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Microbial bioremediation has emerged promisingly to improve crop tolerance to cadmium (Cd). Moreover, Cd tolerance and phosphate acquisition in plants positively correlated under P solubilizing bacteria inoculation, yet there is no evidence on specific mechanisms influencing Cd tolerance and plant P acquisition. The present study evaluates Cd tolerance in rock P-amended durum wheat in response to inoculation with P solubilizing bacteria (PSB) [three individual isolates Bacillus siamensis, Rahnella aceris, Bacillus cereus and their consortium (PSB Cs )] and consequently reveals key rhizosphere mechanisms involved in both Cd tolerance and P use efficiency. Results show that inoculation overall improved plant growth, rhizosphere parameters and nutrient uptake (P, N, K) under increasing Cd concentrations [8 (Cd 8 ) and 16 (Cd 16 ) ppm Cd 2+ ]. Under Cd 16 , Rahnella aceris induced the most significant plant responses in terms of biomass [shoots (31 %), roots (40 %), and spikes (92 %)], rhizosphere available P (234 %) and root inorganic P (109 %) compared to uninoculated plant. Microbial biomass P (MBP) and root acid phosphatases (APase) were 33-and 13-times higher, respectively, than in uninoculated plants. In addition, inoculation (particularly using PSB Cs ) significantly decreased Cd translocation factor (TF) (Cd 8 : -17 % and Cd 16 : -22 %) and Cd bioaccumulation factor (BAF) (Cd 8 : -6 % and Cd 16 : -40 %) concomitantly to enhanced root morphological traits and P contents in shoots and spikes. Furthermore, PSB inoculation under Cd constraint increased (rhizosphere available P / MBP) and (Root APase / Rhizosphere Apase) ratios that significantly (p < 0.05) correlate with plant P uptake in shoots and spikes. Increase in both ratios was concomitant to a significant decrease in TF and BAF of Cd exemplified by negatively significant correlations (r 2 =0.70 and r 2 =0.57, p < 0.05). This finding elucidates the key role of bacterial inoculation that presumably triggered Cd tolerance and aboveground P owing to increased (rhizosphere available P / MBP) and (Root / Rhizosphere APase) ratios in PSB-inoculated wheat., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Hydrothermal pretreatment of five lignocellulosic substrates (i.e. wheat straw, rice straw, biomass sorghum, corn stover and Douglas fir bark) were conducted in the presence of CO 2 as a catalyst. To maximize disintegration and conversion into bioenergy (methane and hydrogen), pretreatment temperatures and subsequent pressures varied with a range of 26-175 °C, and 25-102 bars, respectively. Among lignin, cellulose and hemicelluloses, hydrothermal pretreatment caused the highest reduction (23-42%) in hemicelluloses while delignification was limited to only 0-12%. These reductions in structural integrity resulted in 20-30% faster hydrolysis rates during anaerobic digestion for the pretreated substrates of straws, sorghum, and corn stover while Douglas fir bark yielded 172% faster hydrolysis/digestion due to its highly refractory nature in the control. Furans and phenolic compounds formed in the pretreated hydrolyzates were below the inhibitory levels for methane and hydrogen production which had a range of 98-340 ml CH 4 /g volatile solids (VS) and 5-26 ml H 2 /g VS, respectively. Results indicated that hydrothermal pretreatment is able to accelerate the rate of biodegradation without generating high levels of inhibitory compounds while showing no discernible effect on ultimate biodegradation., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

