Environmentally sustainable processes for biomass conversion into biofuels and value-added compounds: integrated and intensified approach within a biorefinery concept

Book of Abstracts of CEB Annual Meeting 2017[Excerpt] Lignocellulosic biomass conversion into biofuels is considered a promising alternative to replace fossil fuels, being one of investment priorities of European Union to attain a sustainable growth within Horizon 2020. Nevertheless, lignocellulosic biofuels are not widely implemented on large-scale due to the high initial investment and operational costs. The scientific research carried out has been focused in the development of biomass processing technology for bioethanol production making use of environmentally-friendly pre-treatments and molecular biotechnology tools (metabolic, genetic and physiological engineering) for yeast development. [...]info:eu-repo/semantics/publishedVersio

Valorization of wastes from agrofood and pulp and paper industries within the biorefinery concept: southwestern Europe scenario

Nowadays, the need to attain a sustainable society increasingly demands for the development of an economy based on biorefineries. In Southwestern Europe, agrofood and forest industries produce significant amount of wastes that could satisfy the demand for renewable biomass to be used in a biorefinery scheme alternatively to traditional uses of these residues. This chapter will primarily cover the current scenario regarding the annual volume of residues generated by agrofood (cheese whey, vine pruning waste, and brewer's spent grains) and pulp and paper industry (sawdust, chips, bark, and sludge). Additionally, the present-day use and final destination of these wastes and their main environmental issues will be described and discussed; besides, advanced valorization strategies (e.g., fuels and chemicals) involving a biorefinery approach will be approached, based on current reports according to the chemical composition of each waste. Finally, new insights on valorization of wastes from agrofood and pulp and paper industries, its challenges, and trends for future research will be presented.(undefined)info:eu-repo/semantics/publishedVersio

Current options in the valorisation of vine pruning residue for the production of biofuels, biopolymers, antioxidants, and bio-composites following the concept of biorefinery: a review

Europe is considered the largest producer of wine worldwide, showing a high market potential. Several wastes are generated at the different stages of the wine production process, namely, vine pruning, stalks, and grape marc. Typically, these residues are not used and are commonly discarded. Portugal generates annually approximately 178 thousand metric tons of wine production waste. In this context, the interest in redirecting the use of these residues has increased due to overproduction, great availability, and low costs. The utilization of these lignocellulosic biomasses derived from the wine industry would economically benefit the producers, while mitigating impacts on the environment. These by-products can be submitted to pre-treatments (physical, chemical, and biological) for the separation of different compounds with high industrial interest, reducing the waste of agro-industrial activities and increasing industrial profitability. Particularly, vine-pruning residue, besides being a source of sugar, has high nutritional value and may serve as a source of phenolic compounds. These compounds can be obtained by bioconversion, following a concept of biorefinery. In this framework, the current routes of the valorisation of the pruning residues will be addressed and put into a circular economy context.This study was funded by the European Regional Development Fund (ERDF) within the programme Interreg V-A España-Portugal (POCTEP) 2014–2020, through the project BIOVINO (0688_BIOVINO_6_E), by the Foundation for Science and Technology (FCT, Portugal) under the scope of the strategic funding of UIDB/04469/2020 and UIDP/05937/2020 units and by CISAS projects supporting the two (M.J. and F.M.) authors, and by the Ministry of Science and Innovation (MICIN) through the grant RYC2020-030690-I (to A.R.).info:eu-repo/semantics/publishedVersio

Biorefinery approach for the valorization of vine pruning residue

Lignocellulosic biomass (namely vine pruning residue, VPR) conversion into biofuels is considered a promising alternative to replace fossil fuels. In this work, VPR was submitted to hydrothermal treatment under isothermal conditions (180 and 200oC for 10-90min), in order to assess the effect of the treatment on the VPR fractionation. Liquid phase was analyzed for oligosaccharides composition and solid phase was submitted to enzymatic saccharification at liquid to solid ratio of 25 g/g and enzyme to substrate ratio of 25 FPU/g for glucose production. 62% of xylan was solubilized into xylose and xylooligosaccharides (2 and 11 g/L) and 70-98% of glucan remained in the pretreated VPR. Enzymatic saccharification of pretreated VPR was improved with the hardness of treatment. Overall, hydrothermal process (180oC, 60 min) was suitable for the production of xylose and xylooligosaccharides and to obtain a susceptible treated biomass for glucose production (13 g/L with 73% of conversion).CNPqCAPESBraskemPortuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, COMPETE 2020 (POCI- 01-0145-FEDER-006684), Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER- 027462), INOU 15-08 project (supported by Deputación de Ourense

Eco-friendly strategy for the joint valorization of invasive macroalgae and fast-growing wood to produce advanced biofuels

