BIOCONVERSION OF FATTY-ACIDS INTO METHYL KETONES BY SPORES OF PENICILLIUM-ROQUEFORTI IN A WATER ORGANIC-SOLVENT, 2-PHASE SYSTEM

C5-C-9 methyl ketones can be produced from the corresponding C6-C-10 fatty acids by spores of Penicillium roquefortii in a water-organic solvent, two-phase system operated using a fed-batch procedure carried out at constant substrate concentration. The organic phase consists of an industrial isoparaffin solvent which can be considered as tetradecane. The reaction is initially performed by resting spores, which have the best biocatalyst activity, and swelling of spores appears later. Optimization involves both increased initial reaction rate and late spore swelling. The biocatalyst is obtained by cultivation of the fungus by solid state fermentation on buckwheat seeds, and the simplest way to carry out bioconversion reactions is to use the whole sporulation medium without discarding the buckwheat grains. This method gives the best results, and 21 g l-1 2-pentanone, 73 g l-1 2-heptanone, and 57 g l-1 2-nonanone were recovered in this way.