Chemical and Energetic Characterization of the Wood of Prosopis laevigata: Chemical and Thermogravimetric Methods.

Diverse methodologies exist to determine the chemical composition, proximate analysis, and calorific value of biomass. Researchers select and apply a specific methodology according to the lignocellulosic material they study and the budgetary resources available. In this project, we determined the primary chemical constitution and proximate analysis of Prosopis laevigata (Humb. & Bonpl.) Jonhst wood using a traditional chemical method and a novel procedure based on the deconvolution of the DTG signal produced by TGA. The highest calorific value was verified using a calorimetric pump based on mathematical models. We also conducted elemental analysis and a microanalysis of ash, and applied Fourier transform infrared spectroscopic analysis (FT-IR). The means of the results obtained by the chemical method and TGA-DTG, respectively, were: hemicelluloses 7.36%-(8.72%), cellulose 48.28%-(46.08%), lignin 30.57%-(32.44%), extractables 13.53%-(12.72%), moisture 2.03%-(4.96%), ash 1.77%-(1.90%), volatile matter 75.16%-(74.14%), and fixed carbon 23.05%-(18.93%). The procedure with the calorimetric pump generated a calorific value above 20.16 MJ/kg. The range generated by the various models was 18.23-21.07 MJ/kg. The results of the elemental analysis were: carbon 46.4%, hydrogen 6.79%, oxygen 46.43%, nitrogen 0.3%, and sulfur 0.5%. The microanalysis of ash identified 18 elements. The most abundant ones were potassium ˃ calcium ˃ sodium. Based on the infrared spectrum (FT-IR) of Prosopis laevigata wood, we detected the following functional groups: OH, C-H, C=O, CH2, CH3, C-O-C, C-OH, and C4-OH. Our conclusion is that the TGA-DTG method made it possible to obtain results in less time with no need for the numerous reagents that chemical procedures require. The calorific value of P. laevigata wood is higher than the standards. Finally, according to our results, proximate analysis provides the best model for calculating calorific value.

Classification of Amazonian fast-growing tree species and wood chemical determination by FTIR and multivariate analysis (PLS-DA, PLS).

Fast-growing trees like Capirona, Bolaina, and Pashaco have the potential to reduce forest degradation because of their ecological features, the economic importance in the Amazon Forest, and an industry based on wood-polymer composites. Therefore, a practical method to discriminate specie (to avoid illegal logging) and determine chemical composition (tree breeding programs) is needed. This study aimed to validate a model for the classification of wood species and a universal model for the rapid determination of cellulose, hemicellulose, and lignin using FTIR spectroscopy coupled with chemometrics. Our results showed that PLS-DA models for the classification of wood species (0.84 ≤ R2 ≤ 0.91, 0.12 ≤ RMSEP ≤ 0.20, accuracy, specificity, and sensibility between 95.2 and 100%) were satisfied with the full spectra and the differentiation among these species based on IR peaks related to cellulose, lignin, and hemicellulose. Besides, the full spectra helped build a three-species universal PLS model to quantify the principal wood chemical components. Lignin (RPD = 2.27, [Formula: see text] = 0.84) and hemicellulose (RPD = 2.46, [Formula: see text] = 0.83) models showed a good prediction, while cellulose model (RPD = 3.43, [Formula: see text] = 0.91) classified as efficient. This study showed that FTIR-ATR, together with chemometrics, is a reliable method to discriminate wood species and to determine the wood chemical composition in juvenile trees of Pashaco, Capirona, and Bolaina.

Evaluation of the efficiency of a Venturi scrubber in particulate matter collection smaller than 2.5 µm emitted by biomass burning.

