Biodiesel production from crude Jatropha oil catalyzed by non-commercial immobilized heterologous Rhizopus oryzae and Carica papaya lipases

Comparative modelling, molecular docking and immobilization studies on Rhizopus oryzae lipase: evaluation of potentials for fatty acid methyl esters synthesis

Elucidation of lipase-substrate interactions will guide the proper industrial use and applicability of the enzyme. The aim of this study was to predict the 3 D structure of Rhizopus oryzae ZAC3 (RoZAC3) lipase, study its interactions with some natural substrates and evaluate the feasibility of fatty acid methyl esters (FAME) production by the immobilized lipase. Protein identification of RoZAC3 lipase was carried out using LC-MS/MS. The 3 D structure of the lipase was built using homology modelling and natural substrates such as tributyrin, tripalmitin and triolein were docked to the optimized 3 D model for investigation of enzyme-ligand interactions. RoZAC3 lipase, immobilized by adsorption on Lewatit VP OC 1600 was applied in the synthesis of fatty acid methyl esters (FAME). From the phylogenetic analysis, it was observed that RoZAC3 lipase was closely related (48%) to Rhizopus javanicus lipase (Q7M4U7). The predicted 3 D model was validated using the SWISS model validation server. Ramachandran and ERRAT plots were used to assess the amino acid environment and overall quality of the model. From the docking studies, the values of the binding energies obtained for tributyrin, tripalmitin and triolein were - 5.37, -5.27 and -5.77 respectively. At an enzyme:immobilization support ratio of 50 mg/g, transesterification reaction duration of 18 h and a temperature of 40 oC, the conversion reached above 80%. The molecular docking studies provided information on the interaction/modifications between the RoZAC3 lipase and triacylglycerols that can be exploited for numerous applications. The immobilized lipase could serve in hydro-esterification reactions adaptable for biodiesel production.Communicated by Ramaswamy H. Sarma.

Feruloyl Esterase (LaFae) from Lactobacillus acidophilus: Structural Insights and Functional Characterization for Application in Ferulic Acid Production

Ferulic acid and related hydroxycinnamic acids, used as antioxidants and preservatives in the food, cosmetic, pharmaceutical and biotechnology industries, are among the most abundant phenolic compounds present in plant biomass. Identification of novel compounds that can produce ferulic acid and hydroxycinnamic acids, that are safe and can be mass-produced, is critical for the sustainability of these industries. In this study, we aimed to obtain and characterize a feruloyl esterase (LaFae) from Lactobacillus acidophilus. Our results demonstrated that LaFae reacts with ethyl ferulate and can be used to effectively produce ferulic acid from wheat bran, rice bran and corn stalks. In addition, xylanase supplementation was found to enhance LaFae enzymatic hydrolysis, thereby augmenting ferulic acid production. To further investigate the active site configuration of LaFae, crystal structures of unliganded and ethyl ferulate-bound LaFae were determined at 2.3 and 2.19 Å resolutions, respectively. Structural analysis shows that a Phe34 residue, located at the active site entrance, acts as a gatekeeper residue and controls substrate binding. Mutating this Phe34 to Ala produced an approximately 1.6-fold increase in LaFae activity against p-nitrophenyl butyrate. Our results highlight the considerable application potential of LaFae to produce ferulic acid from plant biomass and agricultural by-products.

Bio-Based Materials versus Synthetic Polymers as a Support in Lipase Immobilization: Impact on Versatile Enzyme Activity

To improve enzyme stability, the immobilization process is often applied. The choice of a support on which the enzymes are adsorbed plays a major role in enhancing biocatalysts’ properties. In this study, bio-based (i.e., chitosan, coffee grounds) and synthetic (i.e., Lewatit VP OC 1600) supports were used in the immobilization of lipases of various microbial origins (yeast (Yarrowia lipolytica) and mold (Aspergillus oryzae)). The results confirmed that the enzyme proteins had been adsorbed on the surface of the selected carriers, but not all of them revealed comparably high catalytic activity. Immobilized CALB (Novozym 435) was used as a commercial reference biocatalyst. The best hydrolytic activity (higher than that of CALB) was observed for Novozym 51032 (lipase solution of A. oryzae) immobilized on Lewatit VP OC 1600. In terms of synthetic activity, there were only slight differences between the applied carriers for A. oryzae lipase, and the highest measures were obtained for coffee grounds. All of the biocatalysts had significantly lower activity in the synthesis reactions than the reference catalyst.

