scholarly journals Microbial Production of Biodegradable Lactate-Based Polymers and Oligomeric Building Blocks From Renewable and Waste Resources

2021 ◽  
Vol 8 ◽  
Author(s):  
John Masani Nduko ◽  
Seiichi Taguchi
Keyword(s):  
Plant Biomass ◽  
Building Blocks ◽  
Industrial Applications ◽  
Enzyme Engineering ◽  
Energy Reserves ◽  
Renewable Biomass ◽  
The Past ◽  
Naturally Occurring ◽  
Secretory Production ◽  
The Cost

Polyhydroxyalkanoates (PHAs) are naturally occurring biopolymers produced by microorganisms. PHAs have become attractive research biomaterials in the past few decades owing to their extensive potential industrial applications, especially as sustainable alternatives to the fossil fuel feedstock-derived products such as plastics. Among the biopolymers are the bioplastics and oligomers produced from the fermentation of renewable plant biomass. Bioplastics are intracellularly accumulated by microorganisms as carbon and energy reserves. The bioplastics, however, can also be produced through a biochemistry process that combines fermentative secretory production of monomers and/or oligomers and chemical synthesis to generate a repertoire of biopolymers. PHAs are particularly biodegradable and biocompatible, making them a part of today’s commercial polymer industry. Their physicochemical properties that are similar to those of petrochemical-based plastics render them potential renewable plastic replacements. The design of efficient tractable processes using renewable biomass holds key to enhance their usage and adoption. In 2008, a lactate-polymerizing enzyme was developed to create new category of polyester, lactic acid (LA)–based polymer and related polymers. This review aims to introduce different strategies including metabolic and enzyme engineering to produce LA-based biopolymers and related oligomers that can act as precursors for catalytic synthesis of polylactic acid. As the cost of PHA production is prohibitive, the review emphasizes attempts to use the inexpensive plant biomass as substrates for LA-based polymer and oligomer production. Future prospects and challenges in LA-based polymer and oligomer production are also highlighted.

scholarly journals Biocatalytic Conversion of 5-Hydroxymethylfurfural by Galactose Oxidase: Toward Scalable Technology Using Integrated Process and Enzyme Engineering

2020 ◽  
Author(s):  
William Birmingham ◽  
Asbjørn Toftgaard Pedersen ◽  
Mafalda Dias Gomes ◽  
Mathias Bøje Madsen ◽  
Michael Breuer ◽  
...  
Keyword(s):  
Production Efficiency ◽  
Cost Effective ◽  
Building Blocks ◽  
Enzyme Engineering ◽  
Galactose Oxidase ◽  
Integrated Process ◽  
Direct Preparation ◽  
The Cost ◽  
Further Development ◽  
Scalable Production

5-Hydroxymethylfurfural (HMF) has emerged as a crucial bio-based chemical building block in the drive towards developing materials from renewable resources, due to its direct preparation from sugars and its readily diversifiable scaffold. A key obstacle in transitioning to bio-based plastic production lies in meeting the necessary industrial production efficiency, particularly in the cost-effective conversion of HMF to valuable intermediates. To address the challenge of developing scalable technology for oxidizing crude HMF to more valuable chemicals, we have integrated process and enzyme engineering to provide a galactose oxidase (GOase) variant with remarkably high activity toward HMF, improved O2 binding and excellent productivity (>1,000,000 TTN). The process concept presented here for GOase catalysed selective oxidation of HMF to 2,5-diformylfuran offers a productive and efficient platform for further development, thereby laying the groundwork for a biocatalytic route to scalable production of furan-based chemical building blocks from sustainable feedstocks.<br>

scholarly journals Biocatalytic Conversion of 5-Hydroxymethylfurfural by Galactose Oxidase: Toward Scalable Technology Using Integrated Process and Enzyme Engineering

2020 ◽  
Author(s):  
William Birmingham ◽  
Asbjørn Toftgaard Pedersen ◽  
Mafalda Dias Gomes ◽  
Mathias Bøje Madsen ◽  
Michael Breuer ◽  
...  
Keyword(s):  
Production Efficiency ◽  
Cost Effective ◽  
Building Blocks ◽  
Enzyme Engineering ◽  
Galactose Oxidase ◽  
Integrated Process ◽  
Direct Preparation ◽  
The Cost ◽  
Further Development ◽  
Scalable Production

