scholarly journals Engineering central pathways for industrial-level D-(-)-acetoin biosynthesis in Corynebacterium glutamicum

2020 ◽  
Author(s):  
Lingxue Lu ◽  
Yufeng Mao ◽  
Mengyun Kou ◽  
Zhenzhen Cui ◽  
Biao Jin ◽  
...  
Keyword(s):  
Corynebacterium Glutamicum ◽  
Citrate Synthase ◽  
Value Added ◽  
Environmentally Friendly ◽  
Product Yield ◽  
Microbial Fermentation ◽  
Near Future ◽  
Optically Pure ◽  
Environmentally Friendly Production ◽  
Competitive Product

Abstract Background: Acetoin, especially the optically pure L-(+)- or D-(-)-enantiomer, is a high-value-added bio-based platform chemical and important potential pharmaceutical intermediate. Over the past decades, intense efforts have been devoted to the production of acetoin through green biotechniques. However, efficient and economical methods for the production of optically pure acetoin enantiomers are rarely reported. Previously, we systematically engineered the GRAS microorganism Corynebacterium glutamicum to efficiently produce D-(-)-acetoin from glucose. Nevertheless, its yield and average productivity were still unsatisfactory for industrial bioprocesses. Results: In this study, cellular carbon fluxes in the acetoin producer CGR6 were further redirected toward acetoin synthesis using several metabolic engineering strategies, including blocking anaplerotic pathways, attenuating key genes of the TCA cycle and integrating additional copies of the alsSD operon into the genome. Among them, the combination of attenuation of citrate synthase and inactivation of phosphoenolpyruvate carboxylase showed a significant synergistic effect on acetoin production. Finally, the optimal engineered strain CGS11 produced a titer of 102.45 g/L acetoin with a yield of 0.419 g/g glucose at a rate of 1.86 g/L/h in a 5 L fermenter. The optical purity of the resulting D-(-)-acetoin surpassed 95%. To the best of our knowledge, this is the highest titer of highly enantiomerically enriched D-(-)-acetoin, together with a competitive product yield and productivity, achieved in a simple, green process without expensive additives or substrates. This process therefore opens the possibility to achieve easy, efficient, economical and environmentally-friendly production of D-(-)-acetoin via microbial fermentation in the near future. Conclusion: To the best of our knowledge, this is the highest titer of highly enantiomerically enriched D-(-)-acetoin, together with a competitive product yield and productivity, achieved in a simple, green processes without expensive additives or substrates. This process therefore opens the possibility to achieve easy, efficient, economical and environmentally-friendly production of D-(-)-acetoin via microbial fermentation in the near future.

scholarly journals Engineering central pathways for industrial-level (3R)-acetoin biosynthesis in Corynebacterium glutamicum

2020 ◽  
Author(s):  
Lingxue Lu ◽  
Yufeng Mao ◽  
Mengyun Kou ◽  
Zhenzhen Cui ◽  
Biao Jin ◽  
...  
Keyword(s):  
Corynebacterium Glutamicum ◽  
Citrate Synthase ◽  
Optical Purity ◽  
Value Added ◽  
Tca Cycle ◽  
Product Yield ◽  
The Tca Cycle ◽  
Acetoin Production ◽  
Industrial Level ◽  
Optically Pure

Abstract Background: Acetoin, especially the optically pure (3S)- or (3R)-enantiomer, is a high-value-added bio-based platform chemical and important potential pharmaceutical intermediate. Over the past decades, intense efforts have been devoted to the production of acetoin through green biotechniques. However, efficient and economical methods for the production of optically pure acetoin enantiomers are rarely reported. Previously, we systematically engineered the GRAS microorganism Corynebacterium glutamicum to efficiently produce (3R)-acetoin from glucose. Nevertheless, its yield and average productivity were still unsatisfactory for industrial bioprocesses.Results: In this study, cellular carbon fluxes in the acetoin producer CGR6 were further redirected toward acetoin synthesis using several metabolic engineering strategies, including blocking anaplerotic pathways, attenuating key genes of the TCA cycle and integrating additional copies of the alsSD operon into the genome. Among them, the combination of attenuation of citrate synthase and inactivation of phosphoenolpyruvate carboxylase showed a significant synergistic effect on acetoin production. Finally, the optimal engineered strain CGS11 produced a titer of 102.45 g/L acetoin with a yield of 0.419 g/g glucose at a rate of 1.86 g/L/h in a 5 L fermenter. The optical purity of the resulting (3R)-acetoin surpassed 95%.Conclusion: To the best of our knowledge, this is the highest titer of highly enantiomerically enriched (3R)-acetoin, together with a competitive product yield and productivity, achieved in a simple, green processes without expensive additives or substrates. This process therefore opens the possibility to achieve easy, efficient, economical and environmentally-friendly production of (3R)-acetoin via microbial fermentation in the near future.

