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SparkGREEN Project: Green technologies for valorization of agri-food residues
No full textHuge amount of agricultural residues is underutilized, often burned. It is estimated that around 5Gts of
agricultural biomass is wasted annually. Lignocellulose is a cheap and abundant natural source of linear polymer
cellulose and aromatic polymer lignin. Cellulose, lignin and hemicellulose are intertwined and interlinked within
the lignocellulose structure which hinders significantly their valorizations in separate processes. Cellulose and its
monomer glucose, can be exploited in various processes, from paper production to valorization towards
microcrystaline cellulose or biotransformation into platform chemicals. Glucose from cellulose and hexoses and
pentoses from hemicellulose can be used for biotechnological production of bio-based chemicals like organic
acids. However, conventional processes for fractionation of lignocellulose substrates with acids or alkali, like the
pulp mill process, result in around 55% yield. Remaining lignin is left in aggregated form, as kraft technical
lignin which can not be easily depolymerised and is often burned. However, if alternative green methods are
used for fractionation of lignocellulosic biomass, it is possible to achieve higher recovery rates and to valorize
both lignin and carbohydrate fractions. SparkGREEN is testing green technologies like natural deep eutectic
solvents (NADES), cold plasma, enzymes and microorganisms to enable simultaneous recovery of carbohydrates
and lignin in less aggregated form, suitable for modifications and higher-value applications, including cosmetics,
food packaging etc. Depending on the lignocellulosic substrate, different fractionation routes have shown
promise. We studied residues remaining after processing of medicinal herbs (e.g. common nettle) and corn stalks
as model substrates.
Cascading process of NADES extraction of herbal residues and subsequent fermentation with lactic acid bacteria
enabled increase in content of phenolic acids and flavonoids, with higher stability and maintained antioxidant
activity over prolonged storage. These processes were performed under mild conditions, with elevated
temperatures used only for NADES preparation. Additionally, this way obtained extracts were fortified with
potentially probiotic biomass with high viability over 7 logN. NADES showed promise in delignification of corn
stalks while non-thermal technology of cold plasma enabled delignification but also substantial modifications of
lignin, including production of oxi-lignin and microlignin spheres, which opens new possibilities for application.
These treatments and strategies, including NADES and cold plasma treatment also have shown promise for
application in anaerobic digestion, resulting in higher biogas production. It remains to estimate feasibility and
profitability of these processes at larger scale, but it is clear that these technologies open opportunities to design
new, higher value products on currently wasted resources
Probiotic immobilization on food industry waste
No full textIntroduction: The production of cold-pressed oils is a process with a low
resource utilization percentage, representing a fast-growing industry with a
tendency for large waste accumulation. When producing 1kg of flaxseed oil,
2kg of cake remains, which is not recognized in the Serbian market, and
(>90%) ends up as waste. A flaxseed cake is rich in fibers, proteins (~35%),
and bioactive or potential bioactive components. Fibers and proteins make it
a potential good carrier for probiotic immobilization. ..
Engineering titanium-based biomaterials: high-pressure torsion and surface nanostructuring
No full textThe coarse-grained (CG) and ultrafine-grained (UFG) Ti-13Nb-13Zr alloys were used as tested materials in this study. The UFG alloy was obtained using a high-pressure torsion process (HPT) under a pressure of 4.1 GPa with a rotational speed of 0.2 rpm up to 5 rotations at room temperature. The structure of titanium alloy may be modified by high-pressure torsion (HPT) which is one of the most popular severe plastic deformation (SPD) methods. HPT process leads to the forming of submicron-sized grains in structure. Also, the HPT process leads to improving the mechanical and corrosion properties of titanium alloy. In order to analyze the influence of the HPT process on the morphology and characteristics of the nanostructured surface, Ti-13Nb-13Zr alloy was modified by anodic oxidation.
Anodic oxidation in the 1M H3PO4 + NaF electrolyte was used as a method for the nanostructured surface of titanium-based materials. Scanning electron microscopy (SEM) was used to characterize the morphology of the surface, while surface roughness was determined using atomic force microscopy (AFM). The surface mechanical properties before and after the anodic oxidation were examined using the nanoindentation test. Corrosion resistance was tested in artificial saliva with a pH value of 5.5 at 37°C, to simulate the environment in the human body.
