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.

Biofuel from wastewater-grown microalgae: A biorefinery approach using hydrothermal liquefaction and catalyst upgrading.

Third-generation biofuels from microalgae are becoming necessary for sustainable energy. In this context, this study explores the hydrothermal liquefaction (HTL) of microalgae biomass grown in wastewater, consisting of 30% Chlorella vulgaris, 69% Tetradesmus obliquus, and 1% cyanobacteria Limnothrix planctonica, and the subsequent upgrading of the produced bio-oil. The novelty of the work lies in integrating microalgae cultivation in wastewater with HTL in a biorefinery approach, enhanced using a catalyst to upgrade the bio-oil. Different temperatures (300, 325, and 350 °C) and reaction times (15, 30, and 45 min) were tested. The bio-oil upgrading occurred with a Cobalt-Molybdenum (CoMo) catalyst for 1 h at 375 °C. Post-HTL, although the hydrogen-to-carbon (H/C) ratio decreased from 1.70 to 1.38-1.60, the oxygen-to-carbon (O/C) ratio also decreased from 0.39 to 0.079-0.104, and the higher heating value increased from 20.6 to 36.4-38.3 MJ kg-1. Palmitic acid was the main component in all bio-oil samples. The highest bio-oil yield was at 300 °C for 30 min (23.4%). Upgrading increased long-chain hydrocarbons like heptadecane (5%), indicating biofuel potential, though nitrogenous compounds such as hexadecanenitrile suggest a need for further hydrodenitrogenation. Aqueous phase, solid residues, and gas from HTL can be used for applications such as biomass cultivation, bio-hydrogen, valuable chemicals, and materials like carbon composites and cement additives, promoting a circular economy. The study underscores the potential of microalgae-derived bio-oil as sustainable biofuel, although further refinement is needed to meet current fuel standards.

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.

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.

Biohythane production via anaerobic digestion process: fundamentals, scale-up challenges, and techno-economic and environmental aspects.

Biohythane, a balanced mixture comprising bioH2 (biohydrogen) and bioCH4 (biomethane) produced through anaerobic digestion, is gaining recognition as a promising energy source for the future. This article provides a comprehensive overview of biohythane production, covering production mechanisms, microbial diversity, and process parameters. It also explores different feedstock options, bioreactor designs, and scalability challenges, along with techno-economic and environmental assessments. Additionally, the article discusses the integration of biohythane into waste management systems and examines future prospects for enhancing production efficiency and applicability. This review serves as a valuable resource for researchers, engineers, and policymakers interested in advancing biohythane production as a sustainable and renewable energy solution.

Ultra-Dilute SnCl4-Catalyzed Conversion of Concentrated Glucose to 5-Hydroxymethylfurfural in Aqueous Deep Eutectic Solvent.

5-Hydroxymethylfurfural(HMF) is a versatile chemical synthesized from glucose dehydration catalyzed by metal chloride (MClx) in deep eutectic solvents (DESs). However, the low glucose concentration and high catalyst dosage hinder large-scale HMF production. Herein, we report an aqueous DES of tetraethylammonium bromide(TEAB)-glucose for converting concentrated glucose (40 wt%, relative to TEAB) using ultra-dilute SnCl4 (0.25 mol%), achieving a 62% yield of HMF. Ultra-dilute MClx-catalyzed selective conversion of glucose is feasible only when combining SnCl4 with Br-based DES, which is elucidated by density functional theory and molecular dynamic calculations. Using SnCl4 is essential due to its higher glucose isomerization activity than AlCl3 and CrCl3, which can be attributed to its low-barrier coordination with glucose and its barrier-free separation from fructose. Halide anions in DESs strongly interact with glucose, hindering the MClx-glucose coordination and thereby reducing MClx's activity for glucose isomerization. Consequently, Br-based DESs facilitate higher activity of MClx than Cl-based DESs, due to the weaker interaction between halide anion and glucose. In addition, we elucidated the side reactions including condensation, polymerization, and isomerization, and proposed a reaction network. Our findings clarify the differential activity of MClx and the impact of halide anions in DESs on MClx's activity.