Metal-Organic Frameworks as bio- and heterogeneous catalyst supports for biodiesel production

As biodiesel (BD)/Fatty Acid Alkyl Esters (FAAE) is derived from vegetable oils and animal fats, it is a cost-effective alternative fuel that could complement diesel. The BD is processed from different catalytic routes of esterification and transesterification through homogeneous (alkaline and acid), heterogeneous and enzymatic catalysis. However, heterogeneous catalysts and biocatalysts play an essential role towards a sustainable alternative to homogeneous catalysts applied in biodiesel production. The main drawback is the supporting material. To overcome this, currently, Metal-Organic Frameworks (MOFs) have gained significant interest as supports for catalysts due to their extremely high surface area and numerous binding sites. This review focuses on the advantages of using various MOFs structures as supports for heterogeneous catalysts and biocatalysts for the eco-friendly biodiesel production process. The characteristics of these materials and their fabrication synthesis are briefly discussed. Moreover, we address in a general way basic items ranging from biodiesel synthesis to applied catalysts, giving great importance to the enzymatic part, mainly to the catalytic mechanism in esterification/transesterification reactions. We provide a summary with recommendations based on the limiting factors.

Producing Natural Flavours from Isoamyl Alcohol and Fusel Oil by Using Immobilised Rhizopus oryzae Lipase

Enzymatic synthesis of short-chain esters (flavours) might enable their labelling as natural, increasing their value. Covalently immobilised Rhizopus oryzae lipase (EO-proROL) was used to synthesise isoamyl butyrate and acetate. In cyclohexane, the best performer reaction solvent, 1.8 times higher yield of isoamyl butyrate (ca. 100%) than isoamyl acetate (ca. 55%) was obtained. Optimum initial acid concentration (410 mM) and acid:alcohol mole ratio (0.5) were established by a central composite rotatable design to maximise isoamyl butyrate single-batch and cumulative production with reused enzyme. These conditions were used to scale up the esterification (150 mL) and to assess yield, initial esterification rate, productivity and enzyme operational stability. Commercial isoamyl alcohol and fusel oil results were found to be similar as regards yield (91% vs. 84%), initial reaction rate (5.4 µM min−1 with both substrates), operational stability (40% activity loss after five runs with both) and productivity (31.09 vs. 28.7 mM h−1). EO-proROL specificity for the structural isomers of isoamyl alcohol was also evaluated. Thus, a successful biocatalyst and product conditions ready to be used for isoamyl ester industrial production are here proposed.

Prospects of Catalysis for Process Sustainability of Eco-Green Biodiesel Synthesis via Transesterification: A State-Of-The-Art Review

Environmental pollution caused by conventional petro-diesel initiates at time of crude oil extraction and continues until its consumption. The resulting emission of poisonous gases during the combustion of petroleum-based fuel has worsened the greenhouse effect and global warming. Moreover, exhaustion of finite fossil fuels due to extensive exploitation has made the search for renewable resources indispensable. In light of this, biodiesel is a best possible substitute for the regular petro-diesel as it is eco-friendly, renewable, and economically viable. For effective biodiesel synthesis, the selection of potential feedstock and choice of efficient catalyst is the most important criteria. The main objective of this bibliographical review is to highlight vital role of different catalytic systems acting on variable feedstock and diverse methods for catalysis of biodiesel synthesis reactions. This paper further explores the effects of optimized reaction parameters, modification in chemical compositions, reaction operating parameters, mechanism and methodologies for catalysts preparation, stability enhancement, recovery, and reusability with the maximum optimum activity of catalysts. In future, the development of well-planned incentive structures is necessary for systematic progression of biodiesel process. Besides this, the selection of accessible and amended approaches for synthesis and utilization of specific potential catalysts will ensure the sustainability of eco-green biodiesel.

