Sugarcane bagasse derived xylooligosaccharides produced by an arabinofuranosidase/xylobiohydrolase from Bifidobacterium longum in synergism with xylanases.

Arabinoxylan is a major hemicellulose in the sugarcane plant cell wall with arabinose decorations that impose steric restrictions on the activity of xylanases against this substrate. Enzymatic removal of the decorations by arabinofuranosidases can allow a more efficient arabinoxylan degradation by xylanases. Here we produced and characterized a recombinant Bifidobacterium longum arabinofuranosidase from glycoside hydrolase family 43 (BlAbf43) and applied it, together with GH10 and GH11 xylanases, to produce xylooligosaccharides (XOS) from wheat arabinoxylan and alkali pretreated sugarcane bagasse. The enzyme synergistically enhanced XOS production by GH10 and GH11 xylanases, being particularly efficient in combination with the latter family of enzymes, with a degree of synergism of 1.7. We also demonstrated that the enzyme is capable of not only removing arabinose decorations from the arabinoxylan and from the non-reducing end of the oligomeric substrates, but also hydrolyzing the xylan backbone yielding mostly xylobiose and xylose in particular cases. Structural studies of BlAbf43 shed light on the molecular basis of the substrate recognition and allowed hypothesizing on the structural reasons of its multifunctionality.

Changes in the extractability and fractionation of cadmium and copper in a contaminated soil amended with various sugarcane bagasse-based materials.

Heavy-metal contamination in soil has long been a persistent challenge and the utilization of agricultural waste for in-situ stabilization remediation presents a promising approach to tackle this problem. Agricultural wastes exhibit promising potential in the remediation of contaminated land and modification could improve the adsorption performance markedly. Citric acid and Fe3O4 treated sugarcane bagasse adsorbed more heavy metals than raw materials in the aqueous system, employing these materials for heavy metal remediation in soil holds significant implications for broadening the raw material source of passivators and enhancing waste utilization efficiency. In this paper, a 120-day soil incubation study was conducted to compare the effects of pristine sugarcane bagasse (SB), citric-acid modified (SSB1, SSB2 and SSB3 with increasing proportion of citric acid) and citric-acid/Fe3O4 modified (MSB1, MSB4 and MSB7 with increasing proportion of Fe3O4) sugarcane bagasse at 1 % addition rate on cadmium (Cd) and copper (Cu) passivation. The SB, SSB1 and MSB1 did not always decrease the content of CaCl2-extractable Cd while all the seven amendments decreased the CaCl2-extractable Cu during the experiment period. Among all materials, SSB3 and MSB7 exhibited the highest efficiency in reducing the concentrations of CaCl2-extractable Cd and Cu. At Day 120, SB, SSB3 and MSB7 reduced the content of CaCl2-extractable Cd by 8 %, 18 % and 24 %, and of CaCl2-extractable Cu by 25 %, 50 % and 61 %, respectively. The efficiency of Cd and Cu immobilization was associated positively with the pH, functional groups and H-bonds of the amendments. The results suggest that the efficiency of sugarcane bagasse in heavy-metal passivation can be largely enhanced through chemical modifications using high proportions of citric acid and Fe3O4.

Removal of Cr(VI) from Wastewater Using Acrylonitrile Grafted Cellulose Extracted from Sugarcane Bagasse.

