Ultrasound effect on a biorefinery lignin-cellulose mixture.

Forest biorefineries provide multiple new avenues for applied research. The main concept lies in the malleability of the processes and their stepwise organization. The core element of the biorefinery concept addressed in the present study is the pretreatment step; here, wood biomass is converted into free hemicellulosic sugars, lignin and cellulose. In traditional approaches, the pretreatment step is a starting point for isolating and separating lignin or cellulose through different processes. In this study, instead of performing any separation, a lignin-cellulose mixture was used as its own material, and the effects of ultrasound treatment with a probe system at 20 kHz, with various amplitude, sonication time and dry matter content were investigated with the aim of assessing the formation of a nanocellulose structure with a high lignin content (>30 %) and investigating the stability of the lignin-cellulose mixture under aqueous conditions. We demonstrated the importance of dry matter content for the specific particle size and water retention values for this mixture. US treatment of lignin-cellulose mixtures <4 % dry matter formed a gel-like material, with low particle size (90 % below 30 µm and smallest at nanoscale). Low dry matter loading led to better US transfer and higher conversion of cellulose to <100 nm nanoparticles. Our study can serve as a baseline for future developments in the field of stable emulsions, filtering materials or inputs for material synthesis.

Poly(3-hydroxybutyrate) production for food packaging from biomass derived carbohydrates by cupriavidus necator DSM 545.

The extensive utilization of conventional plastics has resulted in a concerning surge in waste. A potential solution lies in biodegradable polymers mostly derived from renewable sources. Cupriavidus necator DSM 545 is a microorganism capable, under stress conditions, of intracellularly accumulating Poly(3-hydroxybutyrate) (PHB), a bio-polyester. This study aimed to identify optimal conditions to maximize the intracellular accumulation of PHB and its global production using natural media obtained by processing lignocellulosic residues of cardoon, a low-cost feedstock. An intracellular PHB accumulation was observed in all of the tested media, indicating a metabolic stress induced by the lack of macronutrients. Increasing C/N ratios led to a significant decrease in cellular biomass and PHB production. Furthermore C. necator DSM 545 was incapable of consuming more than 25 g/L of supplied monosaccharides. Surprisingly, in the samples supplied with 60 % of the pentose-rich liquid fraction, complete consumption of xylose was observed. This result was also confirmed by subsequent tests using Medium 1 growth media containing xylose as the sole carbon source. Using a diluted medium with a C/N ratio of 5, a PHB production of 5.84 g/L and intracellular PHB accumulation of 77 % w/w were respectively achieved. Finally, comparative shelf-life tests conducted against conventional pre-packaging materials in PP suggested that PHB films performed similarly in preserve ready-to-eat products.

Exploring different processes for starch extraction from microalgae and synthesis of starch-chitosan plastic films.

Microalgae could become a more sustainable starch source than conventional crops. However, available refinery processes are lacking. In this study, we develop different innovative processes to refine microalgal starch and obtaining starch-based bioplastics. After lipid extraction, defatted microalgae were treated by different routes: enzymatic treatment with Alcalase; sonication in hot water or dimethyl sulfoxide (DMSO) followed by precipitation with ethanol. Enzymes allows to extract 70 % of proteins while recovering 75 % of the initial starch in the residual pellet, with a purity of 58 %. The most effective configuration based on sonication and water/DMSO extraction allowed to recover up to 80 % starch with 80-91 % purity. Chitosan improved the mechanical properties of the obtained starch-based films. The use of defatted algae or purified starch gave different properties to the films (as rigidity and water stability) showing the possibility to tailor the material characteristics depending on the biorefinery route applied.

Waste from the food industry: Innovations in biorefineries for sustainable use of resources and generation of value.