Lignocellulosic residues as supports for enzyme immobilization, and biocatalysts with potential applications

Growing demand for agricultural production means a higher quantity of residues produced. The reuse and recycling of agro-industrial wastes reduce worldwide greenhouse emissions. New opportunities are derived from this kind of residuals in the biotechnological field generating valuable products in growing sectors such as transportation, bioenergy, food, and feedstock. The use of natural macromolecules towards biocatalysts offers numerous advantages over free enzymes and friendliness with the environment. Enzyme immobilization improves enzyme properties (stability and reusability), and three types of supports are discussed: inorganic, organic, and hybrid. Several examples of agro-industrial wastes such as coconut wastes, rice husks, corn residues and brewers spent grains (BSG), their properties and potential as supports for enzyme immobilization are described in this work. Before the immobilization, biological and non-biological pretreatments could be performed to enhance the waste potential as a carrier. Additionally, immobilization methods such as covalent binding, adsorption, cross-linking and entrapment are compared to provide high efficiency. Enzymes and biocatalysts for industrial applications offer advantages over traditional chemical processes with respect to sustainability and process efficiency in food, energy, and bioremediation fields. The wastes reviewed in this work demonstrated a high affinity for lipases and laccases and might be used in biodiesel production and textile wastewater treatment, among other applications.

Integrated bioprocess for structured lipids, emulsifiers and biodiesel production using crude acidic olive pomace oils

Olive pomace oil (OPO), a by-product of olive oil industry, is directly consumed after refining. The novelty of this study consists of the direct use of crude high acidic OPO (3.4-20% acidity) to produce added-value compounds, using sn-1,3-regioselective lipases: (i) low-calorie dietetic structured lipids (SL) containing caprylic (C8:0) or capric (C10:0) acids by acidolysis or interesterification with their ethyl esters, (ii) fatty acid methyl esters (FAME) for biodiesel, and (iii) sn-2 monoacylglycerols (emulsifiers), as by-product of FAME production by methanolysis. Immobilized Rhizomucor miehei lipase showed similar activity in acidolysis and interesterification for SL production (yields: 47.8-53.4%, 7 h, 50℃) and was not affected by OPO acidity. Batch operational stability decreased with OPO acidity, but it was at least three-fold in interesterification that in acidolysis. Complete conversion of OPO into FAME and sn-2 monoacylglycerols was observed after 3 h-transesterification (glycerol stepwise addition) and lipase deactivation was negligeable after 11 cycles.

Sustainable biodiesel generation through catalytic transesterification of waste sources: a literature review and bibliometric survey

Sustainable renewable energy production is being intensely disputed worldwide because fossil fuel resources are declining gradually. One solution is biodiesel production via the transesterification process, which is environmentally feasible due to its low-emission diesel substitute. Significant issues arising with biodiesel production are the cost of the processes, which has stuck its sustainability and the applicability of different resources. In this article, the common biodiesel feedstock such as edible and non-edible vegetable oils, waste oil and animal fats and their advantages and disadvantages were reviewed according to the Web of Science (WOS) database over the timeframe of 1970-2020. The biodiesel feedstock has water or free fatty acid, but it will produce soap by reacting free fatty acids with an alkali catalyst when they present in high portion. This reaction is unfavourable and decreases the biodiesel product yield. This issue can be solved by designing multiple transesterification stages or by employing acidic catalysts to prevent saponification. The second solution is cheaper than the first one and even more applicable because of the abundant source of catalytic materials from a waste product such as rice husk ash, chicken eggshells, fly ash, red mud, steel slag, and coconut shell and lime mud. The overview of the advantages and disadvantages of different homogeneous and heterogeneous catalysts is summarized, and the catalyst promoters and prospects of biodiesel production are also suggested. This research provides beneficial ideas for catalyst synthesis from waste for the transesterification process economically, environmentally and industrially.

Effect of Different TiO2 Morphologies on the Activity of Immobilized Lipase for Biodiesel Production

Lipase catalytic activity is greatly influenced by immobilization on nanoparticles. In this study, lipase from Aspergillus niger was immobilized on TiO₂ nanoparticles with different morphologies: microspheres, nanotubes, and nanosheets. All TiO₂ samples were prepared by a hydrothermal method. Lipase/TiO₂ nanocomposites were prepared by a physical adsorption method through hydrophobic interactions. The prepared composites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM). The catalytic activity of free and immobilized lipases was tested using sunflower oil in the presence of methanol to produce biodiesel at 40 °C for 90 min. The lipase immobilized on TiO₂ microspheres showed the highest activity compared to the lipase immobilized on TiO₂ nanotubes and nanosheets. To optimize the lipase-to-microsphere ratio, lipase was immobilized on TiO₂ microspheres in different microspheres/lipase, w/w, (S/L) ratios of 1:1, 1:0.75, 1:0.5, and 1:0.25. It was noticed that the hydrolytic activity follows the order 1:0.25 > 1:0.5 > 1:75 > 1:1. The immobilization yield activities were found to be 113, 123, 125, and 130% for the microspheres/lipase (S/L) ratios of 1:1, 1:0.75, 1:0.5, and 1:0.25, respectively.

