Exploration of Polyphenols Extracted from Cytisus Plants and Their Potential Applications: A Review.

The increasing world population means an increased demand for sustainable processes and products related to foods, particularly those with added health benefits. Plants can be an alternative source of nutritional and biofunctional ingredients. Cytisus plants are an underexploited bioresource, currently prevalent in the Mediterranean Basin and western Asia. This manuscript addresses the processing potential of Cytisus plants for the development of added-value products, including food formulations, food packaging, cosmetics, and therapeutic applications. Most research has reported that Cytisus spp. are a promising source of inexpensive bioactive polyphenol compounds. Cytisus flowers should be considered and exploited as raw materials for the development of new food ingredients (antioxidants, preservatives, additives, etc.), nutraceuticals, or even direct therapeutic agents (anticancer, antibacterial, etc.). In order to evaluate the socioeconomic effect of these underutilized plants, more research is needed to assess their valorization for therapeutic and dietary possibilities, as well as the economic impact.

Process modeling, environmental and economic sustainability of the valorization of whey and eucalyptus residues for resveratrol biosynthesis.

Biomass is one of the renewable resources with the greatest potential, not only because of the possibility of energy recovery but also because of its content in components of interest. In this context, the regions of Galicia and Portugal have large areas of land dedicated to forestry, agriculture and livestock, and the large amount of waste generated represents a cost for the producer. The importance of these facts has aroused great interest in society to focus its interest on improving the current situation while seeking a benefit, both environmental and economic, from existing resources. That is why the integration of biotechnological processes and biorefinery for their valorization are considered key aspects in the way of producing bioproducts and bioenergy. This research article proposes a process for producing resveratrol from whey from the dairy industry and eucalyptus residues from forestry exploitation. In order to evaluate its suitability, a techno-economic analysis and an environmental assessment have been carried out using the Life Cycle Assessment (LCA) methodology. The results obtained show the potential of these scenarios both from the economic point of view, by obtaining a minimum sale price of resveratrol to ensure the viability of the process below the market average, and from the environmental point of view, being eucalyptus residues those that result in a lower contribution to the environment per unit of resveratrol produced. Future research should focus on increasing the throughput of the production process to increase its profitability and on reducing energy requirements throughout the process, as these have been the main critical points identified. In addition, following the sensitivity assessment, it has been concluded that opting for renewable energy is the most sustainable option.

Resveratrol production for the valorisation of lactose-rich wastes by engineered industrial Saccharomyces cerevisiae.

Resveratrol is an antioxidant with applications in the food and cosmetic industries. Its biosynthesis can side the hindrances of its extraction from plants. The dairy industry generates tonnes of lactose-rich wastes, which can be a carbon source. Saccharomyces cerevisiae is an industrial workhorse for biotechnological processes, being unable to naturally metabolise lactose. Here, an S. cerevisiae strain was engineered for de novo production of resveratrol from lactose. A resveratrol titre of 210 mg/L from 100 g/L of lactose in synthetic media was achieved. Process optimization increased by 35% the production by a two-stage process, one favouring ethanol production and a subsequent one with stronger agitation favouring ethanol and lactose consumption with conversion into resveratrol. Resveratrol production from cheese whey was further attained. To the best knowledge of the authors, this is the first report on resveratrol production from lactose, relevant in dairy wastes, establishing grounds for future resveratrol-producing lactose-based processes.

Resveratrol Production from Hydrothermally Pretreated Eucalyptus Wood Using Recombinant Industrial Saccharomyces cerevisiae Strains.

