Growth of biological films — microscopical investigations and computer simulations

Biological thin films of Escherichia coli, Baccilus subtilis, Baccilus pabuli and purple sulphur bacteria are grown on different substrates from a solution which is incubated with bacteria and contains also the nutrient for the bacteria to grow and divide. The biofilm growth is investigated experimentally by light and scanning force microscopy (SFM). The resulting surface structures are substrate dependent both in terms of morphology and coverage. A three parameter Monte Carlo simulation model for the growth process is developed and is shown to match well the observed experimental structures for suitable choices of the variable parameters.