Metal-organic framework-enabled biomass conversion technologies for microalgae bio-refinery in the food industry.

Biomass is a valuable renewable energy adapted as an alternative to traditional fossil fuels. Apart from fuels, biomass is synthesized into highly valuable products that are used in various forms including biofuels, biochemical, bioproducts, packing material, and find practice in pharmaceutical, cosmetics, and nutraceuticals industries. Particularly, microalgae a third-generation feedstock known for its rich carbon content possesses protein lipids and carbohydrates produces a variety of green products such as bioethanol, biohydrogen, biodiesel, and biomethane, and also fixes carbon emission to a certain amount in the atmosphere. However, microalgae conversion in the presence of a catalyst such as a metal-organic framework (MOF) yields high-quality valuable products. A MOF is a porous crystalline material where the structure and pore size can be controlled making it suitable for catalytic reactions and appropriate conversion paths. This review briefly explains the prevailing status of microalgae as a sustainable biomass and features its components for microalgae biorefinery into valuable products and its application in the food industry. MOF properties, characteristics and various MOF-based conversion technologies for biomass conversion with its application are elaborated. In addition, usage of value products produced from microalgae biorefinery in the food industry and its importance is elucidated. In addition, the challenges in integrating biorefinery processes with food industry operations and their solutions are also presented. © 2024 Society of Chemical Industry.

Direct Itaconate Production from Brown Macroalgae Using Engineered Vibrio sp. dhg.

Itaconate is a promising platform chemical with broad applicability, including the synthesis of poly(methyl methacrylate). Most studies on microbial itaconate production entail the use of crop-based feedstock, which imposes constraints due to its limited supply. Brown macroalgae have recently gained attention as next-generation biomass owing to their high biomass productivity and carbohydrate content and amenability to mass production. Therefore, the use of macroalgae for itaconate production warrants exploration. In this study, the direct production of itaconate from brown macroalgae was demonstrated using engineered Vibrio sp. dhg, which has emerged as an efficient platform host for brown macroalgal biorefineries. Specifically, to enhance production, cis-aconitate decarboxylase (Cad) from Aspergillus terreus was heterologously expressed and isocitrate dehydrogenase (icd) was deleted. Notably, the resulting strain, VIC, achieved itaconate titers of 2.5 and 1.5 g/L from a mixture of alginate and mannitol (10 g/L of each) and 40 g/L of raw Saccharina japonica (S. japonica), respectively. Overall, this study highlights the utility of brown macroalgae as feedstock, as well as that of Vibrio sp. dhg as a platform strain for improving itaconate bioproduction.

Harnessing ultrasound-derived hydroxyl radicals for the selective oxidation of aldehyde functions.

Ultrasonic irradiation holds potential for the selective oxidation of non-volatile organic substrates in the aqueous phase by harnessing hydroxyl radicals as chemical initiators. Here, a mechanistic description of hydroxyl radical-initiated glyoxal oxidation is constructed by gleaning insights from photolysis and radiation chemistry to explain the yields and kinetic trends for oxidation products. The mechanistic description and kinetic measurements reported herein reveal that increasing the formation rate of hydroxyl radicals by changing the ultrasound frequency increases both the rates of glyoxal consumption and the selectivity towards C2 acid products over those from C-C cleavage. Glyoxal consumption also occurs more rapidly and with greater selectivity towards C2 acids under acidic conditions, which favor the protonation of carboxylate intermediates into their less reactive acidic forms. Leveraging such pH and frequency effects is crucial to mitigating product degradation by secondary reactions with hydroxyl radicals and oxidation products (specifically hydrogen peroxide and superoxide). These findings demonstrate the potential of ultrasound as a driver for the selective oxidation of aldehyde functions to carboxylic acids, offering a sustainable route for valorizing biomass-derived platform molecules.

The green seaweed Ulva: tomorrow's "wheat of the sea" in foods, feeds, nutrition, and biomaterials.

