TY - JOUR
T1 - The effects of extrinsic factors on the structural and mechanical properties of Pseudomonas fluorescens biofilms
T2 - A combined study of nutrient concentrations and shear conditions
AU - Allen, Ashley
AU - Habimana, Olivier
AU - Casey, Eoin
N1 - Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2018/5/1
Y1 - 2018/5/1
N2 - The growth of biofilms on surfaces is a complicated process influenced by several environmental factors such as nutrient availability and fluid shear. In this study, combinations of growth conditions were selected for the study of Pseudomonas fluorescens biofilms including as cultivation time (24- or 48 h), nutrient levels (1:1 or 1:10 King B medium), and shear conditions (75 RPM shaking, 0.4 mL min −1 or 0.7 mL min −1). The use of Confocal Laser Scanning Microscopy (CLSM) determined biofilm structure, while liquid-phase Atomic Force Microscopy (AFM) techniques resolved the mechanical properties of biofilms. Under semi-static conditions, high nutrient environments led to more abundant biofilms with three times higher EPS content compared to biofilms grown under low nutrient conditions. AFM results revealed that biofilms formed under these conditions were less stiff, as shown by their Young's modulus values of 2.35 ± 0.08 kPa, compared to 4.98 ± 0.02 kPa for that of biofilms formed under low nutrient conditions. Under dynamic conditions, however, biofilms exposed to low nutrient conditions and high shear rates led to more developed biofilms compared to other tested dynamic conditions. These biofilms were also found to be significantly more adhesive compared to their counterparts grown at higher nutrient conditions.
AB - The growth of biofilms on surfaces is a complicated process influenced by several environmental factors such as nutrient availability and fluid shear. In this study, combinations of growth conditions were selected for the study of Pseudomonas fluorescens biofilms including as cultivation time (24- or 48 h), nutrient levels (1:1 or 1:10 King B medium), and shear conditions (75 RPM shaking, 0.4 mL min −1 or 0.7 mL min −1). The use of Confocal Laser Scanning Microscopy (CLSM) determined biofilm structure, while liquid-phase Atomic Force Microscopy (AFM) techniques resolved the mechanical properties of biofilms. Under semi-static conditions, high nutrient environments led to more abundant biofilms with three times higher EPS content compared to biofilms grown under low nutrient conditions. AFM results revealed that biofilms formed under these conditions were less stiff, as shown by their Young's modulus values of 2.35 ± 0.08 kPa, compared to 4.98 ± 0.02 kPa for that of biofilms formed under low nutrient conditions. Under dynamic conditions, however, biofilms exposed to low nutrient conditions and high shear rates led to more developed biofilms compared to other tested dynamic conditions. These biofilms were also found to be significantly more adhesive compared to their counterparts grown at higher nutrient conditions.
KW - Atomic force microscopy
KW - Biofilm
KW - Biofilm viscoelastic properties
KW - Confocal laser scanning microscopy
KW - Nutrient concentration
KW - Pseudomonas fluorescens
KW - Shear
UR - http://www.scopus.com/inward/record.url?scp=85042334276&partnerID=8YFLogxK
U2 - 10.1016/j.colsurfb.2018.02.035
DO - 10.1016/j.colsurfb.2018.02.035
M3 - 文章
C2 - 29471219
AN - SCOPUS:85042334276
SN - 0927-7765
VL - 165
SP - 127
EP - 134
JO - Colloids and Surfaces B: Biointerfaces
JF - Colloids and Surfaces B: Biointerfaces
ER -