License to mill: Proteins were continuously extracted from polysaccharides, lignin, and polyphenol by combining ultrafine milling with electrostatic separation. Such a fractionation process does not involve any solvent, catalyst, or external source of heating. In addition, this dry process is compatible with downstream enzymatic reactions, thus opening an attractive route for producing valuable chemicals from biomass., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Agricultural biogas plants are increasingly being used in Europe as an alternative source of energy. To optimize the sizing and operation of existing or future biogas plants, a better knowledge of different feedstocks is needed. Our aim is to characterize 132 common agricultural feedstocks in terms of their chemical composition (proteins, fibers, elemental analysis, etc.) and biochemical methane potential shared in five families: agro-industrial products, silage and energy crops, lignocellulosic biomass, manure, and slurries. Among the families investigated, manures and slurries exhibited the highest ash and protein contents (10.3–13.7% DM). High variabilities in C/N were observed among the various families (19.5% DM for slurries and 131.7% DM for lignocellulosic biomass). Methane potentials have been reported to range from 63 Nm3 CH4/t VS (green waste) to 551 Nm3 CH4/t VS (duck slurry), with a mean value of 284 Nm3 CH4/t VS. In terms of biodegradability, lower values of 52% and 57% were reported for lignocelluloses biomasses and manures, respectively, due to their high fiber content, especially lignin. By contrast, animal slurries, silage, and energy crops exhibited a higher biodegradability of 70%. This database will be useful for project owners during the pre-study phases and during the operation of future agricultural biogas plants. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the effect of extrusion at high solid loading on corn stover (CS) properties and its enzymatic hydrolysis. This biomass was extruded under different screw speeds and different solid loadings and the impact of these parameters on the physicochemical properties was evaluated. It was found that lignocellulosic components were not significantly affected by the pretreatment, while the surface area increased with solid loading and rotation speed. Different enzyme cocktails were used for the enzymatic hydrolysis of extruded and untreated CS. Overall, mild twin‐extrusion enhanced the enzymatic hydrolysis of CS through an increase in glucose and xylose yields by 134–212% and 214–294%, respectively, when using Trichoderma longibrachiatum cellulase. The highest sugar content was obtained from CS extruded under 400 g total solids per liter and 200 rpm. The energy efficiency of the pretreatment was also assessed and was found to be maximal at 400 g total solids per liter and 200 rpm. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The lignocellulosic material contained in agricultural residues like straws, represents a resource with many points of biomolecular interest but their extraction is subject to a succession of treatments highly energy-consuming and generating effluents. Due to the strength of the supramolecular structure of the lignocellulosic matrix at various levels, it is difficult to improve the efficiency of separation processes for these materials. The utilization of biomass constituents often requires pretreatment, which is a crucial step in the separation into constituents. The rice straw must firstly be fractionated by grinding, which can also require pretreatment to improve efficiency. The question arises as to how best to identify and model the mechanisms involved in the grinding process with or without pretreatment. The aim of this study was to complete the characterization of the grinding process using a hydro-textural approach applied to biopowders to help with identification of the mechanisms involved. Experimental trials were conducted with rice straw through several milling steps, which led to decreasing particle sizes. The physical properties (density, cohesion, coefficient of friction, ability to flow) were characterized for some of the obtained powders, which were then described with a hydro-textural diagram. The results reveal that the breakdown process led to a “loss of porosity” regardless of the size of the powder particles. The fragmentation seemed to be located in the “zones of stronger porosities”. These structures containing residual water, decreased weakly with grinding. Assuming that the water was located within cells of the straw (intracellular water), given the power law, which correlates compactness to median diameter (d 50 ), we introduced a characteristic size, which corresponds to the physical limit of optimal grinding. Its value, calculated from the model, is nearly equal to the cell wall thickness: lim ϕ → 1 d 50 = e cell . ~ 2 μm . [ABSTRACT FROM AUTHOR]

We have investigated the effect of non-thermal atmospheric plasma (NTAP) on the structure of microcrystalline cellulose. In particular, by means of different characterization methods, we demonstrate that NTAP promotes the partial cleavage of the β-1,4 glycosidic bond of cellulose leading to the release of short-chain cellodextrins that are reassembled in situ, preferentially at the C6 position, to form branched glucans with either a glucosyl or anhydroglucosyl terminal residue. The ramification of cellulosic chain induced by NTAP yields branched glucans that are soluble in DMSO or in water, thus opening a straightforward access to processable glucans from cellulose. Importantly, the absence of solvent and catalyst considerably facilitates downstream processing as compared to (bio)catalytic processes which typically occur in diluted conditions. [ABSTRACT FROM AUTHOR]

Ball milling of cellulose in the presence of a catalytic amount of H2SO4 was found to be a promising pre-treatment process to produce butyl glycosides in high yields. Conversely to the case of water, n-butanol has only a slight effect on the recrystallization of ball-milled cellulose. As a result, thorough depolymerization of cellulose prior the glycosylation step is no longer required, which is a pivotal aspect with respect to energy consumption. This process was successfully transposed to wheat straw from which butyl glycosides and xylosides were produced in good yields. Butyl glycosides and xylosides are important chemicals as they can be used as hydrotropes but also as intermediates in the production of valuable amphiphilic alkyl glycosides. [ABSTRACT FROM AUTHOR]

Mechanical size reduction is considered as a primordial step of current and future lignocellulosic biorefinery. In this sense, it is of high interest to understand who are the biochemical and structural features of the lignocellulosic biomass, which affect the Specific Energy Requirement (SER), and in consequence the cost of mechanical size reduction processes. First, it was shown that the initial moisture content of the lignocellulosic biomass affect the SER and the final particle size distribution. The highest the moisture content gives raise the highest SER. Then, at fixed initial moisture content (≈7% DW), structural and biochemical features of lignocellulosic biomass that can affect the SER were determined. It was noticed that both arabinose/xylose ratio and accessible surface area lead to increasing the SER. On the contrary, the content of cellulose, lignin, crystallinity and p -coumaric acids links were found to have a positive effect on the reduction of the SER. [ABSTRACT FROM AUTHOR]