Biorefineries have attracted significant attention from the scientific community and various industrial sectors due to their use of unconventional biomass sources to produce biofuels and other value-added compounds. Various agro-industrial residues can be applied in biorefinery systems, making them economically and environmentally attractive. However, the cost, efficiency, and profitability of the process are directly affected by the choice of biomass, pre-treatments, and desired products. In biorefineries, the simultaneous production of different products during processing is a valuable approach. Chemical, physical, biological, or combined treatments can generate numerous compounds of high commercial interest, such as phenolic compounds. These treatments, in addition to modifying the biomass structure, are essential for the process's viability. Over the years, complex treatments with high costs and environmental impacts have been simplified and improved, becoming more specific in generating high-value resources as secondary outputs to the main process (generally related to the release of sugars from lignocelluloses to produce second-generation ethanol). Innovative methods involving microorganisms and enzymes are the most promising in terms of efficiency and lower environmental impact. Biorefineries enable the use of varied raw materials, such as different agro-industrial residues, allowing for more efficient resource utilization and reducing dependence on non-renewable sources. In addition to producing low-carbon biofuels, biorefineries generate a variety of high-value by-products, such as packaging materials, pharmaceuticals, and nutritional ingredients. This not only increases the profitability of biorefineries but also contributes to a circular economy.

Lignocellulose Treatment Using a Flow-Through Variant of OrganoCat Process.

This study adapts the biphasic OrganoCat system into a flow-through (FT) reactor, using a heated tubular setup where a mixture of oxalic acid and 2-methyltetrahydrofuran (2-MTHF) is pumped through beech wood biomass. This method minimizes solvent-biomass contact time, facilitating rapid product removal and reducing the risk of secondary reactions. A comparative analysis with traditional batch processes reveals that the FT system, especially under severe conditions, significantly enhances extraction efficiency, yielding higher amounts of lignin and sugars with reduced solid residue. Notably, the FT system shows partial hydrolysis of the cellulose, which increases with temperature while not producing significant amounts of furfural or 5-HMF, indicating more efficient depolymerization of polysaccharides without substantial sugar degradation. A statistical design of experiments (DOE) using a Box-Behnken design elucidates the influence of process variables (time, solvent flow rate, temperature) on the yield. Key findings highlight reactor temperature as the dominant factor affecting yields, with process time showing a significant but less pronounced impact. This study demonstrates the potential of the FT OrganoCat system for efficient lignocellulosic biomass fractionation and represents an advancement towards continuous lignocellulose processing, contributing to our knowledge of process optimization for improved biorefinery applications.

Optimizing a biorefinery design for the valorization of Rugulopteryx okamurae by extracting bioactive compounds and enhancing methane production.

The Mediterranean Sea has suffered recently from the unprecedent invasion of the alien macroalga Rugulopteryx okamurae due to global warming and climate change putting at risk the natural local ecosystem. Since 2015 this alga has colonized a great area on the western coast of the Mediterranean Sea and it has been also spotted in other areas such as the Azores Islands or the south of France. The arrival of alga tides into the coasts also provokes collateral environmental problems that need to be addressed. Seaweed-based biorefineries are considered a promising alternative within a circular economy model. This study aims to assess the potential of R. okamurae as raw material for the extraction of reducing sugars (RS) and total polyphenolic compounds (TPC) with antioxidant capacities, the subsequent production of methane from the extracted residue, and the final use of the anaerobic digestate as fertilizer. However, the presence of bioactive compounds greatly varies due to seasonality, location or even natural degradation. In order to provide some insights about these issues, two different batches were assessed: i.e. natural and ashore R. okamurae. As brown algae are characterised by a cell wall composed of crystalline cellulose and lignin, the biomasses studied were mechanically pretreated (dried at 100 °C and milled during 60 s) before the single and sequential extraction processes. Results showed that the extraction of the targeted compounds increased by 30-80 % when the biomasses were extracted sequentially. Similarly, the biochemical methane potential of the extracted solid residues increased as the RS and TPC content was reduced (120-150 NLCH4 kg-1VS), with no significant impact regarding the biomass origin (natural or ashore) or the extraction process order. An increase in the kinetic constant k (first-order model) of 150% and 75% was observed when the fresh biomass was extracted with water and ethanol, respectively, compared to the value obtained for the unextracted biomass. Finally, the physicochemical characteristics of the different anaerobic digestates generated were assessed for their potential use as biofertilizer. In this study, most of the digestate' liquid fractions (7 out of 10) comply with European regulations for organic fertilizers and could be used directly.

