Biocatalyst Concentration Research Articles

Biocatalytic Production of Solketal Esters from Used Oil Utilizing Treated Macauba Epicarp Particles as Lipase Immobilization Support: A Dual Valorization of Wastes for Sustainable Chemistry

This study describes the production of solketal esters from used soybean cooking oil (USCO) via enzymatic hydroesterification. This process consists of the complete hydrolysis of USCO into free fatty acids (FFAs) catalyzed by crude lipase extract from Candida rugosa (CRL). The resulting FFAs were recovered and utilized as the raw material for an esterification reaction with solketal, which was achieved via an open reaction. For this purpose, lipase Eversa® Transform 2.0 (ET2.0) was immobilized via physical adsorption on treated epicarp particles from Acrocomia aculeata (macauba), a lignocellulosic residue. A protein loading of 25.2 ± 1.3 mg g−1 with a support and immobilization yield of 64.8 ± 2.5% was achieved using an initial protein loading of 40 mg g−1 of support. The influence of certain parameters on the esterification reaction was evaluated using a central composite rotatable design (CCRD). Under optimal conditions, a FFAs conversion of 72.5 ± 0.8% was obtained after 150 min of reaction at 46 °C using a biocatalyst concentration of 20% wt. and a FFAs–solketal molar ratio of 1:1.6. The biocatalyst retained 70% of its original activity after ten esterification batches. This paper shows the conversion of two agro-industrial waste into valuable materials (enzyme immobilization support and solketal esters).

Efficient Bio-Oxidation of Cellobiose with Engineered Gluconobacter oxydans to Provide Highly Concentrated Cellobionic Acid

Cellobionic acid (CBA) can be obtained through the oxidation of cellobiose, the monomer of cellulose. CBA serves as a plant-based alternative to its stereoisomer lactobionic acid, which is used in the pharmaceutical, cosmetic, and food industries. Gluconobacter oxydans is a well-established whole-cell biocatalyst with membrane-bound dehydrogenases (mDH) for regio-specific oxidations. As G. oxydans wildtype cells show low cellobiose oxidation activities, the glucose mDH from Pseudomonas taetrolens was overexpressed in G. oxydans BP9, a multi mDH deletion strain. Whole-cell biotransformation studies were performed with resting cells of the engineered G. oxydans in stirred tank bioreactors. Initial biomass specific cellobionate formation rates increased with increasing cellobiose concentrations up to 190 g L−1, and were constant until the solubility limit. The maximal volumetric CBA formation rates and the oxygen uptake rates increased linearly with the concentration of engineered G. oxydans. This enables the estimation of the maximum biocatalyst concentration limited by the maximum oxygen transfer rate of any bioreactor. Thus, 5.2 g L−1 G. oxydans was sufficient to produce 502 g L−1 CBA with >99% yield in a simple aerobic batch process. The highly concentrated CBA will reduce downstream processing costs considerably after cell separation.

Biomanufacturing of ricinoleic acid from castor oil using immobilized lipase of Pseudomonas guariconensis as biocatalyst

The efficacy of castor oil hydrolysis to ricinoleic acid by a Pseudomonas guariconensis lipase immobilized on glutaraldehyde-activated ferromagnetic nanoparticles was investigated. The prepared nanoparticles were characterized using FTIR and DLS and used as a novel biocatalyst for the production of ricinoleic acid. The optimum reaction conditions for the hydrolysis reaction by Fe3O4-APTES-Glu-lipase were optimized through the response surface methodology (RSM) which resulted in a maximum conversion of 62.5 ± 0.76%. The optimized reaction conditions are the temperature of 40 0C, pH 9, water: oil ratio of 4:1, and biocatalyst concentration of 4% w/w of the oil used. Moreover, the immobilized biocatalyst showed high stability with minimal reduction of hydrolytic efficiency after six consecutive cycles of reuse.

Branched saturated esters and diesters: Sustainable synthesis of excellent biolubricants

The enzymatic production of biolubricants with desirable properties such as high viscosity index and resistance to oxidation is investigated. These characteristics are ascribed to their branched structure and high molecular weight, as well as, to the absence of unsaturated bonds in the molecule. Solvent-free processes with moderate enzyme concentrations (up to 5% wt.) and reaching conversions of 95% or more, have been conducted. Firstly, up to fifteen branched esters and diesters, all of them saturated, are obtained from a branched acid, 2-methylhexanoic acid, and a variety of linear and branched alcohols and linear diols. Among them, three esters have viscosity indexes close to 200 or higher (1,10-decanediolyl 2-methylhexanoate, 1,12-dodecanediolyl 2-methylhexanoate and 2-octyl-1-dodecanoyl 2-methylhexanoate). For the synthesis of these compounds, optimization of biocatalyst concentration and temperature has been carried out, reaching conversions above 95% within operation times between 2 and 3.5 h.

