scholarly journals Enzymes from Marine Polar Regions and Their Biotechnological Applications

Marine Drugs ◽  
2019 ◽  
Vol 17 (10) ◽  
pp. 544 ◽  
Author(s):  
Stefano Bruno ◽  
Daniela Coppola ◽  
Guido di Prisco ◽  
Daniela Giordano ◽  
Cinzia Verde
Keyword(s):  
Thermal Stability ◽  
Low Temperatures ◽  
Catalytic Properties ◽  
Catalytic Efficiency ◽  
Research Area ◽  
Industrial Applications ◽  
Polar Regions ◽  
Biotechnological Applications ◽  
Cold Adapted ◽  
Cold Environments

The microorganisms that evolved at low temperatures express cold-adapted enzymes endowed with unique catalytic properties in comparison to their mesophilic homologues, i.e., higher catalytic efficiency, improved flexibility, and lower thermal stability. Cold environments are therefore an attractive research area for the discovery of enzymes to be used for investigational and industrial applications in which such properties are desirable. In this work, we will review the literature on cold-adapted enzymes specifically focusing on those discovered in the bioprospecting of polar marine environments, so far largely neglected because of their limited accessibility. We will discuss their existing or proposed biotechnological applications within the framework of the more general applications of cold-adapted enzymes.

scholarly journals Molecular basis of cold adaptation

2002 ◽  
Vol 357 (1423) ◽  
pp. 917-925 ◽  
Author(s):  
Salvino D'Amico ◽  
Paule Claverie ◽  
Tony Collins ◽  
Daphné Georlette ◽  
Emmanuelle Gratia ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Low Temperatures ◽  
Specific Activity ◽  
Significant Proportion ◽  
Catalytic Efficiency ◽  
Reaction Rates ◽  
Molecular Characteristics ◽  
Cold Adapted ◽  
X Ray Crystallography ◽  
Eukaryotic Organisms

Cold–adapted, or psychrophilic, organisms are able to thrive at low temperatures in permanently cold environments, which in fact characterize the greatest proportion of our planet. Psychrophiles include both prokaryotic and eukaryotic organisms and thus represent a significant proportion of the living world. These organisms produce cold–evolved enzymes that are partially able to cope with the reduction in chemical reaction rates induced by low temperatures. As a rule, cold–active enzymes display a high catalytic efficiency, associated however, with a low thermal stability. In most cases, the adaptation to cold is achieved through a reduction in the activation energy that possibly originates from an increased flexibility of either a selected area or of the overall protein structure. This enhanced plasticity seems in turn to be induced by the weak thermal stability of psychrophilic enzymes. The adaptation strategies are beginning to be understood thanks to recent advances in the elucidation of the molecular characteristics of cold–adapted enzymes derived from X–ray crystallography, protein engineering and biophysical methods. Psychrophilic organisms and their enzymes have, in recent years, increasingly attracted the attention of the scientific community due to their peculiar properties that render them particularly useful in investigating the possible relationship existing between stability, flexibility and specific activity and as valuable tools for biotechnological purposes.

Biotechnological perspectives of microorganisms isolated from the Polar Regions

2018 ◽  
Vol 39 (3) ◽  
pp. 137
Author(s):  
Viktoria Shcherbakova ◽  
Olga Troshina
Keyword(s):  
Wastewater Treatment ◽  
Low Temperature ◽  
Liquid Water ◽  
Polar Regions ◽  
Biotechnological Applications ◽  
Cold Adapted ◽  
Culture Independent ◽  
Biotechnological Processes ◽  
Improved Methods ◽  
Culture Dependent

Polar permanently frozen grounds cover more than 20% of the earth's surface, and about 60% of the Russian territories are permafrost. In the permafrost environments, the combination of low temperature and poor availability of liquid water make these habitats extremely inhospitable for life. To date, both culture-dependent and culture-independent methods have shown that permafrost is a habitat for microorganisms of all three domains: Bacteria, Archaea and Eukarya. An overview of applying psychrophilic and psychrotolerant bacteria and archaea isolated from Arctic and Antarctic permafrost ecosystems in biotechnological processes of wastewater treatment, production of cold-adapted enzymes, etc. is discussed here. The study of existing collections of microorganisms isolated from permanently cold habitats, improved methods of sampling and enrichment will increase the potential biotechnological applications of permafrost bacteria and archaea producing unique biomolecules.

scholarly journals Ag2O–MnO2/Graphene Oxide Nanocomposite

2020 ◽  
Author(s):  
Farooq Syed ◽  
Mujeeb Khan ◽  
Mohammed Rafi Shaik ◽  
Mufsir Kuniyil ◽  
M Rafiq Siddiqui ◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Specific Activity ◽  
Catalytic Efficiency ◽  
Cost Effective ◽  
Catalytic Performance ◽  
Industrial Applications ◽  
Recoverable Catalyst ◽  
Aerial Oxidation ◽  
Milling Method ◽  
State Mixing