Brown algae biomass for fucoxanthin, fucoidan and alginate; update review on structure, biosynthesis, biological activities and extraction valorisation.

Natural compounds promoting human health are the main focus of research nowadays. Fucoxanthin, fucoidan and alginate are such bioactive compounds that are extracted from marine brown algae. Extracting these 3 compounds through successive extraction enhances the commercial value of the brown algae biomass. There are studies on successive extraction of fucoidan and alginate but not with fucoxanthin which displays various biological bioactivities. Alginate, a polysaccharide presents 45 % in the cell wall of brown algae. Fucoidan, a sulphated polysaccharide proved showing various bioactivities. These bioproducts yield are vary depending on the species. Dictyota species recorded high fucoxanthin content of 7 %. Ascophyllum nodosum was found with high fucoidan of 16.08 % by direct extraction. Maximum alginate of 45.79 % was recorded from the brown alga Sargassum cymosum and by successive extraction 44 % was recorded from Ecklonia radiata. Fucoxanthin exits in two isomers as trans and cis forms. Based on linkage, fucoidan structure is found in 3 forms as 1,3- or 1,4- or alternating 1,3- and 1,4-linked fucose in the polysaccharide residues. Fucoidan composition vary depending on the degree of sulphation, the composition of monosaccharides and location of collection. In alginate, its property relies on the mannuronic acid and guluronic acid composition. Biosynthesis of these 3 compounds is not much explored. Keeping this view which signify sequential extraction towards biomass valorisation, fucoxanthin, fucoidan and alginate extracted from the brown algae species focusing yield, extraction, characterization, biosynthesis and biological activities were compiled and critically analysed and discussed in this review.

Sustainable algal biorefinery: A review on current perspective on technical maturity, supply infrastructure, business and industrial opportunities.

The environmental problems associated with the use of fossil fuels demand a transition to renewable sources for fuels and energy. A biorefinery approach has often been considered and microalgae as a feedstock has been pampered for its numerous possibilities to produce biofuels. Depending on the species and cultivation conditions, microalgae can produce fats, proteins and sugars. These raw materials can thus be utilized in the production of biofuels, bioenergy and biochemicals. For this reason, algal biofuels are considered as sustainable and renewable options for climate related challenges. However, there are many issues such as supply infrastructure, business and refinery opportunities, as well as their efficacy, tied to sustainable production of these energetic materials from algae. Thus, technical maturity, scalability, energy and material balance demands coupled with cost, nutrient resources demand, certification and legislation are needed to demonstrate the biorefinery opportunities of algal biomass valorisation. This paper therefore recommends that various consortiums tasked with algal biofuel projects should be chosen for a more holistic integrated multidisciplinary approach to address the advancement of algal biofuel technology.

Microbes' role in environmental pollution and remediation: a bioeconomy focus approach.

Bioremediation stands as a promising solution amid the escalating challenges posed by environmental pollution. Over the past 25 years, the influx of synthetic chemicals and hazardous contaminants into ecosystems has required innovative approaches for mitigation and restoration. The resilience of these compounds stems from their non-natural existence, distressing both human and environmental health. Microbes take center stage in this scenario, demonstrating their ability of biodegradation to catalyze environmental remediation. Currently, the scientific community supports a straight connection between biorefinery and bioremediation concepts to encourage circular bio/economy practices. This review aimed to give a pre-overview of the state of the art regarding the main microorganisms employed in bioremediation processes and the different bioremediation approaches applied. Moreover, focus has been given to the implementation of bioremediation as a novel approach to agro-industrial waste management, highlighting how it is possible to reduce environmental pollution while still obtaining value-added products with commercial value, meeting the goals of a circular bioeconomy. The main drawbacks and challenges regarding the feasibility of bioremediation were also reported.