Monolayer textile-based co-laminar flow biocompatible enzymatic biofuel cell

In this study, a body-friendly textile-based enzymatic glucose biofuel cell, which is applicable to wearable electronics, was developed. The microchannel of the biofuel cell was patterned by silk screen printing using Ecoflex. To develop this body-friendly wearable enzymatic fuel cell, a bi-enzyme system composed of glucose oxidase-catalase and glucose oxidase-horseradish peroxidase was applied to the anode and cathode, respectively. The catholyte mixed with glucose was saturated with O2 to enhance the fuel cell performance. The cell performance was affected by concentrations of enzyme biocatalyst and glucose. The best performance of the newly developed fuel cell was the peak power density of 43.6 ± 1.97 μW cm−2. The fuel cell was tested in an electrolyte physiological condition, and its power density was reduced to 25 %. Compared to the paper-based enzymatic fuel cell, the power density was approximately 11 % lower; however, the duration (11 h) was significantly longer. The performance of the proposed fuel cell was slightly lower than that of traditional enzymatic biofuel cells. Nevertheless, it is expected that the proposed body-friendly enzymatic biofuel cell has future promise as a power source for flexible bioelectronics.

Investigation of process stability of a whole-cell biocatalyst with Baeyer–Villiger monooxygenase activity in continuous bioreactors

The stability of a whole-cell biocatalyst based on genetically modified Escherichia coli cells harboring cyclohexanone monooxygenase was investigated in a free and immobilized form in continuous bioreactors. The biotransformation of a bicyclic ketone to a racemic mixture of the corresponding lactones by an enzymatic cascade was performed in a membrane bioreactor (MBR) for free cells and in a fluidized-bed bioreactor (FBBR) for immobilized cells. Both reactors were operated at the residence time of 6.25 h with the biocatalyst concentration of 1 % w/w. Different oxygen mass transfer rates were set via the impeller speed in MBR or air flow rate in FBBR, respectively. The potential of continuous bioreactors to achieve a steady state was utilized for the analysis of different factors affecting the biocatalyst stability. An apparent steady state could be maintained in these bioreactors up to 40 h. The operation at high conversions or high oxygenation rates allowed to exclude poisoning by substrate or oxygen as causes of biocatalyst activity loss. Further experiments showed that the cells did not lose viability or plasmid. The problem in biocatalyst stability was not in the stability of cyclohexanone monooxygenase but in insufficient regeneration of cofactors. The only partially effective measure was the addition of catalase with the feed concentration of 0.025 g/L that decomposed hydrogen peroxide formed in the enzymatic cascade. However, both free and immobilized biocatalysts lost their activity completely in about a week.

Synthesis of novel biocatalyst from organic waste protonated with acid treatment for hydrogen production

In this research study, orange peel-based biocatalysts developed from different acid protonation were used as a metal-free catalyst for hydrogen production from sodium borohydride (NaBH4). In order to prepare the orange peel-based biocatalyst with higher catalytic activity, experiments were conducted with pure orange peel, different acid molar concentrations, and calcination temperatures. The physical morphology, surface texture, and chemical interaction were thoroughly analyzed by XRD, FTIR Raman, FESEM, BET, and TGA. As a result of the experiment, it was determined that the highly acid-treated biocatalyst (40% H3PO4, 40% H2SO4, 40% HCl) and calcinated at 450 °C for 1 h had higher catalytic activity. As a result, bio-hydrogen production at 35 °C and 70 °C methanolysis with 3% NaBH4 catalyzed by a mixture of acid-treated catalysts were found as 46,213 and 63,842 ml min−1g.cat−1, respectively. However, with the increase of molar concentration of biocatalyst with 40% individual acid prolonged samples, the HGR rates will not have a satisfactory value in comparison with the 40% mixture of the acid-treated catalyst due to less number of active sites.

Enzymatic Transesterification of Atlantic Salmon (Salmo salar) Oil with Isoamyl Alcohol.