Energy demand has increased worldwide, and biomass burning is one of the solutions most used by industries, especially in countries that have a great potential in agriculture, such as Brazil. However, these energy sources generate pollutants, consisting of particulate matter (PM) with a complex chemical composition, such as sugarcane bagasse (SB) burning. Controlling these emissions is necessary; therefore, the aim was to evaluate PM collection using a rectangular Venturi scrubber (RVS), and its effects on the composition of the PM emitted. Considering the appropriate use of biomass as an industrial fuel and the emerging need for a technique capable of efficiently removing pollutants from biomass burning, this study shows the control of emissions as an innovation in a situation such as the industrial one with the use of a Venturi scrubber in fine particle collection, in addition to using portable and representative isokinetic sampling equipment of these particles. The pilot-scale simulation of the biomass burning process, the representative sampling of fine particles and obtaining parameters to control pollutant emissions for a Venturi scrubber, meets the current situation of concern about air quality. The average collection efficiency values were 96.6% for PM> 2.5, 85.5% for PM1.0-2.5, and 66.9% for PM< 1.0. The ionic analysis for PM< 1.0 filters showed potassium, chloride, nitrate, and nitrite at concentrations ranging from 20.12 to 36.5 µg/m3. As the ethanol and sugar plants will continue to generate electricity with sugarcane bagasse burning, emission control technologies and cost-effective and efficient portable samplers are needed to monitor particulate materials and improve current gas cleaning equipment projects.

Determination of total extractives and cellulose content of Ipe wood submitted to thermal modification process / Determinação dos extrativos totais e teor de celulose da madeira de Ipê submetida ao processo de modificação térmica

The demand for products from wood has been expanding, because of this, there is a need for studies related to the quality and application of these materials. Thus, the present research aimed to evaluate theextractive and cellulose content of Ipê wood submitted to the thermal modification process. To carry out the study, fourindividuals of Handroanthus chrysotrichus(Mart. ex DC.) Mattos, 11 years old, were slaughtered. Subsequently, samples measuring 2.5 x2.5 x 41 cm were prepared and placed in an oven with forced air circulation, at temperatures of 120, 150, 180 and 210 ºC, for a period of 4 h. Then, random portions of the specimens were sectioned and ground in a knife mill, and then, sieved in the 40/60 mesh fraction, to carry out the chemical tests of total extractives and cellulose content. The data were processed and submitted to the Tukey average test, using the R software. The results of the chemical properties studied indicated variations according to the temperatures, not showing a stabilization trend between the treatments applied. A relationship between the behavior of these properties and the other technological characteristics of the works available in the literature was observed. In general, further studies are recommendedon the chemical properties of wood of this species associatedwith the application of high temperatures.(AU)

A demanda de produtos oriundos da madeira vem se expandindo, por conta disso, há a necessidade de estudosrelacionados à qualidade e aplicação desses materiais. Com isso, a presente pesquisa teve como objetivo avaliaro teor de extrativos e de celulose da madeirade Ipê submetida ao processo de modificação térmica. Para realização do estudo foram abatidos quatroindivíduos de Handroanthuschrysotrichus (Mart. ex DC.) Mattos, com 11 anos de idade. Posteriormente, confeccionaram-se amostras de 2,5 x 2,5 x 41 cm, as quais foram acondicionadas em estufa com circulação de ar forçada, nas temperaturas de 120, 150, 180 e 210 ºC, por um período de 4 h. Em seguida, porções aleatórias dos corpos de prova foram seccionadas e trituradas em moinho de facas, e então, peneiradas nafração de 40/60 mesh, para arealização dos ensaios químicos de teor de extrativos totais e teor de celulose. Os dados foram processados e submetidos ao teste de médias de Tukey, utilizando o software R. Os resultados das propriedades químicas estudadas indicaramvariações de acordo com as temperaturas, não apresentando uma tendência de estabilização entre os tratamentos aplicados. Uma relação entre o comportamento dessas propriedades com as demais características tecnológicas dos trabalhos disponíveis na literatura foi observada. De modo geral, são recomendados mais estudos acerca das propriedades químicas da madeira dessa espécie associados a aplicação de altas temperaturas.(AU)

Production of kraft pulp from Ochroma pyramidale wood / Produção de celulose kraft a partir da madeira de Ochroma pyramidale