Unlocking the anion effect on steerable production of 5-hydroxymethylfurfural.

Homogeneous metal salt catalysts play a pivotal role in industrial production of 5-hydroxymethylfurfural (HMF). Herein, we first proposed the anion effect on steerable production of HMF using metal salts with different anions as catalyst in a biphasic system of tetrahydrofuran (THF)/NaCl aqueous solution (NaCl aq). Notably, the anions affected the catalytic activity of the metal salts, leading to an order of magnitude difference in the HMF yields, i.e., AlBr3（74.0 mol%）> AlCl3 (60.8 mol%) > Al2(SO4)3 (35.2 mol%) > Al(NO3)3 (14.9 mol%). The anion effect on steerable production of HMF could be attributed to the proximity effect and electron tension. Anions form close-range interactions with glucose molecules by proximity effect to promote electron transfer, facilitating the isomerization of glucose to fructose. Besides, anions induce a reduction of the electron cloud density of glucose carbon atoms, generating electron tension that rapidly transforms glucose from the ground state to the transition state, thereby increasing the HMF yield. Based on the revelation of anions effect and evaluation of techno-economic process, we expect to provides theoretical guidance for high-throughput screening of metal salt catalysts in industrial biorefinery.

Lignin self-assembly phenomena and valorization strategies for pulping, biorefining, and materials development: Part 1. The physical chemistry of lignin self-assembly.

Physical chemistry aspects are emphasized in this comprehensive review of self-assembly phenomena involving lignin in various forms. Attention to this topic is justified by the very high availability, low cost, and renewable nature of lignin, together with opportunities to manufacture diverse products, for instance, polymers/resins, bioplastics, carbon fibers, bio-asphalt, sunscreen components, hydrophobic layers, and microcapsules. The colloidal lignin material, nanoparticles, and microstructures that can be formed as a result of changes in solvent properties, pH, or other adjustments to a suspending medium have been shown to depend on many factors. Such factors are examined in this work based on the concepts of self-assembly, which can be defined as an organizing principle dependent on specific attributes of the starting entities themselves. As a means to promote such concepts and to facilitate further development of nano-scale lignin products, this article draws upon evidence from a wide range of studies. These include investigations of many different plant sources of lignin, processes of delignification, solvent systems, anti-solvent systems or other means of achieving phase separation, and diverse means of achieving colloidal stability (if desired) of resulting self-assembled lignin structures. Knowledge of the self-organization behavior of lignin can provide significant structural information to optimize the use of lignin in value-added applications. Examples include chemical conditions and preparation procedures in which lignin-related compounds of particles organize themselves as spheres, hollow spheres, surface-bound layers, and a variety of other structures. Published articles show that such processes can be influenced by the selection of lignin type, pulping or extraction processes, functional groups such as phenolic, carboxyl, and sulfonate, chemical derivatization reactions, solvent applications, aqueous conditions, and physical processes, such as agitation. Precipitation from non-aqueous solutions represents a key focus of lignin self-assembly research. The review also considers stabilization mechanisms of self-assembled lignin-related structures.

A high-performance anion-exchange chromatographic method for the fast analysis and precise determination of varied glucose-derived acids during biomass biorefinery.

Glucose-derived acids for the further production of value-added medicine, food additives, and polymers, will promote lignocellulosic biomass biorefinery industry. In response to the diversity and complexity, a new method was established by employing high performance anion exchange chromatography (HPAEC) coupled with a CarboPac™ PA200 column, for the precise and fast determination of glucose, gluconic acid, glucuronic acid, 2-ketogluconic acid, 5-ketogluconic acid and glucaric acid. Based on the analysis of tiny varieties in retention behavior, a gradient elution mode was designed and optimized for the quantitative and qualitative analysis. The protocol displayed acceptable linearity (R2 ≥ 0.995), commendable average recovery rate (95.28% âˆ¼ 99.89%), satisfactory precision (RSD% ≤ 1.5%), and sufficient resolution (R > 6). Additionally, this method was successfully applied to the high-value biorefining process, which confirmed the practicability and accuracy. The results demonstrated that HPAEC has good detection performance for glucose and its derivative acids, and provide key identification technical support for the high-value utilization of lignocellulose.