In this experimental study, biodiesel was synthesized from the salmon oil using the Lipozyme®RM IM (Bagsværd, Denmark) as a biocatalyst. Isoamyl alcohol was used as an acyl acceptor in the transesterification process. The aim of this study is to select the best process conditions, aiming to obtain the highest transesterification degree that meets the requirements of the EN 14214 standard. Response surface methodology (RSM) was used for statistical analysis and optimization of process parameters. A four-factor experimental design was modelled by central compositional design (CCD) to investigate the effects of biocatalyst concentration, isoamyl alcohol-to-oil molar ratio, temperature, and duration on transesterification degree. It was determined that the optimal parameters for biodiesel synthesis were the following: an enzyme concentration of 11% (wt. of oil mass); a process temperature of 45 °C; a process duration of 4 h; and an alcohol-to-oil molar ratio of 6:1. The transesterification degree of biodiesel reached 87.23%. The stepwise addition of isoamyl alcohol during the transesterification process further increased the degree of transesterification to 96.5%.

Process optimization for enzymatic production of a valuable biomass-based ester from levulinic acid.

The enzymatic production of isoamyl levulinate via esterification of isoamyl alcohol (IA) and levulinic acid (LA), a biomass-based platform chemical with attractive properties, in a solvent system has been performed in this study. For such a purpose, a low-cost liquid lipase (Eversa® Transform 2.0) immobilized by physical adsorption via hydrophobic interactions (mechanism of interfacial activation) on mesoporous poly(styrenene-divinylbenzene) (PSty-DVB) beads was used as heterogeneous biocatalyst. It was prepared at low ionic strength (5mmol.L-1 buffer sodium acetate pH 5.0) and 25℃ using an initial protein loading of 40mg.g-1 of support. Maximum protein loading of 31.2 ± 2.8mg.g-1 of support and an immobilization yield of 83% was achieved. The influence of relevant factors (biocatalyst concentration and reaction temperature) on ester production was investigated using a central composite rotatable design (CCRD). Maximum acid conversion percentage of 65% was achieved after 12h of reaction at 40°C, 20% of mass of heterogeneous biocatalyst per mass of reaction mixture (20% m.m-1), and LA:IA molar ratio of 1:1.5 in a methyl isobutyl ketone (MIBK) medium. The biocatalyst retained around of 30% of its initial activity after five consecutive esterification batches under optimal experimental conditions. The proposed experimental procedure can be considered as an acceptable green process (EcoScale score of 66.5), in addition to the fact that a new strategy is proposed to sustainably produce a valuable industrial ester (isoamyl levulinate) from biomass-based materials using an immobilized and low-cost commercial lipase as catalyst.

Enhancing the biodesulphurization capacity of Rhodococcus sp. FUM94 in a biphasic system through optimization of operational factors

The biodesulfurization activity of bacteria through the 4S pathway in aqueous-oil emulsions is affected by various operational factors. These factors also demonstrate interacting effects that influence the potential for field applications of biodesulfurization technology and can solely be deciphered through multi-variable experiments. In this study, the effects of the influential factors and their interactions on the desulfurizing activity of a newly identified desulfurizing bacterium, Rhodococcus sp, FUM94 were quantitatively investigated. The capacity improvement achieved through optimized values obtained in this study is significant due to its simple implementation to large scale processes. This is the most simple and the most cost-effective way to scale-up a biodesulfurization process.Using response surface methodology (RSM). Optimum values of the factors were identified with the objective of maximizing biodesulfurization activity. Results revealed that the desulfurization activity of the biocatalyst increased from 0.323 ± 0.072 to 46.57 ± 4.556 mmol 2-Hydroxybiphenyl (kg dry cell weight)-1 h-1 at the optimized conditions of 6 h reaction time, 2 g.L-1 biocatalyst concentration, 0.54 mM (100 ppm) dibenzothiophene (DBT) concentration (sulfur source), and 25% oil phase fraction. Desirability analysis proved that the selected conditions are the most desirable combination of factors (desirability value = 0.896) to achieve the highest biodesulfurization activity of the biocatalyst. A comparison between the biodesulfurization capacity achieved in this study and the capacities reported in similar studies published in the past two decades revealed that biodesulfurization under optimized operational conditions outperforms previously proposed techniques.

