Optimization of enzyme production of fatty acid methyl esters

• Main Author: Luković, Nevena
• Other Authors: Knežević-Jugović, Zorica, Bezbradica, Dejan, Mijin, Dušan, Mojović, Ljiljana, Antov, Mirjana
• Format: Doctoral or Postdoctoral Thesis
• Language: unknown
• Published: Univerzitet u Beogradu, Tehnološko-metalurški fakultet 2014
• Subjects: fatty acid methyl esters; biodiesel; lipases; transesterification; enzyme immobilization; метил естри масних киселина; биодизел; липаза; тренсестерификација; имобилизација ензима; Rugosa; Antarc*; Antarctica
• Online Access: http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4614; http://eteze.bg.ac.rs/application/showtheses?thesesId=3349; https://fedorabg.bg.ac.rs/fedora/get/o:11830/bdef:Content/download; http://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=45874447; http://TechnoRep.tmf.bg.ac.rs/bitstream/id/2140/4611.pdf; https://hdl.handle.net/21.15107/rcub_technorep_4614

Тhis thesis deals with the transesterification of sunflower oil in the solvent-free system. The catalytic activity of lipases from different sources (Candida rugosa, Rhizomucor miehei, Candida antarctica) has been examined in terms of transesterification activity and stability. The optimal conditions for the methanolysis reaction have been determined using response surface methodology (RSM) leading to the high fatty acid methyl esters yield. The reaction temperature, the biocatalyst, the water concentration and the substrate molar ratio have been the investigated variables. After that, the possibility of different acyl acceptors has been investigated. Further results suggest that the use of methyl acetate as an acyl acceptor could significantly improve the immobilized system stability. This has been verified in industrially feasible reactor design. Different process parameters have been investigated as well as the operational stability of the immobilized lipase. The second part of the thesis was focused on the development of the immobilized enzyme with the best catalytic properties. The covalent immobilization of native lipase from C. rugosa and native lipase from C. antarctica on polymer carriers containing epoxy groups have been analyzed. The efficiency of modified commercial carrier Eupergit® C 250L with cysteine and glutaraldehyde has been studied. It was found that immobilized lipase form C. antarctica can be successfully used as a biocatalyst in the biodiesel synthesis. The obtained yields are in the range of commercial available immobilized enzymes. U okviru ove teze ispitivana je mogućnost enzimskog postupka sinteze metil estara masnih kiselina (biodizela) iz biljnog ulja, postupkom transesterifikacije. Ispitano je katalitičko dejstvo lipaza iz različitih izvora sa aspekta transesterifikacione aktivnosti i stabilnosti u sistemima bez organskog rastvarača. Koristile su se komercijalne lipaze iz različitih mikroorganizama (Candida rugosa, Rhizomucor miehei, Candida antarctica) a potom je metodom ...