14 research outputs found
An integrated and intensified approach for enhanced bioethanol production and validation with different lignocellulosic materials
With the increase of fossil fuels prices and environmental concerns derived of its use, the search
of new energy sources has become a central subject. Lignocellulosic biomass is a renewable and
abundant source of organic material in amount enough to satisfy the growing energetic needs and
suitable for the bioconversion into biofuels. The appropriate use of lignocellulosic biomass to
produce biofuels must integrate several requirements: selection of the appropriate raw
materials, effective biomass pre-treatment to improve the enzymatic saccharification of
cellulose into glucose and efficient conversion of hexoses and pentoses from the pre-treatment
into biofuels. In this context, great progress has been accomplished in terms of lignocellulosic
bioethanol production, but an integrated approach of all stages involved in the process is still a
goal to be achieved. The main highlighted challenges are: reduction of processing costs, recovery
and valorisation of all biomass fractions, and development of robust microorganisms able to
successfully convert all the available sugars into the desired biofuels under harsh and intensified
conditions. (Menon and Rao, 2012) Recent works showed the importance of suitable strain
selection from industrial environments (Pereira et al., 2014) for efficient lignocellulose
fermentation and for its engineered modification in order to metabolize xylose (Romaní et al.,
2015). In this context, the aim of this work was the development of efficient ethanol process
from several lignocellulosic materials, derived from agricultural products (corn cob and wheat
straw) and hardwood materials (eucalyptus and paulownia wood), alongside different nutritional
sources using a new robust constructed yeast strain for xylose and glucose co-consumption
isolated from industrial environment able to withstand harsh environments
Towards a cost-effective bioethanol process: yeast development to overcome challenges derived from lignocellulosic processing
The use of renewable biomass to supply the increasing energetic needs and to partially replace fossil fuels is nowadays recognized as a suitable and desirable alternative to attain a sustainable growth based on a bioeconomy. In spite of the intensive research on lignocellulose-to-ethanol production processes, second generation (2G) bioethanol is still not cost competitive and specific challenges remain. These processes are as a whole substantially more complex than initially thought as several types of biomass may be used as substrate, each with specific challenges. A range of biomass pre-treatments may be applied for biomass fractionation, each with its own specificities and leading to different inhibitor profiles. Finally, different hydrolysis/fermentation schemes may be used. The optimization of these processes has to consider the integration of all the stages
of the process and should be done together. One of the key aspects for the development of cost-effective lignocellulose-to-bioethanol processes is the engineering of the yeast strain. There is still a lack of robust and sugars-fast fermentation yeast strains for 2G bioethanol. Recently, we have screened and selected naturally robust yeast strains from industrial environments[1] and engineering some of the more promising strains with the xylose metabolic pathway[2] and inhibitor tolerance genes[3]. We will present the results of the simultaneous engineering of xylose metabolization pathway together with inhibitor tolerance in diverse robust background strains and its performance in different hydrolysates obtained from distinct types of biomass. The heterogeneous outcome of the genetic engineering in different hydrolysates show that tolerance and xylose engineering must be customized to the strain background and hydrolysate used in the process. The results obtained highlight that yeast development must not only be integrated in the process but it must also be tailor-made for each specific process.
[1]Pereira et al.(2014)Bioresource Technology 161:192-199.
[2]Romani et al.(2015)Bioresource Technology 179:150-158.
