High-value Products Research Articles

Highly selective photocatalytic Aqueous-CO2 reduction to CH4 and CH3OH using In(OH)3/ZnIn2S4 spherical composites for High-Value Fuel production

Photocatalytic CO2 reduction presents an environmentally friendly and economically viable approach to combat the energy crisis and advance carbon neutrality. In this study, we fabricated a In(OH)3/ZnIn2S4 heterojunction photocatalyst for the photocatalytic reduction of aqueous-CO2. This innovative approach not only led to a substantial increase in the production rates of CO, CH3OH, and CH4, with the respective peak rates reaching 23.45, 29.57, and 45.25 µmol g−1h−1, but also enhanced the selectivity of premium chemical fuels (CH3OH and CH4) to an impressive 91.1 %. The remarkable outcomes can be attributed to the synergistic interplay between the constructed heterojunction and the introduced sodium bicarbonate. The formation of the heterojunction efficiently facilitated the charge separation and transfer, while the incorporation of In(OH)3 notably boosted the carbon source capture capacity. Furthermore, the direct hydrolysis of sodium bicarbonate served as a vital carbon source and acted as a proton donor, effectively boosting the production of high-value chemical fuels. These findings offer invaluable insights for the development of highly active and selective photocatalysts.

Ancestral sequence reconstruction of a robust β-1,4-xylanase and efficient expression in Bacillus subtilis

Xylanases are a class of glycoside hydrolases commonly used in the food, papermaking, and textile industries. However, most xylanases are rapidly inactivated under harsh industrial conditions. Here, a unique and robust GH11 xylanase, AncXyn18, was designed using an ancestral sequence reconstruction strategy, sequence analysis, structure prediction, and experimental verification. It displayed desirable robustness with high alkali resistance and thermostability, retaining >50 % of the initial activity after incubation at pH 10.0 or 70 °C for 10 h. Furthermore, the engineered strain Bs-AncXyn18-Du12 based on the dual promoter PsigW-P43 increased the enzyme activity of AncXyn18 7.5-fold, reaching 58.2 U/mL. This work offers a theoretical basis for the improvement of xylanases, which will benefit the enzymatic bioconversion of xylan-containing agricultural waste into high-value oligosaccharide products and promote green industrial development.

The Heteropolyacid-Catalyzed Conversion of Biomass Saccharides into High-Added-Value Products and Biofuels

The industrial processes used to produce paper and cellulose generate many lignocellulosic residues. These residues are usually burned to produce heat to supply the energy demands of other processes, increasing greenhouse gas emissions and resulting in a high environmental impact. Instead of burning these lignocellulosic residues, they can be converted into saccharides, which are feedstock for high-value products and biofuels. Keggin heteropolyacids are efficient catalysts for obtaining saccharides from cellulose and hemicellulose and converting them into bioproducts or biofuel. Furfural, 5-hydroxymethylfurfural, levulinic acid, and alkyl levulinates are important platform molecules obtained from saccharides and raw materials in the biorefinery processes used to produce fine chemicals and biofuels. This review discusses the significant progress achieved in the development of the processes based on heteropolyacid-catalyzed reactions to convert biomass and their residues into furfural, 5-hydroxymethylfurfural, levulinic acid, and alkyl levulinates in homogeneous and heterogeneous reaction conditions. The different modifications that can be performed to a Keggin HPA structure, such as the replacement of the central atom (P or Si) with B or Al, the doping of the heteropolyanion with metal cations, and a proton exchange with metal or organic cations, as well as their impact on the catalytic activity of HPAs, are detailed and discussed herein.