The impact of the HPT process on the morphology of the nanostructured surface (homogeneity of the modified surface, diameter, wall thickness, and length of nanotubes) has been shown. It has been shown that anodic oxidation increases the roughness of the surface, while this increase is more pronounced after the HPT process. Characterization of the CG and UFG TNZ alloy surface after anodic oxidation showed a decrease in the values of surface mechanical properties, whereby they approached the values of the mechanical properties of human bone tissue. Also, results showed that corrosion resistance was increased after anodic oxidation, for both materials
Whole-cell biotransformation of Epilobium parviflorum by-products in natural deep eutectic solvents
No full textGlobally, we are facing increasing pollution, and in order to protect the environment, it is necessary to manage waste responsibly. A certain part of the globally wasted resources can be used to obtain valuable products in an economically and environmentally sustainable way. For example, the biomass remaining during the production of herbs for tea bags, in powder form, can be used to obtain a wide range of products: plant extracts rich in bioactive compounds, biofuels, biobased chemicals, etc. Alternatively, the by-products can be composted, but in this way the bioactive compounds are minimally used and their full potential for health cannot be exploited. In addition, these compounds present in compost can cause dysbiosis of the soil microbiome, either by promoting or inhibiting the growth of specific microorganisms, which can significantly affect soil quality and ecosystem balance. Epilobium parviflorum is a plant with a diverse chemical profile that remains unexploited in the by-products of the herbal tea industry. Extracts of E. parviflorum have shown the presence of flavonoids (including myricitrin, isomyricitrin, quercitrin, rutin, etc.), steroids, triterpenes, macrocyclic tannins and fatty acids, etc. (Remmel et al., 2012). This plant is commonly used to treat diarrhea, colitis and hormonal disorders of the urinary tract (Granica et al., 2014). Bioactive compounds can be valorized from E. parviflorum by-products by appropriate extraction with environmentally friendly solvents such as natural deep eutectic solvents (NADES). NADES are green biocompatible alternatives to conventional organic solvents, which are widely used in the extraction of biologically active compounds (Li, 2022). They can enable the selective extraction of biologically active compounds. Also, interactions of NADES and biologically active compounds may have a protective effect and increase their stability (da Silva et al., 2021). NADES are suitable solvent candidates for whole-cell biotransformation by probiotic bacteria due to their established biocompatibility with probiotics (Lee et al., 2022).
This study is aimed to investigate the biological valorization of E. parviflorum by-products, using NADES as an environmentally friendly extraction solvent. The whole-cell biotransformation using Lactobacillus salivarius ATCC 11741 as a model GRAS probiotic microorganism was performed to improve the bioactivity of the extracts. The extraction was obtained in three different biocompatible NADES: betaine/1,3-propanediol (1:4), betaine/D-glucose/water (1:1:5), and betaine/sorbitol/water (1:1:3). To ensure the appropriate viscosity, 30% distilled water was added as a co-solvent. The obtained extracts were diluted, filtered through microbiological filters and fermented with L. salivarius for 24 h at 37°C. Uninoculated extracts under the same conditions were used as controls. During fermentation, viable cell number, DPPH (Trolox equivalent/g biomass – TE/g biomass), TPC (Gallic acid equivalent/g biomass – GAE/g biomass), and TFC (Quercetin equivalent/g biomass – QE/g biomass) were monitored.
Fermentation of all tested NADES extracts of E. parviflorum with L. salivarius showed the potential to increase DPPH, TPC, and TFC activities while maintaining a high viable cell number. It was observed that viable cell number depended on the NADES used for extraction, with the highest (108 CFU/ml) being observed in the extract obtained with betaine/D-glucose/water (1:1:5) NADES. The highest TPC (279.4 GAE/g biomass) and DPPH (7.4 TE/g biomass) were recorded after 24 h of fermentation in the extract obtained with betaine/1,3-propanediol (1:4) NADES. The highest TFC (234.9 QE/g biomass) after 24 h of fermentation was recorded in the extract obtained with betaine/sorbitol/water (1:1:3) NADES. No significant changes were observed in DPPH, TPC and TFC of the control samples during the incubation period, indicating the stability of the NADES extracts.