A highly efficient low-cost adsorbent was prepared using raw and chemically modified cellulose isolated from sugarcane bagasse for decontamination of Cr(VI) from wastewater. First, cellulose pulp was isolated from sugarcane bagasse by subjecting it to acid hydrolysis, alkaline hydrolysis and bleaching with sodium chlorate (NaClO3). Then, the bleached cellulose pulp was chemically modified with acrylonitrile monomer in the presence Fenton's reagent (Fe+2/H2O2) to carry out grafting of acrylonitrile onto cellulose by atom transfer radical polymerization. The developed adsorbent (acrylonitrile grafted cellulose) was analyzed by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Both raw cellulose and acrylonitrile grafted cellulose were used for chromium removal from wastewater. The effects of metal ion concentration, pH, adsorbent dose and time were studied, and their values were optimized. The optimum conditions for the adsorption of Cr(VI) onto raw and chemically modified cellulose were: metal ion concentration: 50 ppm, adsorbent dose: 1 g, pH: 6, and time: 60 min. The maximum efficiencies of 73% and 94% and adsorption capacities of 125.95 mg/g and 267.93 mg/g were achieved for raw and acrylonitrile grafted cellulose, respectively. High removal efficiency was achieved, owing to high surface area of 79.92 m2/g and functional active binding cites on grafted cellulose. Isotherm and kinetics studies show that the experimental data were fully fitted by the Freundlich isotherm model and pseudo first-order model. The adsorbent (acrylonitrile grafted cellulose) was regenerated using three different types of regenerating reagents and reused thirty times, and there was negligible decrease (19%) in removal efficiency after using it for 30 times. Hence, it is anticipated that acrylonitrile could be utilized as potential candidate material for commercial scale Cr(VI) removal from wastewater.

Ozone-activated lignocellulose films blended with chitosan for edible film production.

This work focuses on the influence of ozone pretreatment on the fractionation and solubilization of sugarcane bagasse and soda bagasse pulp fibers in sodium hydroxide/urea solution, as well as the application of regenerated cellulose for producing edible films. The methodology involved pretreating lignocelluloses with ozone for 20 to 120 min before dissolving in sodium hydroxide/urea solution. The influence of the pretreatment conditions on cellulose dissolution yield was investigated. Regenerated cellulose films were then formed, with and without the addition of 2 % chitosan. Mechanical, physical, structural, thermal, and antimicrobial attributes were determined as a function of ozonation conditions of raw materials and chitosan content. The findings exhibited positive effects of short ozonation on enhancing mechanical strength, cohesion, and hydrophobicity. The prolonged ozonation of 120 min demonstrated optimal improvements in continuity, swelling, and antibacterial resistance of obtained films. Incorporating chitosan enhanced tensile performance, stiffness, and vapor barriers but increased moisture absorption. Tailoring the activation of biomass through ozone pretreatment and chitosan addition resulted in renewable films with adjustable properties to meet diverse packaging requirements, particularly for fruit protective coatings, ensuring the preservation of post-harvest quality.

One pot synthesis of furan-modified lignin from agricultural waste via lignin-first approach.

This study investigated a lignin-first approach to produce furan-modified lignin from sugarcane bagasse (SB), rice hull (RH), and sunn hemp biomass (SHB) using 5 methylfurfural (MF) and 5 methul-2-furanmethanol (MFM). The reaction time (5 h) was selected based on the delignification of SB using methanol and Ru/C catalyst which yielded the highest hydroxyl content. Delignification of SB with various MF weight ratios (1:1, 1:2, 1:3, 2:1, and 3:1) revealed that 1:1 and 2:1 ratios produced the highest hydroxyl content (7.7 mmol/g) and bio-oil yield (23.2 % wt% total weight). Further exploration identified that RH and MF at 1:1 ratio and SHB and MF at a 2:1 ratio produced the highest hydroxyl content (13.0 mmol/g) and bio-oil yield (31.6 % wt% tot. weight). This study developed a one-step method to extract and modify lignin with furan compounds simultaneously while opening new avenues for developing value-added products.

Nutritional and antioxidant potential of Pleurotus djamor (Rumph. ex Fr.) Boedijn produced on agronomic wastes banana leaves and sugarcane bagasse substrates.