Direct parallel electrosynthesis of high-value chemicals from atmospheric components on symmetry-breaking indium sites

To tackle significant environmental and energy challenges from increased greenhouse gas emissions in the atmosphere, we propose a method that synergistically combines cost-efficient integrated systems with parallel catalysis to produce high-value chemicals from CO2, NO, and other gases. We employed asymmetrically stretched InO5S with symmetry-breaking indium sites as a highly efficient trifunctional catalysts for NO reduction, CO2 reduction, and O2 reduction. Mechanistic studies reveal that the symmetry-breaking at indium sites substantially improves d-band center interactions and adsorption of intermediates, thereby enhancing trifunctional catalytic activity. Employed in a flow electrolysis system, the catalyst achieves continuous and flexible production of NH3, HCOO-, and H2O2, maintaining over 90% Faradaic efficiency at industrial scales. Notably, the parallel electrolysis device reported in this study effectively produces high-value products like NH4COOH directly from greenhouse gases in pure water, offering an economically efficient solution for small molecule synthesis and unique insights for the sustainable conversion of inexhaustible gases into valuable products. Therefore, this work possesses considerable potential for future practical applications in sustainable industrial processes.

Coaxially Bi/ZnO@ZnSe Array Photocathode Enables Highly Efficient CO2 to C1 Conversion via Long-lived High-energy Photoelectrons.

The key aspect of the photoelectrochemical CO2 reduction reaction (PEC CO2 RR) lies in designing cathode materials that can generate high-energy photoelectrons, enabling the activation and conversion of CO2 into high-value products. In this study, a coaxially wrapped ZnO@ZnSe array heterostructure was synthesized using a simple anion exchange strategy and metallic Bi nanoparticles (NPs) were subsequently deposited on the surface to construct a Bi/ZnO@ZnSe photocathode with high CO2 conversion capability. This array photocathode possesses a large aspect ratio, which simultaneously satisfies a low charge carrier migration path and a large specific surface area that facilitates mass transfer. Additionally, the barrier formed at the n-n heterojunction interface hinders the transfer of high-energy photoelectrons from ZnSe to lower energy levels, resulting in their rapid capture by Bi while maintaining a relatively long lifetime. These captured electrons act as active sites, efficiently converting CO2 into CO with a Faradaic efficiency above 88.9 % at -0.9 V vs. RHE and demonstrating superior stability. This work provides a novel approach for synthesizing high-energy photoelectrode materials with long lifetimes.

Fatty Acid Composition, Oxidative Status, and Content of Biogenic Elements in Raw Oats Modified Through Agricultural Practices

The chemical composition of raw oat grain is responsible for the high dietary value and health-promoting properties of oat products. This article presents the results of a study investigating the biofortification of grain in two oat genotypes—hulless and hulled—through agronomic treatments: chemical plant protection against weeds and fungi and mineral nitrogen fertilization. The applied agronomic treatments induced different changes in the fatty acid profiles, content of tocopherols, macronutrients, and micronutrients in the grain of hulled and hulless oats. Plant health contributed to higher concentrations of unsaturated fatty acids and potassium in oat grain. In turn, nitrogen fertilization decreased the content of unsaturated fatty acids, potassium, and copper and increased the content of saturated fatty acids, calcium, and manganese in oat grain. At the same time, agronomic treatments reduced the tocopherol content of the grain, which implies that the nutritional value of oats increases in the absence of chemical plant protection agents. The correlations between the content of desirable chemical compounds and agronomic treatments were stronger in hulless oat grain, which may suggest that the agronomic modification of oat-based foods is more effective in this genotype. The content of exogenous alpha-linoleic acid C18:3 n-3 and alpha-tocopherol was higher in grain harvested from the control treatment (without chemical plant protection), whereas grain harvested from fully protected treatments accumulated more essential gamma-linolenic acid C18:3 n-6. The content of gamma-tocopherol and copper in oat grain was higher in the absence of nitrogen fertilization.