Resource recovery and treatment of wastewaters using filamentous fungi.

Industrial wastewater, often characterized by its proximity to neutral pH, presents a promising opportunity for fungal utilization despite the prevalent preference of fungi for acidic conditions. This review addresses this discrepancy, highlighting the potential of certain industrial wastewaters, particularly those with low pH levels, for fungal biorefinery. Additionally, the economic implications of biomass recovery and compound separation, factors that require explicit were emphasized. Through an in-depth analysis of various industrial sectors, including food processing, textiles, pharmaceuticals, and paper-pulp, this study explores how filamentous fungi can effectively harness the nutrient-rich content of wastewaters to produce valuable resources. The pivotal role of ligninolytic enzymes synthesized by fungi in wastewater purification is examined, as well as their ability to absorb metal contaminants. Furthermore, the diverse benefits of fungal biorefinery are underscored, including the production of protein-rich single-cell protein, biolipids, enzymes, and organic acids, which not only enhance environmental sustainability but also foster economic growth. Finally, the challenges associated with scaling up fungal biorefinery processes for wastewater treatment are critically evaluated, providing valuable insights for future research and industrial implementation. This comprehensive analysis aims to elucidate the potential of fungal biorefinery in addressing industrial wastewater challenges while promoting sustainable resource utilization.

Adaptive evolution of Paecilomyces variotii enhanced the biodetoxification of high-titer inhibitors in pretreated lignocellulosic feedstock.

High inhibitor concentrations in lignocellulose feedstock negatively affect the degradation rate of biodetoxification strains. This study designed two adaptive laboratory evolutions in solid substrate and liquid medium to boost the biodetoxification capacity of P. variotii to high titers of lignocellulose-derived inhibitors, resulting in two evolved strains AC70 and ZW70. The results showed that the evolutionary adaptation in liquid medium could better boost the acetic acid assimilation compared to that on solid substrate. Transcriptional analysis revealed that the evolved strains exhibited a significant upregulation of adh, acs, ach1, and ackA directly related to the initial steps of acetate and furan aldehydes metabolisms. ZW70 strain can effectively remove the high concentration inhibitors cocktail from the hydrolysates derived from pretreated wheat straw and furfural residues. The biodetoxified hydrolysates by ZW70 were successfully used for cellulose chiral L-lactic acid production with the titers of ∼110 g/L, which were over 20 % higher than that detoxified by parental strain.

Copper(II) and Zinc(II) Complexes with Bacterial Prodigiosin Are Targeting Site III of Bovine Serum Albumin and Acting as DNA Minor Groove Binders.

The negative environmental and social impacts of food waste accumulation can be mitigated by utilizing bio-refineries' approach where food waste is revalorized into high-value products, such as prodigiosin (PG), using microbial bioprocesses. The diverse biological activities of PG position it as a promising compound, but its high production cost and promiscuous bioactivity hinder its wide application. Metal ions can modulate the electronic properties of organic molecules, leading to novel mechanisms of action and increased target potency, while metal complex formation can improve the stability, solubility and bioavailability of the parent compound. The objectives of this study were optimizing PG production through bacterial fermentation using food waste, allowing good quantities of the pure natural product for further synthesizing and evaluating copper(II) and zinc(II) complexes with it. Their antimicrobial and anticancer activities were assessed, and their binding affinity toward biologically important molecules, bovine serum albumin (BSA) and DNA was investigated by fluorescence emission spectroscopy and molecular docking. The yield of 83.1 mg/L of pure PG was obtained when processed meat waste at 18 g/L was utilized as the sole fermentation substrate. The obtained complexes CuPG and ZnPG showed high binding affinity towards target site III of BSA, and molecular docking simulations highlighted the affinity of the compounds for DNA minor grooves.