Intermediate pyrolysis of red algal biomass was performed in a fixed-bed tubular reactor. To study the parametric effect on product distribution, the experiments were carried out at different temperatures ranging from 400 to 600 °C and different heating rates of 15, 30 and 50 °C/min. The objective of this study is to understand the effect of pyrolysis temperature and heating rate on the yields and compositions of the pyrolysis products of red algal biomass. The bio-oil, biochar and biogas yields ranged between 33 and 45 wt%, 29 and 42 wt%, and 18 and 35 wt%, respectively, at different pyrolysis conditions. The highest bio-oil yield (45.02%) was obtained at 450 °C temperature at a heating rate of 50 °C/min. The bio-oil was characterized by proximate and ultimate analysis, FTIR, 1HNMR and GC–MS analysis whereas the biochar was characterized by proximate, ultimate, FTIR, SEM and BET. Higher heating value and density of the bio-oil were 20.11 MJ/kg, 1289 kg/m3, respectively. The bio-oil with relatively high fuel potential can be obtained from the pyrolysis of the red algal biomass. The characterization of bio-oil showed a high percentage of aliphatic functional groups and presence of phenolic, ketone- and nitrogen-containing groups. The characterization results showed that the bio-oil obtained from red algal biomass can be potentially valuable as a source of value-added chemicals. The biochar obtained with a high heating value of 22.89 MJ/kg can be used as an adsorbent as well as a solid fuel. [ABSTRACT FROM AUTHOR]

Because of their rich composition in carbohydrates, lignocellulosic residues represent an interesting source of biomass to produce biohydrogen by dark fermentation. Nevertheless, pretreatments should be applied to enhance the solubilization of holocelluloses and increase their further conversion into biohydrogen. The aim of this study was to investigate the effect of thermo-alkaline pretreatment alone and combined with enzymatic hydrolysis to enhance biohydrogen production from sunflower stalks. A low increase of hydrogen potentials from 2.3 ± 0.9 to 4.4 ± 2.6 and 20.6 ± 5.6 mL of H2 g–1 of volatile solids (VS) was observed with raw sunflower stalks and after thermo-alkaline pretreatment at 55 °C, 24 h, and 4% NaOH and 170 °C, 1 h, and 4% NaOH, respectively. Enzymatic pretreatment alone showed an enhancement of the biohydrogen yields to 30.4 mL of H2 g–1 of initial VS, whereas it led to 49 and 59.5 mL of H2 g–1 of initial VS when combined with alkaline pretreatment at 55 and 170 °C, respectively. Interestingly, a diauxic effect was observed with sequential consumption of sugars by the mixed cultures during dark fermentation. Glucose was first consumed, and once glucose was completely exhausted, xylose was used by the microorganisms, mainly related to Clostridium species. [ABSTRACT FROM AUTHOR]

Abstract: Dark fermentation using mixed cultures is an attractive biological process for producing hydrogen (H2) from lignocellulosic biomass at a low cost. Physicochemical pretreatment is generally used to convert lignocellulosic materials into monosaccharides. However, the processes also involved release degradation byproducts which can, in turn, inhibit microbial growth and metabolism and, hence, impact substrate conversion. In this study, the impact on H2 production of lignocellulose-derived compounds (i.e. furan derivatives, phenolic compounds and lignins) was assessed along with their effect on bacterial communities and metabolisms. Batch tests were carried out using xylose as model substrate (1.67molH2 molxylose −1 in the control test). All the putative inhibitory compounds showed a significant negative impact on H2 production performance (ranging from 0.34 to 1.39molH2 molxylose −1). The H2 yields were impacted more strongly by furan derivatives (0.40–0.51molH2 molxylose −1) than by phenolic compounds (1.28–1.39molH2 molxylose −1). Except for the batch tests supplemented with lignins, the lag phase was shorter for inhibitors having the highest molecular weight (8 days versus 22 days for the lowest MW). Variability of the lag phase was clearly related to a shift in bacterial community structure, as shown by multivariate ordination statistics. The decrease in H2 yield was associated with a decrease in the relative abundance of several H2-producing clostridial species. Interestingly, Clostridium beijerinkii was found to be more resistant to the inhibitors, making this bacterium an ideal candidate for H2 production from hydrolyzates of lignocellulosic biomass. [Copyright &y& Elsevier]