Brazil stands out in the international scenario in the production of short-fiber pulp. Despite the great Brazilian biodiversity, that production is based on exotic Eucalyptus clones. In this sense, there may be great potential in the assessment of new sources of fibers from the Brazilian flora, including the Amazon. The present study aimed to assess the technical potential of the wood of Ochroma pyramidale (Malvaceae) for the production of kraft pulp. Four-year-old trees were harvested from a commercial forest for lumber production in Mato Grosso state (Brazil). We determined the wood's chemical compositions (holocellulose, Klason lignin, soluble lignin, extractives and ash contents), physical properties (density and porosity), and fiber morphology (fiber length, width and thickness, lumen diameter, wall fraction, coefficient of flexibility, and slenderness and Runkel ratios). The wood was subjected to pulping with an effective alkali charge ranging from 10 to 24%, with intervals of 2%. Ochroma pyramidale wood presented characteristics favorable to the production of cellulosic pulp, such as appropriate fiber dimensions and low lignin, extractives, and ash content. The amount of residual active alkali and pH of the black liquor were positively related to the increase of the alkali charge employed in the pulping process. The increase of alkali charge decreased the pulp yield, kappa number and waste content, and increased the hexenuronic acid concentration.(AU)

O Brasil se destaca no cenário internacional em relação a produção de celulose de fibra curta. Apesar da grande biodiversidade brasileira, essa produção está baseada em clones de espécies exóticas de Eucalyptus. Nesse contexto, pode haver grande potencial na avaliação de novas fontes de fibras da flora brasileira, incluindo a região amazônica. O presente estudo teve como objetivo avaliar o potencial tecnológico da madeira de Ochroma pyramidale (Malvaceae) para produção de celulose kraft. Indivíduos de quatro anos de idade foram colhidos em um plantio comercial para produção de serrados no Estado do Mato Grosso. Determinamos as propriedades químicas (teores de holocelulose, lignina Klason, lignina solúvel, extrativos e cinzas), físicas (massa específica e porosidade) e morfologia de fibras (comprimento e largura de fibras, diâmetro do lume, espessura e fração de parede, coeficiente de flexibilidade, índice de enfeltramento e de Runkel) da madeira. Na polpação kraft a carga alcalina aplicada variou entre 10 e 24%, com intervalo de 2%. A madeira de Ochroma pyramidale apresentou características favoráveis à produção de polpa celulósica, como dimensões apropriadas das fibras e baixos teores de lignina, extrativos e cinzas. Os teores de álcali ativo residual e pH do licor negro apresentaram relação crescente com a carga alcalina aplicada nos processos de polpação. O acréscimo da carga alcalina reduziu o rendimento em polpação, número kappa, teor de rejeitos e aumentou o teor de ácidos hexenurônicos.(AU)

Determination of hemicellulose, cellulose, holocellulose and lignin content using FTIR in Calycophyllum spruceanum (Benth.) K. Schum. and Guazuma crinita Lam.

Capirona (Calycophyllum spruceanum (Benth.) K. Schum.) and Bolaina (Guazuma crinita Lam.) are fast-growing Amazonian trees with increasing demand in timber industry. Therefore, it is necessary to determine the content of cellulose, hemicellulose, holocellulose and lignin in juvenile trees to accelerate forest breeding programs. The aim of this study was to identify chemical differences between apical and basal stem of Capirona and Bolaina to develop models for estimating the chemical composition using Fourier transform infrared (FTIR) spectra. FTIR-ATR spectra were obtained from 150 samples for each species that were 1.8 year-old. The results showed significant differences between the apical and basal stem for each species in terms of cellulose, hemicellulose, holocellulose and lignin content. This variability was useful to build partial least squares (PLS) models from the FTIR spectra and they were evaluated by root mean squared error of predictions (RMSEP) and ratio of performance to deviation (RPD). Lignin content was efficiently predicted in Capirona (RMSEP = 0.48, RPD > 2) and Bolaina (RMSEP = 0.81, RPD > 2). In Capirona, the predictive power of cellulose, hemicellulose and holocellulose models (0.68 < RMSEP < 2.06, 1.60 < RPD < 1.96) were high enough to predict wood chemical composition. In Bolaina, model for cellulose attained an excellent predictive power (RMSEP = 1.82, RPD = 6.14) while models for hemicellulose and holocellulose attained a good predictive power (RPD > 2.0). This study showed that FTIR-ATR together with PLS is a reliable method to determine the wood chemical composition in juvenile trees of Capirona and Bolaina.

