Immobilized Forms of the Ophiostoma piceae Lipase for Green Synthesis of Biodiesel. Comparison with Eversa Transform 2.0 and Cal A.

Félix A López,Lorena Alcaraz,Leonor Rodríguez-Sánchez,María Molina-Gutiérrez,María Jesús Martínez,Alicia Prieto

doi:10.3390/jof7100822

Abstract

In this work, we analyzed the suitability of a versatile recombinant lipase, secreted by Ophiostoma piceae (OPEr) and produced in Pichia pastoris, as a catalyst of the synthesis of biodiesel. The enzyme was immobilized by five covalent procedures and by hydrophobicity on functionalized nanoparticles of magnetite or of a novel Zn/Mn oxide named G1. Then, they were tested for green production of biodiesel by solventless enzymatic transesterification of discarded cooking oil and methanol (1:4) at 25 °C. The results were compared with those shown by free OPEr and the commercial lipases Eversa® and Cal A®. Several preparations with immobilized OPEr produced high synthesis yields (>90% transesterification), comparable to those obtained with Eversa®, the commercial enzyme designed for this application. Three of the biocatalysts maintained their catalytic efficiency for nine cycles. The process catalyzed by AMNP-CH-OPEr was scaled from 500 µL to 25 mL (50 times), improving its efficiency.

Highlights

Biodiesel is a non-toxic and biodegradable liquid fuel composed of long chain fatty acid alkyl esters with short chain alcohols, generally methanol and ethanol [1]
Characterization of the Novel Zn/Mn Mixed Oxide Used as Immobilization Carrier viously characterized using Fourier transform infrared spectroscopy (FTIR) and by transnude, amino-functionalized, and GA-activated carriers havethe been previmissionThe (TEM)
This is especially relevant for AMNP-GA-OPEr, whose specific activity was between two and three times lower than that of the rest, justifying its reduced synthetic activity. The efficiency of this catalyst is likely to be comparable to that of the others if the catalytic dose were leveled. Leaving this preparation aside and considering the value of the calculated standard deviations, the results indicate that the activity of all nanobiocatalysts in the synthesis of FAMEs is similar

Summary

Introduction

Biodiesel is a non-toxic and biodegradable liquid fuel composed of long chain fatty acid alkyl esters with short chain alcohols, generally methanol and ethanol [1]. The synthesis of these compounds can be driven by chemical or enzymatic catalysts, and industrial production is usually done by chemical transesterification of triglycerides, generally with alkaline catalysts [2]. In this reaction, soaps are produced, especially if the oil used contains free fatty acids, and this secondary reaction reduces biodiesel yields and makes the separation and purification of the products notably difficult [3,4]. There is a tendency to use non-edible oils or urban wastes as sources of triglycerides, in order to fit within a circular economy scheme and to reduce the expense attributable to raw materials [6], which should not exceed 50% of production costs [1]

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Discussion

Conclusion