Ulva, a genus of green macroalgae commonly known as sea lettuce, has long been recognized for its nutritional benefits for food and feed. As the demand for sustainable food and feed sources continues to grow, so does the interest in alternative, plant-based protein sources. With its abundance along coastal waters and high protein content, Ulva spp. have emerged as promising candidates. While the use of Ulva in food and feed has its challenges, the utilization of Ulva in other industries, including in biomaterials, biostimulants, and biorefineries, has been growing. This review aims to provide a comprehensive overview of the current status, challenges and opportunities associated with using Ulva in food, feed, and beyond. Drawing on the expertise of leading researchers and industry professionals, it explores the latest knowledge on Ulva's nutritional value, processing methods, and potential benefits for human nutrition, aquaculture feeds, terrestrial feeds, biomaterials, biostimulants and biorefineries. In addition, it examines the economic feasibility of incorporating Ulva into aquafeed. Through its comprehensive and insightful analysis, including a critical review of the challenges and future research needs, this review will be a valuable resource for anyone interested in sustainable aquaculture and Ulva's role in food, feed, biomaterials, biostimulants and beyond.

Towards Sustainable Production of Polybutylene Adipate Terephthalate: Non-biological Catalytic Syntheses of Biomass-derived Constituents.

Renewable chemicals, which are made from renewable resources such as biomass, have attracted significant interest as substitutes for natural gas- or petroleum-derived chemicals to enhance the sustainability of the chemical and petrochemical industries. Polybutylene adipate terephthalate (PBAT), which is a copolyester of 1,4-butanediol (1,4-BDO), adipic acid (AA), and dimethyl terephthalate (DMT) or terephthalic acid (TPA), has garnered significant interest as a biodegradable polymer. This study assesses the non-biological production of PBAT monomers from biomass feedstocks via heterogeneous catalytic reactions. The biomass-based catalytic routes to each monomer are analyzed and compared to conventional routes. Although no fully commercialized catalytic processes for direct conversion of biomass into 1,4-BDO, AA, DMT, and TPA are available, emerging and promising catalytic routes have been proposed. The proposed biomass-based catalytic pathways toward 1,4-BDO, AA, DMT, and TPA are not yet fully competitive with conventional fossil fuel-based pathways mainly due to high feedstock prices and the existence of other alternatives. However, given continuous technological advances in the renewable production of PBAT monomers, bio-based PBAT should be economically viable in the near future.

Pressure-driven membrane processes for the recovery and recycling of deep eutectic solvents: A seaweed biorefinery case study.

Deep eutectic solvents (DES) are green alternatives for conventional solvents. They have gained attention for their potential to extract valuable compounds from biomass, such as seaweed. In this framework, a case study was developed to assess the feasibility of pressure-driven membrane processes as an efficient tool for the recovery of deep eutectic solvents and targeted biomolecules. For this purpose, a mixture composed of the DES choline chloride - ethylene glycol (ChCl-EG) 1:2, water and alginate was made to mimic a DES extraction from seaweed. An integrated separation process design was proposed where ultrafiltration-diafiltration-nanofiltration (UF-DF-NF) was coupled. UF and DF were found to be effective for the separation of alginate with an 85 % yield. DES was likewise recovered by 93 %, proving the membrane filtrations' technical feasibility. The NF performance to separate the DES from the water, for its recycling, laid by a 45 %-50 % retention and a final concentrated DES solution of 18 %(v/v).

Engineering two-component systems for advanced biosensing: From architecture to applications in biotechnology.

Two-component systems (TCSs) are prevalent signaling pathways in bacteria. These systems mediate phosphotransfer between histidine kinase and a response regulator, facilitating responses to diverse physical, chemical, and biological stimuli. Advancements in synthetic and structural biology have repurposed TCSs for applications in monitoring heavy metals, disease-associated biomarkers, and the production of bioproducts. However, the utility of many TCS biosensors is hindered by undesired performance due to the lack of effective engineering methods. Here, we briefly discuss the architectures and regulatory mechanisms of TCSs. We also summarize the recent advancements in TCS engineering by experimental or computational-based methods to fine-tune the biosensor functional parameters, such as response curve and specificity. Engineered TCSs have great potential in the medical, environmental, and biorefinery fields, demonstrating a crucial role in a wide area of biotechnology.

