scholarly journals Cold-Active Lipase-Based Biocatalysts for Silymarin Valorization through Biocatalytic Acylation of Silybin

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1390
Author(s):  
Giulia Roxana Gheorghita ◽  
Victoria Ioana Paun ◽  
Simona Neagu ◽  
Gabriel-Mihai Maria ◽  
Madalin Enache ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Culture Media ◽  
Immobilized Lipase ◽  
Industrial Applications ◽  
Fatty Acid Esters ◽  
Covalent Attachment ◽  
Characterization Methods ◽  
Resin Beads ◽  
Cold Active ◽  
Active Lipase

Extremophilic biocatalysts represent an enhanced solution in various industrial applications. Integrating enzymes with high catalytic potential at low temperatures into production schemes such as cold-pressed silymarin processing not only brings value to the silymarin recovery from biomass residues, but also improves its solubility properties for biocatalytic modification. Therefore, a cold-active lipase-mediated biocatalytic system has been developed for silybin acylation with methyl fatty acid esters based on the extracellular protein fractions produced by the psychrophilic bacterial strain Psychrobacter SC65A.3 isolated from Scarisoara Ice Cave (Romania). The extracellular production of the lipase fraction was enhanced by 1% olive-oil-enriched culture media. Through multiple immobilization approaches of the cold-active putative lipases (using carbodiimide, aldehyde-hydrazine, or glutaraldehyde coupling), bio-composites (S1–5) with similar or even higher catalytic activity under cold-active conditions (25 °C) have been synthesized by covalent attachment to nano-/micro-sized magnetic or polymeric resin beads. Characterization methods (e.g., FTIR DRIFT, SEM, enzyme activity) strengthen the biocatalysts’ settlement and potential. Thus, the developed immobilized biocatalysts exhibited between 80 and 128% recovery of the catalytic activity for protein loading in the range 90–99% and this led to an immobilization yield up to 89%. The biocatalytic acylation performance reached a maximum of 67% silybin conversion with methyl decanoate acylating agent and nano-support immobilized lipase biocatalyst.

scholarly journals Organic Solvent Tolerant Lipases and Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Shivika Sharma ◽  
Shamsher S. Kanwar
Keyword(s):  
Organic Solvent ◽  
Immobilized Lipase ◽  
Industrial Applications ◽  
Fatty Acid Esters ◽  
Reverse Direction ◽  
Organic Media ◽  
Two Phase ◽  
Organic Solvent Tolerant ◽  
Solvent Tolerant ◽  
Esterification Reactions

Lipases are a group of enzymes naturally endowed with the property of performing reactions in aqueous as well as organic solvents. The esterification reactions using lipase(s) could be performed in water-restricted organic media as organic solvent(s) not only improve(s) the solubility of substrate and reactant in reaction mixture but also permit(s) the reaction in the reverse direction, and often it is easy to recover the product in organic phase in two-phase equilibrium systems. The use of organic solvent tolerant lipase in organic media has exhibited many advantages: increased activity and stability, regiospecificity and stereoselectivity, higher solubility of substrate, ease of products recovery, and ability to shift the reaction equilibrium toward synthetic direction. Therefore the search for organic solvent tolerant enzymes has been an extensive area of research. A variety of fatty acid esters are now being produced commercially using immobilized lipase in nonaqueous solvents. This review describes the organic tolerance and industrial application of lipases. The main emphasis is to study the nature of organic solvent tolerant lipases. Also, the potential industrial applications that make lipases the biocatalysts of choice for the present and future have been presented.

scholarly journals Rational Engineering of a Cold-Adapted α-Amylase from the Antarctic Ciliate Euplotes focardii for Simultaneous Improvement of Thermostability and Catalytic Activity

2017 ◽  
Vol 83 (13) ◽  
Author(s):  
Guang Yang ◽  
Hua Yao ◽  
Matteo Mozzicafreddo ◽  
Patrizia Ballarini ◽  
Sandra Pucciarelli ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Catalytic Efficiency ◽  
Industrial Applications ◽  
Enzyme Engineering ◽  
Content Type ◽  
Cold Adapted ◽  
Wide Range ◽  
Cold Active ◽  
Surface Loops ◽  
The Antarctic

