Enzyme immobilization is a well-known technique that allows the reuse of the biocatalyst and generally improves its stability. These improved characteristics are of fundamental importance to turn ...industrial biocatalysis into viable and competitive processes. The immobilization of enzymes can occur through several physical or chemical techniques. When the increase or retention of the catalytic activity is the main purpose, physical methods should be used because they cause fewer changes in the enzymatic structure. When the reuse and stability are the main targets, a chemical method should be chosen to guarantee stronger enzyme-support interaction. Several materials can be applied for the immobilization of enzymes, either organic or inorganic. Inorganic materials have some advantages, such as high mechanical, thermal and chemical resistance, which are important for the process economy. Among the inorganic materials, ceramics stand out due to their longer shelf life, pore size control during the manufacturing, and novel applications in several industrial processes. Due to the high versatility of lipases and broad range of relevant applications, they are the focus of this review. Lipases are known to have a high affinity with hydrophobic substrates (such as polymers), so there is a lack of studies regarding general aspects of their immobilization in hydrophilic materials as ceramics. Thus, the objective of this work is to provide an overview of the main techniques of enzyme immobilization in ceramic supports highlighting the immobilization of lipases. A general overview of the key parameters to be considered to obtain immobilized enzymes that can be used on a large scale is also presented.
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.
•First report on feijoa leaf extracts obtained by pressurized liquid extraction.•Static PLE provided high antioxidant activity with substantial solvent savings.•SFE extract inhibited the growth of ...typical foodborne pathogens.•Gallic acid, catechin and isoquercetin were the major phenolics identified.•The extracts present potential to be used as natural food additives.
This work investigated the efficiency of pressurized liquid extraction (PLE) and supercritical fluid extraction with cosolvent (SFE) in obtaining feijoa leaf extracts with high antioxidant and antibacterial activities. PLE was performed in customized equipment with environmentally friendly solvents, at 40/80 °C, in dynamic and static mode, and SFE was carried out for 210 min at 30 MPa, 55 °C and 15% ethanol–water as cosolvent. PLE extract (80 °C/ethanol–water/dynamic) provided the highest yield, total phenolic content, and antioxidant activities, but it was not effective as antibacterial agent. In contrast, SFE extract exhibited effectiveness against S. aureus, E. coli, and S. typhimurium, with minimum inhibitory concentration values from 14,211 to 3,553 µg.mL−1. Finally, gallic acid, catechin and isoquercetin were the major phenolics identified by liquid chromatography. Our findings revealed that feijoa leaf extracts by PLE and SFE have remarkable bioactivity, presenting a great potential to be used as natural food additives.
Most paints used for printing in the graphic industry contain traces of heavy metals that are dissolved and carried in the effluent, and the risk posed by these contaminants in the environment is ...associated with toxicity and bioaccumulation in living beings. The aim of this study was to evaluate the use of natural clinoptilolite zeolite (CL) as adsorbent for removal of heavy metals in wastewater from the graphic industry. Adsorption experiments were performed with the CL zeolite for copper(II), chromium(III) and iron(III) so as to determine equilibrium constants and kinetic models. Kinetic assays performed for each metal resulted in removal up to 95.4% iron, 96.0% copper and 85.1% chromium, at 25.0°C and pH 4.0. The zeolite selectivity followed the order Fe>Cr>Cu and the adsorption mechanism followed pseudo-first order kinetic model for copper and chromium and pseudo-second order for iron. The Langmuir model provided the best fit of adsorption isotherms for chromium and copper while Freundlich model was the best for iron. Toxicity and genotoxicity assays in Allium cepa showed the efficiency of the use of CL zeolite as an adsorbent for treating printing industry effluent, showing no toxic and genotoxic potential, contrary to untreated effluent which showed a decrease in germination and increase in total cells with alterations (toxic and genotoxic effect).
Review on Microbial Lipases Production Treichel, Helen; de Oliveira, Débora; Mazutti, Marcio A ...
Food and bioprocess technology,
04/2010, Letnik:
3, Številka:
2
Journal Article
Recenzirano
This review paper provides an overview regarding the main aspects of microbial lipases production. The most important microbial lipase-producing strains for submerged and solid-state fermentations ...are reviewed as well as the main substrates, including the use of agroindustrial residues. Current process techniques (batch, repeated-batch, fed-batch, and continuous mode) are discussed and the main bioreactors configurations are also presented. Furthermore, the present review paper shows a general overview about the development of mathematical models applied to lipase production. Finally, some future perspectives on lipase production are discussed with special emphasis on lipase engineering and the use of mathematical models as a useful tool for process improvement and control.