A comprehensive review on biological funnel mechanism in lignin valorization: Pathways and enzyme dynamics.

Lignin, a significant byproduct of the paper and pulp industry, is attracting interest due to its potential utilization in biomaterial-based sectors and biofuel production. Investigating biological methods for converting lignin into valuable products is crucial for effective utilization and has recently gained growing attention. Several microorganisms effectively decomposed low molecular weight lignins, transforming them into intermediate compounds via upper and lower metabolic pathways. This review focuses on assessing bacterial metabolic pathways involved in the breakdown of lignin into aromatic compounds and their subsequent utilization by different bacteria through various metabolic pathways. Understanding these pathways is essential for developing efficient synthetic metabolic systems to valorize lignin and obtain valuable industrial aromatic chemicals. The concept of "biological funneling," which involves examining key enzymes, their interactions, and the complex metabolic pathways associated with lignin conversion, is crucial in lignin valorization. By manipulating lignin metabolic pathways and utilizing biological routes, many aromatic compounds can be synthesized within cellular factories. Although there is insufficient evidence regarding the complete metabolism of polyaromatic hydrocarbons by particular microorganisms, understanding lignin-degrading enzymes, regulatory mechanisms, and interactions among various enzyme systems is essential for optimizing lignin valorization. This review highlights recent advancements in lignin valorization, bio-funneling, multi-omics, and analytical characterization approaches for aromatic utilization. It provides up-to-date information and insights into the latest research findings and technological innovations. The review offers valuable insights into the future potential of biological routes for lignin valorization.

One-pot, microwave (MW)-assisted production of furfural from almond-, oil-, and wine-derived co-products through biorefinery-based approaches.

This work outlines the first microwave (MW)-assisted protocol for the production of biofuel precursor furfural (FF) from the raw agricultural waste almond hull (AH), olive stone (OS), and the winemaking-derived grape stalk (GS), grape marc (GM) and exhausted grape marc (EGM) through a one-pot synthesis process. To enhance the overall yield, a catalytic process was firstly developed from xylose, major constituent of hemicellulose present in lignocellulosic biomass. This method afforded FF with 100 % selectivity, yielding over 85 % in isolated product when using H2SO4, as opposed to a 37 % yield with AlCl3·6H2O, at 150 °C in only 10 min. For both catalysts, the developed methodology was further validated, proving adaptable and efficient in producing the targeted FF from the aforementioned lignocellulosic raw materials. More specifically, the employment of AlCl3·6H2O resulted in the highest selectivity (up to 89 % from GM) and FF yield (42 % and 39 % molar from OS and AH, respectively), maintaining notable selectivity for the latter (61 and 48 % from AH and OS). At this regard, and considering the environmental factor of sustainability, it is important to point out the role of AlCl3·6H2O in contrast to H2SO4, thus mitigating detrimental substances. This study provides an important management of agricultural waste through sustainable practises for the development of potential bio-based chemicals, aligning with Green Chemistry and process intensification principles.

Advancements in medium chain fatty acids production through chain elongation: Key mechanisms and innovative solutions for overcoming rate-limiting steps.

The depletion of fossil fuels has prompted an urgent search for alternative chemicals from renewable sources. Current technology in medium chain fatty acids (MCFAs) production though chain elongation (CE) is becoming increasingly sustainable, hence the motivation for this review, which provides the detailed description, insights and analysis of the metabolic pathways, substrates type, inoculum and fermentation process. The main rate-limiting steps of microbial MCFAs production were comprehensively revealed and the corresponding innovative solutions were also critically evaluated. Innovative strategies such as substrate pretreatment, electrochemical regulation, product separation, fermentation parameter optimization, and electroactive additives have shown significant advantages in overcoming the rate-limiting steps. Furthermore, novel regulatory strategies such as quorum sensing and electronic bifurcation are expected to further increase the MCFAs yield. Finally, the techno-economic analysis was carried out, and the future research focuses were also put forward.

Chemicals and fuels from lipid-containing biomass: A comprehensive exploration.

