four or less cells. Similar results were obtained when milk cultures were shaken, transferred to diluent, and shaken again. Glass beads failed to markedly enhance breakup of chains. Leuconostoc citrovorum always grew to form chains with even numbers of cells. When these chains broke up, they most commonly yielded two-, four-, or six-cell fragments. © 1969, American Dairy Science Association. All rights reserved.