Peatlands are essential long-term carbon sinks, yet continued peat extraction for horticulture contributes to greenhouse gas emissions and ecosystem degradation. Here, we introduce artificial peat, a peat-formation-inspired material produced by selectively mimicking natural humification pathways under controlled alkaline conditions. Unlike conventional biomass conversion processes that aim for complete degradation, carbonization, or simple constituent replacement, this approach promotes controlled partial transformation of lignocellulosic biomass into artificial humic substances while preserving a stabilized fibrous framework. Batch and continuous processing routes operated under mild conditions (≤120 °C) using widely available feedstocks, including paludiculture biomass, wood residues, leaves, and agricultural by-products. Artificial humic acid yields ranged from 6.9 to 42.3 wt% in batch systems. Across both processing modes, carbohydrate fractions decreased and lignin underwent partial depolymerization followed by condensation into humified macromolecular structures, accompanied by a marked reduction of readily oxidizable organic matter. Multimodal analyses (elemental composition, Van Krevelen evolution, FTIR, microscopy/EDX, and oxidative thermogravimetry) revealed a transition toward oxygen-rich, condensed architectures with enhanced oxidative stability relative to raw biomass. The applied thermal–alkaline conditions are expected to promote hygienization and seed inactivation, while the conversion of labile biomass components into humic substances suggests improved chemical and potential biological stability. Produced within minutes rather than millennia, artificial peat combines humic functionality with preserved structural integrity, establishing a scalable and resource-efficient alternative to natural peat for sustainable growing media and carbon stabilization applications.

The transformation of poplar biomass into bio-based chemicals, fuels, and lignin-derived products through an integrated biorefinery is essential for realizing its full potential as a sustainable and economically viable feedstock. This study presents a poplar biorefinery approach using mild biphasic pretreatment (p-toluenesulfonic acid/pentanol + AlCl3, 110°C, 40 min) to produce bio-based platform multiple products. The pretreatment achieved efficient fractionation, with 83.2% delignification, 95.2% xylan removal, and minimal cellulose loss (7.8%), enabling high-yield one-pot furfural production (68.5%, 11.3 g/L). Enzymatic hydrolysis of the cellulose-rich residue, combined with fermentation by Clostridium acetobutylicum, produced a bio-solvent mixture of 16.2 g/L, including 10.5 g/L butanol. Depolymerized lignin was recovered and subjected to catalytic hydrogenolysis, yielding 46.4% monomers, 9.3% dimers, and 17.4% oligomers. Processing 140 Mt of poplar biomass annually at scale could deliver substantial environmental and economic gains, avoiding approximately 64.12 Mt of CO2-eq emissions and generating an estimated USD 2.97 billion in annual socioeconomic benefits. Sensitivity analysis confirmed biomass availability as the dominant factor influencing emission reduction. Economic evaluation demonstrated strong financial viability, with an aggregate net present value of USD 65.7 billion projected for full national implementation. This work establishes a holistic and economically compelling biorefinery strategy for the sustainable production of bio-based chemicals and fuels.

The newly isolated Burkholderia sp. SCN-KJ, which is capable of simultaneously producing intracellular polyhydroxybutyrate (PHB) and exopolysaccharide (EPS) from biodiesel-derived crude glycerol, presented a significant challenge in this study because of interference from EPS synthesis. The bceA gene, which encodes a bifunctional protein responsible for mannose-6-phosphate isomerization and the mannose-1-phosphate guanylyltransferase reaction, was identified as a key regulator of EPS production. To address this issue, CRISPR interference (CRISPRi) was employed to target the bceA gene, leading to the complete suppression of EPS synthesis and a significant improvement in PHB yield. Under optimized culture conditions, the ΔbceA mutant strain exhibited complete inhibition of EPS production, resulting in a 1.75-fold increase in the PHB concentration and PHB of a higher molecular weight than that of the wild-type Burkholderia sp. SCN-KJ. These results highlight the effectiveness of dCas9-mediated silencing of the bceA gene in overcoming the challenges posed by EPS interference and underscore its potential for increasing PHB production in Burkholderia sp. SCN-KJ.