Agave: a natural renewable resource with multiple applications.

Agaves are a group of succulent plants that thrive in arid or semiarid environments. Indeed, genes associated with their resilience are a potential resource for genetic engineering of other agronomically important crops grown in adverse climates. Agave is mainly used for the production of distilled (spirits) and non-distilled alcoholic beverages, including tequila, mezcal, bacanora, raicilla, and pulque, all of which have special connections to Mexican history and culture, and contribute to the Mexican economy. In recent years, there has been growing interest to maximize the use of agave plant materials for other purposes, as the bulk of their biomass pre- and post-production is wasted. In traditional practice, during the passage from fields to factories, only agave cores are used, and the leaves and bagasse are not always harnessed. To place this in perspective, during the period from 2010 to 2019, 2674.7 × 106 L of tequila was produced in Mexico, which required 9 607 400 tons of agave cores. This generated approximately the same amount of leaves and 3 842 960 tons of bagasse. The economic base of agave plants can be expanded if expended biomass could be transformed into products that are useful for applications in food, forage, ensilage, agriculture, medicine, energy, environment, textiles, cosmetics, and esthetics. This review focuses on the current utility of agave plants, as well as our perspective for future studies and uses of this formidable plant. © 2020 Society of Chemical Industry.

IR characterization of plant leaves, endemic to semi-tropical regions, in two senescent states.

We are developing a robust and economic electro-optical remote sensing methodology to monitor the state of health and hydration of trees, endemic to subtropical regions. We measured reflectance spectra with Fourier transform infrared (FTIR) of three samples of two different oak trees. We find that spectral bands suitable for monitoring the state of the health and senescence of the oak include intervals around 0.9 µm and 1.8 µm. The easiest and the most cost-effective strategy would be to implement an electro-optical remote sensing radiometric system featuring a commercial camera incorporating a traditional charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) detectors and a wideband transmission filter, from about 0.8 to 1 µm.

Imaging and Analysis of the Content of Callose, Pectin, and Cellulose in the Cell Wall of Arabidopsis Pollen Tubes Grown In Vitro.

To achieve fertilization, pollen tubes have to protect and properly deliver sperm cells through the pistil to the ovules. Pollen tube growth is a representative example of polarized growth where new components of the cell wall and plasma membrane are continuously deposited at the tip of the growing cell. The integrity of the cell wall is of fundamental importance to maintain apical growth. For this reason, pollen tube growth has become an excellent model to study the role of polysaccharides and structural cell wall proteins involved in polar cell expansion. However, quantification of structural polysaccharides at the pollen tube cell wall has been challenging due to technical complexity and the difficulty of finding specific dyes. Here, we propose simple methods for imaging and quantification of callose, pectin , and cellulose using specific dyes such as Aniline Blue, Propidium Iodide, and Pontamine Fast Scarlet 4B.

Cell wall remodeling under salt stress: Insights into changes in polysaccharides, feruloylation, lignification, and phenolic metabolism in maize.

