Performing under pressure: esterification activity of dry fermented solids in subcritical and supercritical CO 2

  • PDF / 314,185 Bytes
  • 7 Pages / 547.087 x 737.008 pts Page_size
  • 18 Downloads / 209 Views

DOWNLOAD

REPORT


(0123456789().,-volV) ( 01234567 89().,-volV)

ORIGINAL RESEARCH PAPER

Performing under pressure: esterification activity of dry fermented solids in subcritical and supercritical CO2 Dominicky Cristina Serrano . Marcos Lu´cio Corazza . David Alexander Mitchell . Nadia Krieger

Received: 28 May 2020 / Accepted: 9 October 2020 Ó Springer Nature B.V. 2020

Abstract Objective Lipases are often used in immobilized form, but commercial immobilized lipases are costly. An alternative is to produce lipases in solid-state fermentation, dry the solids and then use the ‘‘dry fermented solids’’ (DFS) directly. We produced DFS by growing Burkholderia contaminans on a mixture of sugarcane bagasse and sunflower seed meal and used the DFS to esterify oleic acid with ethanol in subcritical and supercritical CO2 at 40 °C. Results Compared to a control without CO2 at atmospheric pressure, subcritical CO2 at 30 bar

D. C. Serrano  M. L. Corazza  D. A. Mitchell  N. Krieger (&) Postgraduate Program in Chemical Engineering, Federal University of Parana´, P.O. Box 19011, Central Polytechnic, Curitiba, Parana´ 81531-980, Brazil e-mail: [email protected] M. L. Corazza Department of Chemical Engineering, Federal University of Parana´, P.O. Box 19011, Central Polytechnic, Curitiba, Parana´ 81531-980, Brazil D. A. Mitchell Department of Biochemistry and Molecular Biology, Federal University of Parana´, P.O. Box 19046, Central Polytechnic, Curitiba, Parana´ 81531-980, Brazil N. Krieger Department of Chemistry, Federal University of Parana´, P.O. Box 19061, Central Polytechnic, Curitiba, Parana´ 81531-980, Brazil

improved esterification activity 1.2-fold. Higher pressures, including supercritical pressures up to 150 bar, reduced activity to less than 80% of the control. At 30 bar, the esterification activity was improved a further 1.8-fold with the addition of 9% water (i.e. 9 g water per 100 g oleic acid) to the reaction medium. Conclusion A subcritical CO2 atmosphere, with the addition of a small amount of water, improved the esterification activity of DFS containing lipases of Burkholderia contaminans. Keywords Lipases  Burkholderia contaminans  Solid-state fermentation  Subcritical carbon dioxide  Supercritical carbon dioxide  Ethyl oleate

Introduction Lipases (triacylglycerol ester hydrolases, EC 3.1.1.3) catalyze various reactions of commercial interest (Sarmah et al. 2018). They are often immobilized, allowing them to be separated easily from the reaction medium and reused. Commercial immobilized lipases are often used to produce high-value products, such as intermediates for the synthesis of chiral drugs. However, the high costs of these commercial preparations preclude their use in the production of lower-value products such as biodiesel.

123

Biotechnol Lett

The costs of immobilized lipases can be lowered by using ‘‘dry fermented solids’’ (DFS). In this case, a lipase-producing microorganism is cultivated by solid-state fermentation and then the fermented solids are dried and added directly to the reaction medium to catalyz