Lipases are an important group of biocatalysts for many industrial applications. Two new commercial low-cost lipases Eversa® Transform and Eversa® Transform 2.0 was immobilized on four different ...hydrophobic supports: Lewatit-DVB, Purolite-DVB, Sepabeads-C18, and Purolite-C18. The performance of immobilized lipases was investigated in the transesterification of sunflower oil solvent-free in an anhydrous medium. Interesting results were obtained for both lipases and the four supports, but with Sepabeads support the lipases Eversa showed high catalytic activity. However, the more stable and efficient derivative was Eversa® Transform immobilized on Sepabeads C-18. A 98 wt% of ethyl ester of fatty acid (FAEE) was obtained, in 3 h at 40ºC, ethanol/sunflower oil molar ratio of 3:1 and a 10 wt% of the immobilized biocatalyst. After 6 reaction cycles, the immobilized biocatalyst preserved 70 wt% of activity. Both lipases immobilized in Sepabeads C-18 were highly active and stable in the presence of ethanol. The immobilization of Eversa Transform and Eversa Transform 2.0 in hydrophobic supports described in this study appears to be a promising alternative to the immobilization and application of these news lipases still unexplored.
Immobilized lipase is a cost-effective biocatalyst for a wide variety of industrial applications, mainly in food, cosmetics, and pharmaceutics due to the huge number of so-called chemically catalyzed ...reactions of industrial interest that can be replaced by immobilized-enzyme catalysis. In this scenario, there is a growing demand to develop new products, supports, and immobilization protocols, as well as to elucidate the reaction mechanism aiming to cross the barrier imposed by the cost of immobilized lipases. As a large number of researchers have focused their efforts in order to find new applications taking into account new products emerging continuously, it is important to clarify the traditional and alternative process routes using immobilized lipases. In the past decade, almost 5000 research endeavors were reported, and this number continues to rise. This review reports the past 10 years of research work on the techniques used for lipase immobilization proposing a brief introduction about traditional immobilization techniques and an overview of the reactions catalyzed by immobilized lipases with a focus on applications and some products obtained by each pathway.
► Influence of pre-treatment using different gases towards FOS production. ► Best results were found when enzymes were previously treated with LPG. ► An innovative and profitable alternative to the ...FOS industry.
This work is focused on the synthesis of the fructooligosaccharides (FOS) from sucrose and inulin, using free, immobilized and pre-treated immobilized inulinase from Kluyveromyces marxianus NRRL Y 7571 and Aspergillus niger in an aqueous–organic system. Initially, the influence of pre-treatment using four different gases, propane, n-butane, CO2 and liquefied petroleum gas (LPG), was investigated towards FOS production and best results were found when both enzymes were previously treated with LPG. The best reaction yields were obtained when the immobilized enzymes were treated with LPG. Considering FOS synthesis using the enzyme from A. niger, yields of 26.62% of GF2 (kestose), 30.62% of GF3 (nystose) and 8.47% of GF4 (fructosyl nystose) were achieved using sucrose as substrate. Using inulinases from K. marxianus NRRL Y 7571, 11.89% of GF2 and 20.83% of GF3 were obtained, using inulin as substrate. However, promising results were achieved using the free form of inulinase from A. niger (77.19% of GF2; 14.03% of GF3 and 0.07% of GF4) using inulin as substrate.
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.
•Investigated batch enzymatic production of biodiesel in ultrasound solvent-free system.•Developed novel concept of enzymatic biodiesel production from macauba fruit oil.•High yields of enzymatic ...biodiesel production in a short period of time was obtained.
The objective of this study is to evaluate the batch enzymatic production of biodiesel in solvent-free system under ultrasound using as substrates ethanol, soybean oil and macauba fruit oil. For this purpose, a Plackett & Burman experimental design was carried out for soybean oil while a 24−1 design was conducted for macauba oil in order to maximize the biodiesel conversion for each system. Good conversions to fatty acid ethyl esters (FAEE), 88% for soybean oil and 75.2% for macauba oil, was obtained thus demonstrating the potential use of ultrasound for this reaction system.
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