Deconstructing sugarcane bagasse lignocellulose by acid-based deep eutectic solvents to enhance enzymatic digestibility

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGBiorefinery with deep eutectic solvent (DES) is an emerging processing technology to overcome the shortcomings of conventional biomass pretreatments. This work evaluates the biorefinery of sugarcane bagasse (SCB) with DES formulated with choline chloride as hydrogen bond acceptor and three hydrogen bond donors: lactic acid, citric acid, and acetic acid. Acetic acid showed unique ionic properties responsible for the selective removal of lignin and the deconstruction of cellulose to improve the digestibility of up to 97.61 % of glucan and 63.95 % of xylan during enzymatic hydrolysis. In addition, the structural characteristics of the polysaccharide-rich material (PRM) were analyzed by X-rays, ATR-FTIR, SEM, and enzymatic hydrolysis, and compared with the original material sample, for a comprehensive understanding of biomass deconstruction using different hydrogen bond donors (HBD) as DES pretreatment.Ministerio de Ciencia e Innovación | Ref. PID2020-115879RB-I00São Paulo​ Research Foundation | Ref. 2018/25511-1São Paulo​ Research Foundation | Ref. 2021/15138-4National Council for Scientific and Technological Development—CNPq | Ref. 312923/2020-1National Council for Scientific and Technological Development—CNPq | Ref. 408783/2021-4Xunta de Galicia | Ref. GPC-ED431B 2021/2

Enhancing the biorefinery of chestnut burrs. Part I. Study of the pretreatment with choline chloride urea diluted deep eutectic solvent

Chestnut burrs (CB) are agro-industrial wastes produced in large amounts during chestnut processing. Despite their high value composition, this type of biomass has been scarcely studied, becoming an important material to be valorized. In this work, a green technology based on the use of diluted choline chloride urea (ChCl:U) deep eutectic solvent (DES) was postulated to deconstruct the lignocellulosic structure. The pretreatment was evaluated using untreated CB and CB previously processed (washed CB or the solid residue obtained after prehydrolysis). Following a biorefinery concept, the samples obtained in this work will be further enzymatically hydrolyzed in Part II to reach fermentable sugars-containing solutions. Several operational parameters such as time (4, 8 and 16 h), temperature (60, 80, 100 and 120 °C), and liquid-solid ratio (LSR) (10:1, 15:1 and 20:1) were studied to improve CB deconstruction. Physicochemical transformations were investigated by ATR-FTIR and SEM analysis. The best delignification rate (∼40%) was achieved applying the DES pretreatment in untreated CB at 100 °C for 16 h and 20:1 (w/w) LSR, being corroborated by physicochemical changes observed by FTIR and SEM.AEs.Agencia Estatal de Investigación | Ref. PID2020-115879RB-I00Xunta de Galicia | Ref. ED431B 2021/23Universidade de Vigo/CISU

Producción de enzimas hidrolíticas a partir de Aspergillus niger en fermentación en estado sólido y su aplicación en residuos lignocelulósicos pretratados con disolventes eutecticos profundos para la obtención de azúcares fermentables