α-Ketoglutarate, a key intermediate in the TCA cycle, is crucial for amino acid synthesis and nitrogen transport. However, microbial engineering for α-ketoglutarate production is hindered by the intrinsic inefficiency of the metabolic network. In this study, transcription factor engineering was performed for the reconstruction of the metabolic network to boost α-ketoglutarate biosynthesis in Candida glabrata. Transcription factors GCR2 and RTG1 were first reinstalled to kick-start the glycolytic pathway and the TCA cycle, respectively, and then optimized to redistribute carbon flux between the two pathways. In addition, pyruvate carriers, MPC1 and MPC2, were introduced to facilitate the transport of cytoplasmic pyruvate to mitochondria, thereby feeding it into the TCA cycle for α-ketoglutarate biosynthesis. Next, transcription factor HAP4 was utilized to rewire the electron transport chain for improving redox balance and reducing overflow metabolism, thereby channeling more carbon flux to α-ketoglutarate production. Finally, the engineered strain C. glabrata KGA17 was capable of producing 210.4 g/L α-ketoglutarate in a 5-L bioreactor. This approach showed significant promise for developing efficient microbial cell factories for high-value chemical production.

Biofuel Research Journal (BRJ) defines "biofuel" in both a specific and generalized context.In the specific sense, BRJ focuses on traditional biofuels and bioproducts derived from biomass.This includes biofuels such as biodiesel, bioethanol, biogas, and algal biofuels, as well as bioproducts like bio-based smart materials, biocomposites, and bio-based chemicals.In a generalized sense, BRJ extends the definition of "biofuel" to include any bio-based technologies, innovations, and strategies that contribute to reducing carbon emissions and fueling the transition toward a sustainable bioeconomy.Here, "biofuel" includes efforts that drive the shift from a carbon-intensive economy to a resilient, bio-based economy.Through this dual approach, BRJ aims to highlight the comprehensive role that both specific biofuels and generalized bio-based innovations play in fostering a sustainable future.

Exploring the potential of advanced distillable solvents as efficient biomass pretreatment agents is critical for biorefineries, enhancing fermentable sugar yields while enabling solvent recovery and recycling without suffering significant losses. Here, we employ distillable amine-based solvents for pretreating a wide range of lignocellulosic feedstocks, aiming to facilitate the industrial release of fermentable sugars from diverse feedstocks through enzymatic hydrolysis. Twenty-two diverse feedstocks, sourced from different geographical regions and representing various biomass categories, were surveyed for chemical (mainly carbohydrates and lignin) and lignin (S, G, and H units) profiles. Several solvents, including ethanolamine, ethanolammonium acetate, butylamine, butylammonium acetate, and triethylamine, were tested for the pretreatment of eight selected biomasses. Among these solvents, butylamine emerged as the most effective due to its favorable sugar release, excellent solvent removal rate, and low boiling point, facilitating solvent recovery and recycling. Extending butylamine pretreatment to all 22 feedstocks demonstrated desirable sugar yields and highly efficient solvent removal in the majority of the biomass sources tested. Agricultural residues and their mixtures showed particularly favorable sugar release. Despite minimal changes in cellulose crystallinity, XRD characterization of sorghum, poplar, and pine before and after butylamine pretreatment showed a decrease in intensity and a slight shift of certain peaks, indicating alterations in cellulose structure. Fourier-transform infrared spectroscopy and thermogravimetric analysis analyses suggested disruption of biomass linkages in hemicellulose and lignin, enhancing enzymatic digestibility. Scale-up experiments of the mixed agricultural feedstocks in a 1 L Parr reactor achieved over 90% glucose liberation and more than 99% butylamine removal, highlighting the scalability of the method. The resulting hydrolysates supported the growth of diverse bacterial and fungal strains, indicating downstream compatibility with commercial fermentation processes. This study presents butylamine as an effective, recoverable pretreatment solvent for a wide range of lignocellulosic feedstocks, offering a promising solution to key biorefinery challenges. The demonstrated scalability and compatibility with various biomass types and blends underscore its potential for industrial application, advancing sustainable biofuel and biochemical production.