A novel sustainable scheme to jointly valorize Sargassum muticum (Sm) and Paulownia wood (PW) was proposed in this work, employing the advanced environmentally friendly microwave-assisted autohydrolysis (MA) as pretreatment. Sm is an invasive macroalga that has been drastically spread in the Atlantic coast of Europe, causing environmental damage. Conversely, Paulownia elongata x fortunei is a fast-growing biomass with a high biomass production and potential for biofuels production. Thus, the concomitant valorization of both biomasses may lead to benefits related to environmental protection and bioeconomy. A sequential approach was proposed: first stage of glucose production from Sm (treated by MA and enzymatic hydrolysis to obtain a glucose-rich liquor), and second stage with MA-pretreated PW followed by saccharification and fermentation, employing in this process the glucose rich solution obtained from algae, to obtain simultaneously second and third generation bioethanol. These approaches enabled to add the ethanol production from both biomasses, leading to up to 45.2 g ethanol/L (70% ethanol yield), boosting ethanol titers compared to using only one biomass (up to 27.8 g/L) and confirming the benefits of combining MA-processed biomass. Furthermore, up to 87% of the energy may be recovered, reflecting a suitable approach within an integrated strategy.Agencia Estatal de Investigación | Ref. PID2019-110031RB-I00Agencia Estatal de Investigación | Ref. CNS2022-136095Xunta de Galicia | Ref. ED431C 2017/62-GRCXunta de Galicia | Ref. ED481B-2022-020Agencia Estatal de Investigación | Ref. RYC2018-026177-IAgencia Estatal de Investigación | Ref. RYC2020-030690-IUniversidade de Vigo/CISU

Hemicellulosic bioethanol production from fast-growing Paulownia biomass

In order to exploit a fast-growing Paulownia hardwood as an energy crop, a xylose-enriched hydrolysate was obtained in this work to increase the ethanol concentration using the hemicellulosic fraction, besides the already widely studied cellulosic fraction. For that, Paulownia elongata x fortunei was submitted to autohydrolysis treatment (210 °C or S0 of 4.08) for the xylan solubilization, mainly as xylooligosaccharides. Afterwards, sequential stages of acid hydrolysis, concentration, and detoxification were evaluated to obtain fermentable sugars. Thus, detoxified and non-detoxified hydrolysates (diluted or not) were fermented for ethanol production using a natural xylose-consuming yeast, Scheffersomyces stipitis CECT 1922, and an industrial Saccharomyces cerevisiae MEC1133 strain, metabolic engineered strain with the xylose reductase/xylitol dehydrogenase pathway. Results from fermentation assays showed that the engineered S. cerevisiae strain produced up to 14.2 g/L of ethanol (corresponding to 0.33 g/g of ethanol yield) using the non-detoxified hydrolysate. Nevertheless, the yeast S. stipitis reached similar values of ethanol, but only in the detoxified hydrolysate. Hence, the fermentation data prove the suitability and robustness of the engineered strain to ferment non-detoxified liquor, and the appropriateness of detoxification of liquor for the use of less robust yeast. In addition, the success of hemicellulose-to-ethanol production obtained in this work shows the Paulownia biomass as a suitable renewable source for ethanol production following a suitable fractionation process within a biorefinery approach.This research was funded by MINECO (Spain) in the framework of the projects “Multistage processes for the integral benefit of macroalgal and vegetal biomass” with reference CTM2015-68503- R,” and “Cutting-edge strategies for a sustainable biorefinery based on valorization of invasive species” with reference PID2019-110031RB-I00, to Consellería de Cultura, Educación e Ordenación Universitaria (Xunta de Galicia) through the contract ED431C 2017/62-GRC to Competitive Reference Group BV1, program partially funded by European Regional Development Fund (FEDER). This study was also supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit.info:eu-repo/semantics/publishedVersio

The L-arabinose isomerase from the food grade Bacillus subtilis for the production of tagatose: a natural sweetener

The increasing concern about adverse health impacts from excessive sugar consumption is the main driving force for the replacement of simple sugar by natural sweeteners (1). Tagatose is a hexose monosaccharide rarely found in nature, namely in some fruits and dairy products. This rare sugar represents a promising sweetener due its low calorie content (1.5 – 2.5 kcal/g), sweetness profile similar to sucrose and prebiotic and anticariogenic properties (2-3).Study supported by the Portuguese Foundation for Science and Technology (FCT, Portugal) under the scope of the strategic funding of UID/BIO/04469/2019 unit and COMPETE 2020 (POCI-01-0145- FEDER-006684), the BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte and Sara L. Baptista doctoral fellowship (SFRH/BD/132717)info:eu-repo/semantics/publishedVersio