Preliminary Evaluation of Watermelon Liquid Waste as an Alternative Substrate for Microalgae Cultivation: A Circular Economy Approach to the Production of High-Value Secondary Products by Chlorella vulgaris, Scenedesmus sp., Arthrospira platensis, and Chlamydomonas pitschmanii

In Italy, watermelon cultivation spans 9510 hectares, with production levels largely influenced by seasonal market demand. As a result, surplus watermelon left unsold by September often remain in the fields, where they decompose naturally and go to waste. A chemical analysis of the watermelon liquid fraction waste (WW) indicates a high carbohydrate concentration, highlighting the potential for biotechnological valorization of this waste stream, converting it into lipids or exopolysaccharides (EPSs). This study investigates the feasibility of utilizing WW as an alternative growth substrate for microalgae, aligning with circular economy principles and advancing sustainable agricultural practices. By repurposing agricultural byproducts, this research supports biorefinery objectives, aiming to convert biomass into high-value secondary products, including biofuels, pigments, and nutraceuticals. Scenedesmus and Chlorella strains demonstrated promising growth and adaptability in WW, achieving biomass yields of 0.95 ± 0.07 g L−1 and 0.37 ± 0.02 g L−1, respectively, with a significant EPS production observed as medium gelation. Although lipid accumulation was limited in this case by the WW substrate, the lipid profiles of both strains were distinctively altered, notably lacking linolenic acid.

Community Service: Tea from Sukun Leaves as a Traditional Beverage with a Modern Approach

This community service activity aims to introduce and develop the potential of sukun (breadfruit) as a raw material for tea production, emphasising the aspects of health, economy, and cultural preservation. Sukun, which has long been known as a traditional food plant, has various benefits that are not widely acknowledged, especially in the form of tea. The program involved the local community in training focused on processing sukun into high-value tea products. In addition, education was provided on packaging and marketing techniques, to enhance the competitiveness of sukun tea products in modern markets. The results of this activity show an increase in community awareness regarding the economic value of sukun, as well as the development of innovative and high-quality sukun tea products, which can be an alternative healthy beverage and support local economic sustainability. Through an integrative approach, this program succeeded in exploring local potential and combining it with modern innovation, thereby revitalizing traditional culinary heritage in a form that aligns with today’s needs.

Changing climate risks for high-value tree fruit production across the United States

Abstract Climate change poses growing risks to global agriculture including perennial tree fruit such as apples that hold important nutritional, cultural, and economic value. This study quantifies historical trends in climate metrics affecting apple growth, production, and quality, which remain understudied. Utilizing the high-resolution gridMET dataset, we analyzed trends (1979-2022) in several key metrics across the U.S. – cold degree days, chill portions, last day of spring frost, growing degree days (GDD), extreme heat days (daily maximum temperature >34°C), and warm nights (daily minimum temperatures >15°C). We found significant trends across large parts of the U.S. in all metrics, with the spatial patterns consistent with pronounced warming across the western states in summer and winter. Yakima County, WA, Kent County, MI, Wayne County, NY—leading apple-producers—showed significant decreasing trends in cold degree days and increasing trends in GDD and warm fall nights. Yakima county, with over 48,870 acres of apple orchards, showed significant changes in five of the six metrics - earlier last day of spring frost, fewer cold degree days, increasing GDD over the overall growth period, and more extreme heat days and warm nights. These trends could negatively affect apple production by reducing the dormancy period, altering bloom timing, increasing sunburn risk, and diminishing apple appearance and quality. Large parts of the U.S. experience detrimental trends in multiple metrics simultaneously that indicate the potential for compounding negative impacts on the production and quality of apples and other tree fruit, emphasizing the need for developing and adopting adaptation strategies.

Development of a starch-fermenting Zymomonas mobilis strain for bioethanol production

