scholarly journals Boosting the value-added aromatics synthesis directly from syngas via Cr2O3 and Ga doped capsule zeolite

2021 ◽  
Author(s):  
Yang Wang ◽  
Weizhe Gao ◽  
Kangzhou Wang ◽  
Xinhua Gao ◽  
Baizhang Zhang ◽  
...  
Keyword(s):  
Industrial Application ◽  
Value Added ◽  
Product Yield ◽  
Tandem Process ◽  
Zeolite P

Even though the transformation of syngas into aromatics has been realized via a methanol-mediated tandem process, the low product yield is still the bottleneck limiting the industrial application of this...

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 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.

Role of Catalyst in Solid Biomass Gasification

2016 ◽  
Author(s):  
K. G. Burra ◽  
A. K. Gupta
Keyword(s):  
Catalytic Activity ◽  
Alkali Metals ◽  
Total Yield ◽  
Value Added ◽  
Clean Energy ◽  
Product Yield ◽  
Energy Yield ◽  
Gaseous Species ◽  
Transitional Metals ◽  
Solid Biomass

Energy recovery from biomass is of pinnacle importance for renewable and sustainable energy development. Gasification techniques offer efficient and effective transformation of solid biomass into gas/liquid fuels and value added materials. This technique offers clean energy production with improved efficiency compared to other transformation techniques. Catalysts offer improved reaction efficiency and product yield. However, a robust catalyst for efficient biomass conversion to fuel gases requires close examination. Transitional metals, being inert compared to alkali metals, have shown good catalytic activity in reformation reactions, such as, high temperature and low temperature water-gas shift reactions in ammonia plants with good heat conductivity and catalytic activity. In this study catalytic conversion of pine wood chips using dry (CO2) gasification is investigated. The catalytic effects of CuO/Al2O3-SiO2 (made by wetness impregnation) on the rate of gasification, along with the gaseous species evolved during the gasification at different temperatures (700°C to 900°C) using CO2 are investigated in a semi-batch type reactor. The H2/CO ratio in the syngas and the temporal evolution of various gases evolved, their total yield, and the energy yield are quantified from the analysis of gases evolved. The results reveal significant enhancement in H2 yield and production rate along with selective dry reformation of CH4, while the effect on CO yields were unaffected. Improved yields of H2 and CH4 but no change in CO suggest the catalytic activity of CuO in enhancing the formation of high molecular weight hydrocarbons.

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 Clean and Efficient Synthesis of High-Quality Silica From Rice Husk Ash

2021 ◽  
Author(s):  
Tang Baoyu ◽  
Zhang Long ◽  
Yu Zaiqian
Keyword(s):  
Rice Husk ◽  
Production Cost ◽  
Rice Husk Ash ◽  
Value Added ◽  
Industrial Effluents ◽  
Product Yield ◽  
Complex Salt ◽  
Chemical Precipitation ◽  
Process Efficiency ◽  
Waste Biomass

Abstract Rice husk ash derived from the rice husk, a renewable waste biomass resource from rice production can be used to produce high value-added silica materials with various applications. But present technologies suffer the shortages of using inorganic acid as the precipitating agent, complex salt-containing wastewater post-treatment, higher production cost, lower product quality, and without the recycling of process additives. In this paper, improved clean chemical precipitation characterizing of recycling the by-product and surfactant used is developed with the highest silica product yield of 99.3%, pore size (21-35 nm), and specific surface area (196-462 m2/g). After the by-product solution is reused 5 times, the yield of silica can still reach 99.1%. The recovery yield of surfactant is 95.3%. The properties of the prepared silica meet the standard of silica for specific applications. The process characterized the recycling of the by-product and surfactant in the process, greener CO2 precipitant, ensuring the greenness, process efficiency, and low production cost. This opens up a new industrialization practical way for up-grading utilization of waste biomass and CO2 containing industrial effluents.

