Improving the soluble lipase-catalyzed biodiesel production through a two-step hydroesterification reaction system.

The application of lipases in liquid formulation instead of immobilized forms in the enzymatic biodiesel synthesis can make the process cost-efficient, more competitive, and sustainable. However, despite the benefits, the long reaction times required to achieve satisfactory yields is still a drawback of this biotechnological process. In this sense, employing the novel low-cost soluble NS40116 lipase, this paper proposes an innovative two-step hydroesterification reaction (TSHR) system as a technique of improving the reaction rate of an enzymatic biodiesel production. With the employment of two central composite statistical design to optimize the parameters of each of the reactions involved, the influence of the parameters "water concentration added to the reaction," "methanol-to-oil molar ratio," and "lipase load" on the process yield, besides the acid value of the samples, was investigated. After only 8 h of reaction, the highest fatty acid methyl ester yield reached was 97.1% with an acid value of 4.62 mg KOH g-1 utilizing a total of 8 wt% water, methanol-to-oil molar ratio of 6.3:1, and 0.70 wt% of lipase. Furthermore, the statistical models for both reactions indicated to be significant with 95% of reliability. Considering that the papers published using soluble lipases in a one-step batch process normally reach similar yields to those obtained in this research after 16 h to 24 h of reaction, the proposed system demonstrated to be a promising option of process configuration for the enzymatic production of biodiesel.

Kinetic and thermodynamic study of enzymatic hydroesterification mechanism to fatty acid methyl esters synthesis.

Eversa® Transform 2.0 lipase used as biocatalyst to biodiesel (fatty acid methyl esters - FAME) synthesis has been the target of interesting studies due to its thermostability and cost-effectiveness. In these researches, data about reaction conditions that result in satisfactory yields were investigated. Nevertheless, kinetic and thermodynamic parameters considering this enzyme are scarce. This paper presents an estimation of kinetic and thermodynamic parameters for the Eversa® Transform 2.0-mediated hydroesterification to FAME synthesis. Kinetic studies were performed for different methanol, water and lipase loads in distinct temperatures. Parameters adjusted by the thermodynamic model indicate that the hydrolysis is decisive in the overall hydroesterification reaction rate and the esterification reaction is endothermic (ΔHe = 38.98 kJ/mol). Formation of enzymatic complexes is favored by increasing the temperature, especially the enzyme-methanol inhibition complex. Statistical analysis showed that the model was not overparameterized, and the small confidence interval indicated good reliability of the estimated parameters.

Production of FAME and FAEE via Alcoholysis of Sunflower Oil by Eversa Lipases Immobilized on Hydrophobic Supports.

The performance of two new commercial low-cost lipases Eversa® Transform and Eversa® Transform 2.0 immobilized in different supports was investigated. The two lipases were adsorbed on four different hydrophobic supports. Interesting results were obtained for both lipases and for the four supports. However, the most active derivative was prepared by immobilization of Eversa® Transform 2.0 on Sepabeads C-18. Ninety-nine percent of fatty acid ethyl ester was obtained, in 3 h at 40 °C, by using hexane as solvent, a molar ratio of 4:1 (ethanol/oil), and 10 wt% of immobilized biocatalyst. The final reaction mixture contained traces of monoacylglycerols but was completely free of diacylglycerols. After four reaction cycles, the immobilized biocatalyst preserved 75% of activity. Both lipases immobilized in Sepabeads C-18 were very active with ethanol and methanol as acceptors, but they were much more stable in the presence of ethanol.

Polyesters from Macrolactones Using Commercial Lipase NS 88011 and Novozym 435 as Biocatalysts.

The demand for environmentally friendly products allied with the depletion of natural resources has increased the search for sustainable materials in chemical and pharmaceutical industries. Polyesters are among the most widely used biodegradable polymers in biomedical applications. In this work, aliphatic polyesters (from globalide and ω-pentadecalactone) were synthesized using a new commercial biocatalyst, the low-cost immobilized NS 88011 lipase (lipase B from Candida antarctica immobilized on a hydrophobic support). Results were compared with those obtained under the same conditions using a traditional, but more expensive, commercial biocatalyst, Novozym 435 (lipase B from C. antarctica immobilized on Lewatit VP OC). When NS 88011 was used in the polymerization of globalide, longer reaction times (240 min)-when compared to Novozym 435-were required to obtain high yields (80-90 wt%). However, higher molecular weights were achieved. When poly(ω-pentadecalactone) was synthesized, high yields and molecular weights (130,000 g mol-1) were obtained and the enzyme concentration showed strong influence on the polyester properties. This is the first report describing NS 88011 in polymer synthesis. The use of this cheaper enzymatic preparation can provide an alternative for polyester synthesis via enzymatic ring-opening polymerization.

Influence of agronomic variables on the macronutrient and micronutrient contents and thermal behavior of mate tea leaves (Ilex paraguariensis).

The influence of agronomic variables (light intensity, age of leaves, and fertilization type) on the content of macronutrients and micronutrients (potassium, calcium, sodium, magnesium, manganese, iron, zinc, and copper) of tea leaves was assessed by acid digestion, followed by flame atomic absorption spectrometry (FAAS). The thermal behavior of mate tea leaves (Ilex paraguariensis) was also studied in this work. Samples of mate (Ilex paraguariensis) were collected in an experiment conducted under agronomic control at Erva-Mate Barão Commerce and Industry LTD (Brazil). The results showed that the mineral content in mate is affected by the agronomic variables investigated. In general, the content of mineral compounds analyzed is higher for younger leaves and for plants cultivated in shadow. Thermal analysis of samples indicated a similar behavior, with three typical steps of decomposition: loss of water, degradation of low-molecular weight compounds, and degradation of residual materials.

Lipase-Catalyzed Glycerolysis of Soybean and Canola Oils in a Free Organic Solvent System Assisted by Ultrasound.

This work shows new and promising experimental data of soybean oil and canola oil glycerolysis using Novozym 435 enzyme as catalyst in a solvent-free system using ultrasound bath for the emulsifier, monoglyceride (MAG), and diacylglycerol (DAG) production. The experiments were conducted in batch mode to study the influence of process variables as temperature (40 to 70 °C), immobilized enzyme content (2.5 to 10 wt%, relative to substrates), molar ratio glycerol/oil (0.8:1 to 3:1), agitation (0 to 1200 rpm) and ultrasound intensity (0 to 132 W cm(-2)). Highest yields of DAG+MAG (75 wt%) were obtained with molar ratio glycerol/canola oil 0.8:1, 70 °C, 900 rpm, 120 min of reaction time, 10 wt% of enzyme concentration, and 52.8 W cm(-2) of ultrasound intensity. When soybean oil was used, the best results in terms of DAG+MAGs (65 wt%) were using molar ratio of glycerol/soybean oil 0.8:1, 70 °C, 900 rpm, 90 min of reaction time, 10 wt% of enzyme content, and 40 % of ultrasound intensity (52.8 W cm(-2)). The results showed that the lipase-catalyzed glycerolysis in a solvent-free system with ultrasound bath can be a potential route for high content production of DAGs and MAGs.