MENZELLA Hugo Gabriel
congresos y reuniones científicas
An enzymatic process for the removal of steryl glucosides, major contaminants of vegetable oil derived biodiesel
Rio de Janeiro
Congreso; Bio Latin America 2014; 2014
Biodiesels derived from vegetable oil suffer from some problems arising from their organic origin, mainly due to the formation of precipitates at various points in the production chain, during transport and in use. The main components of precipitates in biodiesel are steryl glucosides (SGs). Although some alternative methods for removing these precipitates have emerged, none of them has been entirely satisfactory for technical or economic reasons. Recently, we developed an enzymatic process that completely eliminates SGs from soybean biodiesel. The enzyme involved, named EGase1, hydrolyzes SGs to generate soluble sterols and glucose. The aim of this work is to produce EGase1 using a fermentation process at a cost that makes feasible its industrial implementation. The improvement of the expression of EGase1 was addressed by different approaches. These included the optimization of codon usage, the evaluation of different culture conditions, the use of promoters with different strengths, the coexpression of EGase1 with molecular chaperons and the use of alternative E. coli host strains. Such modifications had different impact on EGase expression levels and were combined into a final optimal production system. The resulting strain was used to produce the enzyme in a 1L fermentor using glycerol as carbon source and L-Ara as inductor reaching 10g/L of EGase 1.