Resveratrol is a phenolic compound with strong antioxidant activity, being promising for several applications in health, food, and cosmetics. It is generally extracted from plants or chemically synthesized, in both complex and not sustainable processes, but microbial biosynthesis of resveratrol can counter these drawbacks. In this work, resveratrol production by microbial biosynthesis from lignocellulosic materials was assessed. Three robust industrial Saccharomyces cerevisiae strains known for their thermotolerance and/or resistance to inhibitory compounds were identified as suitable hosts for de novo resveratrol production from glucose and ethanol. Through the CRISPR/Cas9 system, all industrial strains, and a laboratory one, were successfully engineered with the resveratrol biosynthetic pathway via the phenylalanine intermediate. All strains were further screened at 30 °C and 39 °C to evaluate thermotolerance, which is a key feature for Simultaneous Saccharification and Fermentation processes. Ethanol Red RBP showed the best performance at 39 °C, with more than 2.6-fold of resveratrol production in comparison with the other strains. This strain was then used to assess resveratrol production from glucose and ethanol. A maximum resveratrol titer of 187.07 ± 19.88 mg/L was attained from a medium with 2% glucose and 5% ethanol (w/v). Lastly, Ethanol Red RBP produced 151.65 ± 3.84 mg/L resveratrol from 2.95% of cellulose from hydrothermally pretreated Eucalyptus globulus wood, at 39 °C, in a Simultaneous Saccharification and Fermentation process. To the best of our knowledge, this is the first report of lignocellulosic resveratrol production, establishing grounds for the implementation of an integrated lignocellulose-to-resveratrol process in an industrial context.

Metabolic engineering of Saccharomyces cerevisiae for the production of top value chemicals from biorefinery carbohydrates.

The implementation of biorefineries for a cost-effective and sustainable production of energy and chemicals from renewable carbon sources plays a fundamental role in the transition to a circular economy. The US Department of Energy identified a group of key target compounds that can be produced from biorefinery carbohydrates. In 2010, this list was revised and included organic acids (lactic, succinic, levulinic and 3-hydroxypropionic acids), sugar alcohols (xylitol and sorbitol), furans and derivatives (hydroxymethylfurfural, furfural and furandicarboxylic acid), biohydrocarbons (isoprene), and glycerol and its derivatives. The use of substrates like lignocellulosic biomass that impose harsh culture conditions drives the quest for the selection of suitable robust microorganisms. The yeast Saccharomyces cerevisiae, widely utilized in industrial processes, has been extensively engineered to produce high-value chemicals. For its robustness, ease of handling, genetic toolbox and fitness in an industrial context, S. cerevisiae is an ideal platform for the founding of sustainable bioprocesses. Taking these into account, this review focuses on metabolic engineering strategies that have been applied to S. cerevisiae for converting renewable resources into the previously identified chemical targets. The heterogeneity of each chemical and its manufacturing process leads to inevitable differences between the development stages of each process. Currently, 8 of 11 of these top value chemicals have been already reported to be produced by recombinant S. cerevisiae. While some of them are still in an early proof-of-concept stage, others, like xylitol or lactic acid, are already being produced from lignocellulosic biomass. Furthermore, the constant advances in genome-editing tools, e.g. CRISPR/Cas9, coupled with the application of innovative process concepts such as consolidated bioprocessing, will contribute for the establishment of S. cerevisiae-based biorefineries.

Engineered Saccharomyces cerevisiae for lignocellulosic valorization: a review and perspectives on bioethanol production.

The biorefinery concept, consisting in using renewable biomass with economical and energy goals, appeared in response to the ongoing exhaustion of fossil reserves. Bioethanol is the most prominent biofuel and has been considered one of the top chemicals to be obtained from biomass. Saccharomyces cerevisiae, the preferred microorganism for ethanol production, has been the target of extensive genetic modifications to improve the production of this alcohol from renewable biomasses. Additionally, S. cerevisiae strains from harsh industrial environments have been exploited due to their robust traits and improved fermentative capacity. Nevertheless, there is still not an optimized strain capable of turning second generation bioprocesses economically viable. Considering this, and aiming to facilitate and guide the future development of effective S. cerevisiae strains, this work reviews genetic engineering strategies envisioning improvements in 2nd generation bioethanol production, with special focus in process-related traits, xylose consumption, and consolidated bioprocessing. Altogether, the genetic toolbox described proves S. cerevisiae to be a key microorganism for the establishment of a bioeconomy, not only for the production of lignocellulosic bioethanol, but also having potential as a cell factory platform for overall valorization of renewable biomasses.

