engleski

Production of biodiesel by Burkholderia cepacia lipase as a function of process parameters

Despite the already established route of chemically catalysed transesterification reaction in biodiesel production, due to some of its shortcomings, biocatalysts such as lipases present a vital alternative. Namely, it was noticed that one of the key shortcomings for the optimization of the enzyme catalyzed biodiesel synthesis process is the information on the lipase activity in the reaction mixture. In addition to making optimization difficult, it also makes it impossible to compare the results of the independent research. This paper shows how lipase intended for use in biodiesel synthesis can be easily and accurately characterized and what is the enzyme concentration that enables achievement of the desired level of fatty acid methyl esters (FAME) in the final product mixture. Therefore, this study investigated the effect of two different activity loads of <i>Burkholderia cepacia</i> lipase on the biodiesel synthesis varying the pH and temperature optimal for lipase activity. The optimal lipase pH and temperature were determined by two different enzyme assays: spectrophotometric and titrimetric. The <i>B. cepacia</i> lipase pH optimum differentiated between assays, while the lipase optimally hydrolysed substrates at 50 °C. The analysis of FAME during 24 hours of biodiesel synthesis, at two different enzyme concentrations, pH 7, 8 and 10, and using two different buffers, revealed that the transesterification reaction at optimal pH, one hour reaction time and lipase activity load of 250 U per gram of reaction mixture was sufficient to produce more than 99% FAME.

Burkholderia cepacia ; lipase ; pH optimum ; temperature optimum ; substrate specificity ; biodiesel

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