Polaramycin B, and not physical interaction, is the signal that rewires fungal metabolism in the Streptomyces-Aspergillus interaction.

Co-culturing the bacterium Streptomyces rapamycinicus and the ascomycete Aspergillus nidulans has previously been shown to trigger the production of orsellinic acid (ORS) and its derivates in the fungal cells. Based on these studies it was assumed that direct physical contact is a prerequisite for the metabolic reaction that involves a fungal amino acid starvation response and activating chromatin modifications at the biosynthetic gene cluster (BGC). Here we show that not physical contact, but a guanidine containing macrolide, named polaramycin B, triggers the response. The substance is produced constitutively by the bacterium and above a certain concentration, provokes the production of ORS. In addition, several other secondary metabolites were induced by polaramycin B. Our genome-wide transcriptome analysis showed that polaramycin B treatment causes downregulation of fungal genes necessary for membrane stability, general metabolism and growth. A compensatory genetic response can be observed in the fungus that included upregulation of BGCs and genes necessary for ribosome biogenesis, translation and membrane stability. Our work discovered a novel chemical communication, in which the antifungal bacterial metabolite polaramycin B leads to the production of antibacterial defence chemicals and to the upregulation of genes necessary to compensate for the cellular damage caused by polaramycin B.

High-Resolution Profiling of the Functional Heterogeneity of Technical Lignins.

In technical lignins, functionality is strongly related to molar mass. Hence, any technical lignin exhibits concurrent functionality-type distribution (FTD) along its molar mass distribution (MMD). This study combined preparative size-exclusion chromatography with offline characterizations to acquire highly resolved profiles of the functional heterogeneity of technical lignins, which represent crucial information for their material use. The shape of these profiles showed considerable dissimilarity between different technical lignins and followed sigmoid trends. Determining the dispersity in functionality (DF) of lignins via their FTD revealed a rather homogeneous distribution of their functionalities (DF of 1.00-1.21). The high resolution of the acquired profiles of functional heterogeneity facilitated the development of a robust calculation method for the estimation of functional group contents of lignin fractions based simply on their MMD, an invaluable tool to simulate the effects of intended purification processes. Moreover, a more thorough evaluation of separations based on functionality becomes accessible.

Silviridoside: A New Triterpene Glycoside from Silene viridiflora with Promising Antioxidant and Enzyme Inhibitory Potential.

A new triterpene glycoside, silviridoside, was isolated from the aerial parts of Silene viridiflora (Caryophyllaceae) using different chromatographic techniques. The structure of silviridoside was comprehensively elucidated as 3-O-ß-D-galacturonopyranosyl-quillaic acid 28-O-ß-D-glucopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→3)]-ß-D-fucopyranosyl ester by one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HR-MS). Silviridoside showed promising antioxidant activity in different antioxidant assays such as 2,2-diphenyl-1-picrylhydrazyl (DPPH) (2.32 mg TE/g), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (1.24 mg TE/g), cupric-reducing antioxidant capacity (CUPRAC) (9.59 mg TE/g), ferric-reducing antioxidant power (FRAP) (5.13 mg TE/g), phosphomolybdenum (PHD) (0.28 mmol TE/g), and metal-chelating (MCA) (6.62 mg EDTA/g) assays. It exhibited a good inhibitory potential on acetylcholinesterase (AChE) (2.52 mg GALAE/g), butyrylcholinesterase (BChE) (7.16 mg GALAE/g), α-amylase (0.19 mmol ACAE/g), α-glucosidase (1.21 mmol ACAE/g), and tyrosinase (38.83 mg KAE/g). An in silico evaluation of the pharmacodynamic, pharmacokinetic, and toxicity properties of silviridoside showed that the new compound exhibited reasonable pharmacodynamic and pharmacokinetic properties without any mutagenic effect, but slight toxicity. Thus, it could be concluded that silviridoside could act as a promising lead drug for pharmaceutical and nutraceutical developments to combat oxidative stress and various disorders, but a future optimization is necessary.

Lignin Resists High-Intensity Electron Beam Irradiation.

