Transport of Pseudomonas aeruginosa in Porous Media Mediated by Low‐Concentration Surfactants: The Critical Role of Surfactant to Change Cell Surface Hydrophobicity

Abstract

Transport of P. aeruginosa ATCC 9027 in quartz sands mediated by low‐concentration surfactants of sodium dodecyl benzene sulfonate (SDBS) or Triton X‐100 was investigated with column experiments. P. aeruginosa ATCC 9027 was cultured with glucose and hexadecane to produce cells with different initial cell surface hydrophobicity (CSH). Transport behavior of cells was characterized by breakthrough curves (BTCs) and deposition rate coefficients (kd) values were estimated by fitting the BTCs using colloid transport models. Relations between kd and CSH represented by bacterial‐adsorption‐to‐hydrocarbon fraction (BATH fraction) and between kd and cell surface charge represented by zeta potential were analyzed to quantitatively describe the effect of surfactants on cell transport. Results showed that at low concentrations the ionic SDBS increased cell surface charge while the nonionic Triton X‐100 had no effect, while both of them caused significant differentiation of CSH. The kinetic attachment‐detachment model with blocking was the best among the five models tested to fit BTCs and low‐concentration SDBS and Triton X‐100 caused remarkable change of kd. A good linear relation between kd and cell BATH fraction was observed (R2 = 0.82), whereas the linearity between kd and total zeta potential of cell and sand was poor (R2 = 0.11). The data reconstructed from our previous studies showed that the linearity between kd and cell BATH fraction also presented in sands and glass beads for low‐concentration rhamnolipid biosurfactant. In all, these results showed that CSH plays a critical role in cell transport in porous media and changing CSH is a common mechanism for low‐concentration surfactants to mediate the transport, which implies the potential of using low‐concentration surfactants to regulate bacterial transport for bioaugmentation.

Transport and Retention of Free-Living Amoeba Spores in Porous Media: Effects of Operational Parameters and Extracellular Polymeric Substances

“…The changes in calculated interaction energy due to variations in IS cannot explain the observed deposition pattern of D. discoideum spores but represent the breakthrough behavior of spores present in tap water, 39 particularly for biocolloids. 66,67 This analysis suggests that interfacial forces between spores and the quartz surface are significantly influenced by aquatic chemistry but may not be the main contributing factors regulating the deposition mechanisms of amoeba spores in porous media. Contributions from EPS, spore shape, localized heterogeneity, hydrophobicity, and negatively charged proteins, as well as the functional groups of EPS on the surface of amoeba spores, might also play important roles in the phenomena.…”

The impact of environmental factors on the transport and survival of pathogens in agricultural soils from karst areas of Yunnan province, China: Laboratory column simulated leaching experiments

“…Generally, for the same texture soil, the more porosity, the greater the permeability coefficient. Under the same hydraulic gradient, the groundwater flow velocity in the greater porosity soil would be greater, and therefore, the water infiltrated through the greater porosity soil would have a higher concentration of bacteria ( Smith et al, 1985 ; Huysman and Verstraete, 1993 ; Sepehrnia et al, 2019 ; Liu et al, 2020 ). In the present study, the lower TCC value samples were almost collected in the 0.5 porosity soils at 10°C, indicating that the soils with less porosity would retard the migration of coliforms, which could be observed at low temperature, while at high temperature, the retardation effect might be obscured by temperature effect.…”

Interaction between Microplastics and Pathogens in Subsurface System: What We Know So Far

“…Therefore, hydrophobicity is crucial in the early adsorption of germs to hydrophobic surfaces. The non-specific adsorption of germs on abiotic surfaces is favored by strong hydrophobic-ity [87], while hydrophilic viruses and bacteria exhibit greater migratory potential in aquifer media [88,89]. In a study of the colonization of microplastic surfaces by different bacteria in the presence of Tween-80, it was found that highly hydrophobic strains colonized the microplastic surfaces with significantly higher biomass [90].…”