Although cell wall polymers play important roles in the tolerance of plants to abiotic stress, the effects of salinity on cell wall composition and metabolism in grasses remain largely unexplored. Here, we conducted an in-depth study of changes in cell wall composition and phenolic metabolism induced upon salinity in maize seedlings and plants. Cell wall characterization revealed that salt stress modulated the deposition of cellulose, matrix polysaccharides and lignin in seedling roots, plant roots and stems. The extraction and analysis of arabinoxylans by size-exclusion chromatography, 2D-NMR spectroscopy and carbohydrate gel electrophoresis showed a reduction of arabinoxylan content in salt-stressed roots. Saponification and mild acid hydrolysis revealed that salinity also reduced the feruloylation of arabinoxylans in roots of seedlings and plants. Determination of lignin content and composition by nitrobenzene oxidation and 2D-NMR confirmed the increased incorporation of syringyl units in lignin of maize roots. Salt stress also induced the expression of genes and the activity of enzymes enrolled in phenylpropanoid biosynthesis. The UHPLC-MS-based metabolite profiling confirmed the modulation of phenolic profiling by salinity and the accumulation of ferulate and its derivatives 3- and 4-O-feruloyl quinate. In conclusion, we present a model for explaining cell wall remodeling in response to salinity.

An approach to assess and identify polymers in the health-care waste of a Brazilian university hospital.

This work presents the health-care waste (HCW) management and an approach to assess and identify polymers in a General Surgery Unit - Internment Service (GSU) of a Brazilian university hospital, to estimate the main polymers presenting in medical devices that are consumed during a year, discarded either as infecting (Group A) or as scarifying residue (Group E). Among the waste produced from the medical devices, 3.14 ton (98.79%) were composed of polymers (63.06% of plastics and 35.73% elastomers) while around 0.03 ton (1.21%) by metals. The proposed approach is composed of 4 steps: (1) Collecting data about consumed medical devices to be categorized into the residues Groups (A and E); (2) Identifying the polymeric composition with information provided by suppliers; (3) Characterizing the polymer functional groups by Fourier-Transform Infrared Spectroscopy (FTIR) and (4) Determining the polymer melting point by Differential Scanning Calorimetry (DSC). According to the results, the analyzed HCW was composed mainly of polypropylene (80.88%), high-density polyethylene (5.28%), polystyrene (4.51%), and cellulose (3.58%), from a total of 11 different polymers.

Detoxification of sugarcane bagasse hydrolysate with different adsorbents to improve the fermentative process.

Second generation ethanol has the prospect of becoming an important bioenergy alternative. The development of this technology is associated with the lignocellulosic materials' use, with emphasis on agricultural and agroindustrial by-products from which fermentable sugar can be produced. The acid hydrolysis depolymerizes the hemicellulose releasing mainly xylose. Subsequently, the cellulose can be converted into glucose by enzymatic hydrolysis. However, the acid hydrolysis produces toxic compounds, such as furan derivatives, phenolics, and organic acids, which are harmful to fermentative microorganisms. This study investigated different acid concentrations in the sulfuric acid hydrolysis of sugarcane bagasse (1- 5% m/v) and the use of adsorbents with the prerogative to improve the acid hydrolysate (AH) quality for microbial ethanolic fermentation. Cell growth and fermentative yield of Saccharomyces cerevisiae (PE-2) and Scheffersomyces stipitis (NRRL Y-7124) were evaluated. AH was used as a source of pentoses (17.7 g L-1) and molasses (ME) sugarcane as source of hexoses (47 g L-1). The following adsorbents were used: activated charcoal, clay, hydrotalcite and active and inactive cells of PE-2 and NRRL Y-7124, at concentrations ranging (1 - 8% m/v). Results of cell growth and chemical characterization allowed to select the most effective adsorbents with emphasis for active cells that removed 66% furfural and 51% 5-(hydroxymethyl) furfural) (5-HMF) and alcoholic productivity of 23.5 g L-1 in AH and ME substrates, in the presence of mixed culture. These results indicate the application of active yeast cells in the detoxification of acid hydrolysates of the sugarcane bagasse previously to the fermentation.

Coaxial Spinning of All-Cellulose Systems for Enhanced Toughness: Filaments of Oxidized Nanofibrils Sheathed in Cellulose II Regenerated from a Protic Ionic Liquid.