The electron beam irradiation (EBI) of native lignin has received little attention. Thus, its potential use in lignin-based biorefineries is not fully understood. EBI was applied to selected lignin samples and the structural and chemical changes were analyzed, revealing the suitability, limitations, and potential purpose of EBI in wood biorefineries. Isolated milled wood, kraft, and sulfite lignin from beech and eucalyptus were subjected to up to 200 kGy of irradiation. The analysis included gel permeation chromatography for molar masses, heteronuclear single quantum coherence (HSQC)- and 31P NMR and headspace gas chromatography-mass spectrometry for functional groups, and thermogravimetric analysis for thermal stability. Most samples resisted irradiation. Subtle changes occurred in the molecular weight distribution and thermal stability of milled wood lignin. EBI was found to be a suitable pretreatment method for woody biomass if the avoidance of lignin condensation and chemical modification is a high priority.

Comparative hydrolysis analysis of cellulose samples and aspects of its application in conservation science.

Knowledge about the carbohydrate composition of pulp and paper samples is essential for their characterization, further processing, and understanding the properties. In this study, we compare sulfuric acid hydrolysis and acidic methanolysis, followed by GC-MS analysis of the corresponding products, by means of 42 cellulose and polysaccharide samples. Results are discussed and compared to solid-state NMR (crystallinity) and gel permeation chromatography (weight-averaged molecular mass) data. The use of the hydrolysis methods in the context of cellulose conservation science is evaluated, using e-beam treated and artificially aged cellulose samples. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10570-021-04048-6.

Luteapyrone, a Novel Æ´-Pyrone Isolated from the Filamentous Fungus Metapochonia lutea.

In the process of screening for new bioactive microbial metabolites we found a novel Æ´-pyrone derivative for which we propose the trivial name luteapyrone, in a recently described microscopic filamentous fungus, Metapochonia lutea BiMM-F96/DF4. The compound was isolated from the culture extract of the fungus grown on modified yeast extract sucrose medium by means of flash chromatography followed by preparative HPLC. The chemical structure was elucidated by NMR and LC-MS. The new compound was found to be non-cytotoxic against three mammalian cell lines (HEK 263, KB-3.1 and Caco-2). Similarly, no antimicrobial activity was observed in tested microorganisms (gram positive and negative bacteria, yeast and fungi).

Self-Assembly of Soft Cellulose Nanospheres into Colloidal Gel Layers with Enhanced Protein Adsorption Capability for Next-Generation Immunoassays.

Soft cationic core/shell cellulose nanospheres can deform and interpenetrate allowing their self-assembly into densely packed colloidal nanogel layers. Taking advantage of their water-swelling capacity and molecular accessibility, the nanogels are proposed as a new and promising type of coating material to immobilize bioactive molecules on thin films and paper. The specific and nonspecific interactions between the cellulosic nanogel and human immunoglobulin G as well as bovine serum albumin (BSA) are investigated. Confocal microscopy, electroacoustic microgravimetry, and surface plasmon resonance are used to access information about the adsorption behavior and viscoelastic properties of self-assembled nanogels. A significant BSA adsorption capacity on nanogel layers (17 mg m-2 ) is measured, 300% higher compared to typical polymer coatings. This high protein affinity further confirms the promise of the introduced colloidal gel layer, in increasing sensitivity and advancing a new generation of substrates for a variety of applications, including immunoassays, as demonstrated in this work.

A Direct Silanization Protocol for Dialdehyde Cellulose.

Cellulose derivatives have many potential applications in the field of biomaterials and composites, in addition to several ways of modification leading to them. Silanization in aqueous media is one of the most promising routes to create multipurpose and organic-inorganic hybrid materials. Silanization has been widely used for cellulosic and nano-structured celluloses, but was a problem so far if to be applied to the common cellulose derivative "dialdehyde cellulose" (DAC), i.e., highly periodate-oxidized celluloses. In this work, a straightforward silanization protocol for dialdehyde cellulose is proposed, which can be readily modified with (3-aminopropyl)triethoxysilane. After thermal treatment and freeze-drying, the resulting product showed condensation and cross-linking, which was studied with infrared spectroscopy and 13C and 29Si solid-state nuclear magnetic resonance (NMR) spectroscopy. The cross-linking involves both links of the hydroxyl group of the oxidized cellulose with the silanol groups (Si-O-C) and imine-type bonds between the amino group and keto functions of the DAC (-HC=N-). The modification was achieved in aqueous medium under mild reaction conditions. Different treatments cause different levels of hydrolysis of the organosilane compound, which resulted in diverse condensed silica networks in the modified dialdehyde cellulose structure.

