The transient diffusion of fluorescent tracers into biofilm cell clusters of Staphylococcus epidermidis was visualized by time lapse confocal scanning laser microscopy. Rhodamine B diffused into the center of cell clusters that were 200 to 600 microm in diameter within a few minutes. The apparent effective diffusion coefficient calculated from these data averaged 3.7 x 10(-7) cm(2) s(-1) or 11%...

Fluorescently tagged daptomycin accessed the interior of Staphylococcus epidermidis biofilm cell clusters within minutes. The diffusion coefficient of daptomycin in the biofilm was 28% of its value in pure water. Daptomycin activity against staphylococci embedded in biofilms is unlikely to be limited by penetration of the antibiotic into the biofilm.

The ability to simultaneously measure both biofilm thickness and the mass transfer coefficient of an inert tracer through it provides a powerful method to study biofilm development. In this communication previously published data has been collated to interpret global trends in biofilm structure during the transition towards steady-state. It appears that sudden changes in biofilm structure (dire...

A hybrid differential-discrete mathematical model has been used to simulate biofilm structures (surface shape, roughness, porosity) as a result of microbial growth in different environmental conditions. In this study, quantitative two- and three-dimensional models were evaluated by introducing statistical measures to characterize the complete biofilm structure, both the surface structure and vo...

Freshwater biofilms are currently being studied to determine their effect on the capacity of hydroelectric power scheme canals and the structure of their turbulent wall layers. Mean velocity boundary layer profiles and total drag measurements have been conducted in a purpose built recirculating water tunnel on freshwater biofilms grown in a hydroelectric canal. Two different fouled surfaces wer...

The potential bioconversion of synthesis gas (syngas) to fuels and chemicals by microbial cell has attracted considerable attention in past decade. The feasibility of enhancing syngas bioconversion to ethanol and acetate using Clostridium ljungdahlii in a continuous tank bioreactor (CSTBR), kinetics and mass transfer coefficient of carbon monoxide (CO) utilization were evaluated. Two different ...

background: the objective of the study is examining the microbial quality of drinking water in kashan’s villages, and determining the usage of safe water in rural population in terms of microbial quality in the second-half 2007. also the role of kashan rural water and wastewater company (krwwc) in improving drinking water quality in kashan rural areas was investigated. methods: in this descript...