Assessing the environmental footprint of alternative green biorefinery protein extraction techniques from grasses and legumes.

The significant grasslands of Europe and its member states represents a significant feedstock opportunity for circular bioeconomy development. The development of green biorefineries (GBR), to supply protein for the feed industry from grass, could help many European member states to address significant deficits in protein availability and reduce imports. The current study assesses the environmental footprint of alternative GBR protein extraction techniques from grasses and legumes using life cycle assessment. The focus is on comparing feedstock and technology pathways that could displace soya bean imports. The study finds that leaf protein concentrate (LPC) produced from grass had an improved environmental performance when compared to soya bean meal (SBM), across the assessed feedstock (perennial ryegrass or grass-clover mixtures) and technology pathways (one-stage maceration versus multi-stage maceration). For example, in the case of Climate Change the emission intensity for LPC was 57-85 % lower per tonne of crude protein (CP) compared with SBM. Acidification burdens were 54-88 % lower, and Eutrophication: Freshwater burdens were 74-89 % lower. Some scenarios of GBR produced LPC with a larger Energy Resources: Non-Renewable burden than SBM, though this could be mitigated with higher renewable energy (biogas and wind energy) integration within the scenario. Grass-clover scenarios generally achieved a lower intensity of emissions compared to ryegrass scenarios, particularly in the category of Climate Change, where feedstock cultivation represented a significant contributor to impacts. Overall, GBR can produce high quality protein with a lower environmental burden than SBM, but choice of feedstock and system design are critical factors for overall environmental performance.

An integrated biorefinery strategy for Eucalyptus fractionation and co-producing glucose, furfural, and lignin based on deep eutectic solvent/cyclopentyl methyl ether system.

A novel biphasic system containing water-soluble deep eutectic solvent (DES) and cyclopentyl methyl ether (CPME) was developed to treat Eucalyptus for furfural production, extracting lignin and enhancing cellulose enzymatic hydrolysis. Herein effect of DES type, water content in DES, temperature and time on furfural yield in water-soluble DES/CPME pretreatment process was firstly evaluated. A maximum furfural yield of 80.6 % was attained in 10 min at 150 °C with choline chloride (ChCl)/citric acid monohydrate (CAM)/CPME system containing 30 wt% water and 2.5 wt% SnCl4·5H2O, which was higher than that obtained from ChCl/CAM/CPME system without water (55.5 %) and H2O/CPME system (49.7 %). These results demonstrated that the water-soluble DES/CPME system was a powerful method enhancing the furfural production. Under the optimal pretreatment conditions, the delignification and glucose yield were reached to 72.7 % and 94.3 %, respectively. The extracted lignin showed low molecular weight and ß-aryl-ether was obviously cleaved. Additionally, water-soluble DES/CPME pretreatment led to a significant removal of hemicelluloses (100.0 %) and lignin (72.7 %) and introduced morphological changes on cell walls, especially from the cell corner (CC) and secondary wall (SW) layers. Overall, this work proposed a practical one-step fractionation strategy for co-producing furfural, lignin and fermentable sugar, providing a way to biorefinery.

[Metabolic engineering for the efficient co-utilization of glucose and xylose].

Microbial production of chemicals from renewable biomass has emerged as a crucial route for sustainable bio-manufacturing. Lignocellulose with a renewable property and wide sources is supposed to be a promising feedstock for the second-generation biorefinery. The efficient co-utilization of mixed sugars from lignocellulosic hydrolysates represents one of the key challenges in reducing the production cost. However, most microorganisms prefer glucose over xylose due to carbon catabolite repression, which constrains the efficiency of lignocellulosic conversion. Therefore, developing the microbial platforms capable of simultaneously utilizing glucose and xylose is paramount for economically viable industrial-scale production. This article reviews the key strategies and studies of metabolic engineering for promoting efficient co-utilization of glucose and xylose by microorganisms. The representative strategies include relieving glucose repression, enhancing xylose transport, constructing xylose metabolic pathways, and directed evolution.