Global food production faces challenges concerning access to nutritious and sustainably produced food. Pleurotus djamor, however, is an edible mushroom that can be cultivated on agricultural waste. Considering that nutritional and functional potential of mushrooms can change based on cultivation conditions, we examined the influence of substrates with different compositions of banana leaf and sugarcane bagasse on the nutritional, mycochemical, and antioxidant properties of P. djamor. The mushrooms were grown for 120 days and dried in a circulating air oven at 45 °C for three days. We conducted bromatological analyses and mycochemical characterization (1H-NMR, total phenolics, and flavonoids) of the mushrooms and assayed the antioxidant activity of extracts from the dried mushrooms using an ethanol/water solution (70:30 v/v). In general, the substrates produced mushrooms with high protein (18.77 ± 0.24% to 17.80 ± 0.34%) and dietary fiber content (18.02 ± 0.05% to 19.32 ± 0.39%), and with low lipid (0.28 + 0.08% to 0.4 + 0.6%), and caloric content (maximum value: 258.42 + 8.49), with no significant differences between the groups (p ≥ 0.05). The mushrooms also exhibited high levels of total phenolics and flavonoids. The mushrooms cultivated on sugarcane bagasse substrates presented the highest values (p < 0.05). Analysis of the 1H-NMR spectra indicates an abundant presence of heteropolysaccharides, ß-glucans, α-glucans, and oligosaccharides, and all the mushroom extracts exhibited high antioxidant activity. In conclusion, our study demonstrates that agricultural residues permit sustainable production of edible mushrooms while maintaining nutritional and functional properties.

Protective effects of sugarcane polyphenol against UV-B-induced photoaging in Balb/c mouse skin: Antioxidant, anti-inflammatory, and anti-glycosylation Effects.

Although the benefits of sugarcane polyphenol (SP) are well documented, its function in preventing photoaging has not yet been investigated. This study aimed to investigate the protective effects of SP in preventing ultraviolet (UV)-B-induced skin photoaging in Balb/c mice, as well as the underlying mechanism. Chlorogenic acid was determined to be the primary component of SP by using high-performance liquid chromatography-mass spectrometry. SP and chlorogenic acid were orally administrated to mice for 56 days, and UV-B radiation exposure was administered 14 days after SP and chlorogenic acid administration and lasted 42 days to cause photoaging. SP and chlorogenic acid administrations significantly alleviated the UV-B-induced mouse skin photoaging, as indicated by the decrease in epidermal thickness, increase in the collagen (COL) volume fraction, and elevation in type 1 and type 3 COL contents. Notably, both SP and chlorogenic acid effectively reversed the overexpression of matrix metalloproteinase induced by UV-B exposure in the mouse skin. Furthermore, SP and chlorogenic acid reduced the expression of receptor for advanced glycosylation end products in the mice; amplified the activities of antioxidant enzymes superoxide dismutase and catalase; reduced malondialdehyde levels; and decreased inflammatory cytokines interleukin 1ß, interleukin 6, and tumor necrosis factor α levels. SP could be a prospective dietary supplement for anti-photoaging applications due to its antioxidant, anti-inflammatory, and anti-glycosylation attributes, and chlorogenic acid might play a major role in these effects. PRACTICAL APPLICATION: This study can provide a scientific basis for the practical application of sugarcane polyphenols. We expect that sugarcane polyphenols can be used in food and beverage products to provide flavor while combating skin aging.

Polyethyleneimine-functionalized magnetic sugarcane bagasse cellulose film for the efficient adsorption of ibuprofen.

Polyethyleneimine-modified magnetic sugarcane bagasse cellulose film (P-SBC/Fe3O4 film) was simply fabricated for the removal of ibuprofen (IBP), a typical emerging organic contaminant. The P-SBC/Fe3O4 film exhibited an equilibrium adsorption amount of 370.52 mg/g for IBP and a corresponding removal efficiency of 92.63 % under following adsorption conditions: 318 K, pH 4, and 0.25 mg/mL dosage. Thermodynamic studies indicated that adsorption of IBP on the P-SBC/Fe3O4 film was spontaneous (∆G < 0) and endothermic (∆H > 0). The adsorption data conformed to the Freundlich isotherm model and multilayer adsorption model (two layers), and an average of 3-4 active sites on the P-SBC/Fe3O4 film share an IBP molecule. Both the EDR-IDR and AOAS models vividly described the dynamic characteristics of adsorption process. Model fitting results, theoretical calculations, and comprehensive characterization revealed that adsorption is driven by electrostatic interactions between the primary amine of P-SBC/Fe3O4 film and the carboxyl group of IBP molecule, while other weak interactions are also non-ignorable. Furthermore, quantitative calculations based on density functional theory (DFT) underscored the importance of PEI functionalization. In conclusion, P-SBC/Fe3O4 film is an environmentally friendly and cost-effective adsorbent with significant potential for effectively removing IBP, while maintaining its efficacy over multiple cycles.

