Lipases are enzymes that can be secreted by several microorganisms, making interesting the biodiversity exploration for searching new microorganisms able to produce these enzymes. Many agro-industrial residues can be used as potential substrates for production of enzymes. The main objective of this work was the isolation and screening of microorganisms with potential to produce lipases. Among 24 fungi, five were selected as good lipase producers using tributyrin on agar plates and solid state fermentation of soybean bran. Two of them were isolated from soil samples, another two from soybean bran, and one from dairy products. These fungi were identified by microcultivation technique as from Penicillium and Aspergillus genera. Through random amplified polymorphic DNA technique, the most promising strains could be genetically discriminated, selecting two fungi as good lipase producers but genetically different. One isolated from soybean bran could hydrolyze efficiently triglycerides with fatty acids with different chain length. Another isolated from dairy products was only effective to hydrolyze triglycerides with long-chain fatty acids. Two distinct groups could be verified by means of this technique, comprising the most productive strains and the lowest or nonproductive ones in terms of hydrolytic activity.

The named "green chemistry" has been receiving increasing prominence due to its environmentally friendly characteristics. The use of enzymes as catalysts in processes of synthesis to replace the traditional use of chemical catalysts present as main advantage the fact of following the principles of the green chemistry. However, processes of enzymatic nature generally provide lower yields when compared to the conventional chemical processes. Therefore, in the last years, the ultrasound has been extensively used in enzymatic processes, such as the production of esters with desirable characteristics for the pharmaceutical, cosmetics, and food industry, for the hydrolysis and glycerolysis of vegetable oils, production of biodiesel, etc. Several works found in the open literature suggest that the energy released by the ultrasound during the cavitation phenomena can be used to enhance mass transfer (substrate/enzyme), hence increasing the rate of products formation, and also contributing to enhance the enzyme catalytic activity. Furthermore, the ultrasound is considered a "green" technology due to its high efficiency, low instrumental requirement and significant reduction of the processing time in comparison to other techniques. The main goal of this review was to summarize studies available to date regarding the application of ultrasound in enzyme-catalyzed esterification, hydrolysis, glycerolysis and transesterification reactions.

The performance of two new commercial low-cost lipases Eversa® Transform and Eversa® Transform 2.0 immobilized in different supports was investigated. The two lipases were adsorbed on four different hydrophobic supports. Interesting results were obtained for both lipases and for the four supports. However, the most active derivative was prepared by immobilization of Eversa® Transform 2.0 on Sepabeads C-18. Ninety-nine percent of fatty acid ethyl ester was obtained, in 3 h at 40 °C, by using hexane as solvent, a molar ratio of 4:1 (ethanol/oil), and 10 wt% of immobilized biocatalyst. The final reaction mixture contained traces of monoacylglycerols but was completely free of diacylglycerols. After four reaction cycles, the immobilized biocatalyst preserved 75% of activity. Both lipases immobilized in Sepabeads C-18 were very active with ethanol and methanol as acceptors, but they were much more stable in the presence of ethanol.

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