Argan Oil as a Rich Source of Linoleic Fatty Acid for Dietetic Structured Lipids Production

Argan oil is rich in long-chain unsaturated fatty acids (FA), mostly oleic and linoleic, and natural antioxidants. This study addresses the production of low-calorie structured lipids by acidolysis reaction, in a solvent-free system, between caprylic (C8:0; system I) or capric (C10:0; system II) acids and argan oil, used as triacylglycerol (TAG) source. Three commercial immobilized lipases were tested: Novozym^® 435, Lipozyme^® TL IM, and Lipozyme^® RM IM. Higher incorporation degree (ID) was achieved when C10:0 was used as acyl donor, for all the lipases tested. Lipozyme^® RM IM yielded the highest ID for both systems (28.9 ± 0.05 mol.% C10:0, and 11.4 ± 2.2 mol.% C8:0), being the only catalyst able to incorporate C8:0 under the reaction conditions for biocatalyst screening (molar ratio 2:1 FA/TAG and 55 °C). The optimal conditions for Lipozyme^® RM IM in system II were found by response surface methodology (66 °C; molar ratio FA/TAG of 4:1), enabling to reach an ID of 40.9 mol.% of C10:0. Operational stability of Lipozyme^® RM IM in system II was also evaluated under optimal conditions, after eight consecutive 24 h-batches, with biocatalyst rehydration between cycles. The biocatalyst presented a half-life time of 103 h.

Constitutive Expression in Komagataella phaffii of Mature Rhizopus oryzae Lipase Jointly with Its Truncated Prosequence Improves Production and the Biocatalyst Operational Stability

Rhizopus oryzae lipase (ROL) containing 28 C-terminal amino acids of the prosequence fused to the N-terminal mature sequence in ROL (proROL) was successfully expressed in the methylotrophic yeast Komagataella phaffii (Pichia pastoris) under the constitutive glyceraldehyde-3-phosphate dehydrogenase promoter (PGAP). Although the sequence encoding the mature lipase (rROL) was also transformed, no clones were obtained after three transformation cycles, which highlights the importance of the truncated prosequence to obtain viable transformed clones. Batch cultures of the K. phaffii strain constitutively expressing proROL scarcely influenced growth rate and exhibited a final activity and volumetric productivity more than six times higher than those obtained with proROL from K. phaffii under the methanol-inducible alcohol oxidase 1 promoter (PAOX1). The previous differences were less marked in fed-batch cultures. N-terminal analysis confirmed the presence of the 28 amino acids in proROL. In addition, immobilized proROL exhibited increased tolerance of organic solvents and an operational stability 0.25 and 3 times higher than that of immobilized rROL in biodiesel and ethyl butyrate production, respectively. Therefore, the truncated prosequence enables constitutive proROL production, boosts bioprocess performance and provides a more stable biocatalyst in two reactions in which lipases are mostly used at industrial level, esterification (ethyl butyrate) and transesterification (biodiesel).

Categorisation of culturable bioaerosols in a fruit juice manufacturing facility

Bioaerosols are defined as aerosols that comprise particles of biological origin or activity that may affect living organisms through infectivity, allergenicity, toxicity, or through pharmacological or other processes. Interest in bioaerosol exposure has increased over the last few decades. Exposure to bioaerosols may cause three major problems in the food industry, namely: (i) contamination of food (spoilage); (ii) allergic reactions in individual consumers; or (iii) infection by means of pathogenic microorganisms present in the aerosol. The aim of this study was to characterise the culturable fraction of bioaerosols in the production environment of a fruit juice manufacturing facility and categorise isolates as harmful, innocuous or potentially beneficial to the industry, personnel and environment. Active sampling was used to collect representative samples of five areas in the facility during peak and off-peak seasons. Areas included the entrance, preparation and mixing area, between production lines, bottle dispersion and filling stations. Microbes were isolated and identified using 16S, 26S or ITS amplicon sequencing. High microbial counts and species diversity were detected in the facility. 239 bacteria, 41 yeasts and 43 moulds were isolated from the air in the production environment. Isolates were categorised into three main groups, namely 27 innocuous, 26 useful and 39 harmful bioaerosols. Harmful bioaerosols belonging to the genera Staphylococcus, Pseudomonas, Penicillium and Candida were present. Although innocuous and useful bioaerosols do not negatively influence human health their presence act as an indicator that an ideal environment exists for possible harmful bioaerosols to emerge.