The biomaterial polyhydroxybutyrate (PHB) is a promising, renewable, and green alternative polymer. In this study, a method to incorporate gluconate 6-phosphate dehydratase (edd) deletion in Escherichia coli expressing PHB biosynthesis genes from Cupriavidus necator strain A-04 was proposed. The growth of the edd-deficient strain, which is defective in the glycolytic Entner–Doudoroff pathway, decreased significantly in Luria-Bertani (LB) medium supplemented with glucose. Surprisingly, compared with the wild-type strain, the recombinant edd-deficient strain expressing PHB biosynthesis genes exhibited expeditious PHB accumulation with a high PHB content. The edd-deficient strain reached the highest PHB concentration of 7.6 g/L and a 93 wt% PHB content within 30 h of flask-scale cultivation when commercial glucose was used as the sole carbon source. In addition, the resulting strain was able to utilize crude glycerol waste from the biodiesel industry for PHB accretion with a 74.8 wt% content in 24 h. The PHB yields obtained from glucose and crude glycerol waste were 0.37 and 0.20 g PHB/g substrate, respectively. These findings not only broaden the understanding of the effect of glucose metabolism on PHB production but also provide promising candidates for the production of polyhydroxyalkanoates in the future.

The photoenzyme fatty acid photodecarboxylase (FAP) has emerged as a promising catalyst for the redox-neutral biological production of hydrocarbons. Previous studies have shown that FAP can efficiently convert medium-chain fatty acids such as n-octanoic acid into hydrocarbons, outperforming its natural long-chain fatty acid substrates (C16-C18). Such observation expands the potential applications of FAP to include solvents and jet fuels. However, the limited availability of natural sources of n-octanoic acid poses a challenge to the industrial implementation of n-heptane bioproduction. This study investigates the hydrocarbon synthesis capacity of an E. coli strain that expresses FAP and produces n-octanoic acid, the precursor to n-heptane, via a specific octanoyl-ACP thioesterase. Several FAPs and thioesterases were tested. A blue light-inducible promoter ensured high expression of both enzymes, eliminating the need for chemical inducers. Fusion of FAP with thioredoxin increased n-heptane production 12-fold. Using a co-cultivation strategy, where one strain produces n-octanoic acid and another strain converts it to n-heptane, increased hydrocarbon production 14-fold compared to co-expressing FAP and thioesterase. Co-cultures operated in batch mode in 100-mL photobioreactors enabled the recovery of >90%-pure n-heptane, yielding 272 mg·L-1 over 56 h. This work lays the foundation for the development of an industrial bioproduction of n-heptane.

Methanol synthesis via CO2 hydrogenation is a key pathway for producing methanol. Considerable research has focused on enhancing Cu/ZnO-based catalysts for this process. In this study, biochar, a porous material derived from renewable waste, was employed to support the immobilization of Cu/ZnO nanoparticles for CO2 hydrogenation to methanol. The catalyst developed in this work exhibited exceptional performance, with a methanol space-time yield (STY) of 496.5 mgMeOH gCu-1 h-1, selectivity of 71%, and stability (maintaining catalytic activity for over 45 h). These metrics significantly outperformed those of the Cu/ZnO/Al2O3 catalyst (STY of 98.6 mgMeOH gCu-1 h-1, selectivity of 54%, with catalytic activity loss after 25 h) under identical reaction conditions (260 °C, 1 MPa). Structural characterizations revealed that the enhanced catalytic activity and improved stability of the biochar-supported Cu/ZnO nanoparticles, relative to Cu/ZnO/Al2O3, were attributed to the enrichment of Cu-Zn interfacial sites. This was facilitated by the highly efficient dispersion and formation of ultrasmall Cu/ZnO nanoparticles on the biochar surface, along with biochar’s role in enhancing H2 and CO2 adsorption and activation.