Potentially Immunogenic Contaminants in Wood-Based and Bacterial Nanocellulose: Assessment of Endotoxin and (1,3)-ß-d-Glucan Levels.

Knowledge gaps in the biosafety data of the nanocellulose (NC) for biomedical use through various routes of administration call for closer look at health and exposure evaluation. This work evaluated the potentially immunogenic contaminants levels, for example, endotoxin and (1,3)-ß-d-glucan, in four representative NCs, that is, wood-based NCs and bacterial cellulose (BC). The hot-water extracts were analyzed with ELISA assays, HPSEC-MALLS, GC, and NMR analysis. Varying levels of endotoxin and (1,3)-ß-d-glucan contaminats were found in these widely used NCs. Although the ß-(1,3)-d-glucan was not detected from the NMR spectra due to the small extract samples amount (2-7 mg), the anomerics and highly diastereotopic 6-CH2 signals may suggest the presence of ß-(1,4)-linkages with ß-(1,6) branching in the polysaccharides of NCs' hot-water extracts, which were otherwise not detectable in the enzymatic assay. In all, the article highlights the importance of monitoring various water-soluble potentially immunogenic contaminants in NC for biomedical use.

Interaction of ascaridole, carvacrol, and caryophyllene oxide from essential oil of Chenopodium ambrosioides L. with mitochondria in Leishmania and other eukaryotes.

The antileishmanial activity of the essential oil (EO) from Chenopodium ambrosioides L. has been demonstrated in vitro and in animal models, attributed to the major components of the EO. This study focused on the effects of the three major EO compounds carvacrol, caryophyllene oxide (Caryo), and the antileishmanial endoperoxide ascaridole (Asc) on mitochondrial functions in Leishmania tarentolae promastigotes (LtP). EO and Caryo were able to partially inhibit the leishmanial electron transport chain, whereas other components failed to demonstrate a direct immediate effect. Caryo demonstrated inhibition of complex III activity in LtP and in isolated complex III from other species. The formation of superoxide radicals was studied in Leishmania by electron spin resonance spectroscopy in the presence of iron chelators wherein selected compounds failed to trigger a significant immediate additional superoxide production in LtP. However, upon prolonged incubation of Leishmania with Asc and especially in the absence of iron chelators (allowing the activation of Asc), an increased superoxide radical production and significant impairment of mitochondrial coupling in Leishmania was observed. Prolonged incubation with all EO components resulted in thiol depletion. Taken together, the major components of EO mediate their leishmanicidal activity via different mitochondrial targets and time profiles. Further studies are required to elucidate possible synergistic effects of carvacrol and Asc and the influence of minor compounds.

A General Aqueous Silanization Protocol to Introduce Vinyl, Mercapto or Azido Functionalities onto Cellulose Fibers and Nanocelluloses.

The effective and straight-forward modification of nanostructured celluloses under aqueous conditions or as "never-dried" materials is challenging. We report a silanization protocol in water using catalytic amounts of hydrogen chloride and then sodium hydroxide in a two-step protocol. The acidic step hydrolyzes the alkoxysilane to obtain water-soluble silanols and the subsequent addition of catalytic amounts of NaOH induces a covalent reaction between cellulose surficial hydroxyl groups and the respective silanols. The developed protocol enables the incorporation of vinyl, thiol, and azido groups onto cellulose fibers and cellulose nanofibrils. In contrast to conventional methods, no curing or solvent-exchange is necessary, thereby the functionalized celluloses remain never-dried, and no agglomeration or hornification occurs in the process. The successful modification was proven by solid state NMR, ATR-IR, and EDX spectroscopy. In addition, the covalent nature of this bonding was shown by gel permeation chromatography of polyethylene glycol grafted nanofibrils. By varying the amount of silane agents or the reaction time, the silane loading could be tuned up to an amount of 1.2 mmol/g. Multifunctional materials were obtained either by prior carboxymethylation and subsequent silanization; or by simultaneously incorporating both vinyl and azido groups. The protocol reported here is an easy, general, and straight-forward avenue for introduction of anchor groups onto the surface of never-dried celluloses, ready for click chemistry post-modification, to obtain multifunctional cellulose substrates for high-value applications.

Degradation of the Cellulosic Key Chromophore 5,8-Dihydroxy-[1,4]-naphthoquinone by Hydrogen Peroxide under Alkaline Conditions.