BackgroundBiorefinery using microorganisms to produce biofuels and value-added biochemicals derived from renewable biomass offers a promising alternative to meet our sustainable energy and environmental goals. The ethanologenic strain Zymomonas mobilis is considered as an excellent chassis for constructing microbial cell factories for diverse biochemicals due to its outstanding industrial characteristics in ethanol production, high specific productivity, and Generally Recognized as Safe (GRAS) status. Nonetheless, the restricted substrate range constrains its application.ResultsThe truncated ice nucleation protein InaK from Pseudomonas syringae was used as an autotransporter passenger, and α-amylase was fused to the C- terminal of InaK to equip the ethanol-producing bacterium with the capability to ferment renewable biomass. Western blot and flow cytometry analysis confirmed that the amylase was situated on the outer membrane. Whole-cell activity assays demonstrated that the amylase maintained its activity on the cell surface. The recombinant Z. mobilis facilitated the hydrolysis of starch into oligosaccharides and enabled the streamlining of simultaneous saccharification and fermentation (SSF) processes. In a 5% starch medium under SSF, recombinant strains containing Peno reached a maximum titer of 13.61 ± 0.12 g/L within 48 h. This represents an increase of 111.0% compared to the control strain's titer of titer of 6.45 ± 0.25 g/L.ConclusionsBy fusing the truncated ice nucleation protein InaK with α-amylase, we achieved efficient expression and surface display of the enzyme on Z. mobilis. This fusion protein exhibited remarkable enzymatic activity. Its presence enabled a cost-effective bioproduction process using starch as the sole carbon source, and it significantly reduced the required cycle time for SSF. This study not only provides an excellent Z. mobilis chassis for sustainable bioproduction from starch but also highlights the potential of Z. mobilis to function as an effective cellular factory for producing high-value products from renewable biomass.

Determination of Particle Size for Optimum Biogas Production from Ouagadougou Municipal Organic Solid Waste

Anaerobic digestion’s contribution to sustainable development is well established. It is a sustainable production process that enables energy to be saved and produced and efficient pollution control processes to be implemented, thereby contributing to the sustainable development of our societies. Optimizing biogas yields from the anaerobic digestion of municipal organic waste is crucial for maximum energy recovery and has become an important topic of interest. Substrate particle size is a key process parameter in biogas production and precedes other pretreatment methods for most organic materials. This study aims to evaluate the impact of particle size and incubation period on biomethane production from municipal solid waste. Sampling of municipal solid waste was carried out in waste pre-collection in the city of Ouagadougou, Burkina Faso. Waste characterization showed lignocellulolytic green waste (grass, dead leaves), waste composed of fruit and leafy vegetables and leftover food waste. TableCurve 3D v4.0 software was used to develop an optimal mathematical model to correlate particle size and biomethane productivity to describe optimal production parameters. Particle sizes ranging from 2000 to 63 µm high biogas production values, specifically 385.33 and 201.25 L·kg−1 of MSV. PCA analysis clearly showed a high correlation between particle size and biogas production, with optimum production recorded for size 250 µm with a biomethane production value of 187.53 L·kg−1 of MSV. The average relative errors and RMSE for CH4 content were improved by 24.31% and 44.97%, respectively. The data calculated with the developed mathematical model and the existing experimental data were compared and permutated to validate the model. This work enabled the identification of a mathematical model that describes the correlations between the input parameters of an experiment and the monitored parameters, as well as the definition of the particle size that allows for the optimal production of biomethane.

Amorphous silica production from Colombian rice husk: demonstration in scaled-up process Products

Introduction: the agroindustry generates significant waste, posing environmental, health, and economic challenges. Among these, rice husk, a byproduct of the food industry, stands out due to its potential as a source of silicon. Due to its silicon content, rice husk offers a unique opportunity for sustainable energy production and the extraction of high-value products, such as amorphous silicon dioxide (SiO2). However, optimizing processes for its efficient conversion remains a challenge.Objective: the aim of this study was to optimize the nitric acid concentration for the pretreatment of Colombian rice husk in order to produce high-purity amorphous SiO2 and demonstrate the feasibility of scaling up the process.Methods: a two-stage process was developed, which involved treating rice husk with nitric acid, followed by calcination at 620 °C. The nitric acid concentration was optimized to achieve the highest SiO2 purity. Material characterization was performed using thermogravimetric analysis (TGA), X-ray diffraction (XRD), X-ray fluorescence (XRF), and nitrogen adsorption-desorption. To assess the scalability of the process, the treatment was replicated on a larger scale using the optimized acid concentration.Results: the optimized process using a nitric acid concentration of 0.2 M yielded amorphous SiO2 with a purity of 94.9% and a surface area of 298 m²/g. When scaled up, the process achieved SiO2 with a purity of 95.5%, confirming the feasibility of the methodology for industrial applications. Conclusions: the treatment of rice husk with nitric acid followed by calcination proves to be an effective and scalable approach for producing high-purity amorphous SiO2. This process not only holds potential for industrial applications but also provides a sustainable solution for valorizing agroindustrial waste, contributing to the circular economy.