5-Hydroxymethylfurfural (HMF) has emerged as a crucial bio-based chemical building block in the drive towards developing materials from renewable resources, due to its direct preparation from sugars and its readily diversifiable scaffold. A key obstacle in transitioning to bio-based plastic production lies in meeting the necessary industrial production efficiency, particularly in the cost-effective conversion of HMF to valuable intermediates. To address the challenge of developing scalable technology for oxidizing crude HMF to more valuable chemicals, we have integrated process and enzyme engineering to provide a galactose oxidase (GOase) variant with remarkably high activity toward HMF, improved O2 binding and excellent productivity (>1,000,000 TTN). The process concept presented here for GOase catalysed selective oxidation of HMF to 2,5-diformylfuran offers a productive and efficient platform for further development, thereby laying the groundwork for a biocatalytic route to scalable production of furan-based chemical building blocks from sustainable feedstocks.<br>

scholarly journals 3D Printing Hydrogel-Based Soft and Biohybrid Actuators: A Mini-Review on Fabrication Techniques, Applications, and Challenges

2021 ◽  
Vol 8 ◽  
Author(s):  
Wenhuan Sun ◽  
Saul Schaffer ◽  
Kevin Dai ◽  
Lining Yao ◽  
Adam Feinberg ◽  
...  
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Building Blocks ◽  
Stimuli Responsive ◽  
Future Directions ◽  
The Past ◽  
Naturally Occurring ◽  
Tunable Mechanical Properties ◽  
Responsive Hydrogels ◽  
Robotic Applications

Stimuli-responsive hydrogels are candidate building blocks for soft robotic applications due to many of their unique properties, including tunable mechanical properties and biocompatibility. Over the past decade, there has been significant progress in developing soft and biohybrid actuators using naturally occurring and synthetic hydrogels to address the increasing demands for machines capable of interacting with fragile biological systems. Recent advancements in three-dimensional (3D) printing technology, either as a standalone manufacturing process or integrated with traditional fabrication techniques, have enabled the development of hydrogel-based actuators with on-demand geometry and actuation modalities. This mini-review surveys existing research efforts to inspire the development of novel fabrication techniques using hydrogel building blocks and identify potential future directions. In this article, existing 3D fabrication techniques for hydrogel actuators are first examined. Next, existing actuation mechanisms, including pneumatic, hydraulic, ionic, dehydration-rehydration, and cell-powered actuation, are reviewed with their benefits and limitations discussed. Subsequently, the applications of hydrogel-based actuators, including compliant handling of fragile items, micro-swimmers, wearable devices, and origami structures, are described. Finally, challenges in fabricating functional actuators using existing techniques are discussed.

scholarly journals Toward scalable biocatalytic conversion of 5-hydroxymethylfurfural by galactose oxidase using coordinated reaction and enzyme engineering

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
William R. Birmingham ◽  
Asbjørn Toftgaard Pedersen ◽  
Mafalda Dias Gomes ◽  
Mathias Bøje Madsen ◽  
Michael Breuer ◽  
...  
Keyword(s):  
Production Efficiency ◽  
Cost Effective ◽  
Building Blocks ◽  
Enzyme Engineering ◽  
Galactose Oxidase ◽  
Reaction Conditions ◽  
Direct Preparation ◽  
The Cost ◽  
Further Development ◽  
Scalable Production

Abstract5-Hydroxymethylfurfural (HMF) has emerged as a crucial bio-based chemical building block in the drive towards developing materials from renewable resources, due to its direct preparation from sugars and its readily diversifiable scaffold. A key obstacle in transitioning to bio-based plastic production lies in meeting the necessary industrial production efficiency, particularly in the cost-effective conversion of HMF to valuable intermediates. Toward addressing the challenge of developing scalable technology for oxidizing crude HMF to more valuable chemicals, here we report coordinated reaction and enzyme engineering to provide a galactose oxidase (GOase) variant with remarkably high activity toward HMF, improved O2 binding and excellent productivity (>1,000,000 TTN). The biocatalyst and reaction conditions presented here for GOase catalysed selective oxidation of HMF to 2,5-diformylfuran offers a productive blueprint for further development, giving hope for the creation of a biocatalytic route to scalable production of furan-based chemical building blocks from sustainable feedstocks.

