Hydrophobicity of biofilm coatings influences the transport dynamics of polystyrene nanoparticles in biofilm-coated sand.

Engineered nanoparticles (ENPs) are used in the manufacture of over 2000 industrial and consumer products to enhance their material properties and functions or to enable new nanoparticle-dependent functions. The widespread use of ENPs will result in their release to the subsurface and aquatic environments, where they will interact with indigenous biota. Laboratory column experiments were designed to understand the influence of two different Pseudomonas aeruginosa biofilms on the mobility of polystyrene latex nanoparticles in granular porous media representative of groundwater aquifers or riverbank filtration settings.

QCM-D for non-destructive real-time assessment of Pseudomonas aeruginosa biofilm attachment to the substratum during biofilm growth.

Quartz crystal microbalance with dissipation monitoring (QCM-D) was used to investigate initial adhesion and subsequent biofilm growth of wild-type Pseudomonas aeruginosa PAO1 and a pili-deficient (ΔpilA) mutant PAO1 strain. Clean, sterilized, silica-coated QCM-D crystals were pre-coated with lysogeny broth (LB), seeded with a PAO1 strain and allowed to grow for 20 h at 37 °C in fresh LB injected at 100 μL/min. QCM-D signals obtained for the wild-type PAO1 strain during the seeding period depict a large positive frequency shift that returns to baseline after ~20 min that is absent in the ΔpilA mutants, suggesting a dynamic pili-mediated attachment event for the wild-type PAO1 strain.

Transport of industrial PVP-stabilized silver nanoparticles in saturated quartz sand coated with Pseudomonas aeruginosa PAO1 biofilm of variable age.

Understanding the environmental fate and transport of engineered nanoparticles (ENPs) is of paramount importance for the formation and validation of regulatory guidelines regarding these new and increasingly prevalent materials. The present study assessed the transport of an industrial formulation of poly(vinylpyrrolidone)-stabilized silver nanoparticle (PVP-nAg) in columns packed with water-saturated quartz sand and the same sand coated with Pseudomonas aeruginosa PAO1 biofilm of variable age (i.e.

Effect of ciprofloxacin on microbiological development in wetland mesocosms.

An understanding of how antibiotics and other "emerging contaminants" affect both water treatment systems and natural environments is of growing interest. Ciprofloxacin is a broad-spectrum antibiotic active against both Gram-positive and Gram-negative bacteria and has been extensively used over the past 20 years. The objective of this research was to study the effect of an antibiotic such as ciprofloxacin on the development, function and stability of bacterial communities in wetland systems.