Rhizopus oryzae Lipase, a Promising Industrial Enzyme: Biochemical Characteristics, Production and Biocatalytic Applications

Lipases are biocatalysts with a significant potential to enable a shift from current pollutant manufacturing processes to environmentally sustainable approaches. The main reason of this prospect is their catalytic versatility as they carry out several industrially relevant reactions as hydrolysis of fats in water/lipid interface and synthesis reactions in solvent-free or non-aqueous media such as transesterification, interesterification and esterification. Because of the outstanding traits of Rhizopus oryzae lipase (ROL), 1,3-specificity, high enantioselectivity and stability in organic media, its application in energy, food and pharmaceutical industrial sector has been widely studied. Significant advances have been made in the biochemical characterisation of ROL particularly in how its activity and stability are affected by the presence of its prosequence. In addition, native and heterologous production of ROL, the latter in cell factories like Escherichia coli, Saccharomyces cerevisiae and Komagataella phaffii (Pichia pastoris), have been thoroughly described. Therefore, in this review, we summarise the current knowledge about R. oryzae lipase (i) biochemical characteristics, (ii) production strategies and (iii) potential industrial applications.

Entrapping Immobilisation of Lipase on Biocomposite Hydrogels toward for Biodiesel Production from Waste Frying Acid Oil

A new application of biocomposite hydrogels named gelatin-alginate (GA) and pectin alginate (PA) enables the use of the hydrogels as carriers for lipase entrapment during biodiesel production. Waste frying acid oil (WFAO), a raw material, was converted to biodiesel via an esterification reaction catalysed by two different immobilised biocatalysts: gelatin-alginate lipase (GAL) and pectin-alginate lipase (PAL). The highest immobilisation yield of GAL and PAL beads was achieved at 97.61% and 98.30%, respectively. Both of them gave biodiesel yields in the range of 75–78.33%. Furthermore, capability and reusability of biocatalysts were improved such that they could be reused up to 7 cycles. Moreover, the predicted biodiesel properties met the European biodiesel standard (EN14214). Interestingly, entrapped lipase on composite hydrogels can be used as an alternative catalyst choice for replacing the chemical catalyst during the biodiesel production.

A Review on Bio-Based Catalysts (Immobilized Enzymes) Used for Biodiesel Production

The continuous increase of the world’s population results in an increased demand for energy drastically from the industrial and domestic sectors as well. Moreover, the current public awareness regarding issues such as pollution and overuse of petroleum fuel has resulted in the development of research approaches concerning alternative renewable energy sources. Amongst the various options for renewable energies used in transportation systems, biodiesel is considered the most suitable replacement for fossil-based diesel. In what concerns the industrial application for biodiesel production, homogeneous catalysts such as sodium hydroxide, potassium hydroxide, sulfuric acid, and hydrochloric acid are usually selected, but their removal after reaction could prove to be rather complex and sometimes polluting, resulting in increases on the production costs. Therefore, there is an open field for research on new catalysts regarding biodiesel production, which can comprise heterogeneous catalysts. Apart from that, there are other alternatives to these chemical catalysts. Enzymatic catalysts have also been used in biodiesel production by employing lipases as biocatalysts. For economic reasons, and reusability and recycling, the lipases urged to be immobilized on suitable supports, thus the concept of heterogeneous biocatalysis comes in existence. Just like other heterogeneous catalytic materials, this one also presents similar issues with inefficiency and mass-transfer limitations. A solution to overcome the said limitations can be to consider the use of nanostructures to support enzyme immobilization, thus obtaining new heterogeneous biocatalysts. This review mainly focuses on the application of enzymatic catalysts as well as nano(bio)catalysts in transesterification reaction and their multiple methods of synthesis.