Tailoring hierarchical structures in cellulose carbon aerogels from sugarcane bagasse using different crosslinking agents for enhancing electrochemical desalination capability.

Sugarcane bagasse is one of the most common Vietnamese agricultural waste, which possesses a large percentage of cellulose, making it an abundant and environmentally friendly source for the fabrication of cellulose carbon aerogel. Herein, waste sugarcane bagasse was used to synthesize cellulose aerogel using different crosslinking agents such as urea, polyvinyl alcohol (PVA) and sodium alginate (SA). The 3D porous network of cellulose aerogels was constructed by intermolecular hydrogen bonding, which was confirmed by Fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and nitrogen adsorption/desorption. Among the three cellulose aerogel samples, cellulose - SA aerogel (SB-CA-SA) has low density of 0.04 g m-3 and high porosity of 97.38%, leading to high surface area of 497.9 m2 g-1 with 55.67% micropores of activated carbon aerogel (SB-ACCA-SA). The salt adsorption capacity was high (17.87 mg g-1), which can be further enhanced to 31.40 mg g-1 with the addition of CNT. Moreover, the desalination process using the SB-ACCA-SA-CNT electrode was stable even after 50 cycles. The results show the great combination of cellulose from waste sugarcane bagasse with sodium alginate and carbon nanotubes in the fabrication of carbon materials as the CDI-utilized electrodes with high desalination capability and good durability.

Comparative study on liquid versus gas phase hydrochloric acid hydrolysis for microcrystalline cellulose isolation from sugarcane bagasse.

Microcrystalline cellulose (MCC) was successfully synthesized from sugarcane bagasse using a rapid, low-temperature hydrochloric acid (HCl) gas treatment. The primary aim was to develop an energy-efficient "green" cellulose extraction process. Response surface methodology optimized the liquid-phase hydrolysis conditions to 3.3 % HCl at 117 °C for 127 min to obtain MCC with 350 degree of polymerization. An alternative gas-phase approach utilizing gaseous HCl diluted in hot 40 °C air was proposed to accelerate MCC production. The cellulose pulp was moistened to 15-18 % moisture content and then exposed to HCl gas, which was absorbed by the moisture in the cellulose fibers to generate a highly concentrated acidic solution that hydrolyzed the cellulose. The cellulose pulp was isolated from depithed bagasse through soda pulping, multistage bleaching and cold alkali purification. Hydrolysis was conducted by saturating the moist cellulose fibers with gaseous HCl mixed with hot air. Extensive analytical characterization using FT-IR, XRD, SEM, TGA, DSC, particle size, and porosity analyses verified comparable physicochemical attributes between MCC samples prepared via liquid and gas phase methods. The gas-produced MCC revealed 85% crystallinity, 71 Å crystallite dimensions, and thermally stable rod-shaped morphology with an average diameter below 200 µm. The similar material properties validate the proposed gas-based technique as an equally effective yet more energy-efficient alternative to conventional aqueous acid hydrolysis for fabricating highly pure MCC powders from lignocellulose. This sustainable approach enables the value-addition of sugarcane bagasse agro-industrial residue into cellulosic nanomaterials for wide-ranging industrial applications. In summary, the key achievements of this work are rapid MCC production under mild temperatures using HCl gas, optimization of liquid phase hydrolysis, successful demonstration of gas phase method, and extensive characterization verifying equivalence between both protocols. The gas methodology offers a greener cellulose extraction process from biomass.