Systematic metabolic engineering of Corynebacterium glutamicum for the industrial-level production of optically pure d-(−)-acetoin

2017 ◽  
Vol 19 (23) ◽  
pp. 5691-5702 ◽  
Author(s):  
Yufeng Mao ◽  
Jing Fu ◽  
Ran Tao ◽  
Can Huang ◽  
Zhiwen Wang ◽  
...  
Keyword(s):  
Metabolic Engineering ◽  
Corynebacterium Glutamicum ◽  
Value Added ◽  
Industrial Product ◽  
Platform Chemical ◽  
Industrial Level ◽  
Optically Pure ◽  
Level Production

Acetoin is a high-value-added industrial product and a promising bio-based platform chemical.

scholarly journals UK Consumers’ Preferences for Ethical Attributes of Floating Rice: Implications for Environmentally Friendly Agriculture in Vietnam

2021 ◽  
Vol 13 (15) ◽  
pp. 8354
Author(s):  
Vo Hong Tu ◽  
Steven W. Kopp ◽  
Nguyen Thuy Trang ◽  
Andreas Kontoleon ◽  
Mitsuyasu Yabe
Keyword(s):  
Carbon Dioxide Emissions ◽  
Online Survey ◽  
Value Added ◽  
Environmentally Friendly ◽  
Trade Agreement ◽  
Co2 Emission Reduction ◽  
Global Food Security ◽  
Rice Farmers ◽  
Floating Rice ◽  
The Uk

Vietnam plays an important role in bearing global food security. However, Vietnamese rice farmers face several challenges, including pressures to develop sustainable livelihoods while reducing the environmental impacts of their production activities. Various Vietnamese agricultural restructuring policies were promulgated to promote the adoption of environmentally friendly practices to generate high value added for rice farmers, but the farmers are reluctant to adopt them because of perceived lack of demand. Decreasing consumption of rice in Asia and increasing demands in Europe shaped Vietnamese rice exporting policies. New trade agreements, such as the UK–Vietnam Free Trade Agreement, offer new target markets for Vietnamese rice farmers. This research provides empirical evidence related to the preferences of UK consumers for ethical attributes for floating rice imported from Vietnam. Floating rice represents a traditional method of rice cultivation that relies on the natural flooding cycle. Its cultivation uses very few agrochemical inputs and provides several other environmental, economic, and social benefits. In an online survey, the study used a choice experiment that asked 306 UK consumers to report their preferences for one kilo of floating rice with three non-market attributes: reduction in carbon dioxide emissions, allocation of profits to the farmers, and restitution of biodiversity. Overall, study participants favored the attributes of floating rice, but reported utility for only the “fair trade” attribute and for a marginal willingness to pay premiums for profit allocations to farmers. Consumers did not find value in either CO2 emission reduction or biodiversity improvement. Results from the study provide recommendations to develop agricultural programs, distribution strategies, and informational methods to encourage floating rice consumption in the UK.

scholarly journals Towards Sustainable Private Labels in an Autonomous Community during COVID-19—Analysis of Consumer Behavior and Perception on the Example of Tenerife

2021 ◽  
Vol 13 (13) ◽  
pp. 7467
Author(s):  
Maksymilian Czeczotko ◽  
Hanna Górska-Warsewicz ◽  
Wacław Laskowski ◽  
Barbara Rostecka
Keyword(s):  
Consumer Behavior ◽  
Research Question ◽  
Environmentally Friendly ◽  
Food Products ◽  
Organic Production ◽  
Autonomous Community ◽  
Private Labels ◽  
Chi Square ◽  
And Cluster Analysis ◽  
Environmentally Friendly Production

Our study aimed to analyze consumer behavior and perception towards private labels (PLs) in Tenerife as an autonomous community during COVID-19, with special attention given to sustainability aspects. The research was conducted on a sample of 500 adults purchasing PLs using quota selection and the CAWI method. We formulated four research questions related to factors of PL choice, the relationship between frequency of PL purchases, consumers’ age and income, perceived changes in PLs, and evaluation of PL products including sustainability. The latter research question referred to such product characteristics as local and environmentally friendly production, organic production, and production according to traditional technologies using only natural ingredients. For a detailed analysis of consumer behavior, we used Pearson’s chi-square test, the rho-Spearman correlation coefficient, and cluster analysis. The most important factors for purchasing PL products were lower prices compared to leading brands, attachment to a given chain, and the feeling of safety and trust in PL products. The frequency of purchase of PL food products, except for alcohol, significantly negatively correlates with age, which means that the purchase of PLs from the analyzed product categories decreases with age. The increased availability and improved image and quality of PLs were identified as the most important changes in PLs. PL food products were rated by consumers as fresh, minimally processed and with quality certificates. Environmentally friendly production methods, nutritional value, and origin from an area close to home were also indicated.

scholarly journals Defining the Frontiers of Synergism between Cellulolytic Enzymes for Improved Hydrolysis of Lignocellulosic Feedstocks

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1343
Author(s):  
Mpho S. Mafa ◽  
Brett I. Pletschke ◽  
Samkelo Malgas
Keyword(s):  
Value Added ◽  
Product Yield ◽  
Cellulose Hydrolysis ◽  
Cellulolytic Enzymes ◽  
Cellulolytic Enzyme ◽  
Key Factors ◽  
Cellulose Conversion ◽  
Lignocellulosic Feedstocks ◽  
Polysaccharide Monooxygenases ◽  
Hydrolysis Of