L. salivarius is a probiotic lactic acid bacteria known for its health-promoting properties. Fermented NADES extracts of E. parviflorum showed significant potential as a symbiotic with antioxidant and postbiotic properties. Extraction with NADES and biotransformation by L. salivarius could be an important step up for sustainable and environmentally friendly valorization of herbal tea industry by-products. The increased bioactivity and stability obtained by extractions with natural deep eutectic solvents and fermentation suggest a wide range of applications, from food to health and wellness industries
Horseradish (Armoracia rusticana L.) Processing By-Products as Potential Functional Ingredients in Food Production: A Detailed Insight into Phytochemical Composition and Antioxidant Properties
No full textHorseradish (Armoracia rusticana L.) root (HRP) and leaf (HLP) pomaces, by-products of juice production by cold-pressing, were analyzed as a novel potential source of natural antioxidants. Chromatography analysis (UHPLC Q-ToF MS) of the bioactive compounds of pomaces was performed along with spectrophotometric determination of total phenolic content (TPC), total flavonoid content (TFC), total phenolic acid (hydroxycinnamic) content (TPAC), and antioxidant capacity (via 1,1-diphenyl-2-picrylhydrazyl (DPPH•) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic-acid) (ABTS•+) radicals’ scavenging activity and ferric reducing antioxidant power (FRAP)). The concentrations of TPC, TFC, and TPAC differed among the pomaces, significantly favoring HLP. However, both horseradish pomaces (HRP and HLP) contained a considerable amount of various phenolics, with kaempferol and its glucosides dominating. In addition, they exhibit pronounced antioxidant activity, which is confirmed by all three methods used (DPPH, ABTS, and FRAP). These results highlight the potential of valorizing horseradish processing waste as a natural, reliable source of health-promoting bioactive compounds and functional ingredients in food products, thereby fortifying food, preventing oxidation, and prolonging shelf-life. In addition, this study supports endeavors to reduce food waste by providing new insights into the valorization of horseradish pomace, thus contributing to sustainable development and environmental protection
Одржива синтеза наночестица сребра на памучној гази за побољшана антибактеријска својства
No full textWound protection is a critical step in preventing or reducing infections,
as well as in preventing the transmission of infections between patients. Wound dressings
are essential medical products that cover wounds and facilitate healing. The
present study examines the possibility of using Ag nanoparticles (NPs) to impart
antibacterial activity to cotton gauze, a commonly used disposable wound dressing
material. The in situ synthesis of Ag-based NPs on cotton gauze was achieved
using extracts from Populus x euramericana (PE) and Ailanthus altissima (Mill.)
Swingle (AA) leaves. Major phytochemical compounds in the extracts were quantified
using HPLC. FESEM and EDS mapping analyses confirmed the presence
of Ag-based NPs across the fibre surfaces of both samples. The average size of
NPs synthesized in the presence of PE and AA extracts was 88±26 and 82±23 nm,
respectively. A comparable amount of silver was found in the sample obtained
with PE (14.22±0.23 μmol/g) and in the sample synthesized using AA extract
(13.63±1.40 μmol/g). The synthesized samples achieved maximum bacterial
reduction against Gram-negative bacteria Escherichia coli and Gram-positive
Staphylococcus aureus.Заштита рана је кључни корак у превенцији или смањењу инфекција, као и преношења
инфекција између пацијената. Завоји за ране су неопходни медицински производи који
покривају ране и олакшавају зарастање. У овом раду се испитује могућност коришћења
наночестицa сребра за oбезбеђивање антибактеријске активности памучној гази, често
коришћеном материјалу за једнократну употребу за завоје за ране. In situ синтеза нано-
честица на бази сребра на памучној гази постигнута је коришћењем екстраката из листова
Populus x euramericana (PE) и Ailanthus altissima (Mill.) Swingle (AA). Главна фитохемијска
једињења у екстрактима су квантификована помоћу HPLC. FESEM и EDS анализа мапирања
површине потврдиле су присуство наночестица на бази сребра на површини влакана оба
узорка. Просечна величина наночестица синтетизованих у присуству екстраката PE и AA
износила је 88±26 nm односно 82±23 nm. Сличан садржај сребра пронађен је у узорку
добијеном са екстрактом PE (14,22±0,23 μmol/g) у поређењу са узорком синтетисаним
коришћењем екстракта AA (13,63±1,40 μmol/g). Синтетизовани узорци остварују макси-
малну редукцију Грам-негативних бактерија Escherichia coli и Грам-позитивних бактерија
Staphylococcus aureus
Ion-doped mesoporous bioactive glass particles as ciprofloxacin drug delivery vehicles
No full textIn recent years, sol-gel derived mesoporous bioactive glass particles (MBGs) have gained significant attention due to their highly tunable surface properties, which allow for high surface area and large pore volume, key features for applications in regenerative medicine and drug delivery systems. The incorporation of therapeutic ions presents a promising strategy to stimulate specific biological responses and promote tissue regeneration. Additionally, the presence of dopants can influence the mesoporosity, hence affecting drug delivery performance. This study aimed to investigate the influence of binary and multi-ion doping on the surface properties and drug delivery capacity of MBGs.