Multi-feedstock biorefinery for valorization of forest and marginal land resources: comparative autohydrolysis

This work is focused on evaluating two mixtures of lignocellulosic feedstock: forest and marginal land resources, in order to produce glucose under a biorefinery concept. The selection of renewable bio-mixtures, broom (Cytisus sp.), carqueja (Genista tridentate), mimosa (Acacia dealbata), rockrose (Cistus ladanifer), eucalyptus (Eucalyptus globulus) and pine (Pinus pinaster) was based on several criteria, namely, territorial distribution, fire risk during summer months and total sugar content. These species were identified as the most important sources related with the fuel available responsible of forest fire problem in Portugal. Furthermore, the use of multiple bio-mixtures rather than a single raw material can minimize the problems related to biomass availability, seasonality, price volatility and storage, converging in security supply model. The two mixtures were submitted to autohydrolysis pretreatment under non-isothermal conditions (in the range of 190 ºC - 240 ºC corresponding to severity of 3.71 to 4.82) and their susceptibility to enzymatic hydrolysis was evaluated. It was demonstrated that by increasing the pretreatment severity, the cellulose to glucose conversion yield improved from 45 to 90%. This comparative study confirmed autohydrolysis as a suitable process for the valorization of both mixtures within a biorefinery concept.info:eu-repo/semantics/publishedVersio

Valorization of seaweed carbohydrates: autohydrolysis as a selective and sustainable pretreatment

Seaweeds are promising feedstocks; nevertheless, the lack of systematic approaches to recover different high-value fractions in a clean and sustainable mode hampers their exploitation. Due to this necessity, an innovative environmentally friendly strategy was proposed in this article for the development of a sugar platform from Gelidium sesquipedale: for the first time, autohydrolysis followed by enzymatic saccharification (with cellulolytic and agarolytic cocktails) was applied to agarophyte seaweeds. The wide range of severities (between 2.47 and 4.94) studied in this work proved that the autohydrolysis-based process can be tuned to selectively extract different target carbohydrate fractions. Gelling agents (reaching 30 g/100 g DW) can be obtained by the application of low severity treatments, fermentable sugars or oligosaccharides with the nutraceutical potential (reaching 14 g/100 g DW) are produced when severity is increased, and at the highest severity, platform chemicals (reaching 4 g/100 g DW) are the final product. The reduction of processing times compared to traditional extraction methodologies and the elimination of chemicals used in dilute acid treatments make this strategy a clean and sustainable alternative for the valorization of both glucan and galactan fractions of G. sesquipedale.This work was supported by the Portuguese Foundation forScience and Technology (FCT), under the scope of thestrategic funding of UID/BIO/04469/2020 unit and under thescope of the project “AlgaePlas-Biorefinery of macroalgae forvalorization of the carbohydrate fraction to sustainablebioplastics,”PTDC/BII-BIO/29242/2017.info:eu-repo/semantics/publishedVersio

Integrated approach for the valorisation of wine industry residues: production of xylitol and bioethanol

The wine industry is known to generate large volumes of by-products and residues that are not properly treated, representing an environmental problem (1). Vine pruning, wine lees, and grape must offer significant potential to serve as a sustainable source for the production of fuels and chemicals. Metabolic engineering strategies have been establishing Saccharomyces cerevisiae as a cell factory for biorefineries (2). For being sustainable, these biorefineries will require bioethanol and high-value chemical coproduction (2). In this work, an integrated approach was used for the valorisation of hydrothermally pre-treated vine pruning, using the xylose-rich hemicellulosic fraction for xylitol production (3) and the cellulosic fraction to produce bioethanol using genetically modified S. cerevisiae strains. Furthermore, wine lees were explored as nutritional supplements and grape must, rich in fermentable sugars, as both nutrient and carbon source. The xylitol production was optimized using different enzyme loading and inoculum size in a simultaneous saccharification and fermentation (SSF) process. Additionally, the production of bioethanol from the glucan enriched solid fraction was evaluated with the supplementation of wine lees and/or grape must, resulting in ethanol production higher than the critical threshold for distillation economic feasibility. This integrated multi-feedstock approach represents a possible solution for disposal problems of wine-producing industry, meeting the demands for the establishment of a circular economy.This study was supported by the Portuguese Foundation for Science and Technology (FCT, Portugal) under the scope of the strategic funding of UIDB/04469/2020, the PhD grant (SFRH/BD/132717/2017 to SLB) and BIOVINO project (0688_BIOVINO_6_E) funded by INTERREG España - Portugal and European Regionalinfo:eu-repo/semantics/publishedVersio