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Screening and description of novel hydantoinases from distinct environmental sources

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ISBN: 9783866441736 Year: Pages: XVI, 148 p. DOI: 10.5445/KSP/1000007011 Language: ENGLISH
Publisher: KIT Scientific Publishing
Subject: Chemical Engineering
Added to DOAB on : 2019-07-30 20:02:01
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Various bacteria with hydantoinase activity were recovered from terrestrial soil samples of different geographic origins (Antarctica, South Africa, China). Based on these findings it is shown that microorganisms with hydantoinase activity are (i) distributed in various geographically distinct environmental habitats (ii) distributed worldwide (iii) found in certain bacterial genera.

Amino Acids of the Glutamate Family: Functions beyond Primary Metabolism

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889199365 Year: Pages: 206 DOI: 10.3389/978-2-88919-936-5 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Botany
Added to DOAB on : 2016-01-19 14:05:46
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The life of proteins starts and ends as amino acids. In addition to the primary function as protein building blocks, amino acids serve multiple other purposes to make a plant's life worth living. This is true especially for the amino acids of the glutamate family, namely glutamate (Glu), glutamine (Gln), proline (Pro) and arginine (Arg), as well as the product of Glu decarboxylation, ?-aminobutyric acid (GABA). Synthesis, accumulation, interconversion and degradation of these five compounds contribute in many ways to the regulation of plant development and to responses to environmental challenges. Glu and Gln hold key positions as entry points and master regulators of nitrogen metabolism in plants, and have a pivotal role in the regulatory interplay between carbon and nitrogen metabolism. Pro and GABA are among the best-studied compatible osmolytes that accumulate in response to water deficit, yet the full range of protective functions is still to be revealed. Arg, with its exceptionally high nitrogen-to-carbon ratio, has long been recognized as a major storage form of organic nitrogen. Most of the enzymes involved in metabolism of the amino acids of the glutamate family in plants have been identified or can be predicted according to similarity with animal or microbial homologues. However, for some of these enzymes the detailed biochemical properties still remain to be determined in order to understand activities in vivo. Additionally, uncertainties regarding the subcellular localization of proteins and especially the lack of knowledge about intracellular transport proteins leave significant gaps in our understanding of the metabolic network connecting Glu, Gln, Pro, GABA and Arg. While anabolic reactions are distributed between the cytosol and chloroplasts, catabolism of the amino acids of the glutamate family takes place in mitochondria and has been implicated in fueling energy-demanding physiological processes such as root elongation, recovery from stress, bolting and pollen tube elongation. Exceeding the metabolic functions, the amino acids of the glutamate family were recently identified as important signaling molecules in plants. Extracellular Glu, GABA and a range of other metabolites trigger responses in plant cells that resemble the actions of Glu and GABA as neurotransmitters in animals. Plant homologues of the Glu-gated ion channels from mammals and protein kinase signaling cascades have been implicated in these responses. Pollen tube growth and guidance depend on GABA signaling and the root architecture is specifically regulated by Glu. GABA and Pro signaling or metabolism were shown to contribute to the orchestration of defense and programmed cell death in response to pathogen attacks. Pro signaling was additionally proposed to regulate developmental processes and especially sexual reproduction. Arg is tightly linked to nitric oxide (NO) production and signaling in plants, although Arg-dependent NO-synthases could still not be identified. Potentially Arg-derived polyamines constitute the missing link between Arg and NO signaling in response to stress. Taken together, the amino acids of the glutamate family emerge as important signaling molecules that orchestrate plant growth and development by integrating the metabolic status of the plant with environmental signals, especially in stressful conditions. This research topic collects contributions from different facets of glutamate family amino acid signaling or metabolism to bring together, and integrate in a comprehensive view the latest advances in our understanding of the multiple functions of Glu-derived amino acids in plants.

Enzymes and Their Biotechnological Applications

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ISBN: 9783038421481 9783038421474 Year: Pages: 468 DOI: 10.3390/books978-3-03842-147-4 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Added to DOAB on : 2016-05-12 12:11:22
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Thermophiles and Thermozymes

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ISBN: 9783038978169 9783038978176 Year: Pages: 198 DOI: 10.3390/books978-3-03897-817-6 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General)
Added to DOAB on : 2019-04-25 16:37:17
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Interest in the study of life in hot environments, both with respect to the inhabiting microorganisms and the enzymes they produce, is currently very high. The biological mechanisms responsible for the resistance to high temperatures are not yet fully understood, whereas thermostability is a highly required feature for industrial applications. In this e-book, the invited authors provide diverse evidence contributing to the understanding of such mechanisms and the unlocking of the biotechnological potential of thermophiles and thermozymes.