Lignin (L) is the most abundant three-dimensional polymer with versatile yet attractive structural features and chemical properties for applicability as a coating. The properties of lignin are mainly related to its botanical origin, structure and extraction method. Although there has been a lot of interest in using lignin in fertilizing systems, only limited attempts have been dedicated to studying the effect of the lignin structure and origin on the release of P fertilizer. Thus, the aim of this work was to study the effect of lignin polymers, extracted from different plant biomass, as coating materials for P fertilizers. Thus, the effect of the structural features originating from the botanical origin on the properties of coated fertilizers and their slow release were established. To this end, three lignocellulosic biomass, namely olive pomace (OP), barley straw (BS) and wood shavings (WS) were used as feedstock to extract lignin polymers. Those chemical compositions and thermochemical properties were characterized prior to their application as coating for triple super phosphate (TSP) fertilizer. Coated fertilizers were characterized for their morphology and coating thickness prior to their evaluation as slow release P-based fertilizer. A distinct slow P release behavior was reported for lignin-coated fertilizers with TSP@L-OP being the slowest as compared to TSP@L-WS, TSP@L-BS as well as pristine TSP, which confirm that the botanical origin and most likely the chemical structures of lignin has significant impact on the properties of the coating materiel. A 100 % release of P from the uncoated TSP was observed after 3 days, while the released amount ranged from only 16.9 % for TSP@L-OP up to 33.4 % for TSP@L-BS. The impact of these coated fertilizers on nutrients uptake and wheat growth was also scrutinized and an noticeable improvement of wheat shoot biomass was observed with the coated TSP treatments reaching up 57.8 % for TSP@BS, 78.1 % for TSP @WS and 93.7 % for TSP @OP, compared to uncoated TSP. This was concomitant to a slight increase of P concentration in shoots, roots and rhizosphere soil, which confirmed the positive effect of slow release P fertilizers on plant growth. • Slow P release behavior was reported for lignin-coated fertilizers. • Botanic origin of the extracted lignin used as fertilizer coating impacted the P release behavior. • Improvement of wheat shoot biomass was observed with the coated fertilizers. • Addition of lignin-coated fertilizers led to an increase in soil-available P. [ABSTRACT FROM AUTHOR]

The main objective of this work was to study the possibility of using polysaccharides and lignin as a coating material for water-soluble triple superphosphate (TSP) granular fertilizers. In this study, composites based on three polysaccharides (sodium alginate (alginic acid sodium salt): AL, kappa-carrageenan: CR and carboxymethyl cellulose sodium salt: CM) and lignin (LG) were prepared. The lignin used was extracted from olive pomace (OP) biomass using the alkali method. The morphological, mechanical, and surface properties as well as the thermal behavior of the coatings were characterized and compared. Their morphology and thickness revealed by scanning electron microscopy (SEM) showed good adhesion between the fertilizer and coating materials. The results showed that the lignin-carrageenan formulation (LGCR) exhibited the highest water absorbency and elastic modulus. Release tests showed the effect of the TSP/biopolymer mass ratio and that the slowest P release was obtained with the LGCR@TSP formulation composite within 3 day. In addition, 59.5% and 72.5% of P was released after 3 days with the TSP/biopolymer mass ratios of 5/1 and 15/1, respectively, compared to 100% P release with the uncoated TSP. Unlabelled Image [ABSTRACT FROM AUTHOR]

The effect of ultrasonic, alkali and acid pretreatments and their combination on saccharification was investigated, and the impact of the liquid fractions, obtained after the enzymatic hydrolysis of pretreated biomasses, on seed germination was evaluated. Mechanical deconstruction of biomass coupled to chemical and/or physical pretreatments was found to enhance the cellulose to glucose conversion yields for both barley and bean straws. The highest conversion yield of 86% was obtained by ultrasonication coupled to alkaline pretreatment of bean straw, corresponding to 171 mg of glucose/g TS. The maximum conversion yield (48 %) for barley straw was obtained with NaOH pretreatment accounting for approximately 140 mg/gTS. The highest energy efficiency was obtained with NaOH pretreatment (1.7 kg glucose /kWh and 1.9 kg glucose /kWh for barley and bean straws respectively). Therefore, NaOH pretreatment appears the most suitable for an efficient release of glucose from the studied biomasses. As for the effect of the liquid fractions of hydrolysis on seed germination, the diluted effluents (3 %) were found to enhance tomato seeds germination, especially in the case of barley straw, by 17–50 %. This work suggests the valorization of liquid fractions and their reuse for agriculture, which is an option to be considered especially in the context of scarce water resources. Finally, the selected pretreatments based on energy efficiency and environmental impact will be developed at pilot and industrial scale for objective to develop a local and regional bioeconomy. [Display omitted] • Alkaline and Alkaline combined with US had the highest impact on enzymatic hydrolysis. • Ball milling has further improved the yields of sugars achieved after pretreatments. • Alkaline pretreatment was the most energy efficient for biomass saccharification. • Effluents from pretreatments had no negative effect on tomato seeds germination. [ABSTRACT FROM AUTHOR]