Hydrogels of TEMPO-oxidized nanocellulose were stabilized for dry-jet wet spinning using a shell of cellulose dissolved in 1,5-diazabicyclo[4.3.0]non-5-enium propionate ([DBNH][CO2Et]), a protic ionic liquid (PIL). Coagulation in an acidic water bath resulted in continuous core-shell filaments (CSFs) that were tough and flexible with an average dry (and wet) toughness of ∼11 (2) MJ·m-3 and elongation of ∼9 (14) %. The CSF morphology, chemical composition, thermal stability, crystallinity, and bacterial activity were assessed using scanning electron microscopy with energy-dispersive X-ray spectroscopy, liquid-state nuclear magnetic resonance, Fourier transform infrared spectroscopy, thermogravimetric analysis, pyrolysis gas chromatography-mass spectrometry, wide-angle X-ray scattering, and bacterial cell culturing, respectively. The coaxial wet spinning yields PIL-free systems carrying on the surface the cellulose II polymorph, which not only enhances the toughness of the filaments but facilities their functionalization.

Energetic characterization and evaluation of briquettes produced from naturally colored cotton waste.

Cotton crops generate millions of tons of lignocellulosic waste in Brazil that could be used in energy generation; however, the main destination of this raw material is soil incorporation. The aim of this work was to perform an energetic characterization and evaluation of briquettes produced from different agricultural waste of naturally colored cotton for power generation. The cultivars Brasil Sementes (BRS) Jade and Topazio were studied, with white cotton (BRS 286) as standard for comparison purposes. Two different parts of each species, stalk and cotton shell, were analyzed by bulk density, proximate analysis, higher heating value, cellulose, hemicellulose, protein, fat and lignin content, thermogravimetric analysis, and briquette mechanical strength. The results of the energetic characterization indicated a higher energetic potential of the colored species when compared with the white cotton, especially because of the volatile matter content, fixed carbon, and higher heating value. The briquette mechanical strength was higher in the samples formulated by a mixture of stalk and shell. Finally, it was concluded that the waste from colored cotton cultivars, Jade and Topazio, is capable to generate briquettes with good mechanical and physico-chemical characteristics, especially those formed by the mixture of stalk and shell.

Influence of mechanical pretreatment to isolate cellulose nanocrystals by sulfuric acid hydrolysis.

The mechanical pretreatments intensities on characteristics of cellulose nanocrystals (CNC) prior to acid hydrolysis was evaluated. The cellulose was submitted to mechanical pretreatment as: magnetic stirring (CNCst), blending (CNCbl) or grinding by 20 (CNC20x) and 40 (CNC40x) passages in a super mass colloid mill. Then, all samples were submitted to H2SO4 hydrolysis and the CNC were evaluated by total mass yield (TMY%), rheological behavior, size distribution for width/length (WD), crystallinity index (CI%), OSO3- substitution degree (SD) and zeta potential (ζ). After hydrolysis samples exhibited the same SD (190 ±â€¯5 mMol·kg-1), ζ (-55 ±â€¯3 mV) and CI% (65 ±â€¯2), differing only in TMY% and WD. The CNCst showed TMY% of 85%, WD of 8 ±â€¯5 nm and 100-800 nm, with presence of cellulose nanofibers (CNF), suggesting incomplete hydrolysis. The CNCbl and CNC20x revealed TMY% of 65 ±â€¯1, but differed in WD of 8 ±â€¯5 nm and 300 ±â€¯200 nm and 8 ±â€¯5 nm and 200 ±â€¯170 nm, respectively. The results showed that the grinding mechanical pretreatment is mandatory for CNF isolation, but not for CNC. Stability profile after the hydrolytic procedure, CI%, morphology and similar character generated CNC with adequate features and good yield, by simple mechanical stirring or blending, reducing the production's cost and allowing industrial-scale production.

Biofilm Formation by Avian Pathogenic Escherichia coli is Not Related to In Vivo Pathogenicity.