Unlocking Agronutrient Resources: Sorption Strategies for sugar-energy industry waste.

Vinasse and ash from sugarcane bagasse (SCB) are key byproducts in the sugar-energy industry. Vinasse is nutrient-rich but environmentally challenging, while sugarcane bagasse ash (SCBA) offers excellent adsorbent for treating effluents. This work aims to assess the effectiveness of SCBA in removing nitrogen (N) and potassium (K) nutrients from Vinasse. Simulated standard solutions of K2SO4 and (NH4)2HPO4 were used to mimic the nutrient concentrations in Vinasse and optimize experimental parameters such as adsorbent mass and contact time. Kinetic and isotherm models were also applied to elucidate the underlying adsorption mechanisms. Structural, morphological, and thermal analyses revealed the micro-mesoporous and heterogeneous nature of SCBA, primarily composed of SiO2 (quartz and cristobalite). The sorption assessment indicated the ideal conditions involved lower SCBA masses (2.5 g) and 6 h of contact time for the simulated standard solutions. The replicated conditions for Vinasse (at an adjusted sorption time of 24 h) demonstrated nutrient sorption and pH correction of the Vinasse, attributed to the alkaline nature of SCBA. Analysis of the sorption kinetic models for K+ and NH4+ revealed that SCBA interacts diffusively with the environment, not necessarily controlled by adsorption on active sites, indicating non-uniform characteristics. The sorption isotherms for K+ and NH4+ showed the non-linearized Freundlich model was the most suitable, indicating the adsorption sites with varying energy levels and a multilayer sorption process. In conclusion, we successfully demonstrated the sorption of nutrients from Vinasse by SCBA, enhancing the value of these residues and mitigating their environmental impact when used in agricultural applications.

ShF5H1 overexpression increases syringyl lignin and improves saccharification in sugarcane leaves.

The agricultural sugarcane residues, bagasse and straws, can be used for second-generation ethanol (2GE) production by the cellulose conversion into glucose (saccharification). However, the lignin content negatively impacts the saccharification process. This polymer is mainly composed of guaiacyl (G), hydroxyphenyl (H), and syringyl (S) units, the latter formed in the ferulate 5-hydroxylase (F5H) branch of the lignin biosynthesis pathway. We have generated transgenic lines overexpressing ShF5H1 under the control of the C4H (cinnamate 4-hydroxylase) rice promoter, which led to a significant increase of up to 160% in the S/G ratio and 63% in the saccharification efficiency in leaves. Nevertheless, the content of lignin was unchanged in this organ. In culms, neither the S/G ratio nor sucrose accumulation was altered, suggesting that ShF5H1 overexpression would not affect first-generation ethanol production. Interestingly, the bagasse showed a significantly higher fiber content. Our results indicate that the tissue-specific manipulation of the biosynthetic branch leading to S unit formation is industrially advantageous and has established a foundation for further studies aiming at refining lignin modifications. Thus, the ShF5H1 overexpression in sugarcane emerges as an efficient strategy to improve 2GE production from straw.

Bioethanol Production from Characterized Pre-treated Sugarcane Trash and Jatropha Agrowastes.

Low production costs and a potential feedstock supply make lignocellulosic ethanol (bioethanol) an important source of advanced biofuels. The physical and chemical preparation of this kind of lignocellulosic feedstock led to a high ethanol yield. In order to increase the yield of fermentable sugars, pretreatment is an essential process step that alters the lignocellulosic structure and improves its accessibility for the expensive hydrolytic enzymes. In this context, the chemical composition of sugarcane trash (dry leaves, green leaves, and tops) and jatropha (shell and seed cake) was determined to be mainly cellulose, hemicellulose, and lignin. Hydrogen peroxide and sodium hydroxide were applied in an attempt to facilitate the solubilization of lignin and hemicelluloses in five agrowastes. The extraction of hydrogen peroxide was much better than that of sodium hydroxide. A comparative study was done using SEM, EDXA, and FTIR to evaluate the difference between the two methods. The pretreated wastes were subjected to saccharification by commercial cellulases (30 IU/g substrate). The obtained glucose was fortified with nutrients and fermented statically by Saccharomyces cerevisiae F-307 for bioethanol production. The results revealed the bioethanol yields were 325.4, 310.8, 282.9, 302.4 and 264.0 mg ethanol/g treated agrowastes from green leaves of sugarcane, jatropha deolied seed cake, tops sugarcane, dry leaves of sugarcane, and jatropha shell, respectively. This study emphasizes the value of lignocellulosic agricultural waste as a resource for the production of biofuels as well as the significance of the extraction process.