Stabilization of water‐in‐oil emulsions using a wax ester synthesized by a new homemade heterogeneous biocatalyst

AbstractBACKGROUNDCetyl palmitate is a wax ester naturally found in sperm whale spermaceti, and it is of importance in the cosmetics industry. International regulations prohibit the sale of sperm whale spermaceti, so it is now being replaced by pure cetyl palmitate obtained by a chemical route or from mixtures based on jojoba oil. Another alternative is to use an enzymatic route for wax ester synthesis. For such a purpose, a new heterogeneous biocatalyst was prepared by our research group via physical adsorption of Burkholderia cepacia lipase on aerogel modified with a protic ionic liquid (IB‐IL‐OPT). Its catalytic activity was compared with that of a biocatalyst prepared using a non‐chemically modified silica aerogel (IB‐Control). The objective of this work was to apply this homemade heterogeneous biocatalyst to cetyl palmitate synthesis via a direct esterification reaction in a solvent system and to test the final product as a stabilizing agent in water‐in‐oil emulsions.RESULTSIB‐IL‐OPT achieved maximum acid conversion of 95–100% under optimal experimental conditions established using a central composite rotational design: biocatalyst concentration of 14.8% (w/w), molar ratio of 1:1.3, 41 °C for 15 h of reaction under continuous mechanical agitation (200 rpm). The IB‐Control gave 58.8% acid conversion in similar conditions. IB‐IL‐OPT was successively reused for four cycles. The wax ester showed potential as a good emulsifier for virgin coconut oil.CONCLUSIONSThe cetyl palmitate obtained via an enzymatic route without further purification showed good emulsifying potential, forming Pickering emulsions. This opens new perspectives for study and applications in the cosmetics industry. © 2022 Society of Chemical Industry (SCI).

Biodesulfurization of Dibenzothiophene and Its Alkylated Derivatives in a Two-Phase Bubble Column Bioreactor by Resting Cells of Rhodococcus erythropolis IGTS8

Biodesulfurization (BDS) is considered a complementary technology to the traditional hydrodesulfurization treatment for the removal of recalcitrant sulfur compounds from petroleum products. BDS was investigated in a bubble column bioreactor using two-phase media. The effects of various process parameters, such as biocatalyst age and concentration, organic fraction percentage (OFP), and type of sulfur compound—namely, dibenzothiophene (DBT), 4-methyldibenzothiophene (4-MDBT), 4,6-dimethyldibenzothiophene (4,6-DMDBT), and 4,6-diethyldibenzothiophene (4,6-DEDBT)—were evaluated, using resting cells of Rhodococcus erythropolis IGTS8. Cells derived from the beginning of the exponential growth phase of the bacterium exhibited the highest biodesulfurization efficiency and rate. The biocatalyst performed better in an OFP of 50% v/v. The extent of DBT desulfurization was dependent on cell concentration, with the desulfurization rate reaching its maximum at intermediate cell concentrations. A new semi-empirical model for the biphasic BDS was developed, based on the overall Michaelis-Menten kinetics and taking into consideration the deactivation of the biocatalyst over time, as well as the underlying mass transfer phenomena. The model fitted experimental data on DBT consumption and 2-hydroxibyphenyl (2-HBP) accumulation in the organic phase for various initial DBT concentrations and different organosulfur compounds. For constant OFP and biocatalyst concentration, the most important parameter that affects BDS efficiency seems to be biocatalyst deactivation, while the phenomenon is controlled by the affinities of biodesulfurizing enzymes for the different organosulfur compounds. Thus, desulfurization efficiency decreased with increasing initial DBT concentration, and in inverse proportion to increases in the carbon number of alkyl substituent groups.

Production and Characterization of Whole-Cell Rhizopus oryzae CCT3759 to be Applied as Biocatalyst in Vegetable Oils Hydrolysis

