Extremophilic Oxidoreductases for the Industry: Five Successful Examples With Promising Projections

In a global context where the development of more environmentally conscious technologies is an urgent need, the demand for enzymes for industrial processes is on the rise. Compared to conventional chemical catalysts, the implementation of biocatalysis presents important benefits including higher selectivity, increased sustainability, reduction in operating costs and low toxicity, which translate into cleaner production processes, lower environmental impact as well as increasing the safety of the operating staff. Most of the currently available commercial enzymes are of mesophilic origin, displaying optimal activity in narrow ranges of conditions, which limits their actual application under industrial settings. For this reason, enzymes from extremophilic microorganisms stand out for their specific characteristics, showing higher stability, activity and robustness than their mesophilic counterparts. Their unique structural adaptations allow them to resist denaturation at high temperatures and salinity, remain active at low temperatures, function at extremely acidic or alkaline pHs and high pressure, and participate in reactions in organic solvents and unconventional media. Because of the increased interest to replace chemical catalysts, the global enzymes market is continuously growing, with hydrolases being the most prominent type of enzymes, holding approximately two-third share, followed by oxidoreductases. The latter enzymes catalyze electron transfer reactions and are one of the most abundant classes of enzymes within cells. They hold a significant industrial potential, especially those from extremophiles, as their applications are multifold. In this article we aim to review the properties and potential applications of five different types of extremophilic oxidoreductases: laccases, hydrogenases, glutamate dehydrogenases (GDHs), catalases and superoxide dismutases (SODs). This selection is based on the extensive experience of our research group working with these particular enzymes, from the discovery up to the development of commercial products available for the research market.

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Carotenoids as a Protection Mechanism against Oxidative Stress in Haloferax mediterranei

Antioxidants ◽

10.3390/antiox9111060 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1060

Author(s):

Micaela Giani ◽

Rosa María Martínez-Espinosa

Keyword(s):

Oxidative Stress ◽

Large Scale ◽

Antioxidant Properties ◽

Natural Ecosystem ◽

Haloferax Mediterranei ◽

Protection Mechanism ◽

Different Types ◽

Potential Applications ◽

Extremophilic Microorganisms

Haloarchaea are extremophilic microorganisms that in their natural ecosystem encounter several sources of oxidative stress. They have developed different strategies to cope with these harsh environmental conditions, among which bacterioruberin production is a very notable strategy. Bacterioruberin (BR) is a C50 carotenoid synthesized in response to different types of stress. Previous works demonstrated that it shows interesting antioxidant properties with potential applications in biotechnology. In this study, Haloferax mediterranei strain R-4 was exposed to different concentrations of the oxidant compound H2O2 to evaluate the effect on carotenoid production focusing the attention on the synthesis of bacterioruberin. Hfx. mediterranei was able to grow in the presence of H2O2 from 1 mM to 25 mM. Cells produced between 16% and 78% (w/v) more carotenoids under the induced oxidative stress compared to control cultures. HPLC-MS analysis detected BR as the major identified carotenoid and confirmed the gradual increase of BR content as higher concentrations of hydrogen peroxide were added to the medium. These results shed some light on the biological role of bacterioruberin in haloarchaea, provide interesting information about the increase of the cellular pigmentation under oxidative stress conditions and will allow the optimization of the production of this pigment at large scale using these microbes as biofactories.

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From the Discovery of Extremozymes to an Enzymatic Product: Roadmap Based on Their Applications

Frontiers in Bioengineering and Biotechnology ◽

10.3389/fbioe.2021.752281 ◽

2022 ◽

Vol 9 ◽

Author(s):

Giannina Espina ◽

Sebastián A. Muñoz-Ibacache ◽

Paulina Cáceres-Moreno ◽

Maximiliano J. Amenabar ◽

Jenny M. Blamey

Keyword(s):