In silico guided pre-treatment of sugarcane juice with natural inhibitors of polyphenol oxidase (PPO) is a new and effective strategy for development of spray-dried formulation.

Sugarcane juice is a popular beverage and is also processed to produce sugar. The polyphenol oxidase (PPO) in sugarcane juice causes enzymatic browning and makes the process of sugar production complex and cumbersome. Storage of sugarcane juice is also hampered by the high sugar content and rapid microbial fermentation. The present research assessed the potential of lemon juice (LJ) and ginger extract (GE) as natural inhibitors of PPO. Enzyme kinetics and the mechanism of inhibition of LJ and GE were studied. Primary investigation was carried out using molecular docking approach to assess the inhibitory potential of LJ and GE and to determine the nature of interaction between the enzyme and inhibitors. Extracts were used as inhibitors and studies revealed that both reduced the PPO activity. Subsequently, pure bioactive inhibitors such as ascorbic acid, citric acid, and 6-shogaol present in these natural extracts were used to study the mode of inhibition of PPO. Citric acid decreased PPO activity by lowering pH, while ascorbic acid was found to be a competitive inhibitor of PPO with a Ki of 75.69 µM. The proportion of LJ and GE required in sugarcane juice was optimized on the basis of browning index and sensory acceptance. Further, the sugarcane cane juice after inhibition of PPO under optimized conditions was spray dried and evaluated for reconstitution properties. The product formulated in the present study is a new and effective approach to address quality-compromising issues associated with long-term storage of cane juice.

Modulating the properties and structure of lignins produced by alkaline delignification of sugarcane bagasse pretreated with two different mineral acids at pilot-scale.

Sugarcane bagasse was pretreated with dilute phosphoric acid or sulfuric acid to facilitate cellulose hydrolysis and lignin extraction. With phosphoric acid, only 8 % of the initial cellulose was lost after delignification, whereas pretreatment with sulfuric acid resulted in the solubilization of 38 % of the initial cellulose. After enzymatic hydrolysis, the process using phosphoric acid produced approximately 35 % more glucose than that using sulfuric acid. In general, the lignins showed 95-97 % purity (total lignin, w/w), an average molar mass of 9500-10,200 g mol-1, a glass transition temperature of 140-160 °C, and a calorific value of 25 MJ kg-1. Phosphoric acid lignin (PAL) was slightly more polar than sulfuric acid lignin (SAL). PAL had 13 % more oxidized units and 20 % more OH groups than SAL. Regardless of the acid used, the lignins shared similar properties, but differed slightly in the characteristics of their functional groups and chemical bonds. These findings show that pretreatment catalyzed with either of the two acids resulted in lignin with sufficiently good characteristics for use in industrial processes.

Flavonoids and phenolic acids from sugarcane: Distribution in the plant, changes during processing, and potential benefits to industry and health.