The present study aims to produce a mycelium-bound lipase of the fungus Rhizopus oryzae CCT3759 by submerged fermentation in order to be applied as biocatalyst in the hydrolysis of different vegetable oils. Optimal cultivation conditions have been achieved in a medium containing olive oil as inducer for 72 h of fermentation, thus obtaining 30.5 g/L of dry biomass concentration and hydrolytic activity of 389.1 U/g, which corresponds to a total lipase activity around of 12,000 U/L. Maximum hydrolytic activity was observed at pH 6.0 and 40 °C. Kinetic parameters concerning apparent Michaelis–Menten constant (Km = 50.5 mM) and maximum reaction rate (Vmax = 815.4 µmol/g min) have been determined in olive oil emulsion hydrolysis. Thermal stability tests revealed that the enzyme retained 75% of its initial activity after 4 h at 50 °C, whose thermal inactivation constant (Kd) and half-life (t1/2) was 0.073 h−1 and 9.4 h, respectively. The effect of biocatalyst concentration, expressed as activity units—U (200 and 400 U), on the hydrolysis of vegetable oils was investigated under fixed conditions: oil/buffer mass ratio of 25% (m/m), 100 mM buffer sodium phosphate pH 6.0, 40 °C and the mechanical stirring frequency of 600 rpm. As expected, increasing the initial activity from 200 to 400 U leads to higher values of initial reaction rates and hydrolysis percentage. However, initial reaction rate values were similar for six different vegetable oils due to the high accessibility of the lipase to the substrate under such experimental conditions. A complete hydrolysis of olive, cottonseed, sunflower and canola oils has been achieved after 26–30 h of reaction using 400 U of activity. These results suggest a promising application of the produced biocatalyst in the production of free fatty acids, an important class of compounds for oleochemical industries.

Enzymatic production of isopropyl and 2-ethylhexyl esters using γ-linolenic acid rich fungal oil produced from spent sulphite liquor

The enzymatic production of isopropyl and 2-ethylhexyl esters was investigated using fungal oil produced via fermentation of nanofiltrated spent sulphite liquor (SSL). Screening of five oleaginous fungi showed that Cunninghmamella echinulata could accumulate lipids with 12 % (w/w) γ-linolenic acid content in shake flask cultures. Ester formation by the commercial lipase Novozym 435 was favored when transesterifications of fungal oil with isopropyl and 2-ethylhexyl alcohols were performed at 60 °C, 1:3 microbial oil to alcohol molar ratio and 10 % biocatalyst concentration. Transesterifications of individual neutral lipids (NL), glycolipids and sphingolipids (GL + SL) and phospholipids (PL), with isopropanol and 2-ethyl-hexanol showed that the presence of GL + SL and PL in fungal oil hindered ester production. Transesterification of the NL fraction alone with isopropanol and 2-ethylhexanol led to the highest conversion yield of 80.2 % and 73.8 %, respectively. Conversion yields to isopropyl and 2-ethylhexyl esters reached up to 90 % and 80 % (w/w), respectively, when hydrolyzed fungal oil was used. The biocatalyst showed good stability in 5 repeated enzymatic reactions. The physicochemical properties and the ICP-MS analysis of esters demonstrated their potential utilization in cosmetic formulations. This study showed a perspective of valorizing SSL towards the production of value-added fatty acid esters for chemical, cosmetic and pharmaceutical applications.

Nanobiocatalyst beds with Fenton process for removal of methylene blue

The remediation of methylene blue from wastewater using chitosan-sunflower-nano-iron (CSN) beds was examined in this study with the Fenton process. Nano-iron is synthesized using the green synthesis process. Then, biopolymer beds obtained nano-iron, sunflower tray waste, and chitosan. These beds used the Fenton process for removing Methylene blue (MB) from water. Beds synthesis and dye removing are characterized using SEM, TEM, FTIR, and XRD techniques. For the method optimization, the effects of dye concentration, temperature, pH, H2O2, and amount of biocatalyst were studied. The result of the wavelength scan was found 660 nm for methylene blue dye. Using CSN, catalyst was very effective in color removal for MB under optimal conditions. The highest removal rate 98% was obtained at pH 6 for 270 min. The optimum conditions for the MB dye are as follows; dye concentration: 25 mg/L, amount of absorbent: 2.5 mg/mL, temperature: 60 °C, H2O2 amount: 20 mg/L (600 µL, 30%). When the experiment is studied in optimum conditions, max. dye removal was calculated to be 98%. From SEM, TEM, XRD, and FTIR results, the change in the surface of the biocatalyst could be clearly observed. It is understood that the biocatalyst synthesized from the results we obtained easily removed a large amount of dye (MB).

Production of benzyl cinnamate by a low-cost immobilized lipase and evaluation of its antioxidant activity and toxicity

In this work was optimized the production of benzyl cinnamate by enzymatic catalysis using the immobilized lipase NS88011 and to evaluate its biological properties. The optimized condition for this system was 1:3 (acid:alcohol) molar ratio, 59 °C, biocatalyst concentration 4.4 mg.mL−1 for 32 h, with a yield of 97.6 %. The enzyme stability study showed that the enzyme remains active and yields above 60 % until the 13th cycle (416 h), presenting a promising half-life. In the determination of the antioxidant activity of the ester, an inhibitory concentration necessary to inhibit 50 % of the free radical 2,2-diphenyl-1-picryl-hydrazyl DPPH (IC50) of 149.8 mg.mL−1 was observed. For acute toxicity against bioindicator Artemia salina, lethal doses (LD50) of 0.07 and 436.7 μg.mL−1 were obtained for the ester and cinnamic acid, showing that benzyl cinnamate had higher toxicity, indicating potential cytotoxic activity against human tumors.