Avian pathogenic Escherichia coli (APEC) is one of the pathogens that most concerns the poultry industry worldwide due to the economic losses it can cause. APEC persistence and survival, both in the environment and in the host, may be a consequence of biofilm-producing capabilities. The aim of this study was to evaluate APEC strains' biofilm production and its relationship to in vivo pathogenicity. Two hundred thirty-eight APEC isolates from three different origins (broiler bedding material, cellulite lesions, and respiratory diseases) were selected. The in vivo pathogenicity index (PI) was determined. Biofilm formation was evaluated using a microplate assay with analysis of colony morphology in Congo Red agar in order to detect the phenotypic expression of curli fimbriae and cellulose. Regarding biofilm production, it was observed that 55.8% of the strains produced biofilms. In the morphological test, 88.2% of the isolates expressed one or both components at one of the temperatures at least, and 11.8% of the isolates did not express curli or cellulose. Cellulose production was significantly higher at 25 °C. On the other hand, curli production was significantly higher at 37 °C. The study data indicate that there is no association between biofilm production and in vivo pathogenicity.

The Effects of Fillers and Binders on the Accuracy of Tablet Subdivision.

The effects of excipients on the accuracy of tablet subdivision are severely underinvestigated. In this study, placebo tablets were prepared using a combined mixture design of fillers and binders to evaluate the effect of these excipients on subdivision accuracy. The responses assessed were mass loss, mass variation, tablet fragmentation, and increased friability. Dicalcium phosphate dihydrate (DCP) gave rise to more uniform and denser tablets than microcrystalline cellulose (MCC), thus resulting in greater subdivision accuracy. The binder type, hydroxypropylcellulose (HPC) or polyvinylpyrrolidone (PVP), did not affect the subdivision of DCP tablets. On the contrary, the structural similarity between HPC and MCC led to improved subdivision accuracy for MCC tablets. A less accurate subdivision was observed in tablets prepared with a DCP-MCC combination; this finding could be attributed to irregular binder distribution in this matrix. An optimized response was built using desirability analysis. This study helps to illuminate the relationship between fillers and binders to guide formulation scientists in the development of tablets with better subdivision performance.

First evidence of microplastic ingestion by fishes from the Amazon River estuary.

This study investigated occurrence of microplastic particles in digestive tracts of fishes from the Amazon River estuary. A total of 189 fish specimens representing 46 species from 22 families was sampled from bycatch of the shrimp fishery. Microplastic particles removed from fish gastrointestinal tracts were identified using Attenuated Total Reflectance - Fourier Transform Infrared (ATR-FTIR). In total, 228 microplastic particles were removed from gastrointestinal tracts of 26 specimens representing 14 species (30% of those examined). Microplastic particles were categorized as pellets (97.4%), sheets (1.3%), fragments (0.4%) and threads (0.9%), with size ranging from 0.38 to 4.16 mm. There was a positive correlation between fish standard length and number of particles found in gastrointestinal tracts. The main polymers identified by ATR-FTIR were polyamide, rayon and polyethylene. These findings provide the first evidence of microplastic contamination of biota from the Amazon estuary and northern coast of Brazil.

Computational engineering of cellulase Cel9A-68 functional motions through mutations in its linker region.

Microbial cellulosic degradation by cellulases has become a complementary approach for biofuel production. However, its efficiency is hindered by the recalcitrance of cellulose fibres. In this context, computational protein design methods may offer an efficient way to obtain variants with improved enzymatic activity. Cel9A-68 is a cellulase from Thermobifida fusca that is still active at high temperatures. In a previous work, we described a collective bending motion, which governs the overall cellulase dynamics. This movement promotes the approximation of its CBM and CD structural domains (that are connected by a flexible linker). We have identified two residues (G460 and P461) located at the linker that act as a hinge point. Herein, we applied a new level of protein design, focusing on the modulation of this collective motion to obtain cellulase variants with enhanced functional dynamics. We probed whether specific linker mutations would affect Cel9A-68 dynamics through computational simulations. We assumed that P461G and G460+ (with an extra glycine) constructs would present enhanced interdomain motions, while the G460P mutant would be rigid. From our results, the P461G mutation resulted in a broader exploration of the conformational space, as confirmed by clustering and free energy analyses. The WT enzyme was the most rigid system. However, G460P and P460+ explored distinct conformational states described by opposite directions of low-frequency normal modes; they sampled preferentially closed and open conformations, respectively. Overall, we highlight two significant findings: (i) all mutants explored larger conformational spaces than the WT; (ii) the selection of distinct conformational populations was intimately associated with the mutation considered. Thus, the engineering of Cel9A-68 motions through linker mutations may constitute an efficient way to improve cellulase activity, facilitating the disruption of cellulose fibres.

