In situ examination of cell growth and death of Lactococcus lactis

TY - JOUR

T1 - In situ examination of cell growth and death of Lactococcus lactis

AU - Ryssel, Mia

AU - Duan, Zhi

AU - Siegumfeldt, Henrik

PY - 2013/6

Y1 - 2013/6

N2 - 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 Lactococcus 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.

AB - 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 Lactococcus 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.

U2 - 10.1111/1574-6968.12134

DO - 10.1111/1574-6968.12134

M3 - Journal article

C2 - 23516965

SN - 0378-1097

VL - 343

SP - 82

EP - 88

JO - F E M S Microbiology Letters

JF - F E M S Microbiology Letters

IS - 1

ER -