5,8-Dihydroxy-[1,4]-naphthoquinone (DHNQ) is one of the key chromophores in cellulosic materials. Its almost ubiquitous presence in cellulosic materials makes it a target molecule of the pulp and paper industry's bleaching efforts. In the presented study, DHNQ was treated with hydrogen peroxide under alkaline conditions at pH 10, resembling the conditions of industrial hydrogen peroxide bleaching (P stage). The reaction mechanism, reaction intermediates, and final degradation products were analyzed by UV/vis, NMR, GC-MS, and EPR. The degradation reaction yielded C1-C4 carboxylic acids as the final products. Highly relevant for pulp bleaching are the findings on intermediates of the reaction, as two of them, 2,5-dihydroxy-[1,4]-benzoquinone (DHBQ) and 1,4,5,8-naphthalenetetrone, are potent chromophores themselves. While DHBQ is one of the three key cellulosic chromophores and its degradation by H2O2 is well-established, the second intermediate, 1,4,5,8-naphthalenetetrone, is reported for the first time in the context of cellulose discoloration.

Surfactin variants mediate species-specific biofilm formation and root colonization in Bacillus.

Cyclic lipopeptides (cLP) and especially surfactins produced by Bacillus spp. trigger biofilm formation and root colonization and are crucial for biocontrol activity and systemic resistance in plants. Bacillus atrophaeus 176s isolated from the moss Tortella tortuosa produces the cLP fengycins, iturins and surfactins, possesses antifungal activities and can protect tomato, lettuce and sugar beet against Rhizoctonia solani infection. In B. atrophaeus we identified for the first time the variant surfactin C, which differs from surfactin A produced by B. subtilis and B. amyloliquefaciens by an isoleucine instead of a leucine at position 7 of the lipopeptide backbone. The analysis of the complete surfactin gene clusters revealed that the dissimilarity is encoded in the adenylation domain of srfC and show that surfactin variations are distributed in a species-specific manner in bacilli. We demonstrate that the surfactin A and C with subtle structural differences have varying signal strengths on biofilm formation and root colonization and act specifically on the respective producing strain. This became evident as biofilm formation and root colonization but not swarming motility in surfactin biosynthesis mutants was restored differentially in the presence of exogenously supplemented cognate and non-cognate surfactin variants.

Synthesis and Characterization of Periodate-Oxidized Polysaccharides: Dialdehyde Xylan (DAX).

The cleavage of the C2-C3 bond in the building units of 1 → 4-linked polysaccharides by periodate formally results in two aldehyde units, which are present in several masked forms. The structural elucidation of such polysaccharide dialdehydes remains a big challenge. Since polysaccharide derivatives are increasingly applied in materials technology, unveiling the exact structure is of utmost importance. To address this issue for xylan, dialdehyde xylan (DAX, oxidation degree of 91.5%) has been synthesized as water-soluble polymer. The ATR-FTIR spectrum of DAX showed free aldehyde to be absent and exhibited a characteristic absorption at 858 cm(-1) related to hemiacetal groups. By a combination of 1D and 2D NMR techniques, it was confirmed that oxidized xylan is present as poly(2,6-dihydroxy-3-methoxy-5-methyl-3,5-diyl-1,4-dioxane). Based on GPC analysis, the DAX polymer shows a slightly lower molar mass (6.6 kDa) compared to the starting material (7.7 kDa) right after oxidation, and degraded further after one month of storage in 0.1 M NaCl solution (4.3 kDa). The oxidized xylan demonstrated lower thermal stability upon TGA analysis and a greater amount of residual char (20.6%) compared to the unmodified xylan (13.7%).

Impact of selected solvent systems on the pore and solid structure of cellulose aerogels.

