High throughput semi-automated extraction method for the creation of a collection from microbial fermentations of fungi and Actinomycetes

The 'one strain-many compounds' (OSMAC) is a validated approach for maximizing the potential chemical diversity of secondary metabolites and antibiotics from microorganisms. Increasing the number of fermentation conditions per strain raises the probability of detecting bioactive compounds and maximizes the investment.

The use of nutritional arrays, including environmental factors, constitutes a possible solution for turn on the expression of biosynthetic pathways from a given strain by increasing the spectrum of metabolites that it can produce. Since October 2006, a new High Throughput platform for the preparation and evaluation of extracts from fungi and actinomycetes has been developed in our lab based on this approach. The high number of fermentations generated by this technique (up to 20,000/month) challenged our ability for an efficient and semi-automated extraction and sample management.

Prior extract preparation strategies based on the premise, 'the higher the biomass the higher the quantity of secondary metabolites' had a serious impact in our automation possibilities for handling highly parallel micro-fermentations in multiwell plates. Liquid handling robots had many different incompatibilities with direct extracts in multiwell plates, and presented significant obstacles to attaining the desired throughput. These obstacles were overcome in our solution by designing a new system in collaboration with our engineers that would allow, in theory, the solvent dispensing and direct pipetting from multiwell plates as well as the use of disposable tips for extract handling.

The design and implementation of this semi-automated system for performing the extraction of miniaturized fermentation broths from fungi and actinomycetes for a High Throughput creation of a Library of Natural Products Extracts is described.