Process optimization of lignin conversion into value added chemicals by thermochemical pretreatment and electrooxidation on a stainless steel anode

Holzforschung ◽  
2018 ◽  
Vol 72 (3) ◽  
pp. 187-199 ◽  
Author(s):  
Sandeep Singh ◽  
Himadri Roy Ghatak
Keyword(s):  
Value Added ◽  
Product Yield ◽  
Organic Chemical ◽  
Process Conditions ◽  
Chemical Production ◽  
Synthesis Conditions ◽  
Thermochemical Pretreatment ◽  
Independent Process ◽  
Soda Lignin ◽  
Chemical Groups

AbstractWheat straw soda lignin was subjected to thermochemical (TC) pretreatment at low to moderate temperatures followed by electrooxidation (EO) on an SS-304 anode to produce some value-added organic chemicals. The influence of independent process variables on the product yield of major organic chemical groups, namely, aromatic carbonyl compounds (COarom), aromatic hydrocarbons (HCarom), and aliphatic hydrocarbons (HCaliph), was studied. Response surface methodology (RSM) was used to optimize the process conditions for maximizing the amount of chemical production according to the Box-Behnken experimental design (BBD). For COarom, the optimal conditions were 2 h TC pretreatment at 200°C followed by 12 h of EO at 2.24 mA cm−2current density to yield 24.7% of desired products. The optimized synthesis conditions for HCaromare 2 h TC treatment at 200°C yielding 16.1% desired products. As individual compounds, vanillin, acetosyringone, syringaldehyde, acetovanillone,o-xylene and toluene were significantly produced in different product groups. A small amount of organosilicon compounds (ORGSi) and HCaliphwas also produced.

scholarly journals Mevalonate production from ethanol by direct conversion through acetyl-CoA using recombinant Pseudomonas putida, a novel biocatalyst for terpenoid production

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Jeongmo Yang ◽  
Ji Hee Son ◽  
Hyeonsoo Kim ◽  
Sukhyeong Cho ◽  
Jeong-geol Na ◽  
...  
Keyword(s):  
Pseudomonas Putida ◽  
Batch Fermentation ◽  
Fossil Fuels ◽  
Fatty Acid Biosynthesis ◽  
Carbon Sources ◽  
Value Added ◽  
Product Yield ◽  
Cellulosic Biomass ◽  
Ethanol Metabolism ◽  
Acetyl Coa

Abstract Background Bioethanol is one of the most representative eco-friendly fuels developed to replace the non-renewable fossil fuels and is the most successful commercially available bio-conversion technology till date. With the availability of inexpensive carbon sources, such as cellulosic biomass, bioethanol production has become cheaper and easier to perform, which can facilitate the development of methods for converting ethanol into higher value-added biochemicals. In this study, a bioconversion process using Pseudomonas putida as a biocatalyst was established, wherein ethanol was converted to mevalonate. Since ethanol can be converted directly to acetyl-CoA, bypassing its conversion to pyruvate, there is a possibility that ethanol can be converted to mevalonate without producing pyruvate-derived by-products. Furthermore, P. putida seems to be highly resistant to the toxicity caused by terpenoids, and thus can be useful in conducting terpenoid production research. Results In this study, we first expressed the core genes responsible for mevalonate production (atoB, mvaS, and mvaE) in P. putida and mevalonate production was confirmed. Thereafter, through an improvement in genetic stability and ethanol metabolism manipulation, mevalonate production was enhanced up to 2.39-fold (1.70 g/L vs. 4.07 g/L) from 200 mM ethanol with an enhancement in reproducibility of mevalonate production. Following this, the metabolic characteristics related to ethanol catabolism and mevalonate production were revealed by manipulations to reduce fatty acid biosynthesis and optimize pH by batch fermentation. Finally, we reached a product yield of 0.41 g mevalonate/g ethanol in flask scale culture and 0.32 g mevalonate/g ethanol in batch fermentation. This is the highest experimental yield obtained from using carbon sources other than carbohydrates till date and it is expected that further improvements will be made through the development of fermentation methods. Conclusion Pseudomonas putida was investigated as a biocatalyst that can efficiently convert ethanol to mevalonate, the major precursor for terpenoid production, and this research is expected to open new avenues for the production of terpenoids using microorganisms that have not yet reached the stage of mass production.