Los residuos agroindustriales se usan generalmente para hacer compostaje o se abandonan directamente en el campo, lo que produce la proliferación de contaminantes y emisiones tóxicas al medioambiente. Sin embargo, estos desechos están compuestos principalmente de celulosa, hemicelulosa y lignina, componentes químicos que pueden ser utilizados para la generación de un gran número de productos de alto valor agregado. Por lo que es necesario el desarrollo de procesos adecuados para transformar esta biomasa lignocelulósica en una fuente de riqueza, renovable, abundante y económica. De acuerdo con el concepto de biorrefinería, la biomasa lignocelulósica se puede fraccionar en sus tres compuestos principales con el uso de pretratamientos físicos, químicos y biológicos con el propósito de generar disoluciones de azúcares fermentables. Sin embargo, los altos costos de las enzimas y su disponibilidad continúan siendo el cuello de botella para implementar la hidrólisis enzimática de esta biomasa, por ello la industria demanda catalizadores más estables, activos y económicos. Debido a esto, se han llevado a cabo estudios para la producción de enzimas a partir de diferentes residuos, mecanismos de acción, regulación de la expresión en microorganismos y estrategias para hacer el proceso más viable económicamente. Entre los microorganismos que degradan este complejo lignocelulósico, debido a la producción de enzimas hidrolíticas, se encuentran los hongos filamentosos, conocidos como agentes de descomposición de la materia orgánica. Así mismo, ha sido estudiado el uso de pretratamientos químicos que faciliten la digestión de la lignocelulosa, requieran menos energía para llevar a cabo el proceso, generen menos residuos tóxicos secundarios, sean económicos, replicables y escalables. De todos estos trabajos destaca el reciente uso de disolventes eutécticos profundos (DEP) los cuales son capaces de formar mezclas eutécticas y poseen ventajas respecto a los procesos convencionales ya que son biodegradables y de bajo costo, lo cual los hace atractivos para la aplicación y escalado en las industrias para la obtención de una variedad de productos. Por tal motivo, en este trabajo se propone de una parte el estudio del mecanismo de producción de enzimas hidrolíticas a partir de una variedad de hongos del género Asperguillus; por otra parte la deslignificación de los mismos materiales lignocelulósicos con el uso de disolventes eutécticos profundos (DEP); y finalmente el empleo de las enzimas hidrólitas producidas sobre los materiales delignificados para el fraccionamiento de la celulosa y hemicelulosa residual a fin de obtener disoluciones de azúcares fermentables.Os residuos agroindustriais úsanse xeralmente para compostaxe ou son abandonados directamente no campo, dando lugar á proliferación de contaminantes e emisións tóxicas no medio ambiente. Non obstante, estes residuos están compostos principalmente por celulosa, hemicelulosa e lignina, compoñentes químicos que se poden usar para xerar un gran número de produtos de alto valor engadido. Por iso, é necesario desenvolver procesos adecuados para transformar esta biomasa lignocelulosica nunha fonte de riqueza, renovable, abundante e económica. Segundo o concepto de biorrefinería, a biomasa lignocelulosica pode dividirse nos seus tres compostos principais co uso de pretratamentos físicos, químicos e biolóxicos co fin de xerar solucións de azucres fermentables. Non obstante, os elevados custos dos encimas e a súa dispoñibilidade continúan sendo o pescozo de botella para implementar a hidrólise enzimática desta biomasa, polo que a industria demanda catalizadores máis estables, activos e económicos. Debido a isto, realizáronse estudos para a produción de enzimas a partir de diferentes residuos, mecanismos de acción, regulación da expresión en microorganismos e estratexias para facer máis viable económicamente o proceso. Entre os microorganismos que degradan este complexo lignocelulosico, debido á produción de encimas hidrolíticos, hai fungos filamentosos, coñecidos como axentes de descomposición da materia orgánica. Así mesmo, o uso de pretratamentos químicos que faciliten a dixestión da lignocelulosa, requiren menos enerxía para levar a cabo o proceso, xeran menos residuos tóxicos secundarios, sexan económicos, replicables e escalables. De todos estes traballos, destaca o recente uso de disolventes eutécticos profundos (DEP), que son capaces de formar mesturas eutécticas e teñen vantaxes sobre os procesos convencionais xa que son biodegradables e baratos, o que os fai atractivos para a súa aplicación e escalado. en industrias para obter unha variedade de produtos. Por este motivo, o presente traballo propón por unha banda o estudo do mecanismo de produción de encimas hidrolíticas procedentes dunha variedade de fungos do xénero Asperguillus; por outra banda, a delignificación dos mesmos materiais lignocelulosicos co uso de disolventes eutécticos profundos (DEP); e finalmente o uso de encimas hidrófilos producidos sobre os materiais delignificados para o fraccionamento de celulosa residual e hemicelulosa co fin de obter solucións de azucres fermentables.Agroindustrial wastes are generally used for composting or are abandoned directly in the field, resulting in the proliferation of pollutants and toxic emissions into the environment. However, these wastes are mainly composed of cellulose, hemicellulose and lignin, chemical components that can be used to generate a large number of products with high added value. Therefore, it is necessary to develop adequate processes to transform this lignocellulosic biomass into a source of wealth, renewable, abundant and economical. According to the concept of biorefinery, lignocellulosic biomass can be divided into its three main compounds with the use of physical, chemical and biological pretreatments in order to generate solutions of fermentable sugars. However, the high costs of enzymes and their availability continue to be the bottleneck to implement the enzymatic hydrolysis of this biomass, which is why the industry demands more stable, active and economical catalysts. Due to this, studies have been carried out for the production of enzymes from different residues, mechanisms of action, regulation of expression in microorganisms and strategies to make the process more economically viable. Among the microorganisms that degrade this lignocellulosic complex, due to the production of hydrolytic enzymes, are filamentous fungi, known as agents of decomposition of organic matter. Likewise, the use of chemical pretreatments that facilitate the digestion of lignocellulose, require less energy to carry out the process, generate less secondary toxic waste, be economical, replicable and scalable. Of all these works, the recent use of deep eutectic solvents (DEP) stands out, which are capable of forming eutectic mixtures and have advantages over conventional processes since they are biodegradable and inexpensive, which makes them attractive for application and scaling. in industries to obtain a variety of products. For this reason, this work proposes on the one hand the study of the mechanism of production of hydrolytic enzymes from a variety of fungi of the genus Asperguillus; on the other hand the delignification of the same lignocellulosic materials with the use of deep eutectic solvents (DES); and finally the use of the hydrophilic enzymes produced on the delignified materials for the fractionation of residual cellulose and hemicellulose in order to obtain solutions of fermentable sugars

