Can We Improve on the Petri Dish with Porous Culture Supports?

Microbial culture is exemplified by the Petri dish, a tool that (one century after its invention) still remains one of the “gold standards” for microbiological analysis. However, current trends towards automation, massively paralleled assays, and miniaturization (as well as the observation that we still cannot culture most microorganisms), suggest that new ideas in microbial culture are required. In the Petri dish, nutrient containing agar is typically used as the matrix on which microorganisms are cultured. However, new materials such as nanofibres and nanoporous materials may be better choices as supporting matrixes. Further, emerging techniques in microengineering and the fabrication of low cost materials are helping to create new porous disposables that are of sufficiently low cost that they may be used in the routine microbiology laboratory. These disposables are in turn allowing the development of novel miniature culture methods to take place, methods such as microchemostats, cages for growing microorganisms, and “habitats on a chip”. One particularly useful porous ceramic is Porous Aluminium Oxide (PAO), which can be utilized to generate highly subdivided culture chips that possess up to one million separate, miniaturized, growth areas. Indeed, this material has applications in microbiological diagnostics, microbiological research and industrial microbiology. In this chapter, the applications, advantages, and limitations of porous matrixes and accompanying culture chips will be examined. It is expected that these advances will yield significant improvements in microbial culture when compared to the classical Petri dish.

Keywords: Nanoculture, Petri Dish, Nanoporous Aluminium Oxide (PAO), Chemostat, Membrane Enrichment, Microdish Culture Chip (MDCC), High Throughput.