Measuring the cost of environmental compliance for Waikato dairy farmers - a survey approach

2015 ◽  
Vol 77 ◽  
pp. 159-166
Author(s):  
T.O.R. Macdonald ◽  
J.S. Rowarth ◽  
F.G. Scrimgeour
Keyword(s):  
Qualitative Data ◽  
Management Practice ◽  
Dairy Farm ◽  
Environmental Compliance ◽  
Dairy Farmers ◽  
The Past ◽  
Farm Systems ◽  
The Cost ◽  
Farm System ◽  
Survey Approach

The link between dairy farm systems and cost of environmental compliance is not always clear. A survey of Waikato dairy farmers was conducted to establish the real (non-modelled) cost of compliance with environmental regulation in the region. Quantitative and qualitative data were gathered to improve understanding of compliance costs and implementation issues for a range of Waikato farm systems. The average oneoff capital cost of compliance determined through a survey approach was $1.02 per kg milksolids, $1490 per hectare and $403 per cow. Costs experienced by Waikato farmers have exceeded average economic farm surplus for the region in the past 5 years. As regulation increases there are efficiencies to be gained through implementing farm infrastructure and farm management practice to best match farm system intensity. Keywords: Dairy, compliance, farm systems, nitrogen, Waikato

Stress management: Corpus-based insights into vernacular interpretations of stress

2014 ◽  
Vol 10 (1) ◽  
pp. 81-93
Author(s):  
Laurel Smith Stvan
Keyword(s):  
Traumatic Stress ◽  
American English ◽  
Physical Symptom ◽  
The Body ◽  
Post Traumatic Stress ◽  
The Past ◽  
Academic Texts ◽  
Naturally Occurring ◽  
Post Traumatic ◽  
Semantic Shift

Examination of the term stress in naturally occurring vernacular prose provides evidence of three separate senses being conflated. A corpus analysis of 818 instances of stress from non-academic texts in the Corpus of Contemporary American English (COCA) and the Corpus of American Discourses on Health (CADOH) shows a negative prosody for stress, which is portrayed variously as a source outside the body, a physical symptom within the body and an emotional state. The data show that contemporary speakers intermingle the three senses, making more difficult a discussion between doctors and patients of ways to ‘reduce stress’, when stress might be interpreted as a stressor, a symptom, or state of anxiety. This conflation of senses reinforces the impression that stress is pervasive and increasing. In addition, a semantic shift is also refining a new sense for stress, as post-traumatic stress develops as a specific subtype of emotional stress whose use has increased in circulation in the past 20 years.

FEATURES OF MONITORING OF DEGRADED LANDS TO ASSESS POSSIBILITIES FOR THEIR REHABILITATION

2020 ◽  
pp. 37-43
Author(s):  
B.I. KORZHENEVSKIY ◽  
◽  
N.V. KOLOMIYTSEV ◽  
G.YU. TOLKACHEV
Keyword(s):  
Agricultural Land ◽  
Meteorological Data ◽  
Morphological Characteristics ◽  
Energy Reserves ◽  
Land Restoration ◽  
Degraded Land ◽  
Degraded Lands ◽  
The Past ◽  
Unused Land ◽  
Restoration Work

Putting out of using large areas of agricultural lands in the central region over the past years has led to worsening the prospects of their purposed use, although the problem of the relevance of their restoration still remains. For many years the unused land was exposed to both natural exogenous processes such as erosion, suffusion, etc. and biological and chemical changes, usually for the worse for agriculture. There are considered elements of monitoring aimed at assessing the prospects or lack of perspectives of rehabilitation of degraded lands. An energy approach to assessing the state of slopes and soils located within these slopes is presented. The main factors of natural and anthropogenic character in assessing the prospects for land restoration are their steepness, excess relative to local bases of erosion other morphological characteristics of slopes which in general is reduced to an assessment of the energy provision of slopes and soils. So the higher the energy capacity of slopes – they are less promising for development, for soils – there is a reverse picture – the higher their energy reserves, the more promising is their use. Approaches to zoning the territory for monitoring from larger taxons of natural and anthropogenic genesis to the sites of special surveillance within which the prospects for rehabilitation of the agricultural land are evaluated. The most important factor is the material expediency of such actions, i.e. before starting the restoration work it is necessary to assess the profitability or loss of the proposed event. In cases of the material expediency it is feasible as further actions to include energy assessments of slopes and soils; zoning of the object according to the steepness and oriented characteristics of soil washout; and the possibility of obtaining agronomic and meteorological data on a timely basis. The result of the work is a forecast assessment of the prospects for restoring degraded land for the intended purpose using modern databases and WEB-systems.