[3]Cunha et al.(2015)Bioresource Technology 191:7-16
Metabolic engineering industrial yeast strains for efficient hemicellulosic bioethanol production
The constant increase of fossil fuels consumption, raising their prices, and
environmental concerns derived of its use has stimulated the search for new renewable
energy sources. Lignocellulose raw materials (LCMs) derived from agricultural, industrial
and forest biomass can be a source of environmental, economic and strategic benefits,
avoiding the competition with food production, when used as sustainable feedstock. [1]
Nevertheless, lignocellulosic processing to obtain fermentable sugars involves a
pretreatment that generates inhibitor compounds of fermentation process and sugars as
xylose which cannot be naturally consumed by Saccharomyces cerevisiae. Therefore, the
pursuit for robust microorganisms in order to design sustainable processes for cellulosic
and hemicellulosic bioethanol production is one of the main challenges for a cost-effective
lignocellulosic biofuels. The use of natural robust yeast strains can overcome inhibitors
effect, as they are known for a higher fermentation capacity and stress tolerance related
with harsh industrial processes like high sugar and ethanol concentrations, elevated
temperatures, pH variations and presence of toxic compounds. [2] In addition, previous
studies from our group have identified key genes necessary for yeast growth and maximal
fermentation rate in hydrolysates [3,4]. Strains with robust genetic backgrounds have been
shown to already demonstrate enhanced background expression of several genes involved
in the detoxification of some of these inhibitors [5], but different genetic backgrounds have
shown to present diverse responses. [4] On the other hand, the inhibitory load of
lignocellulosic hydrolysates, which varies depending on the raw material and operational
conditions of pretreatment [6], has been shown to differentially influence the consequence
of genetic manipulations [4], highlighting the importance of evaluating their effect under
process-like conditions. In this sense, the aim of this work was to evaluate the effect of
xylose metabolic engineering on different background yeast strains isolated from industrial
environments (cachaça distilleries and first and second bioethanol industries) using
several pretreated lignocellulosic feedstocks
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20
[1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030
Effective bioethanol production from Plant-based biomass by genetically modified yeast strains
Dissertação de mestrado em Biologia Molecular, Biotecnologia e Bioempreendedorismo em PlantasThe exponential use and depletion of fossil fuels reserves have brought to light several
environmental and economic concerns. Bioethanol is of major importance in achieving an efficient
alternative source of energy, being renewable and environmentally sustainable. The selection of
robust yeast strains as chassis for metabolic engineering could contribute to attain a cost-effective
lignocellulosic bioethanol processing. In this selection, the background of metabolic engineering
strains for xylose fermentation could play an important role, being necessary the evaluation of
fermentation performance in several stress environments related with the lignocellulosic bioethanol
processing.
In this work, four robust yeast chassis isolated from industrial environments – PE-2, CA11, CAT-
1 and CCUG53310 – were engineered with the same xylose metabolic pathway. The recombinant
strains were physiologically characterized in synthetic xylose and xylose-glucose medium, on nondetoxified
hemicellulosic hydrolysates of two fast growing hardwoods (Eucalyptus globulus and
Paulownia tomentosa) and agricultural residues (corn cob and wheat straw) and on E. globulus
hydrolysate at different temperatures.
Similar rates of xylose consumption in presence or absence of glucose in synthetic media were
obtained by PE-2-X-dGRE and CA11-X, showing co-fermentation of both sugars. On the other hand,
CAT-1-X was capable of utilize xylose, but only after glucose depletion, while CCUG53310-X exhibited
extreme deficiency in xylose utilization. Low-cost supplementation by agro-industrial residues of
hydrolysate fermentation media demonstrated to be a great substitute for commercial supplements
which could reduce operational cost of process. All of the strains tested were able to efficiently
ferment the different hydrolysates. The highest ethanol yield (0.46 g/g) from Paulownia hydrolysate
was obtained by PE-2-X-dGRE3 within 24 h of fermentation at 30 ºC. In fact, this strain showed
superior fermentation ability in all the hydrolysates. Nevertheless, an evaluation of thermotolerance
of strains showed that, CA11-X exhibited clearly best performance than PE-2-X-dGRE3 at 40 ºC,
utilizing all xylose present in the medium. Results here presented demonstrate that the genetic
background of the chassis strains plays a major role on their capacity to metabolize xylose, which
was here proved to be dependent of the inhibitory composition of the lignocellulosic hydrolysate as
well as of the temperature conditions of the fermentation process. These heterogeneous outcomes
highlight the importance of carefully addressing the engineering of yeast strains for efficient
lignocellulosic ethanol production.O uso e a redução exponencial de combustíveis fósseis trouxeram vários problemas a nível
económico e ambiental. O bioetanol é considerado muito importante para alcançar uma fonte de
energia eficiente, sendo renovável e ambientalmente sustentável. A seleção de estirpes de levedura
robustas como base para engenharia metabólica pode contribuir para alcançar um processo de
bioetanol lignocelulósico rentável. Nesta seleção, o background de estirpes geneticamente
modificadas para a fermentação de xilose pode desempenhar um papel importante, sendo
necessária a avaliação da performance de fermentação em várias condições de stress relacionadas
com o processamento de bioetanol lignocelulósico.