scholarly journals Factorial Analysis on Biovinegar Production from Pineapple Waste Using Mixed Strains

2020 ◽  
Vol 6 (1) ◽  
pp. 32-38
Author(s):  
Yashini K. Selvanathan ◽  
Shalyda M. Shaarani ◽  
Nasratun Masngut
Keyword(s):  
Acid Production ◽  
Raw Materials ◽  
Value Added ◽  
Product Yield ◽  
Fractional Factorial ◽  
Fermentation Time ◽  
Natural Fermentation ◽  
Pineapple Waste ◽  
Pineapple Peel ◽  
Independent Parameters

One of the feasible approaches to oversee pineapple waste deposit without harming the environment is by converting these build-ups into value added items such as biovinegar. The objective of this work is to screen the fermentation parameter to identify the best condition and significant parameters affecting the fermentation. Five independent parameters were investigated, namely; temperature, fermentation time, addition of glucose, part and condition of waste. Fractional factorial design of Design Expert® software was used to investigate the effect of independent parameters as well as the interaction between parameters on the biovinegar production. The work was carried out by natural fermentation in which naturally occurred microorganism readily available on the raw materials (pineapple waste) was used. The result showed that the order of parameter significance in acid production was as follows: temperature > addition of glucose > fermentation time > part of waste > condition of waste. The interaction parameter of fermentation time and addition of glucose had the strongest effect on the acid production. The best fermentation condition was carried out using pineapple peel juice at 30 °C for 8 days in an anaerobic condition with 50 g/L glucose addition. Under these conditions, acid production was 1.12 % w/v in which acetic acid concentration was 0.94 % w/v. The product pH was recorded at 3.57. The product yield and productivity were recorded at 0.1699 g/g and 0.0489 g/L.h, respectively. Exploration on producing biovinegar using mixed strains and pineapple waste as substrate could be another way to reduce environmental pollution and at the same time turning this waste into value added product. Moreover, using the natural fermentation together with the carry over benefit of the pineapple benefitted the quality of produced biovinegar.

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.

scholarly journals Sub-Pilot-Scale Autocatalytic Pyrolysis of Wastewater Biosolids for Enhanced Energy Recovery

Catalysts ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 524 ◽  
Author(s):  
Zhongzhe Liu ◽  
Simcha Singer ◽  
Daniel Zitomer ◽  
Patrick McNamara
Keyword(s):  
Energy Recovery ◽  
Large Scale ◽  
Value Added ◽  
Product Yield ◽  
Pilot Scale ◽  
Gas Production ◽  
Mixing Condition ◽  
Bench Scale ◽  
Readiness Level

Improving onsite energy generation and recovering value-added products are common goals for sustainable used water reclamation. A new process called autocatalytic pyrolysis was developed at bench scale in our previous work by using biochar produced from the biosolids pyrolysis process itself as the catalyst to enhance energy recovery from wastewater biosolids. The large-scale investigation of this process was used to increase the technical readiness level. A sub-pilot-scale catalytic pyrolytic system was constructed for this scaled-up study. The effects of configuration changes in both pyrolytic and catalytic reactors were investigated as well as the effect of vapor-catalyst contact types (i.e., downstream, in-situ) on product yield and quality. The sub-pilot-scale test with downstream catalysis resulted in higher py-gas yields and lower bio-oil yields when compared to results from a previous batch, bench-scale process. In particular, the py-gas yields increased 2.5-fold and the energy contained in the py-gas approximately quadrupled compared to the control test without autocatalysis. Biochar addition to the feed biosolids before pyrolysis (in-situ catalysis) resulted in increased py-gas production, but the increase was limited. It was expected that using a higher input pyrolyzer with a better mixing condition would further improve the py-gas yield.

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