In the presence of citrate, some strains of lactic streptococci grow as long chains of innumerable cells. The results with citrate-negative and citrate-resistant variants suggest that citrate is involved in the cell separation system of the streptococci. Observations of the long chains under scanning and transmission electron microscopes suggest that citrate inhibits a certain step near the final cell separation, or that citrate can stimulate initiation of cell division at multiple sites, thereby leading to the cells in long chains.
Ito, S.; Kobayashi, T.; Ozaki, K.; Morichi, T.; and Saitoh, M.
"Microbial Cell Division and Separation: Effect of Citrate on the Growth of Group N Streptococci,"
Food Structure: Vol. 6
, Article 4.
Available at: http://digitalcommons.usu.edu/foodmicrostructure/vol6/iss1/4