The impact of selected cellulose solvent systems based on the principal constituents tetrabutylammonium fluoride (TBAF), 1-ethyl-3-methyl-1H-imidazolium-acetate, N-methylmorpholine-N-oxide, or calcium thiocyanate octahydrate (CTO) on the properties of cellulose II aerogels prepared from these solvent systems has been investigated as a means towards tailoring cellulose aerogel properties with respect to specific applications. Cotton linters were used as representative plant cellulose. Cellulose was coagulated from solutions with comparable cellulose content, and dried with supercritical carbon dioxide after solvent exchange. The resulting bulk aerogels were comprehensively morphologically and mechanically tested to relate structure and mechanical properties. Different solvent systems caused considerable differences in the properties of the bulk samples, such as internal surface area (nitrogen sorption), morphology, porosity (He pycnometry, thermoporosimetry), and mechanical stability (compression testing). The results of SAXS, WAXS, and solid-state 13C NMR spectroscopy suggest that this is due to different mechanisms of cellulose self-assembling on the supramolecular and nanostructural level, respectively, as reflected by the broad ranges of cellulose crystallinity, fibril diameter, fractal dimension and skeletal density. Both solid state NMR and WAXS experiments confirmed the sole existence of the cellulose II allomorph for all aerogels, with crystallinity reaching a maximum of 46-50 % for CTO-derived aerogels. Generally, higher fibril diameter, degree of crystallinity, hence increased skeletal density were associated with good preservation of shape and dimension throughout conversion of lyogels to aerogels, and enhanced mechanical stability, but somewhat reduced specific surface area. Amorphous, yet highly rigid aerogels derived from TBAF/DMSO mixtures deviated from this trend, most likely due to their particular homogeneous and nanostructured morphology.

Fusarium sporotrichioides Produces Two HT-2-α-Glucosides on Rice.

Fusarium is a genus that mostly consists of plant pathogenic fungi which are able to produce a broad range of toxic secondary metabolites. In this study, we focus on a type A trichothecene-producing isolate (15-39) of Fusarium sporotrichioides from Lower Austria. We assessed the secondary metabolite profile and optimized the toxin production conditions on autoclaved rice and found that in addition to large amounts of T-2 and HT-2 toxins, this strain was able to produce HT-2-glucoside. The optimal conditions for the production of T-2 toxin, HT-2 toxin, and HT-2-glucoside on autoclaved rice were incubation at 12 °C under constant light for four weeks, darkness at 30 °C for two weeks, and constant light for three weeks at 20 °C, respectively. The HT-2-glucoside was purified, and the structure elucidation by NMR revealed a mixture of two alpha-glucosides, presumably HT-2-3-O-alpha-glucoside and HT-2-4-O-alpha-glucoside. The efforts to separate the two compounds by HPLC were unsuccessful. No hydrolysis was observed with two the alpha-glucosidases or with human salivary amylase and Saccharomyces cerevisiae maltase. We propose that the two HT-2-alpha-glucosides are not formed by a glucosyltransferase as they are in plants, but by a trans-glycosylating alpha-glucosidase expressed by the fungus on the starch-containing rice medium.

ß-sitosterol isolated from the leaves of Trema orientalis (Cannabaceae) promotes viability and proliferation of BF-2 cells.

Trema orientalis is a pioneer species in the cannabis family (Cannabaceae) that is widely distributed in Thai community forests and forest edges. The mature leaves are predominantly used as an anti-parasite treatment and feed for local freshwater fish, inspiring investigation of their phytochemical composition and bioactivity. The purpose of this work was to investigate the bioactive compounds in T. orientalis leaf extract and their cytotoxicity in the BF-2 fish cell line (ATCC CCL-91). Flash column chromatography was used to produce 25 mL fractions with a mixture solvent system comprised of hexane, diethyl ether, methanol, and acetone. All fractions were profiled with HPLC-DAD (mobile phase methanol:aqueous buffer, 60:40 v/v) and UV detection (wavelengths 256 and 365 nm). After drying, a yellowish powder was isolated from lipophilic leaf extract with a yield of 280 µg/g dry weight. Structure elucidation by nuclear magnetic resonance (NMR) indicated it to consist of pure ß-sitosterol. The lipophilic extract and pure compound were evaluated for cytotoxicity using BF-2 cells. MTT assays showed both leaf extract and pure compound at 1 µg/mL to increase cell viability after 24 h treatment. The respective half maximal inhibitory concentration (IC50) values of leaf extract and ß-sitosterol were 7,027.13 and 86.42 µg/ml, indicating a lack of toxicity in the BF-2 cell line. Hence, T. orientalis can serve as a source of non-toxic natural lipophilic compounds that can be useful as bioactive ingredients in supplement feed development.

Profiling of historical rag papers by their non-cellulosic polysaccharide composition.