An alginate-confined peroxygenase-CLEA for styrene epoxidation.

Oxyfunctionalisation reactions in neat substrate still pose a challenge for biocatalysis. Here, we report an alginate-confined peroxygenase-CLEA to catalyse the enantioselective epoxidation of cis-β-methylstyrene in a solvent-free reaction system achieving turnover numbers of 96 000 for the biocatalyst and epoxide concentrations of 48 mM.

The production of enantiomerically pure 1-phenylethanol by enzymatic kinetic resolution method using response surface methodology.

As the enantiomers of 1-phenylethanol are valuable intermediates in several industries, the lipase catalyzed kinetic resolution of (R,S) -1-phenylethanol is a relevant research topic. In this study, the goal was to determine the optimum reaction parameters to produce enantiomerically pure 1-phenylethanol by lipase (Novozyme 435) catalyzed kinetic resolution using response surface methodology (RSM). Reactions were performed with 40–400 mM (R,S)-1-phenylethanol, 120–1200 mM vinyl acetate and 2–22 mg/mL biocatalyst concentrations (BC L ), at 20–60 °C and with a stirring rate of 50–400 rpm for 5–120 min. The samples were analyzed using high performance liquid chromatography (HPLC) with a Chiralcel OB column. Optimum reaction parameters to reach 100% enantiomeric excess for the substrate ( ee s ) were determined as follows: substrate concentration (C s ): 240 mM, BC L : 11 mg/mL, at 42 °C with a reaction time of 75 min. Model validation was performed using these conditions and ee s was calculated as 100%, which indicates the predicted model was efficient and accurate. When compared to the literature, it was observed that the reaction time decreased significantly. This is an important result considering the industrial scale perspective.

Enhancing immobilization of Aspergillus oryzae ST11 lipase on polyacrylonitrile nanofibrous membrane by bovine serum albumin and its application for biodiesel production

The partially purified lipase from Aspergillus oryzae ST11 was immobilized on the surface-modified electrospun polyacrylonitrile (PAN) nanofibrous membrane. The effects of time and concentrations of glutaraldehyde and bovine serum albumin (BSA) were studied. The immobilized lipase reached the maximum activity at 180 min with the recovered activity of 44.2% (0.22 U/mg-support) in the absence of BSA. After adding 6 mg/mL BSA and 40 mM glutaraldehyde gave the recovered activity at 86.9% (0.43 U/mg-support). It showed the highest stability at pH 7.5 but the soluble lipase was at pH 7.0. In addition, the immobilized lipase was more stable at pH 4.0 and 9.0. The immobilized lipase preserved 56% activity at 70 °C but the soluble lipase had 34% activity. It conserved 86% activity while the soluble lipase had 18% activity after 13 days of storage at 4 °C. The operating parameters such as biocatalyst concentration, water content, and the molar ratio of methanol and palm oil were optimized for biodiesel production. The highest biodiesel conversion (95%) was obtained with the immobilized lipase 15% (w/w), 40% (w/w) 50 mM Tris-HCl buffer pH 7.0 and methanol/palm oil (3.5:1.0). This immobilized lipase could be reused with 82.9% conversion after 10 cycles of batch production.

Lipase Cocktail for Optimized Biodiesel Production of Free Fatty Acids from Residual Chicken Oil

In this work, the combination of different lipases was employed for the production of biodiesel, using the Free Fatty Acids (FFAs) from Residual Chicken Oil (RCO) as a substrate. As biocatalysts, lipases A and B from Candida antarctica (CALA and CALB, respectively) and lipase from Rhizomucor miehei (RML) were used in different combinations; as a result, the best lipase cocktail was composed of 67% CALB and 33% RML, which was used to optimize the esterification reaction parameters (molar ratio (FFAs/ ethyl alcohol), biocatalyst content, temperature and time) by the Taguchi method. Under optimized conditions (1:5, 15% of lipase cocktail, 30 °C and 3 h), it was possible to achieve 89.95 ± 0.3% of conversion.