Enzymes: principles and biotechnological applications

Robinson, Peter

doi:10.1042/bse0590001

Cited by 797 publications

(507 citation statements)

References 18 publications

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“…It can also be lower in cost compared with extracted enzymes because there is no need for isolation and purification steps, and because cells produce their own enzyme co-factors. [5] Bacterial biofilms are promising for the same reasons, including certain benefits making them candidates for industrial processes as well. [6,7] These include their preference for surface attachment, making them ideal for heterogeneous catalysis; and their protective self-produced extracellular polymeric matrix, which can mitigate challenges related to toxicity, leading to long-term productivity even under harsh conditions.…”

Section: A Generalized Kinetic Framework Applied To Whole-cell Bioelementioning

confidence: 99%

A Generalized Kinetic Framework Applied to Whole‐Cell Bioelectrocatalysis in Bioflow Reactors Clarifies Performance Enhancements for Geobacter Sulfurreducens Biofilms

et al. 2019

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A common kinetic framework for studies of whole‐cell catalysis is vital for understanding and optimizing bioflow reactors. In this work, we demonstrate the applicability of a flow‐adapted version of Michaelis‐Menten kinetics to an electrocatalytic bacterial biofilm. A three‐electrode microfluidic biofilm flow reactor measured increased turnover rates by as much as 50 % from a Geobacter sulfurreducens biofilm as flow rate was varied. Based on parameters from the applied kinetic framework, flow‐induced increases to turnover rate, catalytic efficiency and device reaction capacity could be linked to an increase in catalytic biomass. This study demonstrates that a standardized kinetic framework is critical for quantitative measurements of new living catalytic systems in flow reactors and for benchmarking against well‐studied catalytic systems such as enzymes.

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Section: A Generalized Kinetic Framework Applied To Whole-cell Bioelementioning

confidence: 99%

A Generalized Kinetic Framework Applied to Whole‐Cell Bioelectrocatalysis in Bioflow Reactors Clarifies Performance Enhancements for Geobacter Sulfurreducens Biofilms

et al. 2019

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“…Enzymes are organic molecules, which facilitate interactions between specific reactants and, thereby, trigger (catalyze) chemical reactions. 3 An overall net external energy source is required for chemical reactions in which the aggregate level of energy of the products exceeds that of the reactants. Net energy for chemical reactions can be provided by heat, light or, as already mentioned, by linkage to a chemical reaction that supplies the required chemical energy.…”

Section: Chemical Energymentioning

confidence: 99%

Is KELEA (Kinetic Energy Limiting Electrostatic Attraction) A Source Of Chemical Energy?

W¹

2017

MOJBOC

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Abbreviations: KELEA, kinetic energy limiting electrostatic attraction; ACE, alternative cellular energy; ADP, adenosine diphosphate; ATP, adenosine triphosphate; CPE, cytopathic effect; UV, ultraviolet; GC, ms gas chromatograph-mass spectroscopy; EDX, energy dispersive x-ray IntroductionAll matter is composed of atoms, many of which are combined into molecules. Apart from water, which consists of an oxygen atom bound separately to two hydrogen atoms, the major compounds in living organisms are carbon containing molecules. These include lipid hydrocarbons (carbon plus hydrogen), carbohydrates (carbon plus hydrogen plus oxygen), proteins (carbon plus hydrogen plus oxygen plus nitrogen) and nucleic acids (carbon plus hydrogen plus oxygen plus nitrogen plus phosphorus). These and related groupings of compounds are collectively referred to as organic molecules. The remaining compounds in existence are termed inorganic molecules. Atoms can also remain unbound. The study of chemistry includes the process by which atoms can be switched between the bound and unbound states. It also includes the chemical reactions by which the atoms within a molecule or group of molecules can rearrange to yield different molecules.Several types of chemical bonding occur between atoms and between molecules. i) Unbound atoms and atoms within molecules can be electrically charged due either to having one to three greater or lesser number of electrons, when compared with the number of protons. Atoms with more electrons than protons are electrically negative, while atoms with fewer electrons than protons are positively charged. Atoms with opposing charges can bind electro statically in ionic bonds. ii) Different atoms can bind closer to one another in a covalent manner, which involves the sharing (overlapping) of electrons. Atoms with a propensity to contribute shared electrons are termed nucleophiles, while those able to accept shared electrons are termed electrophiles. iii) A third type of atom binding is typical of metals and results from the external placing of pooled outer electrons from multiple atoms. The pooled electrons act as an enveloping electrostatic constraint on the movement of the enclosed atoms. iv) Molecules can also loosely interact electro statically if the charge distribution within individual atoms undergoes minor coordinated oscillations, or if they are dipolar with regions of excess positive and negative charges. One example is the rapid on-off binding that occurs between dipolar water molecules in the liquid state. The covalent bonding of oxygen with the hydrogen atoms involves sharing of the single electrons from the two hydrogen atoms with the electrons of the oxygen atom. This leaves each hydrogen atom with a slightly positive charge. Conversely, the oxygen atom acquires a slight negative charge. The opposing charges on the hydrogen and oxygen atoms of different water molecules lead to transient, yet repetitive intermolecular bonding. The resulting loose cohesion is referred to as hydrogen bonding and explains why ...

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“…On the other hand, the obtained result is higher than that of trypsin extracted from monterey sardine (Sardinops sagax) (pH 7.0 ~ 8.0) as reported by Yanez et al (2005) Enzyme stability is related to protein net charge at a particular pH. The differences in optimal pH and pH stability are attributed to the net charge of the active center which is affected by the pH of the reaction environment (Robinson, 2015). …”

Section: Thermo-stabilitymentioning

confidence: 67%

Characterization and Purification of Alkaline Proteases From Viscera of Silver Carp (Hypophthalmichthys molitrix) Fish

Atta

El-Hamed

Keshk

2017

AJAS

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Proteases from viscera of Silver carp (Hypophthalmichthys molitrix) fish have been extracted and characterized. The alkaline proteases show optimum activity in 0.2M Tris-HCl buffer at pH 8.5 and 45°C using soluble milk casein as substrate. The crude alkaline protease lost about 35% or 51% of its specific activity if it was heated at 50C or kept at pH 9 for 60 min., respectively. Purification of proteases purified by ammonium sulfate precipitation, gel-filtration using Sephadex G 50 column and ultrafiltration via polyamide membrane (30 KDa) led to increase its specific activity up to 20, 24 and 99 fold, respectively.

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Enzymes: principles and biotechnological applications

Cited by 797 publications

References 18 publications

A Generalized Kinetic Framework Applied to Whole‐Cell Bioelectrocatalysis in Bioflow Reactors Clarifies Performance Enhancements for Geobacter Sulfurreducens Biofilms

A Generalized Kinetic Framework Applied to Whole‐Cell Bioelectrocatalysis in Bioflow Reactors Clarifies Performance Enhancements for Geobacter Sulfurreducens Biofilms

Is KELEA (Kinetic Energy Limiting Electrostatic Attraction) A Source Of Chemical Energy?

Characterization and Purification of Alkaline Proteases From Viscera of Silver Carp (Hypophthalmichthys molitrix) Fish

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