Development of sustainable biorefinery processes applying deep eutectic solvents to agrofood wastes

The growing demand for renewable energies and the application of sustainable and economically viable biorefinery processes have increased the study and application of lignocellulosic biomass. However, due to lignocellulosic biomass recalcitrance hindering its efficient utilization, the pretreatment in the biorefinery is an essential stage for success in the process. Therefore, Deep Eutectic Solvent (DES) has emerged as a promising green pretreatment. During this study, the effect of choline chloride [ChCl]:glycerol and [ChCl]:urea on sugarcane bagasse and brewery bagasse is evaluated. Results have demonstrated that using [ChCl]:glycerol in SCB reduced about 80% and 15% for acid-soluble lignin and Klason lignin, respectively, and improved efficiency on saccharification yields, achieving conversions of 60, 80, and 100% for glucan, xylan, and arabinan, correspondingly. In the case of BSG saccharification yields, about 65% and 98% are attained for glucan and xylan, respectively, when [ChCl]:glycerol was employed. These results confirm the effectiveness and facility of DES pretreatment as a suitable method that can improve the biorefinery processes.Xunta de Galicia | Ref. GPC-ED431B 2021/23Ministerio de Ciencia e Innovación | Ref. PID2020-115879RB-I0

Mis casos Clínicos de Odontopediatría y Ortodoncia

Libro que conjunta casos en el área de Odontopediatría y OrtodonciaEs para los integrantes de la Red de Investigación en Estomatología (RIE) una enorme alegría presentar el tercer libro del 2021, sobre casos clínicos, revisiones de la literatura e investigaciones. La RIE está integrada por cuerpos académicos de la UAEH, UAEM, UAC y UdeG

Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

© 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 licenseBackground: 80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality. Methods: This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494. Findings: Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70–8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39–8·80) and upper-middle-income countries (2·06, 1·11–3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26–11·59) and upper-middle-income countries (3·89, 2·08–7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications. Interpretation: Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications. Funding: National Institute for Health Research Global Health Research Unit

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

© 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licenseBackground: Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide. Methods: A multimethods analysis was performed as part of the GlobalSurg 3 study—a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital. Findings: Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3·85 [95% CI 2·58–5·75]; p<0·0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63·0% vs 82·7%; OR 0·35 [0·23–0·53]; p<0·0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer. Interpretation: Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised. Funding: National Institute for Health and Care Research