Avaliação do potencial biocatalítico da microalga Dunaliella salina na redução assimétrica da acetofenona

Abstract

In this work, marine microalgae from the species Dunaliella salina was using for the bio prospecting study, about their potential employment as biocatalysts reducing reactions using standard substrate, the pro-chiral ketone acetophenone in the production of chiral alcohol (R) -1-phenyl-ethanol. The initial stage of the work consisted in developing a methodology that would provide a control of the synthesis parameters, from simple technological devices that can be reproduced in laboratories, presenting relevant results of enantioselectivity. In this meaning, research was carried out on the conditions of adaptability of microalgae against the presence of the substrate acetophene in algal growth, as a parameter of the addition order, relation between the amount of substrate mass versus volume of microalgae solution and shaking and aeration of the medium, resulting in a reproducible and systematized methodology of the biocatalysts reactions of the acethphenone substrate thus obtaining a controlled biotechnological process. In the development of the methodology with the microalgae D. salina, the biocatalysts reactions were performed using only H2O as the solvent, therefore not making use of organic solvent in the bio reduction process, thus avoiding the formation of by-products and consequent generation of waste for treatment. The D. salina microalgae presented excellent results of enantiomeric excess, 96,7 ee% (Input 9) e 99,4 ee% (Input 10), with respective reaction times of 72 hours and 120 hours. In addition they showed a fast adaptability to the presence of acetophenone substrate and biocatalytic action with 100% conversion values (Input 10), using considerable substrate masses (200mg). The biocatalysis products were analyzed and characterized by chiral column gas chromatography and spectroscopy in the infrared region with Fourrier transform, comparing the results obtained with information in literature (YADAV et al., 2002) and (BISPO, 2016). Therefore, the application of marine microalgae of the species Dunaliella salina, through its intact cells, has been shown to be promising as asymmetric biocatalysts, enabling the advance in research, in addition to prochiral ketones, with others functional groups of interest, such as aldehydes and α,β-ketoesters in the production of enantiomerically pure chiral alcohols.