Semi-pilot scale production of biodiesel from waste frying oil by genetically improved fungal lipases

This paper addresses the issue of combining the usage of waste frying oil (WFO), as a feedstock, and a lipase produced in solid-state fermentation (SSF), as a biocatalyst, for semi-pilot scale production of biodiesel as fatty acid methyl esters (FAME). Two fungal mutants namely; Rhizopus stolonifer 1aNRC11 mutant F (1F) and Aspergillus tamarii NDA03a mutant G (3G) were used as a cocatalyst. The two mutants were cultivated separately by SSF in a tray bioreactor. The dried fermented solid of 1F and 3G mutants were used in a ratio of 3:1, respectively, for WFO transesterification. Optimization of several semi-pilot process stages including SSF and WFO transesterification reaction conditions resulted in 92.3% conversion of WFO to FAME. This FAME yield was obtained after 48 h using 10% cocatalyst (w/w of WFO), 10% water (w/w of WFO) and 3:1 methanol/ WFO molar ratio at 30 °C and 250 rpm. A preliminary economic evaluation of produced biodiesel price (190 $/Ton) is less than half the price of petroleum diesel in Egypt (401$/Ton) and is about 40.3% the price of biodiesel produced using a pure enzyme, which is a promising result. This strategy makes the biodiesel synthesis process greener, economical and sustainable.

Facile One-Pot Immobilization of a Novel Thermostable Carboxylesterase from Geobacillus uzenensis for Continuous Pesticide Degradation in a Packed-Bed Column Reactor

The novel carboxylesterase gene (est741) was cloned from Geobacillus uzenensis. The optimal pH and temperature of Est741 were 8.0 and 50 °C. Through site-directed mutation, the optimum temperature of the mutant M160K(EstM160K) was increased from 50 to 60 °C, and showed enhanced T1/2 of 2.5 h at 70 °C in comparison to the wild type (1.3 h). EstM160K was successfully expressed Pichia pastoris and EstM160K fermentation broth was directly immobilized on epoxy-functionalized supports via a one-pot strategy to obtain the immobilized enzyme lx-EstM160K. Additionally, lx-EstM160K showed enhanced T1/2 of 36.8 h at 70 °C in comparison to free enzyme. lx-EstM160K could degrade various pyrethroid pesticides. After 40 min reaction with 50 U of the lx-EstM160K, the malathion removal was 95.8% with a malathion concentration of 20 mg/L. When 2.5 g lx-EstM160K was added to the 10 mL column reactor with the concentration of bifenthrin was 500 mg/L and the transfer rate of the pump was 0.7 mL/min, the degradation rate of lx-EstM160K to bifenthrin was 90.4%. lx-EstM160K exhibited high operational stability and maintained 72% initial activity after ten batches of continuous reaction for bifenthrin pesticide biodegradation.

Immobilization of Lipozyme TL 100L for methyl esterification of soybean oil deodorizer distillate

An immobilization method for binding cross-linked enzyme aggregates of Lipozyme TL 100L on macroporous resin NKA (CLEA-TLL@NKA) was developed in this study. The esterification activity of CLEA-TLL@NKA reached 6.4 U/mg. The surface structure of immobilized lipase was characterized by scanning electron microscopy. Methyl esterification reaction of soybean oil deodorizer distillate (SODD) was catalyzed by CLEA-TLL@NKA, which the conversion rate reached 98% and its activity retained over 90% after 20 batches of reaction. Compared with the commercial enzyme Lipozyme TLIM, half-life (t _1/2) of CLEA-TLL@NKA increased by 25 times and the catalytic activity increased by approximate 10 times. Thus, CLEA-TLL@NKA had high catalytic activity, good operational stability, and potential industrial application in the field of oil processing.

Novozym 435: the “perfect” lipase immobilized biocatalyst?

Novozym 435 (N435) is a commercially available immobilized lipase produced by Novozymes with its advantages and drawbacks.

Lipases as Biocatalyst for Biodiesel Production

Global shortages of fossil fuels, significant rise in the price of crude oil, and increased environmental concerns have stimulated the rapid growth of biodiesel production. Biodiesel is generally produced through transesterification reaction catalyzed either chemically or enzymatically. Enzymatic transesterification is of interest since it shows advantages over the chemical process and, in addition, is considered a "green" process. This chapter reviews the current status of biodiesel production with a lipase biocatalysis approach, including sources of lipases, kinetics, lipase immobilization techniques, and lipase reaction mechanism for biodiesel production. Factors affecting biodiesel production and the economic feasibility of lipase biodiesel production are also covered.