Exploring the Photocatalytic Cleavage Pathway of the β-5 Linkage Lignin Model Compound on Carbon Nitride.

As a globally abundant source of biomass, lignocellulosic biomass has been the centre of attention as a potential resource for green energy generation and value-added chemical production. A key component of lignocellulosic biomass, lignin, which is comprised of aromatic monomers, is a potential feedstock for value added chemical production. The cleavage processes of the linkages between monomers to obtain high value products, however, requires significant investigation as it is a complex, non-facile process. This study focuses on the photocatalytic valorization of a β-5 lignin model compound, a key linkage in the lignin structure. It was found that greater yields of aromatic products were obtained from the photocatalytic conversion of β-5 lignin model compound using carbon nitride (CN) when compared to Evonik P25 titanium dioxide (TiO2). Products of the β-5 model compound photocatalytic conversion were determined and C-C bond cleavage was observed. It was also determined that the solvent participated in the reactions with the introduction of a cyano group to one of the products. Radical quenching experiments revealed that superoxide radicals participated in the CN photocatalytic conversion. These results reveal for the first time the products and possible mechanism of the photocatalytic transformation of β-5 model compounds using CN photocatalysis.

Sustainable utilization of magnesium slag through carbonation: a pathway to high-value products with vaterite calcium carbonate

In this study, vaterite - rich materials (VRM) were prepared by carbonating magnesium slag (MS) with the addition of glycine as a regulator and the influence of VRM on the preference of cement was also investigated. The results showed that VRM without glycine exhibited only calcite, whereas the presence of glycine led to an increased vaterite content. The formation of rhombic calcite particles was observed in pure carbonated MS samples, while the addition of glycine during the carbonation process led to the formation of spherical vaterite particles. The compressive strength decreased with increasing MS content, while the high surface area of VRM, nucleation effect of vaterite and the pozzolanic reaction of amorphous silica gel led to an enhancement compressive strength. Overall, the prepared VRM offers a promising approach for transforming solid waste into valuable products through CO2 capture and utilization.

Concentrated C2+ Alcohol Production Enabled by Post-Intermediate Modulation and Augmented CO Adsorption in CO Electrolysis.

The electrocatalytic synthesis of multicarbon products from CO2/CO feedstock represents a sustainable method for chemical production with a reduced carbon footprint. Traditional copper catalysts predominantly produce alkenes, but generating valuable and versatile C2+ alcohols, especially high-energy-density C3 alcohols, has been challenging due to issues with selectivity, activity, and stability. Here, we present the construction of Ru-doped Cu nanowires that enhance the selectivity of n-PrOH and C2+ alcohols. In situ Raman spectroscopy shows that our approach promotes both *CO binding and availability, particularly facilitating the formation of high-frequency-bound *CO (*COHFB) and maintaining multiple *CO adsorption modes on Ru-modified and bare low-coordinated Cu nanowires. Density-functional theory (DFT) simulations illustrate that introducing Ru species onto a low-coordinated Cu step surface simultaneously stabilizes CO and alcohol-related intermediates, shifting the dominant reaction pathway toward alcohols and facilitating CO-C2 coupling at the expense of ethylene selectivity. In an alkaline gas-diffusion electrolyzer, we attained a maximum Faradaic efficiency (FE) of 35.9% for n-PrOH and 62.4% for the total C2+ alcohols. Optimizing parameters in the membrane electrode assembly (MEA) system enabled the one-pot generation and separation of C2+ alcohols, achieving a record concentration of 18.8 wt % (4.2 wt % n-PrOH and 14.6 wt % EtOH) with nearly 100% purity at 200 mA/cm2 over 100 h. This work not only provides new insights and guidance for the development of future catalysts from the perspectives of surface science and mechanisms but also highlights the importance of coupling material engineering with reactor engineering to optimize the production process of high-value alcohol products.

