TY - JOUR
T1 - Matrix Production and Sporulation in Bacillus subtilis Biofilms Localize to Propagating Wave Fronts
AU - Srinivasan, Siddarth
AU - Vladescu, Ioana D.
AU - Koehler, Stephan A.
AU - Wang, Xiaoling
AU - Mani, Madhav
AU - Rubinstein, Shmuel M.
N1 - Publisher Copyright:
© 2018 Biophysical Society
PY - 2018/3/27
Y1 - 2018/3/27
N2 - Bacterial biofilms are surface-attached microbial communities encased in self-produced extracellular polymeric substances. Here we demonstrate that during the development of Bacillus subtilis biofilms, matrix production is localized to an annular front propagating at the periphery and sporulation to a second front at a fixed distance at the interior. We show that within these fronts, cells switch off matrix production and transition to sporulation after a set time delay of ∼100 min. Correlation analyses of fluctuations in fluorescence reporter activity reveal that the fronts emerge from a pair of gene-expression waves of matrix production and sporulation. The localized expression waves travel across cells that are immobilized in the biofilm matrix in contrast to active cell migration or horizontal colony spreading. Our results suggest that front propagation arises via a local developmental program occurring at the level of individual bacterial cells, likely driven by nutrient depletion and metabolic by-product accumulation. A single-length scale and timescale couples the spatiotemporal propagation of both fronts throughout development. As a result, gene expression patterns within the advancing fronts collapse to self-similar expression profiles. Our findings highlight the key role of the localized cellular developmental program associated with the propagating front in describing biofilm growth.
AB - Bacterial biofilms are surface-attached microbial communities encased in self-produced extracellular polymeric substances. Here we demonstrate that during the development of Bacillus subtilis biofilms, matrix production is localized to an annular front propagating at the periphery and sporulation to a second front at a fixed distance at the interior. We show that within these fronts, cells switch off matrix production and transition to sporulation after a set time delay of ∼100 min. Correlation analyses of fluctuations in fluorescence reporter activity reveal that the fronts emerge from a pair of gene-expression waves of matrix production and sporulation. The localized expression waves travel across cells that are immobilized in the biofilm matrix in contrast to active cell migration or horizontal colony spreading. Our results suggest that front propagation arises via a local developmental program occurring at the level of individual bacterial cells, likely driven by nutrient depletion and metabolic by-product accumulation. A single-length scale and timescale couples the spatiotemporal propagation of both fronts throughout development. As a result, gene expression patterns within the advancing fronts collapse to self-similar expression profiles. Our findings highlight the key role of the localized cellular developmental program associated with the propagating front in describing biofilm growth.
UR - http://www.scopus.com/inward/record.url?scp=85044640146&partnerID=8YFLogxK
U2 - 10.1016/j.bpj.2018.02.002
DO - 10.1016/j.bpj.2018.02.002
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
C2 - 29590605
AN - SCOPUS:85044640146
SN - 0006-3495
VL - 114
SP - 1490
EP - 1498
JO - Biophysical Journal
JF - Biophysical Journal
IS - 6
ER -