In this study, we reported the eco-friendly fabrication of Ag2O–MnO2/GRO nanocomposites by the solid-state mixing of separately prepared GRO and Ag2O–MnO2 NPs using ball milling method, a mechanochemical approach. The prepared material was studied for the catalytic effect of GRO in the system for the aerial oxidation of a variety of alcohols. It was found that the (1%)Ag2O–MnO2/(5 wt.%)GRO nanocatalyst demonstrated a high conversion ability (~100%) and excellent selectivity in the presence of O2 as a clean oxidant. The higher catalytic properties of the nanocomposite were attributed to the presence of GRO, which exhibited extraordinary catalytic properties like improved surface area, excellent chemical compatibility, and stability, as well as the introduction of several defects in the obtained nanocomposite that enhance the catalytic performance. The specific activity of 13.3 mmol·g−1·h−1 is obtained for the catalyst i.e. (1%)Ag2O–MnO2/(5 wt.%)GRO, which is reportedly superior to the various other catalysts previously reported in the literature for the same conversion reaction. Our catalytic strategy was highly selective, producing only desired products with no over-oxygenation to carboxylic acids. The merits of our catalytic methodology were: (a) facile process, (b) inexpensive and clean oxidant, (c) no surfactants or nitrogenous bases were required, (d) mild catalytic conditions, (e) cost-effective recoverable catalyst, (f) complete convertibility, (g) full selectivity, (h) rapid process, and (i) applicable to virtually all types of alcohols. So, these highlights made this catalytic strategy to be highly applicable in the industrial applications for manufacturing of carbonyls. To the best of our knowledge, this was the first study of utilizing Ag2O–MnO2/GRO composite as a catalyst for the oxidation of alcohols, highlighting the catalytic efficiency of GRO.

Developing cold-adapted biomass for the anaerobic treatment of domestic wastewater at low temperatures (4, 8 and 15 °C) with inocula from cold environments

2017 ◽  
Vol 112 ◽  
pp. 100-109 ◽  
Author(s):  
Evangelos Petropoulos ◽  
Jan Dolfing ◽  
Russell J. Davenport ◽  
Emma J. Bowen ◽  
Thomas P. Curtis
Keyword(s):  
Low Temperatures ◽  
Domestic Wastewater ◽  
Anaerobic Treatment ◽  
Cold Adapted ◽  
Cold Environments

Purification and characterization of a psychrophilic catalase from Antarctic Bacillus

2008 ◽  
Vol 54 (10) ◽  
pp. 823-828 ◽  
Author(s):  
Wei Wang ◽  
Mi Sun ◽  
Wanshun Liu ◽  
Bin Zhang
Keyword(s):  
Activation Energy ◽  
Low Temperatures ◽  
Catalytic Efficiency ◽  
Small Subunit ◽  
Purification And Characterization ◽  
Cold Adapted ◽  
Optimal Activity ◽  
Ph Range ◽  
Antarctic Seawater

Catalase from Bacillus sp. N2a (BNC) isolated from Antarctic seawater was purified to homogeneity. BNC has a molecular mass of about 230 kDa and is composed of four identical subunits of 56 kDa. The catalase showed optimal activity at 25 °C and at a pH range of 6–11. The enzyme could be inhibited by azide, hydroxylamine, and mercaptoethanol. These characteristics suggested that BNC is a small-subunit monofunctional catalase. The activation energy of BNC was 13 kJ/mol and the apparent kcat/Km values were 3.6 × 106 and 4 × 106 L·mol–1·s–1 at 4 and 25 °C, respectively. High catalytic efficiency of BNC at low temperatures enables this bacterium to scavenge H2O2 efficiently. BNC exhibited activation energy, catalytic efficiency, and thermostability comparable with some mesophilic homologues. Such similarity of enzymatic characteristics to mesophilic homologues, although uncommon among the cold-adapted enzymes in general, has also been observed in other psychrophilic small-subunit monofunctional catalases.

scholarly journals Efficient Biocatalytic Synthesis of Chiral Intermediate of Pregabalin Using Immobilized Talaromyces thermophilus Lipase

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Xu Ding ◽  
Xiao-Ling Tang ◽  
Ren-Chao Zheng ◽  
Yu-Guo Zheng
Keyword(s):  
Industrial Production ◽  
Kinetic Resolution ◽  
Catalytic Properties ◽  
Immobilized Lipase ◽  
Acid Ethyl Ester ◽  
Catalytic Efficiency ◽  
Hydrolytic Activity ◽  
Industrial Applications ◽  
Repeated Use ◽  
Optimized Conditions

A mutant L206F/P207F/L259F of Talaromyces thermophilus lipase (TTL) exhibited high hydrolytic activity towards 2-carboxyethyl-3-cyano-5-methylhexanoic acid ethyl ester (CNDE) for synthesis of (S)-2-carboxyethyl-3-cyano-5-methylhexanoic acid (S-CCMA), a key chiral intermediate of pregabalin. However, low conversion at high CNDE concentration and unreusability of the free TTL mutant restricted its industrial applications. In this study, the TTL mutant was immobilized onto epoxy resin and its catalytic properties for kinetic resolution of CNDE were investigated. Under the optimized conditions, the immobilized lipase exhibited an increased catalytic efficiency even at a CNDE concentration of 3 M with 49.7% conversion and 95% eep. The conversion retained higher than 46.3% even after 10 times repeated use of the immobilized lipase in n-heptane-water biphasic system. These results demonstrated great potential of the immobilized TTL mutant for industrial production of the chiral intermediate of pregabalin.

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.

Effect of the hydrophilicity of the polymer matrix on immobilized α-chymotrypsin

1984 ◽  
Vol 49 (6) ◽  
pp. 1552-1556
Author(s):  
Minoru Kumakura ◽  
Isso Kaetsu
Keyword(s):  
Thermal Stability ◽  
Enzyme Activity ◽  
Pore Size ◽  
Polymer Matrix ◽  
Low Temperatures ◽  
Radiation Polymerization ◽  
Thermal Stability Of

α-Chymotrypsin was immobilized by radiation polymerization at low temperatures and the effect of the hydrophilicity of the polymer matrix on the enzyme activity and thermal stability was studied. The activity and thermal stability of immobilized chymotrypsin increased with the increasing hydrophilicity of the polymer matrix or monomer. The thermal stability was affected by the form and pore size of the polymer matrix; chymotrypsin immobilized on a soft-gel polymer matrix exhibited an enhanced thermal stability.

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