Yeast Biotechnology 2.0

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ISBN: 9783038974314 / 9783038974321 Year: Pages: 216 DOI: 10.3390/books978-3-03897-432-1 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Biotechnology --- Biology
Added to DOAB on : 2019-01-10 10:41:31
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Yeasts are truly fascinating microorganisms. Due to their diverse and dynamic activities, they have been used for the production of many interesting products, such as beer, wine, bread, biofuels, and biopharmaceuticals. Saccharomyces cerevisiae (brewers’ or bakers’ yeast) is the yeast species that is surely the most exploited by humans. Saccharomyces is a top-choice organism for industrial applications, although its use for producing beer dates back to at least the 6th millennium BC. Bakers’ yeast has been a cornerstone of modern biotechnology, enabling the development of efficient production processes. Today, diverse yeast species are explored for industrial applications. This Special Issue “Yeast Biotechnology 2.0” is a continuation of the first Special Issue, “Yeast Biotechnology” (https://www.mdpi.com/books/pdfview/book/324). It compiles the current state-of-the-art of research and technology in the area of “yeast biotechnology” and highlights prominent current research directions in the fields of yeast synthetic biology and strain engineering, new developments in efficient biomolecule production, fermented beverages (beer, wine, and honey fermentation), and yeast nanobiotechnology.]