In response to address the climate crisis, there has been a growing focus on substituting conventional refinery-derived products with those derived from biorefineries. The utilization of lipids as primary materials or intermediates for the synthesis of chemicals and fuels, which are integral to the existing chemical and petrochemical industries, is a key step in this transition. This review provides a comprehensive overview of the production of sustainable chemicals (acids and alcohols), biopolymers, and fuels (including gasoline, kerosene, biodiesel, and heavy fuel oil) from lipids derived from terrestrial and algal biomass. The production of chemicals from lipids involves diverse methods, including polymerization, epoxidation, and separation/purification. Additionally, the transformation of lipids into biofuels can be achieved through processes such as catalytic cracking, hydroprocessing, and transesterification. This review also suggests future research directions that further advance the lipid valorization processes, including enhancement of catalyst durability at harsh conditions, development of deoxygenation process with low H2 consumption, investigation of precise separation of target compounds, increase in lipid accumulation in algal biomass, and development of methods that utilize residues and byproducts generated during lipid extraction and conversion.

Chemical approaches for the biomass valorisation: a comprehensive review of pretreatment strategies.

The most abundant natural renewable resource in the world, lignocellulosic biomass (LCB), has the potential to be exploited as a substitute green feedstock for the synthesis of various chemicals, materials, and biofuels. The annual global production of 13 billion tonnes of LCB offers an opportunity to cater to the increasing energy and materials requirement of process industries and also restricts the discharge of greenhouse gases. Although LCB is enriched with valuable ingredients such as cellulose, lignin, and hemicellulose, its recalcitrant nature limits its efficient utilisation. These components of LCB are strongly interlinked with each other, which resists their isolation and conversion valorisation into useful products. To disrupt the complicated structure of LCB and to isolate the lignocellulosic components in pure form, pretreatment is a crucial process in the bio-refinery, ensuring the economic feasibility of downstream processes. This review provides an outline of the structure, composition, and various sources of LCB; and the necessity of the pretreatment. Moreover, this article provides an in-depth analysis of the underlying mechanisms, advantages, and limitations of various pretreatment methods, such as physical, chemical, biological, and physicochemical. Further, the impact of chemical pretreatment techniques on the physicochemical characteristics of the material that is extracted from the biomass is also covered in detail through the rigorous evaluation of performance metrics, including substrate digestibility, sugar yield, inhibitor production, and energy requirements. This review provides a balanced and comprehensive overview of the state-of-the-art pretreatment strategies and their impact on biomass valorisation that will be useful to the scientists, engineers, and policy makers interested in biomass conversion technologies.

Tailoring Cu-SiO2 Interaction through Nanocatalyst Architecture to Assemble Surface Sites for Furfural Aqueous-Phase Hydrogenation to Cycloketones.

In this contribution, nanocatalysts with rather diverse architectures were designed to promote different intimacy degrees between Cu and SiO2 and consequently tune distinct Cu-SiO2 interactions. Previously synthesized copper nanoparticles were deposited onto SiO2 (NPCu/SiO2) in contrast to ordinarily prepared supported Cu/SiO2. NPCu@SiO2 and SiO2@Cu core-shell nanocatalysts were also synthesized, and they were all bulk and surface characterized by XRD, TGA, TEM/HRTEM, H2-TPR, XANES, and XPS. It was found that Cu0 is the main copper phase in NPCu/SiO2 while Cu2+ rules the ordinary Cu/SiO2 catalyst, and Cu0 and electron-deficient Cuδ+ species coexist in the core-shell nanocatalysts as a consequence of a deeper metal-support interaction. Catalytic performance could not be associated with the physical properties of the nanocatalysts derived from their architectures but was associated with the more refined chemical characteristics tuned by their design. Cu/SiO2 and NPCu/SiO2 catalysts led to the formation of furfuryl alcohol, evidencing that catalysts holding weak or no metal-support interaction have no significant impact on product distribution even in the aqueous phase. The establishment of such interactions through advanced catalyst architecture, allowing the formation of electron-deficient Cuδ+ moieties, particularly Cu2+ and Cu+ as unveiled by spectroscopic investigations, is critical to promoting the hydrogenation-ring rearrangement cascade mechanism leading to cycloketones.