Effect of spineless-cactus mucilage on the in vitro rumen fermentation of cellulose, starch, and protein / Efeito da mucilagem da palma forrageira sobre a fermentação ruminal in vitro da celulose, amido e proteína

The aim of this study was to evaluate the effect of the levels of spineless-cactus mucilage on the in vitro rumen fermentation of cellulose, starch, and protein. A completely randomized experimental design was adopted with a 5 × 3 factorial arrangement consisting of five levels of spineless-cactus mucilage (0, 5, 10, 20, and 40%) and three substrates (carboxymethylcellulose, starch, and trypticase). Treatments were evaluated in a ruminal environment simulated by in vitro incubation at different times of assessment: 0, 3, 6, 12, 24, and 48 h. The incubation procedure was repeated three times, totaling three evaluations per incubation time for each treatment. There was an interaction (P<0.05) between the mucilage levels and substrate for all evaluated ruminal parameters, except for the concentration of microbial protein after 48 h of fermentation and for the proportions of acetate and butyrate fermentation at time 0 h. There was a quadratic increase (P<0.05) in the concentration of ammoniacal nitrogen after 48 h of incubation in the media containing carboxymethylcellulose and trypticase. pH values decreased quadratically (P<0.05) as a function of the mucilage levels in the media containing carboxymethylcellulose and trypticase. Overall, no expressive alterations were observed between the individual molar proportions of acetate, propionate, and butyrate with the addition of spineless-cactus mucilage levels to the different substrates. Spineless- cactus mucilage affects the pattern of fermentation of starch, cellulase, and protein performed by rumen microorganisms.

Objetivou-se com esta pesquisa avaliar o efeito dos níveis de mucilagem de palma forrageira sobre a fermentação ruminal in vitro de celulose, amido e proteína. Utilizou-se um delineamento experimental inteiramente casualizado, disposto em um esquema fatorial 5 × 3, com 5 níveis de mucilagem de palma forrageira (0, 5, 10, 20 e 40%) e três substratos (carboxymetilcelulose, amido e trypticase). Os tratamentos foram avaliados em ambiente ruminal simulado por incubação in vitro em diferentes tempos de incubação: 0, 3, 6, 12, 24 e 48 horas. O procedimento de incubação foi repetido três vezes, perfazendo-se o total de três avaliações por tempo de incubação para cada tratamento. Houve interação (P<0,05) entre os níveis de mucilagem e substratos para todos os parâmetros ruminais avaliados, com exceção da concentração de proteína microbiana após 48 horas de fermentação e para as proporções de acetato e butirato às 0 hora de fermentação. Houve aumento quadrático (P<0,05) para a concentração de nitrogênio amoniacal após 48 horas de incubação nos meios, contendo carboxymetilcelulose e trypticase. Os valores de pH reduziram de forma quadrática (P<0,05) em função dos níveis de mucilagem nos meios contendo carboxymetilcelulose e trypticase. De maneira geral, não foram observadas alterações expressivas entre as proporções molares individuais de acetato, propionato e butirato com a adição dos níveis de mucilagem de palma forrageira aos diferentes substratos. A inclusão de níveis de mucilagem de palma forrageira afeta o padrão de fermentação do amido, celulose e proteína realizada por microrganismos ruminais.