Hemicellulose and pectin are noteworthy components of historical European rag papers, and have not been studied in detail so far. Rag papers were made from used textiles, and fiber-based utilities, such as ropes and bags. These had been prepared until the mid-19th century from plant-based fibers. Their polysaccharide composition could relate to their condition and history. This information can be expected to hold importance for the preservation and conservation of historical objects. We investigated a collection of rag papers of different age for their composition of non-cellulosic polysaccharides, and compared the findings with modern rag papers and wood pulps. Furthermore, a non-destructive determination of the hemicellulose and pectin content by near-infrared spectroscopy was developed. Historical rag papers had a lower hemicellulose/pectin content than pulps; the fractions of rhamnose, galactose, and arabinose were higher, while xylose was lower. In modern rag papers, xylose tended to be at the higher end of the range, which suggests a degradation of hemicelluloses/pectin over time or a change in raw materials and manufacturing. Rag papers also showed higher crystallinity than wood pulp papers. These findings provide insights into rag paper characteristics and offer potential classification methods.

HPLC, NMR Based Characterization, Antioxidant and Anticancer Activities of Chemical Constituents from Therapeutically Active Fungal Endophytes.

Fungi generate different metabolites some of which are intrinsically bioactive and could therefore serve as templates for drug development. In the current study, six endophytic fungi namely Aspergillus flavus, Aspergillus tubigenesis, Aspergillus oryzae, Penicillium oxalicum, Aspergillus niger and Aspergillus brasiliensis were isolated and identified from the medicinal plant, Silybum marianum. These endophytic fungi were identified through intra transcribed sequence (ITS) gene sequencing. The bioactive potentials of fungal extracts were investigated using several bioassays such as antibacterial activity by well-diffusion, MIC, MBC, anti-biofilm, antioxidant, and haemolysis. The Pseudomonas aeruginosa strain PAO1 was used to determine the antibiofilm activity. The ethyl acetate extract of Aspergillus flavus showed strong to moderate efficacy against Staphylococcus aureus, Escherichia coli, P. aeruginosa, and Bacillus spizizenii. Aspergillus flavus and Aspergillus brasiliensis exhibited significant antibiofilm activity with IC50 at 4.02 and 3.63 mg/ml while A. flavus exhibited maximum antioxidant activity of 50.8%. Based on, HPLC, LC-MS and NMR experiments kojic acid (1) and carbamic acid (methylene-4, 1-phenylene) bis-dimethyl ester (2) were identified from A. flavus. Kojic acid exhibited DPPH free radical scavenging activity with an IC50 value of 99.3 µg/ml and moderate activity against ovarian teratocarcinoma (CH1), colon carcinoma (SW480), and non-small cell lung cancer (A549) cell lines. These findings suggest that endophytic fungi are able produce promising bioactive compounds which deserve further investigation.

Fluorescent cellulose aerogels containing covalently immobilized (ZnS)x(CuInS2)1-x/ZnS (core/shell) quantum dots.

Photoluminiscent (PL) cellulose aerogels of variable shape containing homogeneously dispersed and surface-immobilized alloyed (ZnS)x(CuInS2)1-x/ZnS (core/shell) quantum dots (QD) have been obtained by (1) dissolution of hardwood prehydrolysis kraft pulp in the ionic liquid 1-hexyl-3-methyl-1H-imidazolium chloride, (2) addition of a homogenous dispersion of quantum dots in the same solvent, (3) molding, (4) coagulation of cellulose using ethanol as antisolvent, and (5) scCO2 drying of the resulting composite aerogels. Both compatibilization with the cellulose solvent and covalent attachment of the quantum dots onto the cellulose surface was achieved through replacement of 1-mercaptododecyl ligands typically used in synthesis of (ZnS)x(CuInS2)1-x/ZnS (core-shell) QDs by 1-mercapto-3-(trimethoxysilyl)-propyl ligands. The obtained cellulose-quantum dot hybrid aerogels have apparent densities of 37.9-57.2 mg cm-3. Their BET surface areas range from 296 to 686 m2 g-1 comparable with non-luminiscent cellulose aerogels obtained via the NMMO, TBAF/DMSO or Ca(SCN)2 route. Depending mainly on the ratio of QD core constituents and to a minor extent on the cellulose/QD ratio, the emission wavelength of the novel aerogels can be controlled within a wide range of the visible light spectrum. Whereas higher QD contents lead to bathochromic PL shifts, hypsochromism is observed when increasing the amount of cellulose at constant QD content. Reinforcement of the cellulose aerogels and hence significantly reduced shrinkage during scCO2 drying is a beneficial side effect when using α-mercapto-ω-(trialkoxysilyl) alkyl ligands for QD capping and covalent QD immobilization onto the cellulose surface.