Application of commercial and non-commercial immobilized lipases for biocatalytic production of ethyl lactate in organic solvents

This study explores the potential for enhancing the production of ethyl lactate (EL), a green solvent, through enzymatic esterification. Different solvents were compared as organic media for conversion of lactate and ethanol into EL, catalyzed by Novozym 435. Chloroform and hexane were the most effective in low acid concentrations (0.01-0.1M) exhibiting maximum EL yields of 88% and 75% respectively. The yield of EL improved as the solvent's LogP increased up to a value of 2. Non-commercial immobilized biocatalysts consisting heterologous Rhizopous oryzae (rROL) and Candida rugosa (CRL) lipases immobilized on hydrophobic supports were compared to commercial biocatalysts clarifying that Novozym 435 and Lipozyme RM IM could be efficiently applied. Operational stability tests were conducted using Novozym 435, which retained higher activity in chloroform as compared to hexane. Although non-commercial biocatalysts were not competitive in esterification, they exhibited significant activity towards hydrolysis constituting a valuable alternative to higher-cost options.

Modulation of the regioselectivity of Thermomyces lanuginosus lipase via biocatalyst engineering for the Ethanolysis of oil in fully anhydrous medium

Background

Enzymatic ethanolysis of oils (for example, high oleic sunflower oil containing 90% of oleic acid) may yield two different reaction products depending on the regioselectivity of the immobilized lipase biocatalyst. Some lipase biocatalysts exhibit a 1,3-regioselectivity and they produced 2 mols of fatty acid ethyl ester plus 1 mol of sn2-monoacylglycerol (2-MAG) per mol of triglyceride without the release of glycerol. Other lipase biocatalysts are completely non-regioselective releasing 3 mols of fatty acid ethyl ester and 1 mol of glycerol per mol of triglyceride. Lipase from Thermomyces lanuginosus (TLL) adsorbed on hydrophobic supports is a very interesting biocatalyst for the ethanolysis of oil. Modulation of TLL regioselectivity in anhydrous medium was intended via two strategies of TLL immobilization: a. - interfacial adsorption on different hydrophobic supports and b.- interfacial adsorption on a given hydrophobic support under different experimental conditions.

Results

Immobilization of TLL on supports containing divinylbenezene moieties yielded excellent 1,3-regioselective biocatalysts but immobilization of TLL on supports containing octadecyl groups yielded non-regioselective biocatalysts.

On the other hand, TLL immobilized on Purolite C18 at pH 8.5 and 30 °C in the presence of traces of CTAB yielded a biocatalyst with a perfect 1,3-regioselectivity and a very interesting activity: 2.5 μmols of oil ethanolyzed per min per gram of immobilized derivative. This activity is 10-fold higher than the one of commercial Lipozyme TL IM. Immobilization of the same enzyme on the same support, but at pH 7.0 and 25 °C, led to a biocatalyst which can hydrolyze all ester bonds in TG backbone.

Conclusions

Activity and regioselectivity of TLL in anhydrous media can be easily modulated via Biocatalysis Engineering producing very active immobilized derivatives able to catalyze the ethanolysis of triolein. When the biocatalyst was 1,3-regioselective a 33% of 2-monoolein was obtained and it may be a very interesting surfactant. When biocatalyst catalyzed the ethanolysis of the 3 positions during the reaction process, a 99% of ethyl oleate was obtained and it may be a very interesting drug-solvent and surfactant. The absence of acyl migrations under identical reaction conditions is clearly observed and hence the different activities and regioselectivities seem to be due to the different catalytic properties of different derivatives of TLL.

Monitoring the Activity of Immobilized Lipase with Quinizarin Diester Fluoro-Chromogenic Probe

Quinizarin diester is used as a fluoro-chromogenic substrate of the activity of lipase supported in poly(methylmetacrylate) beads (CALB, Novozym^® 435) dispersed in organic solvents. The monoester and diester of quinizarin are both non-fluorescent species contrasting with the enzymatic product quinizarin that shows optical absorption in the visible region and strong fluorescence signal. The enzymatic conversion is accomplished by spectroscopic measurements and it follows a sigmoid curve from which the mean reaction time of the enzymatic process can be determined. This parameter indicates the enzyme activity of the immobilized lipase. Its dependency with the amount of lipase allowed the determination of the ratio of the catalytic rate and the Michaelis constant (k_c/K_m) and the experimental value found was (1.0 ± 0.1) × 10⁻² mg⁻¹/min in the case of quinizarin diacetate.

Identification of lipolytic enzymes isolated from bacteria indigenous to Eucalyptus wood species for application in the pulping industry

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Phenol red screening plates is the best method for detecting lipolytic activity.

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Substrate specificity is affected by temperature and pH.

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Essential to test substrates at various pH and temperature to determine optima.

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Lipolytic enzymes indigenous to Eucalyptus sp. can assist in pitch control.