A modified microemulsion-assisted sol-gel synthesis method was utilized to prepare the particles co-doped with Sr and Mg ions (denoted as SrMg-MBGs) and multi-doped with Sr,Mg,Cu,Zn ions (referred to mMBGs). The obtained particles were subsequently analyzed for their morphological and surface characteristics, and their capacity for ciprofloxacin drug loading and release. Brunauer-Emmett-Teller (BET) analysis revealed that binary doping only slightly increased volume of mesopores (Vmeso) and micropores (Vmicro), while multi-doping significantly increased Vmicro and specific surface area (SSA). High-Resolution Transmission Electron Microscopy (HR-TEM) revealed that doping significantly influences pore size and morphology. Additionally, synthesis parameters of MBGs were found to influence particle size and porosity, leading to marked increase in SSA. UV-Vis spectroscopy analysis were employed to determine drug loading capacity and release behavior, and it was found that ion-doping had a significant impact on drug loading capacity. Overall, this study highlights the potential of doped MBGNs as drug delivery systems, and underscores the need for further research into their application in targeted therapeutics.
Acknowledgement: This research was funded by the Science Fund of Republic of Serbia #GRANT No.7470, Novel hybrid biomimetic macroporous composites with tuned biodegradability, improved osteointegration and anticancer properties for bone tissue regeneration – HyBioComBone and by Ministry of Science, Technological Development and Innovations, Republic of Serbia (No. 451-03-136/2025-03/200135, 451-03-136/2025-03/200287)
Role of viscoelasticity in the buckling-to-folding transition of epithelial monolayers under uni-axial compression
No full textEpithelial tissues often experience, and respond to, in-plane compression. This occurs during embryonic development and continues throughout adult life, driven by both internal and external forces. Gaining insight into such processes is essential for understanding the mechanisms of tissue morphogenesis, and therefore carries significant implications for developmental biology and regenerative medicine. Although the biological mechanisms associated with epithelial folding have been extensively researched, the physical mechanisms are only beginning to be clarified. One of the primary factors contributing to the relaxation of epithelial monolayers, following externally induced buckling and folding, is the viscoelasticity related to energy storage and dissipation resulting from their compression. Physical mechanisms involve the interplay between physical parameters such as: the epithelial surface tension, viscoelastic Poisson's ratio, bending modulus, internally generated strain and corresponding mechanical stress. The main focus of this review is to point out how interconnected relaxation processes influence epithelial buckling and folding as an integral part of the viscoelasticity, and how cells can regulate the extent of the folding depending on the magnitude of the externally applied compressive stress. This complex phenomenon is elaborated on substrate-devoid epithelial monolayers, considered as a simple model system under in vitro conditions
Amino-lignin microspheres loaded with Fe3O4 nanoparticles as support for xylanase immobilization: application in prebiotics synthesis
No full textIntroduction: In recent years, hybrid nanomaterials engineering has
emerged as an exciting research area in materials design. One promising
strategy concerning enzyme immobilization is to use hybrid polymer
nanomaterials consisting of inorganic nanoparticles coated with natural
polymers to create more efficient industrial enzymes, particularly for
producing green and sustainable energy or biomass-derived bioactive
compounds. Specifically, a hybrid system integrating lignin and magnetite
oxide nanoparticles shows promise due to lignin's abundance as a low-cost,
renewable resource for producing eco-friendly adsorbents and coatings.
Additionally, superparamagnetic magnetite (Fe₃O₄) particles, known for their
biocompatibility and low toxicity, have diverse applications in biocatalysis,
drug delivery, and bioimaging. This combination of lignin and Fe₃O₄
nanoparticles could yield a hybrid material with enhanced stability, chemical
resistance, magnetic functionality, and a strong affinity for enzyme
molecules