Industrial Revolution ◽

Hot Spring ◽

Thermophilic Bacterium ◽

Research Report ◽

Environmentally Conscious ◽

Toxic Compounds ◽

Optimal Activity ◽

Actual Application ◽

Commercial Enzymes ◽

Nonstandard Conditions

With the advent of the industrial revolution, the use of toxic compounds has grown exponentially, leading to a considerable pollution of the environment. Consequently, the development of more environmentally conscious technologies is an urgent need. Industrial biocatalysis appears as one potential solution, where a higher demand for more robust enzymes aims to replace toxic chemical catalysts. To date, most of the commercially available enzymes are of mesophilic origin, displaying optimal activity in narrow ranges of temperature and pH (i.e., between 20°C and 45°C, neutral pH), limiting their actual application under industrial reaction settings, where they usually underperform, requiring larger quantities to compensate loss of activity. In order to obtain novel biocatalysts better suited for industrial conditions, an efficient solution is to take advantage of nature by searching and discovering enzymes from extremophiles. These microorganisms and their macromolecules have already adapted to thrive in environments that present extreme physicochemical conditions. Hence, extremophilic enzymes stand out for showing higher activity, stability, and robustness than their mesophilic counterparts, being able to carry out reactions at nonstandard conditions. In this brief research report we describe three examples to illustrate a stepwise strategy for the development and production of commercial extremozymes, including a catalase from an Antarctic psychrotolerant microorganism, a laccase from a thermoalkaliphilic bacterium isolated from a hot spring and an amine-transaminase from a thermophilic bacterium isolated from a geothermal site in Antarctica. We will also explore some of their interesting biotechnological applications and comparisons with commercial enzymes.

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Microcavities

10.1093/oso/9780198782995.001.0001 ◽

2017 ◽

Cited By ~ 52

Author(s):

Alexey V. Kavokin ◽

Jeremy J. Baumberg ◽

Guillaume Malpuech ◽

Fabrice P. Laussy

Keyword(s):

Quantum Wells ◽

Strong Light ◽

Fundamental Physics ◽

Postgraduate Students ◽

Optical Cavities ◽

Semiconductor Quantum Wells ◽

Exciton Polaritons ◽

Different Types ◽

Potential Applications ◽

Experimental Findings

Both rich fundamental physics of microcavities and their intriguing potential applications are addressed in this book, oriented to undergraduate and postgraduate students as well as to physicists and engineers. We describe the essential steps of development of the physics of microcavities in their chronological order. We show how different types of structures combining optical and electronic confinement have come into play and were used to realize first weak and later strong light–matter coupling regimes. We discuss photonic crystals, microspheres, pillars and other types of artificial optical cavities with embedded semiconductor quantum wells, wires and dots. We present the most striking experimental findings of the recent two decades in the optics of semiconductor quantum structures. We address the fundamental physics and applications of superposition light-matter quasiparticles: exciton-polaritons and describe the most essential phenomena of modern Polaritonics: Physics of the Liquid Light. The book is intended as a working manual for advanced or graduate students and new researchers in the field.

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Toxic or Not Toxic, That Is the Carbon Quantum Dot’s Question: A Comprehensive Evaluation with Zebrafish Embryo, Eleutheroembryo, and Adult Models

Polymers ◽

10.3390/polym13101598 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1598

Author(s):

Chih-Yu Chung ◽

Yu-Ju Chen ◽

Chia-Hui Kang ◽

Hung-Yun Lin ◽

Chih-Ching Huang ◽

...

Keyword(s):

Zebrafish Embryo ◽

Comprehensive Evaluation ◽

Aquatic Organisms ◽

Carbon Quantum Dots ◽

Adult Zebrafish ◽

Fish Embryo ◽

Wide Range ◽

Different Types ◽

Low Toxicity

Carbon quantum dots (CQDs) are emerging novel nanomaterials with a wide range of applications and high biocompatibility. However, there is a lack of in-depth research on whether CQDs can cause acute or long-term adverse reactions in aquatic organisms. In this study, two different types of CQDs prepared by ammonia citrate and spermidine, namely CQDAC and CQDSpd, were used to evaluate their biocompatibilities. In the fish embryo acute toxicity test (FET), the LD50 of CQDAC and CQDSpd was about 500 and 100 ppm. During the stage of eleutheroembryo, the LD50 decreased to 340 and 55 ppm, respectively. However, both CQDs were quickly eliminated from embryo and eleutheroembryo, indicating a lack of bioaccumulation. Long-term accumulation of CQDs was also performed in this study, and adult zebrafish showed no adverse effects in 12 weeks. In addition, there was no difference in the hatchability and deformity rates of offspring produced by adult zebrafish, regardless of whether they were fed CQDs or not. The results showed that both CQDAC and CQDSpd have low toxicity and bioaccumulation to zebrafish. Moreover, the toxicity assay developed in this study provides a comprehensive platform to assess the impacts of CQDs on aquatic organisms in the future.

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Stretchable dual cross-linked silicon elastomer with superhydrophobic surface and fast triple self-healing ability at room temperature

Soft Matter ◽

10.1039/d0sm02175j ◽

2021 ◽

Author(s):

Yuxing Shan ◽

shuai liang ◽

Xiangkai Mao ◽

Jie Lu ◽

Lili Liu ◽

...