Lignocellulose has economic potential as a bio-resource for the production of value-added products (VAPs) and biofuels. The commercialization of biofuels and VAPs requires efficient enzyme cocktail activities that can lower their costs. However, the basis of the synergism between enzymes that compose cellulolytic enzyme cocktails for depolymerizing lignocellulose is not understood. This review aims to address the degree of synergism (DS) thresholds between the cellulolytic enzymes and how this can be used in the formulation of effective cellulolytic enzyme cocktails. DS is a powerful tool that distinguishes between enzymes’ synergism and anti-synergism during the hydrolysis of biomass. It has been established that cellulases, or cellulases and lytic polysaccharide monooxygenases (LPMOs), always synergize during cellulose hydrolysis. However, recent evidence suggests that this is not always the case, as synergism depends on the specific mechanism of action of each enzyme in the combination. Additionally, expansins, nonenzymatic proteins responsible for loosening cell wall fibers, seem to also synergize with cellulases during biomass depolymerization. This review highlighted the following four key factors linked to DS: (1) a DS threshold at which the enzymes synergize and produce a higher product yield than their theoretical sum, (2) a DS threshold at which the enzymes display synergism, but not a higher product yield, (3) a DS threshold at which enzymes do not synergize, and (4) a DS threshold that displays anti-synergy. This review deconvolutes the DS concept for cellulolytic enzymes, to postulate an experimental design approach for achieving higher synergism and cellulose conversion yields.

scholarly journals Branching features of apple cultivars in integrated and organic production technology

2018 ◽  
Vol 24 (3-4) ◽  
Author(s):  
P. Dremák ◽  
Á. Csihon ◽  
I. Gonda
Keyword(s):  
Organic Farming ◽  
Production Technology ◽  
Production System ◽  
Production Systems ◽  
Environmentally Friendly ◽  
Organic Production ◽  
Integrated System ◽  
Integrated Production ◽  
Apple Cultivars ◽  
Environmentally Friendly Production

In our study, vegetative characteristics of 39 apple cultivars were evaluated in environmentally friendly production systems. Numbers of the branches of the central leader in different high zones were shown. According to our results, number of the branches of the axis was probably larger in the integrated production system, compared to the organic one, which is related to the conditional status of the trees. Based on our experiences training and maintaining canopies in integrated system was easier, as relative more extensive canopies were needed in organic farming.

scholarly journals Application of Microalgal Stress Responses in Industrial Microalgal Production Systems

Marine Drugs ◽  
2021 ◽  
Vol 20 (1) ◽  
pp. 30
Author(s):  
Jia Wang ◽  
Yuxin Wang ◽  
Yijian Wu ◽  
Yuwei Fan ◽  
Changliang Zhu ◽  
...  
Keyword(s):  
Stress Responses ◽  
Production Systems ◽  
Strain Improvement ◽  
Value Added ◽  
Product Yield ◽  
Adaptive Laboratory Evolution ◽  
Laboratory Evolution ◽  
Theoretical Support ◽  
Further Development ◽  
Value Added Products

Adaptive laboratory evolution (ALE) has been widely utilized as a tool for developing new biological and phenotypic functions to explore strain improvement for microalgal production. Specifically, ALE has been utilized to evolve strains to better adapt to defined conditions. It has become a new solution to improve the performance of strains in microalgae biotechnology. This review mainly summarizes the key results from recent microalgal ALE studies in industrial production. ALE designed for improving cell growth rate, product yield, environmental tolerance and wastewater treatment is discussed to exploit microalgae in various applications. Further development of ALE is proposed, to provide theoretical support for producing the high value-added products from microalgal production.

scholarly journals Potensi Minyak Kelapa Sawit Sebagai Bahan Baku Busa Pemadam Kebakaran Lahan Gambut di Indonesia: Suatu Tijauan Pustaka

2020 ◽  
Author(s):  
Purwo Subekti
Keyword(s):  
Palm Oil ◽  
Raw Materials ◽  
Value Added ◽  
Environmentally Friendly ◽  
Domestic Demand ◽  
Oil Products ◽  
Raw Material ◽  
Fire Extinguisher ◽  
Vegetable Raw Materials ◽  
Peat Fires

This researchs aims to to find out about the potential of palm oil as a raw material of foam firefighting peat fires in Indonesia.By using the method of literature approach to previous researchers, can be in the know that the vegetable raw materials with thepotential to be developed in Indonesia as a raw material of foam extinguishing peat fires is palm oil. In addition to theavailability of environmentally friendly palm oil is also guaranteed and sustained since 2015, Indonesia produced palm oil andits derivatives amounted to 32.5 million tons, to meet the domestic demand of 18.77% while exports amounted to 81.23%..Utilization of palm oil as a raw material foam fire extinguisher is one form of support to the Indonesian government in order toincrease the downstream and value-added palm oil products as well as reduce the level of risk of peat fires

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