Activated carbon obtained from amazonian biomass tailings (acai seed): Modification, characterization, and use for removal of metal ions from water.

Acai seed was used herein as an Amazon biomass waste for the synthesis of activated and modified carbon in order to find a possible use for the large volume of residues generated during the processing of this fruit and to add value to this residue. Activated carbon materials were used to remove Pb2+, Fe2+, and Mg2+ metal ions from water. The efficiency of removal of these ions by the acai seed activated carbon was compared with that by commercial activated carbon. Activated carbon materials were prepared by carbonization and chemical activation using two KOH impregnation ratios, namely 1:1 (ACK1) and 5:1 (ACK5), by mass. These samples were modified by treatment with nitric acid under microwave heating (ACK1-M) and (ACK5-M), respectively. The result of the elemental analysis indicated that this biomass has carbon and sulfur contents of 43.29% and 0.10% wt, respectively. The textural parameters showed that the obtained activated carbon samples presented high surface areas between 1462 and 2774 m2 g-1. Raman analysis revealed the different degrees of graphitization of the activated carbon materials. Boehm titration identified the presence of phenolic, carboxylic, and lactonic groups in samples that were confirmed by Fourier transform infrared spectroscopy. In the metal adsorption tests, ACK5-M showed better removal efficiency, reaching 86% removal for Pb2+, 69% for Fe2+, and 8% for Mg2+in 1 h of contact time; these results were superior to those obtained for commercial carbon. The results indicated that acai seed can be used for the production of activated carbon and can also be used for metal removal.

Selection and subsequent physiological characterization of industrial Saccharomyces cerevisiae strains during continuous growth at sub- and- supra optimal temperatures.

A phenotypic screening of 12 industrial yeast strains and the well-studied laboratory strain CEN.PK113-7D at cultivation temperatures between 12 °C and 40 °C revealed significant differences in maximum growth rates and temperature tolerance. From those 12, two strains, one performing best at 12 °C and the other at 40 °C, plus the laboratory strain, were selected for further physiological characterization in well-controlled bioreactors. The strains were grown in anaerobic chemostats, at a fixed specific growth rate of 0.03 h-1 and sequential batch cultures at 12 °C, 30 °C, and 39 °C. We observed significant differences in biomass and ethanol yields on glucose, biomass protein and storage carbohydrate contents, and biomass yields on ATP between strains and cultivation temperatures. Increased temperature tolerance coincided with higher energetic efficiency of cell growth, indicating that temperature intolerance is a result of energy wasting processes, such as increased turnover of cellular components (e.g. proteins) due to temperature induced damage.

Molecular and physiological basis of Saccharomyces cerevisiae tolerance to adverse lignocellulose-based process conditions.

Lignocellulose-based biorefineries have been gaining increasing attention to substitute current petroleum-based refineries. Biomass processing requires a pretreatment step to break lignocellulosic biomass recalcitrant structure, which results in the release of a broad range of microbial inhibitors, mainly weak acids, furans, and phenolic compounds. Saccharomyces cerevisiae is the most commonly used organism for ethanol production; however, it can be severely distressed by these lignocellulose-derived inhibitors, in addition to other challenging conditions, such as pentose sugar utilization and the high temperatures required for an efficient simultaneous saccharification and fermentation step. Therefore, a better understanding of the yeast response and adaptation towards the presence of these multiple stresses is of crucial importance to design strategies to improve yeast robustness and bioconversion capacity from lignocellulosic biomass. This review includes an overview of the main inhibitors derived from diverse raw material resultants from different biomass pretreatments, and describes the main mechanisms of yeast response to their presence, as well as to the presence of stresses imposed by xylose utilization and high-temperature conditions, with a special emphasis on the synergistic effect of multiple inhibitors/stressors. Furthermore, successful cases of tolerance improvement of S. cerevisiae are highlighted, in particular those associated with other process-related physiologically relevant conditions. Decoding the overall yeast response mechanisms will pave the way for the integrated development of sustainable yeast cell-based biorefineries.

