Open AccessIn situ examination of cell growth and death of L actococcus lactis
Author(s) -
Ryssel Mia,
Duan Zhi,
Siegumfeldt Henrik
Publication year - 2013
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/1574-6968.12134
Subject(s) - lactococcus lactis , mutant , biology , phenotype , in situ , microbiology and biotechnology , growth rate , wild type , lactococcus , bacteria , genetics , chemistry , gene , lactic acid , geometry , mathematics , organic chemistry
This study enables in situ studying of the growth and death of a large number of individual cells in a solid matrix. A wild type of L actococcus lactis and several mutants with varying expression of GuaB was investigated. Large variability in the final size of individual microcolonies arising from clonal cells was observed. However, when growth was averaged over 16 locations in a specimen, the SEM was small and notable differences could be observed between the investigated strains, where mutants with lower expression of GuaB had a slower growth rate. The results show that the slow‐growing mutants exhibited a lower fraction of dead cells, which indicate that slow‐growing mutants are slightly more robust than the faster‐growing strains. The large variability in the final size of individual microcolonies arising from clonal cells was quite surprising. We suggest that the control of the size of a microcolony is, at least partially, related to the actual microcolony depended on phenotypic heterogeneity. These findings are important to consider whenever a solid medium with discrete microcolonies is investigated.