Asymmetric and Selective Biocatalysis

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ISBN: 9783038978466 9783038978473 Year: Pages: 154 DOI: 10.3390/books978-3-03897-847-3 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Chemistry (General)
Added to DOAB on : 2019-06-26 09:16:44
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This Issue contains one communication, six articles, and two reviews. The communication from Paola Vitale et al. represents a work where whole cells were used as biocatalysts for the reduction of optically active chloroalkyl arylketones followed by a chemical cyclization to give the desired heterocycles. Among the various whole cells screened (baker’s yeast, Kluyveromyces marxianus CBS 6556, Saccharomyces cerevisiae CBS 7336, Lactobacillus reuteri DSM 20016), baker’s yeast provided the best yields and the highest enantiomeric ratios (95:5) in the bioreduction of the above ketones. In this respect, valuable chiral non-racemic functionalized oxygen-containing heterocycles (e.g., (S)-styrene oxide, (S)-2-phenyloxetane, (S)-2-phenyltetrahydrofuran), amenable to be further elaborated on, can be smoothly and successfully generated from their prochiral precursors. Studies about pure biocatalysts with mechanistical studies, application in different reactions, and new immobilization methods for improving their stability were reported in five different articles. The article by Su-Yan Wang et al. describes the cloning, expression, purification, and characterization of an N-acetylglucosamine 2-epimerase from Pedobacter heparinus (PhGn2E). For this, several N-acylated glucosamine derivatives were chemically synthesized and used to test the substrate specificity of the enzyme. The mechanism of the enzyme was studied by hydrogen/deuterium NMR. The study at the anomeric hydroxyl group and C-2 position of the substrate in the reaction mixture confirmed the epimerization reaction via ring-opening/enolate formation. Site-directed mutagenesis was also used to confirm the proposed mechanism of this interesting enzyme. The article by Forest H. Andrews et al. studies two enzymes, benzoylformate decarboxylase (BFDC) and pyruvate decarboxylase (PDC), which catalyze the non-oxidative decarboxylation of 2-keto acids with different specificity. BFDC from Pseudomonas putida exhibited very limited activity with pyruvate, whereas the PDCs from S. cerevisiae or from Zymomonas mobilis showed virtually no activity with benzoylformate (phenylglyoxylate). After studies using saturation mutagenesis, the BFDC T377L/A460Y variant was obtained, with 10,000-fold increase in pyruvate/benzoylformate. The change was attributed to an improvement in the Km value for pyruvate and a decrease in the kcat value for benzoylformate. The characterization of the new catalyst was performed, providing context for the observed changes in the specificity. The article by Xin Wang et al. compares two types of biocatalysts to produce D-lysine L-lysine in a cascade process catalyzed by two enzymes: racemase from microorganisms that racemize L-lysine to give D,L-lysine and decarboxylase that can be in cells, permeabilized cells, and the isolated enzyme. The comparison between the different forms demonstrated that the isolated enzyme showed the higher decarboxylase activity. Under optimal conditions, 750.7 mmol/L D-lysine was finally obtained from 1710 mmol/L L-lysine after 1 h of racemization reaction and 0.5 h of decarboxylation reaction. D-lysine yield could reach 48.8% with enantiomeric excess (ee) of 99%. In the article by Rivero and Palomo, lipase from Candida rugosa (CRL) was highly stabilized at alkaline pH in the presence of PEG, which permitted its immobilization for the first time by multipoint covalent attachment on different aldehyde-activated matrices. Different covalent immobilized preparation of the enzyme was successfully obtained. The thermal and solvent stability was highly increased by this treatment, and the novel catalysts showed high regioselectivity in the deprotection of per-O-acetylated nucleosides. The article by Robson Carlos Alnoch et al. describes the protocol and use of a new generation of tailor-made bifunctional supports activated with alkyl groups that allow the immobilization of proteins through the most hydrophobic region of the protein surface and aldehyde groups that allows the covalent immobilization of the previously adsorbed proteins. These supports were especially used in the case of lipase immobilization. The immobilization of a new metagenomic lipase (LipC12) yielded a biocatalyst 3.5-fold more active and 5000-fold more stable than the soluble enzyme. The PEGylated immobilized lipase showed high regioselectivity, producing high yields of the C-3 monodeacetylated product at pH 5.0 and 4 °C. Hybrid catalysts composed of an enzyme and metallic complex are also treated in this Special Issue. The article by Christian Herrero et al. describes the development of the Mn(TpCPP)-Xln10A artificial metalloenzyme, obtained by non-covalent insertion of Mn(III)-meso-tetrakis(p-carboxyphenyl)porphyrin [Mn(TpCPP), 1-Mn] into xylanase 10A from Streptomyces lividans (Xln10A). The complex was found able to catalyze the selective photo-induced oxidation of organic substrates in the presence of [RuII(bpy)3]2+ as a photosensitizer and [CoIII(NH3)5Cl]2+ as a sacrificial electron acceptor, using water as oxygen atom source. The two published reviews describe different subjects with interest in the fields of biocatalysis and mix metallic-biocatalysis, respectively. The review by Anika Scholtissek et al. describes the state-of-the-art regarding ene-reductases from the old yellow enzyme family (OYEs) to catalyze the asymmetric hydrogenation of activated alkenes to produce chiral products with industrial interest. The dependence of OYEs on pyridine nucleotide coenzyme can be avoided by using nicotinamide coenzyme mimetics. In the review, three main classes of OYEs are described and characterized. The review by Yajie Wang and Huimin Zhao highlights some of the recent examples in the past three years that combine transition metal catalysis with enzymatic catalysis. With recent advances in protein engineering, catalyst synthesis, artificial metalloenzymes, and supramolecular assembly, there is great potential to develop more sophisticated tandem chemoenzymatic processes for the synthesis of structurally complex chemicals. In conclusion, these nine publications give an overview of the possibilities of different catalysts, both traditional biocatalysts and hybrids with metals or organometallic complexes to be used in different processes—particularly in synthetic reactions—under very mild reaction conditions.

Advances and New Perspectives in Marine Biotechnology

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ISBN: 9783038421061 9783038421092 Year: Volume: Volume 1 Pages: 428 DOI: 10.3390/books978-3-03842-109-2 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Biotechnology
Added to DOAB on : 2015-10-22 10:01:02
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As the Century of Biology begins to bear fruit, through the translation of predictive biological understanding into applications that enhance the human condition and maintain biodiversity, the almost infinite potential of marine biological resources will be unlocked. Although Marine Biotechnology already has delivered products for medicine, food, bioenergy, nanomaterials, and bioremediation, less than 5% of our vast oceanic environment has been explored. Marine Biotechnology is a scientifically and economically expanding enterprise that is poised to harness the enormous but uncharted functional diversity of marine life, with its novel and rich array of biodesigns and biosynthetic capabilities. From this pursuit comes new genes, chemicals, materials, and inspirations for the benefit of industry, nutrition, and medicine, and which enable the sustainable use and management of the world’s oceans. This Special Issue in Marine Drugs highlights the cutting-edge developments in Marine Biotechnology with a collection of papers written by authors who are leading experts in the field, including selected papers from the 10th International Marine Biotechnology Conference (IMBC-2013), the premier meeting in marine biotechnology, which is held under the auspices of the International Marine Biotechnology Association.