HAA1 and PRS3 overexpression boosts yeast tolerance towards acetic acid improving xylose or glucose consumption: unravelling the underlying mechanisms.

Acetic acid tolerance and xylose consumption are desirable traits for yeast strains used in industrial biotechnological processes. In this work, overexpression of a weak acid stress transcriptional activator encoded by the gene HAA1 and a phosphoribosyl pyrophosphate synthetase encoded by PRS3 in a recombinant industrial Saccharomyces cerevisiae strain containing a xylose metabolic pathway was evaluated in the presence of acetic acid in xylose- or glucose-containing media. HAA1 or PRS3 overexpression resulted in superior yeast growth and higher sugar consumption capacities in the presence of 4 g/L acetic acid, and a positive synergistic effect resulted from the simultaneous overexpression of both genes. Overexpressing these genes also improved yeast adaptation to a non-detoxified hardwood hydrolysate with a high acetic acid content. Furthermore, the overexpression of HAA1 and/or PRS3 was found to increase the robustness of yeast cell wall when challenged with acetic acid stress, suggesting the involvement of the modulation of the cell wall integrity pathway. This study clearly shows HAA1 and/or, for the first time, PRS3 overexpression to play an important role in the improvement of industrial yeast tolerance towards acetic acid. The results expand the molecular toolbox and add to the current understanding of the mechanisms involved in higher acetic acid tolerance, paving the way for the further development of more efficient industrial processes.

Integrated approach for selecting efficient Saccharomyces cerevisiae for industrial lignocellulosic fermentations: Importance of yeast chassis linked to process conditions.

In this work, four robust yeast chassis isolated from industrial environments were engineered with the same xylose metabolic pathway. The recombinant strains were physiologically characterized in synthetic xylose and xylose-glucose medium, on non-detoxified hemicellulosic hydrolysates of fast-growing hardwoods (Eucalyptus and Paulownia) and agricultural residues (corn cob and wheat straw) and on Eucalyptus hydrolysate at different temperatures. Results show that the co-consumption of xylose-glucose was dependent on the yeast background. Moreover, heterogeneous results were obtained among different hydrolysates and temperatures for each individual strain pointing to the importance of designing from the very beginning a tailor-made yeast considering the specific raw material and process.

Conversion of waste produced by the deodorization of palm oil as feedstock for the production of biodiesel using a catalyst prepared from waste material.

The distillate produced by deodorization of palm oil (DDPO) is a waste that corresponds to 4% of the product formed in this process. DDPO is 83% free of fatty acids (FFA), making it a good material for biodiesel production. In this paper, a catalyst prepared from a waste material, Amazon flint kaolin, was used for the esterification of DDPO with methanol. Leached metakaolin treated at 950°C and activated with 4M sulfuric acid (labeled as MF9S4) offered maximum esterification activity (92.8%) at 160°C with a DDPO:methanol molar ratio of 1:60 and a 4-h reaction time. The influences of reaction parameters, such as the molar ratio of the reactants, alcohol chain length, temperature, time and the presence of glycerides and unsaponifiable matter, have also been investigated. Based on the catalytic results, esterification of DDPO using MF9S4 can be a cheaper alternative for production of sustainable fuels.

Sistema de multimidia para comunicacao surdo-surdo e surdo-ouvinte em linguas brasileira e americana de sinais via redes de computador / Multimedia Communications System for the Deaf on Brazilian and American Sign Language through Computer Networks

Um sistema de multimidia para comunicacao via redes de computador e descrito. Permite comunicacao entre surdos, e entre surdos e ouvintes. Contem milhares de sinais da Lingua Brasileira de Sinais emparelhados aos sinais da Lingua Americana de Sinais, bem como suas palavras correspondentes em portugues e ingles nas formas escrita e falada. Os sinais sao distribuidos em categorias semanticas, e podem ser selecionados para compor frases por meio de aparelhos de imput alternativo, tais como telas-sensiveis-ao-toque, detectores de sopro, movimento, direcao do olhar, ou gemidos. Alem de comunicacao, o sistema permite redigir relatorios, proferir discursos, e aprender lingua de sinais