Screening and catalytic activity in organic synthesis of novel fungal and yeast lipases

A total of 969 microbial strains were isolated from soil samples and tested to determine their lipolytic activity by employing screening techniques on solid and in liquid media. Ten lipase-producing microorganisms were selected and their taxonomic identification was carried out. From these strains Achremonium murorum, Monascus mucoroides, Arthroderma ciferri, Fusarium poae, Ovadendron sulphureo-ochraceum and Rhodotorula araucariae are described as lipase-producers for the first time. Hydrolysis activity of the crude lipases against both tributyrin and olive oil was measured. Heptyl oleate synthesis was carried out to test the activity of the selected lipases as biocatalysts in organic medium. All the selected lipases were tested as biocatalysts in several organic reactions using unnatural substrates. Lipases from the fungi Fusarium. oxysporum and O. sulphureo-ochraceum gave the best yields and enantioselectivities in the esterification of carboxylic acids. F. oxysporum and Penicillium chrysogenum lipases were the most active ones for the acylation of alcohols without steric hindrance. A. murorum lipase is very useful for the esterification of menthol. F. oxysporum and Fusarium. solani lipases were very stereoselective in the synthesis of carbamates.