ABSTRACT The α-amylases are endo-acting enzymes that hydrolyze starch by randomly cleaving the 1,4-α-d-glucosidic linkages between the adjacent glucose units in a linear amylose chain. They have significant advantages in a wide range of applications, particularly in the food industry. The eukaryotic α-amylase isolated from the Antarctic ciliated protozoon Euplotes focardii (EfAmy) is an alkaline enzyme, different from most of the α-amylases characterized so far. Furthermore, EfAmy has the characteristics of a psychrophilic α-amylase, such as the highest hydrolytic activity at a low temperature and high thermolability, which is the major drawback of cold-active enzymes in industrial applications. In this work, we applied site-directed mutagenesis combined with rational design to generate a cold-active EfAmy with improved thermostability and catalytic efficiency at low temperatures. We engineered two EfAmy mutants. In one mutant, we introduced Pro residues on the A and B domains in surface loops. In the second mutant, we changed Val residues to Thr close to the catalytic site. The aim of these substitutions was to rigidify the molecular structure of the enzyme. Furthermore, we also analyzed mutants containing these combined substitutions. Biochemical enzymatic assays of engineered versions of EfAmy revealed that the combination of mutations at the surface loops increased the thermostability and catalytic efficiency of the enzyme. The possible mechanisms responsible for the changes in the biochemical properties are discussed by analyzing the three-dimensional structural model. IMPORTANCE Cold-adapted enzymes have high specific activity at low and moderate temperatures, a property that can be extremely useful in various applications as it implies a reduction in energy consumption during the catalyzed reaction. However, the concurrent high thermolability of cold-adapted enzymes often limits their applications in industrial processes. The α-amylase from the psychrophilic Antarctic ciliate Euplotes focardii (named EfAmy) is a cold-adapted enzyme with optimal catalytic activity in an alkaline environment. These unique features distinguish it from most α-amylases characterized so far. In this work, we engineered a novel EfAmy with improved thermostability, substrate binding affinity, and catalytic efficiency to various extents, without impacting its pH preference. These characteristics can be considered important properties for use in the food, detergent, and textile industries and in other industrial applications. The enzyme engineering strategy developed in this study may also provide useful knowledge for future optimization of molecules to be used in particular industrial applications.

Review of characterization methods for water-soluble polymers used in oil sand and heavy oil industrial applications

2016 ◽  
Vol 24 (4) ◽  
pp. 460-470 ◽  
Author(s):  
Xiaomeng Wang
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
Environmental Fate ◽  
Industrial Applications ◽  
Water Soluble ◽  
Oil Sand ◽  
Characterization Methods ◽  
Water Soluble Polymers ◽  
Soluble Polymers ◽  
Terrestrial Animal

Water-soluble polymers have been used in many applications in the oil sand and heavy oil industries, including drilling, enhanced oil recovery, tailings treatment, and water treatment. Because they are water soluble, residual polymer can remain with the aqueous phase, potentially leading to environmental impacts. Investigating the environmental fate of these water-soluble polymers is particularly important as they may be toxic to aquatic biota or terrestrial animal life. However, since polymers are somewhat complex because of their high molecular weight, there are many challenges in their measurement, especially in complex matrices. In this paper, polymers used in oilfield applications, particularly in the oil sand or heavy oil industries, are reviewed and various analytical methods for polymer characterization are compared.