Productivity and adaptive properties of different origin potato varieties in the Russia’s Far East south

The paper presents the results of a study on the productivity of potato genotypes of different origin depending on the water availability in soil, including the hydrothermal coefficient of Selyaninov (HTC). The group of mid-season varieties was noted to have the highest productivity (710 g/plant). Waterlogging occurred during the growing period of plants (HTC ≥ 2.5), especially at the stage of tuber formation, negatively affecting productivity. High productivity was observed in the years with relatively favorable weather conditions (2019, 2021, and 2022) when the index of environmental conditions (I) was positive and ranged within +201.63 – +221.35. The average productivity of all the specimens was 950 g/plant. Very low productivity (420–670 g/plant) was observed in 2015–2018, 2020, and 2023 due to waterlogging (I = -99.52 – -269.81). Among the studied specimens, we identified the following varieties that were characterized by not only high productivity (above 900 g/plant) but also high responsiveness to changes in the environmental conditions and stability (average bi = 1.49; S2d·103 = 0.42): early-maturing varieties – Antonina, Bastion, Kolymskii, Krepysh, Matushka, Meteor, Pamyati Kulakova, Udacha, Vitesse, Red Lady, and Red Scarlett; medium-early varieties – Arktika, Briz, Zoya, Kamchatka, Lileya, Charodei, and Gala; mid-season varieties – Ocharovanie, Utro, and Favorit; medium-late and late varieties – Kazachok and Pobeda. The research allowed us to identify potato specimens with high productivity (1040-1480 g/plant), marketability (83.2–92.8%), plasticity (bi = 1.20–1.85), stability (S2d = 0,15–5,77), homeostasis (Hom = 9.51–40.62) and breeding value (Sc = 532.79–852.14) under the conditions of the south of the Russian Far East: early maturing varieties – Bastion, Kolymskii, Krepysh, and Pamyati Kulakova; medium-early varieties – Arktika and Zoya; mid-season variety Alyaska; medium-late and late varieties – Vetraz’ and Pobeda.

Study on dissociation mechanism and process of regenerated cryolite

Solid waste produced in the process of aluminum electrolysis is a substantial secondary source of fluorine, the fluoride electrolyte in aluminum electrolysis carbon slag accounts for about 75%. Regenerative cryolite, extracted from anode carbon residue through flotation or calcination, possesses a significant potential for fluorine recovery. The fluoride in regenerated cryolite is mainly insoluble, making its efficient dissociation crucial for utilizing the solid waste from aluminum electrolysis. This study uses regenerative cryolite and sodium carbonate to examine how roasting temperature, time, and the reagent-to-cryolite ratio (R/C) affect cryolite dissociation. Dissociation efficiency is measured using indices like baking loss, leaching loss, fluoride ion concentration in the leachate, and fluoride ion conversion rate. Optimal dissociation is achieved at 780-820°, 2.0-2.5 hours roasting time, and an R/C ratio of 1.0-1.2. Orthogonal experimental results highlight the predominant influence of R/C, with roasting temperature being the secondary factor and roasting time having the least impact. Notably, at 780°, 2.0 hours, and an R/C ratio of 1.2:1, the fluoride ion conversion rate reaches a peak of 94.23%. This allows for recycling and production of high-value fluoride products, benefiting both the environment and the economy.

Operando Reconstruction of CuO/SnO2 Nanosheets Promotes the Syngas Production from the Electrochemical CO2 Reduction Reaction.