Neste trabalho, quatro estirpes de Saccharomyces cerevisiae – PE-2, CA11, CAT-1 e
CCUG53310 – foram geneticamente modificadas com a mesma via metabólica para o consumo de
xilose. As estirpes recombinantes foram caracterizadas fisiologicamente em meio sintético de xilose
e glucose-xilose, em hidrolisados hemicelulósicos não-detoxificados de duas madeiras de rápido
crescimento (Eucalyptus globulus e Paulownia tomentosa) e dois resíduos de agricultura (palha de
trigo e espiga de milho) e em hidrolisado de E. globulus a diferentes temperaturas.
Taxas de consumo de xilose semelhantes na presença ou ausência de glucose em meios
sintéticos foram obtidas pelas estirpes PE-2-X-dGRE e CA11-X, mostrando co-fermentação de ambos
os açúcares. Por outro lado, CAT-1-X foi capaz de utilizar a xilose, mas apenas após a depleção da
glucose, enquanto que CCUG53310-X mostrou grande deficiência na utilização de xilose.
Suplementação low-cost com resíduos agroindustriais em fermentações de hidrolisados mostraram
ser bons substitutos para suplementos comerciais, o que reduziria os custos do processo. Todas as
estirpes testadas foram capazes de fermentar os diferentes hidrolisados. A maior taxa de produção
de etanol (0.46 g/g) em Paulownia foi obtida pela PE-2-X-dGRE3 em 24h, a 30 ºC, que mostrou
superior de capacidade de fermentação em todos os hidrolisados. No entanto, numa avaliação da
termotolerância das estirpes, CA11-X mostrou claramente uma melhor performance do que PE-2-XdGRE3
a 40 ºC, utilizando toda a xilose presente no meio. Os resultados aqui apresentados
demonstram que o background genético das estirpes desempenha um papel importante na sua
capacidade de metabolizar xilose, tendo sido provado que está dependente da inibição da
composição de hidrolisados lignocelulósicos, bem como das condições térmicas e do processo de
fermentação. Estas consequências heterogéneas destacam a importância de delinear
cuidadosamente a engenharia genética das estirpes de leveduras para a produção eficiente de etanol
lignocelulósico.This work was support by the Strategic Project of UID/BIO/04469/2013 CEB Unitsd
Produção de cultivares de morangueiro polinizadas pela abelha jataí em ambiente protegido
Córdoba, 28 y 29 de junio de 2018
Actas del X Seminario Internacional de Investigación en UrbanismoEl seminario tiene como objetivo facilitar una instancia de reflexión compartida sobre las investigaciones en el campo del urbanismo y generar un intercambio entre investigadores sobre los fenómenos de la urbanización y la transformación urbana y territorial en distintos países iberoamericanos. Se propone analizar las características de los procesos de transformación del territorio y los factores que los explican, en relación con las estrategias de planificación, proyecto y renovación sostenible destinadas a ciudades y regiones. Se pretende integrar diferentes escalas y perspectivas de análisis, propias del planeamiento y la gestión urbana, metropolitana y regional, del diseño urbano y arquitectónico; de la geografía y la sociología urbanas, que habitualmente se examinan aisladamente en distintos foros.
En el marco de este encuentro, y en conmemoración del primer centenario de la Reforma Universitaria iniciada en Córdoba –movimiento estudiantil que sienta las bases del actual sistema universitario nacional-se cree propicia la ocasión para reflexionar además sobre la relación entre ciudad y universidad, sobre ciudades universitarias, sobre la contribución desde la Universidad Nacional de Córdoba y del resto de las universidades latinoamericanas al urbanismo de nuestras ciudades
NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics
Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data
NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics
Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data