Advances and New Perspectives in Marine Biotechnology

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ISBN: 9783038421078 9783038421108 Year: Volume: Volume 2 Pages: 654 DOI: 10.3390/books978-3-03842-110-8 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Biotechnology
Added to DOAB on : 2015-10-22 10:04:44
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As the Century of Biology begins to bear fruit, through the translation of predictive biological understanding into applications that enhance the human condition and maintain biodiversity, the almost infinite potential of marine biological resources will be unlocked. Although Marine Biotechnology already has delivered products for medicine, food, bioenergy, nanomaterials, and bioremediation, less than 5% of our vast oceanic environment has been explored. Marine Biotechnology is a scientifically and economically expanding enterprise that is poised to harness the enormous but uncharted functional diversity of marine life, with its novel and rich array of biodesigns and biosynthetic capabilities. From this pursuit comes new genes, chemicals, materials, and inspirations for the benefit of industry, nutrition, and medicine, and which enable the sustainable use and management of the world’s oceans. This Special Issue in Marine Drugs highlights the cutting-edge developments in Marine Biotechnology with a collection of papers written by authors who are leading experts in the field, including selected papers from the 10th International Marine Biotechnology Conference (IMBC-2013), the premier meeting in marine biotechnology, which is held under the auspices of the International Marine Biotechnology Association.

Analysis of Peptides and Proteins by Electrophoretic Techniques

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ISBN: 9783039212279 / 9783039212286 Year: Pages: 110 DOI: 10.3390/books978-3-03921-228-6 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Chemistry (General)
Added to DOAB on : 2019-08-28 11:21:27
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The characterization of peptides and proteins is central to understanding their function and expression in biological matrices. Moreover, these macromolecules are important biomarkers of many human diseases. In recent years, the performance of separation techniques based on electromigration have significantly increased. The development of microdevices has reduced sample consumption and waste production while high-sensitivity detectors, such as mass spectrometry (MS) or laser-induced fluorescence (LIF), have significantly improved with regards to separation efficiency and detection limits. All of these advancements have led to appreciably enlarged fields of application. Nowadays, a multitude of studies using separation techniques based on electromigration to study proteins and peptides from numerous real matrices are available in the literature. This Special Issue covers the most recent knowledge and advances in the study of peptides and proteins using several electrophoresis techniques, as well as the characterization of relevant proteins and peptides in application areas such as clinical studies, functional foods, and toxicology.

Enzyme-Mediated Stereoselective Synthesis

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ISBN: 9783039219360 / 9783039219377 Year: Pages: 116 DOI: 10.3390/books978-3-03921-937-7 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Chemistry (General) --- Inorganic Chemistry
Added to DOAB on : 2020-01-07 09:08:26
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This book is a collection of studies focused on the exploitation of enzyme stereoselectivity for the synthesis of relevant chemicals, such as innovative materials, chiral building blocks, natural products, and flavor and fragrance compounds. Different catalytic approaches are reported. The first study describes a resolution-based process for the stereoselective synthesis of the enantiomeric forms of the flavor compound linaloyl oxide, whereas other enantiomeric enriched aroma compounds were obtained through a novel microbial approach based on solid-state fermentation. Two relevant works exploit the potential of the biocatalyzed reduction reactions. The first of these contributions describes the enantioselective synthesis of ?-nitroalcohols by enzyme-mediated reduction of ?-nitroketones, whereas a second contribution reports the preparation of chiral 1,4-diaryl-1,4-diols through ADH-catalyzed bioreduction of the corresponding diketones. Concerning enantioenriched alcohol derivatives, natural hydroxy fatty acids are prepared by means of the biocatalytic hydration reaction of natural fatty acids using the probiotic bacterium Lactobacillus rhamnosus as a whole-cell biocatalyst. Further studies describe the use of modified pullulan polysaccharide for lipase immobilization and the recent advances in synthetic applications of ?-transaminases for the production of chiral amines.

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