Keyword(s):

Superhydrophobic Surface ◽

Room Temperature ◽

Superhydrophobic Surfaces ◽

Self Healing ◽

Wearable Electronics ◽

Actual Application ◽

Potential Applications

Abstract. Stretchable elastomers with superhydrophobic surfaces have potential applications in wearable electronics. However, various types of damage inevitably occur on these elastomers in actual application, resulting in deterioration of the...

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Mesoporous Silica Nanoparticles: Their Projection in Nanomedicine

ISRN Materials Science ◽

10.5402/2012/608548 ◽

2012 ◽

Vol 2012 ◽

pp. 1-20 ◽

Cited By ~ 26

Author(s):

María Vallet-Regí

Keyword(s):

Drug Delivery ◽

Mesoporous Silica ◽

Silica Nanoparticles ◽

Mesoporous Silica Nanoparticles ◽

Surrounding Medium ◽

Stimuli Responsive ◽

Guest Molecules ◽

Different Types ◽

Potential Applications ◽

Inorganic Nanomaterials

Mesoporous silica nanoparticles are receiving growing attention by the scientific biomedical community. Among the different types of inorganic nanomaterials, mesoporous silica nanoparticles have emerged as promising multifunctional platforms for nanomedicine. Since their introduction in the drug delivery landscape in 2001, mesoporous materials for drug delivery are receiving growing scientific interest for their potential applications in the biotechnology and nanomedicine fields. The ceramic matrix efficiently protects entrapped guest molecules against enzymatic degradation or denaturation induced by pH and temperature as no swelling or porosity changes take place as a response to variations in the surrounding medium. It is possible to load huge amounts of cargo into the mesopore voids and capping the pore entrances with different nanogates. The application of a stimulus provokes the nanocap removal and triggers the departure of the cargo. This strategy permits the design of stimuli-responsive drug delivery nanodevices.

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Microgels and Nanoparticles: Where Micro and Nano Go Hand in Hand

Zeitschrift für Physikalische Chemie ◽

10.1515/zpch-2014-0578 ◽

2015 ◽

Vol 229 (1-2) ◽

Author(s):

Beatriz H. Juarez ◽

Luis M. Liz-Marzán

Keyword(s):

Magnetic Nanoparticles ◽

Optical Tweezers ◽

Hybrid System ◽

Inorganic Nanoparticles ◽

Stimuli Responsive ◽

Single Particles ◽

Nanoscale Systems ◽

Different Types ◽

Potential Applications ◽

Very High

AbstractThe integration of different types of materials in a single hybrid system allows the combination of multiple functionalities, which can even be used in conjunction with each other. This strategy has been exploited in nanoscale systems for the creation of so-called smart nanomaterials. Within this category, the combination of inorganic nanoparticles with stimuli-responsive microgels is of very high interest because of the wide variety of potential applications. We present here a short overview of this type of materials in which the nano- and micro-scales get nicely integrated, with a great potential to expand the range of technological applications. We focus mainly on the integration of metal nanoparticles, either by themselves or in combination with semiconductor and magnetic nanoparticles. Various examples of the synergic properties that can be obtained are described, as well as the possibility to extract useful information when optical tweezers are used to manipulate single particles. We expect that this review will stimulate additional research in this field.

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Text Analysis of Project Completion Reports

10.18235/0003611 ◽

2021 ◽

Author(s):

César E. Montiel Olea ◽

Leonardo R. Corral

Keyword(s):

Text Analysis ◽

Text Documents ◽

Project Completion ◽

Analysis Tools ◽

Development Effectiveness ◽

Different Types ◽

Potential Applications ◽

Project Cycle ◽

Main Instrument ◽

Unique Dataset

Project Completion Reports (PCRs) are the main instrument through which different multilateral organizations measure the success of a project once it closes. PCRs are important for development effectiveness as they serve to understand achievements, failures, and challenges within the project cycle they can feed back into the design and execution of new projects. The aim of this paper is to introduce text analysis tools for the exploration of PCR documents. We describe and apply different text analysis tools to explore the content of a sample of PCRs. We seek to illustrate a way in which PCRs can be summarized and analyzed using innovative tools applied to a unique dataset. We believe that the methods presented in this investigation have numerous potential applications to different types of text documents routinely prepared within the Inter-American Development Bank (IDB).