This study highlights the importance of determining substrate specificity at variable experimental conditions. Lipases and esterases were isolated from microorganisms cultivated from Eucalyptus wood species and then concentrated (cellulases removed) and characterized. Phenol red agar plates supplemented with 1% olive oil or tributyrin was ascertained to be the most favourable method of screening for lipolytic activity. Lipolytic activity of the various enzymes were highest at 45–61 U/ml at the optimum temperature and pH of between at 30–35 °C and pH 4–5, respectively. Change in pH influenced the substrate specificity of the enzymes tested. The majority of enzymes tested displayed a propensity for longer aliphatic acyl chains such as dodecanoate (C₁₂), myristate (C₁₄), palmitate (C₁₆) and stearate (C₁₈) indicating that they could be characterised as potential lipases. Prospective esterases were also detected with specificity towards acetate (C₂), butyrate (C₄) and valerate (C₅). Enzymes maintained up to 95% activity at the optimal pH and temperature for 2–3 h. It is essential to test substrates at various pH and temperature when determining optimum activity of lipolytic enzymes, a method rarely employed. The stability of the enzymes at acidic pH and moderate temperatures makes them excellent candidates for application in the treatment of pitch during acid bi-sulphite pulping, which would greatly benefit the pulp and paper industry.

One-step synthesis of high-yield biodiesel from waste cooking oils by a novel and highly methanol-tolerant immobilized lipase

This study reported a novel immobilized MAS1 lipase from marine Streptomyces sp. strain W007 for synthesizing high-yield biodiesel from waste cooking oils (WCO) with one-step addition of methanol in a solvent-free system. Immobilized MAS1 lipase was selected for the transesterification reactions with one-step addition of methanol due to its much more higher biodiesel yield (89.50%) when compared with the other three commercial immobilized lipases (<10%). The highest biodiesel yield (95.45%) was acquired with one-step addition of methanol under the optimized conditions. Moreover, it was observed that immobilized MAS1 lipase retained approximately 70% of its initial activity after being used for four batch cycles. Finally, the obtained biodiesel was further characterized using FT-IR, ¹H and ¹³C NMR spectroscopy. These findings indicated that immobilized MAS1 lipase is a promising catalyst for biodiesel production from WCO with one-step addition of methanol under high methanol concentration.

Classification of lipolytic enzymes and their biotechnological applications in the pulping industry

In the pulp and paper industry, during the manufacturing process, the agglomeration of pitch particles (composed of triglycerides, fatty acids, and esters) leads to the formation of black pitch deposits in the pulp and on machinery, which impacts on the process and pulp quality. Traditional methods of pitch prevention and treatment are no longer feasible due to environmental impact and cost. Consequently, there is a need for more efficient and environmentally friendly approaches. The application of lipolytic enzymes, such as lipases and esterases, could be the sustainable solution to this problem. Therefore, an understanding of their structure, mechanism, and sources are essential. In this report, we review the microbial sources for the different groups of lipolytic enzymes, the differences between lipases and esterases, and their potential applications in the pulping industry.

Solid-surface activated recombinant Rhizopous oryzae lipase expressed in Pichia pastoris and chemically modified variants as efficient catalysts in the synthesis of hydroxy monodeprotected glycals

A highly active, specific and regioselective heterogeneous lipase biocatalyst was developed for the monodeprotection of peracetylated glycals.

Biodiesel production from crude jatropha oil catalyzed by immobilized lipase/acyltransferase from Candida parapsilosis in aqueous medium

The lipase/acyltransferase from Candida parapsilosis (CpLIP2) immobilized on two synthetic resins (Accurel MP 1000 and Lewatit VP OC 1600) was used as catalyst for the production of biodiesel (fatty acid methyl esters, FAME) by transesterification of jatropha oil with methanol, in a lipid/aqueous system. The oil was dispersed in a buffer solution (pH 6.5) containing methanol in excess (2M in the biphasic system; molar ratio methanol/acyl chains 2:1). Transesterification was carried out at 30°C, under magnetic stirring, using 10% (w/w) of immobilized enzyme in relation to oil. The maximum FAME yields were attained after 8h reaction time: 80.5% and 93.8%, when CpLIP2 immobilized on Accurel MP 1000 or on Lewatit VP OC 1600 were used, respectively. CpLIP2 on both Accurel MP 1000 and Lewatit VP OC 1600 showed high operational stability along 5 consecutive 8h batches.