Formation of Carbon-Oxygen Bond Mediated by Hypervalent Iodine Reagents Under Metal-free Conditions

2020 ◽  
Vol 17 ◽  
Author(s):  
Ayesha Jalil ◽  
Yaxin O Yang ◽  
Zhendong Chen ◽  
Rongxuan Jia ◽  
Tianhao Bi ◽  
...  
Keyword(s):  
Natural Products ◽  
Bond Formation ◽  
Building Blocks ◽  
Review Article ◽  
Hypervalent Iodine ◽  
Metal Free ◽  
Bioactive Natural Products ◽  
The Past ◽  
Oxygen Bond ◽  
Privileged Scaffolds

: Hypervalent iodine reagents are a class of non-metallic oxidants have been widely used in the construction of several sorts of bond formations. This surging interest in hypervalent iodine reagents is essentially due to their very useful oxidizing properties, combined with their benign environmental character and commercial availability from the past few decades ago. Furthermore, these hypervalent iodine reagents have been used in the construction of many significant building blocks and privileged scaffolds of bioactive natural products. The purpose of writing this review article is to explore all the transformations in which carbon-oxygen bond formation occurred by using hypervalent iodine reagents under metal-free conditions

Attraction of prey

2018 ◽  
Author(s):  
John D. Horner ◽  
Bartosz J. Płachno ◽  
Ulrike Bauer ◽  
Bruno Di Giusto
Keyword(s):  
Visual Cues ◽  
Synergistic Action ◽  
Carnivorous Plants ◽  
Future Research ◽  
Acoustic Cues ◽  
Qualitative And Quantitative Analysis ◽  
Qualitative And Quantitative ◽  
The Past ◽  
The Cost ◽  
Prey Attraction

The ability to attract prey has long been considered a universal trait of carnivorous plants. We review studies from the past 25 years that have investigated the mechanisms by which carnivorous plants attract prey to their traps. Potential attractants include nectar, visual, olfactory, and acoustic cues. Each of these has been well documented to be effective in various species, but prey attraction is not ubiquitous among carnivorous plants. Directions for future research, especially in native habitats in the field, include: the qualitative and quantitative analysis of visual cues, volatiles, and nectar; temporal changes in attractants; synergistic action of combinations of attractants; the cost of attractants; and responses to putative attractants in electroantennograms and insect behavioral tests.

scholarly journals Dissecting cellobiose metabolic pathway and its application in biorefinery through consolidated bioprocessing in Myceliophthora thermophila

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Jingen Li ◽  
Shuying Gu ◽  
Zhen Zhao ◽  
Bingchen Chen ◽  
Qian Liu ◽  
...  
Keyword(s):  
Malic Acid ◽  
Plant Biomass ◽  
Consolidated Bioprocessing ◽  
Cellulase Activity ◽  
Industrial Applications ◽  
Efficient Production ◽  
Myceliophthora Thermophila ◽  
Final Strain ◽  
Cellobiose Metabolism ◽  
Cost Efficient

Abstract Background Lignocellulosic biomass has long been recognized as a potential sustainable source for industrial applications. The costs associated with conversion of plant biomass to fermentable sugar represent a significant barrier to the production of cost-competitive biochemicals. Consolidated bioprocessing (CBP) is considered a potential breakthrough for achieving cost-efficient production of biomass-based fuels and commodity chemicals. During the degradation of cellulose, cellobiose (major end-product of cellulase activity) is catabolized by hydrolytic and phosphorolytic pathways in cellulolytic organisms. However, the details of the two intracellular cellobiose metabolism pathways in cellulolytic fungi remain to be uncovered. Results Using the engineered malic acid production fungal strain JG207, we demonstrated that the hydrolytic pathway by β-glucosidase and the phosphorolytic pathway by phosphorylase are both used for intracellular cellobiose metabolism in Myceliophthora thermophila, and the yield of malic acid can benefit from the energy advantages of phosphorolytic cleavage. There were obvious differences in regulation of the two cellobiose catabolic pathways depending on whether M. thermophila JG207 was grown on cellobiose or Avicel. Disruption of Mtcpp in strain JG207 led to decreased production of malic acid under cellobiose conditions, while expression levels of all three intracellular β-glucosidase genes were significantly up-regulated to rescue the impairment of the phosphorolytic pathway under Avicel conditions. When the flux of the hydrolytic pathway was reduced, we found that β-glucosidase encoded by bgl1 was the dominant enzyme in the hydrolytic pathway and deletion of bgl1 resulted in significant enhancement of protein secretion but reduction of malate production. Combining comprehensive manipulation of both cellobiose utilization pathways and enhancement of cellobiose uptake by overexpression of a cellobiose transporter, the final strain JG412Δbgl2Δbgl3 produced up to 101.2 g/L and 77.4 g/L malic acid from cellobiose and Avicel, respectively, which corresponded to respective yields of 1.35 g/g and 1.03 g/g, representing significant improvement over the starting strain JG207. Conclusions This is the first report of detailed investigation of intracellular cellobiose catabolism in cellulolytic fungus M. thermophila. These results provide insights that can be applied to industrial fungi for production of biofuels and biochemicals from cellobiose and cellulose.

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