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Concepts for Developing Physical Gels of Chitosan and of Chitosan Derivatives

Gels ◽

10.3390/gels4030067 ◽

2018 ◽

Vol 4 (3) ◽

pp. 67 ◽

Cited By ~ 16

Author(s):

Pasquale Sacco ◽

Franco Furlani ◽

Gaia de Marzo ◽

Eleonora Marsich ◽

Sergio Paoletti ◽

...

Keyword(s):

Molecular Weight ◽

Electrostatic Interactions ◽

Chitosan Derivatives ◽

Modified Chitosan ◽

Physical Chemical ◽

Degree Of Acetylation ◽

Potential Applications ◽

Low Toxicity ◽

Physical Interactions ◽

Biomedical Field

Chitosan macro- and micro/nano-gels have gained increasing attention in recent years, especially in the biomedical field, given the well-documented low toxicity, degradability, and non-immunogenicity of this unique biopolymer. In this review we aim at recapitulating the recent gelling concepts for developing chitosan-based physical gels. Specifically, we describe how nowadays it is relatively simple to prepare networks endowed with different sizes and shapes simply by exploiting physical interactions, namely (i) hydrophobic effects and hydrogen bonds—mostly governed by chitosan chemical composition—and (ii) electrostatic interactions, mainly ensured by physical/chemical chitosan features, such as the degree of acetylation and molecular weight, and external parameters, such as pH and ionic strength. Particular emphasis is dedicated to potential applications of this set of materials, especially in tissue engineering and drug delivery sectors. Lastly, we report on chitosan derivatives and their ability to form gels. Additionally, we discuss the recent findings on a lactose-modified chitosan named Chitlac, which has proved to form attractive gels both at the macro- and at the nano-scale.

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Reliability and validity of a new accelerometer-based device for detecting physical activities and energy expenditure

PeerJ ◽

10.7717/peerj.5775 ◽

2018 ◽

Vol 6 ◽

pp. e5775 ◽

Cited By ~ 2

Author(s):

Yanxiang Yang ◽

Moritz Schumann ◽

Shenglong Le ◽

Shulin Cheng

Keyword(s):

Energy Expenditure ◽

Real Life ◽

Reliability And Validity ◽

Correlation Coefficients ◽

Test Reliability ◽

Free Living ◽

Health Maintenance ◽

Intra Class Correlation ◽

Global Context ◽

Different Types

Background Objective assessments of sedentary behavior and physical activity (PA) by using accelerometer-based wearable devices are ever expanding, given their importance in the global context of health maintenance. This study aimed to determine the reliability and validity of a new accelerometer-based analyzer (Fibion) for detecting different PAs and estimating energy expenditure (EE) during a simulated free-living day. Methods The study consisted of two parts: a reliability (n = 18) and a validity (n = 19) test. Reliability was assessed by a 45 min protocol of repeated sitting, standing, and walking (i.e., 3 × 15 min, repeated twice), using both Fibion and ActiGraph. Validity was assessed by a 12 h continuous sequence tasks of different types (sitting, standing, walking, and cycling) and intensities (light [LPA], moderate [MPA], and vigorous [VPA]) of PA. Two Fibion devices were worn on the thigh (FT) and in the pocket (FP), respectively and were compared with criteria measures, such as direct observation (criterion 1) and oxygen consumption by a portable gas analyzer, K4b2 (criterion 2). Results FT (intra-class correlation coefficients (ICCs): 0.687–0.806) provided similar reliability as the Actigraph (ICCs: 0.661–0.806) for EE estimation. However, the measurement error (ME) of FT compared to the actual time records indicated an underestimation of duration by 5.1 ± 1.2%, 3.8 ± 0.3% and 14.9 ± 2.6% during sitting, walking, and standing, respectively. During the validity test, FT but not FP showed a moderate agreement but lager variance with the criteria (1 and 2) in assessing duration of sitting, long sitting, LPA, MPA, and VPA (p > 0.05, ICCs: 0.071–0.537), as well as for EE estimation of standing, LPA, MPA, and VPA (p > 0.05, ICCs: 0.673–0.894). Conclusions FT provided similar reliability to that of the Actigraph. However, low correlations between subsequent measurements of both devices indicated large random MEs, which were somewhat diminished during the simulated 12 h real-life test. Furthermore, FT may accurately determine the types, intensities of PA and EE during prolonged periods with substantial changes in postures, indicating that the location of the accelerometer is essential. Further study with a large cohort is needed to confirm the usability of Fibion, especially for detecting the low-intensity PAs.

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