Biocatalytic esterification of fatty acids using a low-cost fermented solid from solid-state fermentation with Yarrowia lipolytica

Abstract

This study aimed to evaluate the use of a lyophilized fermented solid (named solid enzymatic preparation, SEP), with lipase activity, as a low-cost biocatalyst for esterification reactions of fatty acids present in acid raw materials for biodiesel synthesis. The SEP was obtained by solid-state fermentation (SSF) of soybean bran using the strain of Yarrowia lipolytica IMUFRJ 50682 and contains the lipases secreted by this yeast. The esterification reaction of ethanol and the predominant fatty acids present in different acid oil sources for biodiesel production (oleic, linoleic, stearic and palmitic acids) was investigated. Oleic acid conversion of above 85% was obtained after 24 h, using 30 wt% of SEP and ethanol/oleic acid molar ratio of 1, at 30 °C, in a reaction medium with and without solvent (n-hexane). Similar results were achieved with stearic (79%), palmitic (82%) and linoleic (90%) acids. The reusability of SEP was investigated over ten successive batches by washing it with different solvents (ethanol, water or n-hexane) between the cycles of ethyl oleate synthesis. Washing with water allowed the SEP to be reused for six cycles maintaining over 80% of the conversion reached in the first cycle. These results show the potential of this biocatalyst to reduce the content of free fatty acids in acid oils for biodiesel synthesis with a potential to be applied in a broad plethora of raw materials.

Using Enzymes to Harvest Fatty Acids from Galactosyldiacylglycerols, the Most Abundant Lipids in Plant Biomass

“…Whatever the enzyme and alcohol, it is worth noting that the final levels of FAAE were close to those expected at the thermodynamic equilibrium between long-chain FA and their esters. 24 Like the galactolipids from which they are generated, FAAE contained ALA as the main fatty acid (Figure 8).…”

Yarrowia lipolytica Yeast: A Treasure Trove of Enzymes for Biocatalytic Applications—A Review

“…Over the last 30 years, Y. lipolytica yeast has been utilized for various applications, including the production of biodiesel [42], oils and fats processing [43], biosynthesis of aromas, antimicrobial or antioxidant esters [32,[44][45][46][47][48][49], as well as polymer degradation [50,51].…”

“…Biodiesel is a type of fuel that is derived from renewable sources such as vegetable oils, animal fats, or recycled cooking oils. Typically, it is a mixture of methyl or ethyl es- Over the last 30 years, Y. lipolytica yeast has been utilized for various applications, including the production of biodiesel [42], oils and fats processing [43], biosynthesis of aromas, antimicrobial or antioxidant esters [32,[44][45][46][47][48][49], as well as polymer degradation [50,51].…”

A Temporal Evolution Perspective of Lipase Production by Yarrowia lipolytica in Solid-State Fermentation

“…The latter served as a basis for other studies on lipase production and application. Silva et al [85] used solid enzymatic preparation (SEP) in esterification reactions to decrease the free fatty acid content in acid oils used for biodiesel production. The authors also evaluated the catalyst properties regarding its reuse, reaching 6 batches of reused SEP. Souza et al [63] improved lipase production by using higher inoculum and soybean oil supplementation.…”