Sugarcane (Saccharum sp.) plants are grown in warmer climates throughout the world and processed to produce sugar as well as other useful byproducts such as molasses and bagasse. Sugarcane is rich in (poly)phenols, but there has been no attempt to critically evaluate the published information based on the use of suitable methodologies. The objective of this review is to evaluate the quantitative and qualitative (poly)phenolic profiles of individual parts of the sugarcane plant and its multiple industrial products, which will help develop new processes and uses for sugarcane (poly)phenols. The quantitative analysis involves the examination of extraction, concentration, and analytical techniques used in each study for each plant part and product. The qualitative analysis indicates the identification of various (poly)phenols throughout the sugarcane processing chain, using only compounds elucidated through robust analytical methodologies such as mass spectrometry or nuclear magnetic resonance. In conclusion, sugarcane (poly)phenols are predominantly flavonoids and phenolic acids. The main flavonoids, derivatives of apigenin, luteolin, and tricin, with a substantial proportion of C-glycosides, are consistently found across all phases of sugarcane processing. The principal phenolic acids reported throughout the process include chlorogenic acids, as well as ferulic and caffeic acids mostly observed after hydrolysis. The derivation of precise quantitative information across publications is impeded by inconsistencies in analytical methodologies. The presence of multiple (poly)phenols with potential benefits for industrial applications and for health suggests sugarcane could be a useful provider of valuable compounds for future use in research and industrial processes.

Valorization of sugarcane bagasse with in situ grown MoS2 for continuous pollutant remediation and microbial decontamination.

In this study, sugarcane bagasse (SB) was strategically subjected to a delignification process followed by the in situ growth of multi-layered molybdenum disulfide (MoS2) nanosheets with hexagonal phase (2H-phase) crystal structure via hydrothermal treatment. The MoS2 nanosheets underwent self-assembly to form nanoflower-like structures in the aligned cellulose inter-channels of delignified sugarcane bagasse (DSB), the mechanism of which was understood through FTIR and XPS spectroscopic studies. DSB, due to its porous morphology and abundant hydroxyl groups, shows remediation capabilities of methylene blue (MB) dye through physio-sorption but shows a low adsorption capacity of 80.21 mg/g. To improve the removal capacity, DSB after in situ growth of MoS2 (DSB-MoS2) shows enhanced dye degradation to 114.3 mg/g (in the dark) which further improved to 158.74 mg/g during photodegradation, due to catalytically active MoS2. Interestingly, DSB-MoS2 was capable of continuous dye degradation with recyclability for three cycles, reaching an efficiency of > 83%, along with a strong antibacterial response against Gram-positive Staphylococcus aureus (S.aureus) and Gram-negative Escherichia coli (E. coli). The present study introduces a unique strategy for the up-conversion of agricultural biomass into value-added bio-adsorbents, which can effectively and economically address the remediation of dyes with simultaneous microbial decontamination from polluted wastewater streams.

Structural characterization of lignin from the green pretreatments for co-producing xylo-oligosaccharides and glucose: Toward full biomass utilization.

Three green non-enzymatic catalysis pretreatments (NECPs) including autohydrolysis, subcritical CO2-assisted seawater autohydrolysis, and inorganic salt catalysis were utilized to simultaneously produce xylo-oligosaccharides (XOS), glucose, and cellulolytic enzyme lignin (CEL) from sugarcane bagasse (SCB). The yield of XOS in all three NECPs was over 50 % with a competitive glucose yield of enzymatic hydrolysis. And the effects of different pretreatments on the chemical structure and composition of CEL samples were also investigated. The pretreatments significantly increased the thermal stability, yield, and purity of the CEL samples. Moreover, the net yield of lignin was 58.3 % with lignin purity was 98.9 % in the autohydrolysis system. Furthermore, there was a decrease in the molecular weight of CEL samples as the pretreatment intensity increased. And the original lignin structural units sustained less damage during the NECPs, due to the cleavage of the ß-O-4 bonds dominating lignin degradation. Meanwhile, these pretreatments increased the phenolic-OH in CEL samples, making the lignin more reactive, and enhancing its subsequent modification and utilization. Collectively, the described techniques have demonstrated practical significance for the coproduction of XOS and glucose, and lignin, providing a promising strategy for full utilization of biomass.

Understanding microbiome dynamics and functional responses during acidogenic fermentation of sucrose and sugarcane vinasse through metatranscriptomic analysis.