Characterization of a cold-active lipase from Psychrobacter cryohalolentis K5T and its deletion mutants

2013 ◽  
Vol 78 (4) ◽  
pp. 385-394 ◽  
Author(s):  
K. A. Novototskaya-Vlasova ◽  
L. E. Petrovskaya ◽  
E. M. Rivkina ◽  
D. A. Dolgikh ◽  
M. P. Kirpichnikov
Keyword(s):  
Deletion Mutants ◽  
Cold Active ◽  
Active Lipase

scholarly journals Chiral MnIII (Salen) Immobilized on Organic Polymer/Inorganic Zirconium Hydrogen Phosphate Functionalized with 3-Aminopropyltrimethoxysilane as an Efficient and Recyclable Catalyst for Enantioselective Epoxidation of Styrene

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 212 ◽  
Author(s):  
Xiaochuan Zou ◽  
Yue Wang ◽  
Cun Wang ◽  
Kaiyun Shi ◽  
Yanrong Ren ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Supported Catalysts ◽  
Organic Polymer ◽  
Solid Catalyst ◽  
Homogeneous Catalyst ◽  
Hydrogen Phosphate ◽  
Characterization Methods ◽  
Salen Complexes ◽  
Enantioselective Epoxidation ◽  
Better Than

Organic polymers/inorganic zirconium hydrogen phosphate (ZSPP, ZPS-IPPA, and ZPS-PVPA) functionalized with 3-aminopropyltrimethoxysilane were prepared and used to support chiral MnIII (salen) complexes (Jacobsen’s catalyst). Different characterization methods demonstrated that the chiral MnIII (salen) complexes was successfully supported on the surface of the carrier (ZSPP, ZPS-IPPA, or ZPS-PVPA) through a 3-aminopropyltrimethoxysilane group spacer. The supported catalysts effectively catalyzed epoxidation of styrene with m-chloroperbenzoic acid (m-CPBA) as an oxidant in the presence of N-methylmorpholine N-oxide (NMO) as an axial base. These results (ee%, 53.3–63.9) were significantly better than those achieved under a homogeneous counterpart (ee%, 46.2). Moreover, it is obvious that there was no significant decrease in catalytic activity after the catalyst 3 was recycled four times (cons%: from 95.0 to 92.6; ee%: from 64.7 to 60.1). Further recycles of catalyst 3 resulted in poor conversions, although the enantioselectivity obtained was still higher than that of corresponding homogeneous catalyst even after eight times. After the end of the eighth reaction, the solid catalyst was allowed to stand in 2 mol/L of dilute hydrochloric acid overnight, prompting an unexpected discovery that the catalytic activity of the catalyst was recovered again at the 9th and 10th cycles of the catalyst.

scholarly journals Optimization of Cold-Active Lipase Production from Psychrophilic BacteriumMoritellasp. 2-5-10-1 by Statistical Experimental Methods

2013 ◽  
Vol 77 (1) ◽  
pp. 17-21 ◽  
Author(s):  
Quanfu WANG ◽  
Chunyu ZHANG ◽  
Yanhua HOU ◽  
Xuezheng LIN ◽  
Jihong SHEN ◽  
...  
Keyword(s):  
Experimental Methods ◽  
Lipase Production ◽  
Cold Active ◽  
Active Lipase

scholarly journals Deposition of Selective Catalytic Reduction Coating on Wire-Mesh Structure by Atmospheric Plasma Spraying

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3046 ◽  
Author(s):  
Xiaoyu Ma ◽  
Yunlong Ma ◽  
Hui Li ◽  
Yingliang Tian
Keyword(s):  
Catalytic Activity ◽  
Selective Catalytic Reduction ◽  
Plasma Spraying ◽  
Catalytic Reduction ◽  
Industrial Applications ◽  
Atmospheric Plasma Spraying ◽  
Wire Mesh ◽  
Atmospheric Plasma ◽  
Mesh Structure ◽  
Tio2 Support

A series of catalytic coatings consisting of MnOx-CeO2 and TiO2 support were prepared by atmospheric plasma spraying, which was aimed at the application of selective catalytic reduction (SCR) of NOx. The effect of the load of active component on the coating was firstly studied. The results showed that all the coating presented the highest catalytic activity at approximately 350 °C and the coating with the composition of 20MnOx/5CeO2/TiO2 (wt%) achieved the most powerful performance. The coating was then prepared on a wire-mesh structure substrate, which can be easily assembled as a gas filter. The results showed that the specific surface area was greatly increased resulting in the significant improvement of the catalytic activity of the coating. This strategy offered a promising possibility of removing NOx and particulate fliting simultaneously in industrial applications.

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