Electrochemically reducing CO2 (CO2RR) to high-value chemical products is recognized as a promising route to simultaneously reduce the consumption of fossil fuels and carbon emission. The fabrication of syngas with an appropriate H2/CO ratio by CO2RR has been widely studied, but the dynamic evolution of the catalyst is still ambiguous. Herein, the reconstruction of CuO/SnO2 nanosheets (NSs) with a heterojunction structure in the CO2RR process was reported by an in situ X-ray diffractometer technique. The products of the CO2RR on the optimized CuO/SnO2 NSs are CO and H2, achieving a nearly 100% total Faraday efficiency. Moreover, the resulting syngas is maintained at a constant 2:1 ratio of H2/CO over a wide potential of -0.8 to -1.2 V versus the reversible hydrogen electrode. Importantly, the detailed characterizations show that Cu2+ is reduced to Cu during the CO2RR process, while the valence state of Sn remains stable. This study presents strong experimental support for the dynamic evolution process of electrocatalysts in other energy conversion fields.

Machine learning prediction of stalk lignin content using Fourier transform infrared spectroscopy in large scale maize germplasm

Lignin has been recognized as a major factor contributing to lignocellulosic recalcitrance in biofuel production and attracted attentions as a high-value product in the biorefinery field. As the traditional wet chemical methods for detecting lignin content are labor-intensive, time-consuming and environment-toxic, it is an urgent need to develop high-throughput and environment-friendly techniques for large-scale crop germplasms screening. In this study, we conducted a Fourier transform infrared (FTIR) assay on 150 maize germplasms with a diverse lignin composition to build predictive models for lignin content in maize stalk. Principal component analysis (PCA) was applied to the FTIR spectra for use as model inputs. Classification and advanced gradient boosting machine (GBM) algorithms demonstrated higher predictive accuracy (0.82–0.96) compared to traditional linear and regularization algorithms (0.03–0.04) in the training set. Notably, two optimal models, built using the extreme gradient boosting (XGBoost) and light gradient boosting machine (LightGBM) algorithms, achieved R2 values of over 0.91 in the training set and over 0.82 in the test set. Overall, the combination of FTIR and machine learning (ML) algorithms offers a high-throughput and efficient method for predicting lignin content. This approach holds significant potential for genetic breeding and the effective utilization of maize in industrial production.

Utilization of High-Salinity Crude Glycerol Byproduct from Biodiesel Production for Biosynthesis of γ-Aminobutyric Acid in Engineered Halomonas elongata

As the development of renewable energy has become imperative, biodiesel fuel (BDF) has been used as renewable biofuel with the advantage of having lower levels of greenhouse gas emissions. However, the transesterification reaction that produces BDF generates a high-salinity crude glycerol (CG) byproduct, which is difficult to recycle. Halomonas elongata is a moderately halophilic bacterium being used as a cell factory due to its ability to assimilate varieties of substrates for growth in high-salinity conditions. Previously, we engineered a recombinant H. elongata GOP-Gad to biosynthesize and accumulate γ-aminobutyric acid (GABA) as a high-value product. Here, we tested the ability of H. elongata GOP-Gad to use CG as a substrate for cell growth and GABA production. The CG byproduct was obtained from a BDF facility in Unzen City, Nagasaki, Japan, where geothermal energy catalyzed BDF production from waste cooking oil and biomethanol. Prior to use as the sole carbon (C) source in culture media, the CG byproduct was partially purified to remove soap substances and other impurities. Finally, we showed that H. elongata GOP-Gad could grow and accumulate GABA up to 28 μmol/g cell fresh weight in a minimal M63 medium containing 7% w/v NaCl with 4% w/v glycerol from the partially purified CG as a C source and 15 mM (NH4)2SO4 as a nitrogen (N) source. This result demonstrates a new circulatory bioprocess of C and N, in which H. elongata GOP-Gad can use partially purified CG and (NH4)2SO4 as the sole C and N sources for growth and GABA production.