Improving anaerobic digestion of sugarcane vinasse - a high-strength wastewater from ethanol distillation - is a subject of great interest, in view of the reduction of the pollutants and recovery of methane and valuable metabolites as byproducts. Through metatranscriptomic analysis, this study evaluated the active microbiome and metabolic pathways in a continuous acidogenic reactor: Stage 1S (control): 100% sucrose-based substrate (SBS); Stage 2SV (acclimation): 50% SBS and 50% vinasse; Stage 3V: 100% vinasse. Metatranscriptome obtained from each Stage was subjected to taxonomic and functional annotations. Under SBS feeding, pH dropped to pH 2.7 and biohydrogen production was observed. As vinasse was added, pH increased to 4.1-4.5, resulting in community structure and metabolite changes. In Stage 3V, biohydrogen production ceased, and propionate and acetate prevailed among the volatile fatty acids. Release of homoacetogenesis enzymes by Clostridium ljungdahlii and of uptake hydrogenase (EC 1.12.99.6) by Pectinatus frisingensis were linked to hydrogen consumption in Stages 2SV and 3V. Metabolic pathways of vinasse compounds, such as carbohydrates, malate, oxalate, glycerol, sulfate and phenol, were investigated in detail. In pyruvate metabolism, gene transcripts of oadA (oxaloacetate decarboxylase) and mdh (malate dehydrogenase), were upregulated in Stage 3V, being mostly attributed to P. frisingensis. Acetate formation from vinasse degradation was mainly attributed to Megasphaera and Clostridium, and propionate formation to P. frisingensis. Glycerol removal from vinasse exceeded 99%, and gene transcripts encoding for glpF (glycerol uptake facilitator protein), glpK (glycerol kinase) and glpABC (glycerol-3-phosphate dehydrogenase) were expressed mostly by Pectinatus and Prevotella. mRNA profiling showed that active bacteria and gene expression greatly changed when vinasse replaced sucrose, and Pectinatus was the main active bacterium degrading the searched compounds from vinasse. The identification of the main metabolic routes and the associated microorganisms achieved in this work contributes with valuable information to support further optimization of fermentation towards the desired metabolites.

Sugarcane vinasse provokes acute and chronic responses and bioaccumulation of metals in benthic macroinvertebrates.

Brazil is a major producer of sugarcane bioethanol, which has raised concerns about its environmental impact. The industrial process for obtaining ethanol generates a by-product with a high pollution potential called vinasse. If vinasse reaches watercourses, it may affect the biological communities, such as the aquatic macroinvertebrates, which include species sensitive to environmental contamination. Thus, this study evaluated the ecotoxicological effects of sugarcane vinasse on tropical benthic macroinvertebrates (Allonais inaequalis, Chironomus sancticaroli, Strandesia trispinosa, and Hyalella meinerti). The study was divided into three phases. First, acute toxicity tests were carried out with the four species. The species A. inaequalis (average LC50 = 0.460% confidence interval, CI 0.380-0.540%) was more sensitive to vinasse than C. sancticaroli (LC50 0.721%, CI 0.565-0.878%), H. meinerti (EC50 0.781%, CI 0.637-0.925%), and S. trispinosa (EC50 1.283%, CI 1.045-1.522%). In the second phase, the consequences of chronic exposure to vinasse were assessed in the two more sensitive species. Impairments in reproduction and population growth rates for A. inaequalis and on the development, metamorphosis, and body growth of C. sancticaroli larvae occurred. Finally, the bioaccumulation of metals after chronic exposure was determined in the third phase. Vinasse provoked decreases in the body residue of the essential metals Zn and Mn and the accumulation of Cd, Pb, and Cr with the potential for biomagnification throughout the food webs. Low concentrations of vinasse (below 1%) provoked lethal and sublethal effects on benthic organisms, with several cascade effects on aquatic environments, given the ecological importance of this group in freshwater and terrestrial ecosystems.