Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 116
Filtrar
1.
J Dairy Sci ; 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38395394

RESUMO

The objective of this study was to evaluate the interaction of dietary carbohydrate profile and soybean meal (SBM) replacement with either Chlorella pyrenoidosa (CHL) or Spirulina platensis (SPI) on in vitro fermentation. This experiment was conducted as a randomized complete block design, with fermentation run (3 runs) considered as blocks. The treatments were arranged in a 2 × 5 factorial design, where the first factor was the carbohydrate profile, which was composed of diets containing 42.5% NDF and 26.8% starch (HF-LS) or 26.8% NDF and 40.6% starch (LF-HS) and the second factor was the protein source, in which a control diet (100% SBM), partial replacement of SBM with CHL (1/2 CHL) or SPI (1/2 SPI), or total replacement of SBM with CHL or SPI were used. All experimental diets were formulated to have 17% crude protein. The ruminal fluid was collected from 2 lactating Holstein cows, buffered with Van Soest medium at a ratio of 1:2 and added to serum bottles containing 0.50 g of the experimental diets. Bottles were incubated at 39°C for 24 and 48 h in triplicate; headspace pressure was measured, along with gas collection for methane (CH4) quantification at 0, 2, 4, 8, 16, 24, 36, and 48 h after incubation. The final medium was used to measure pH, ammonia, and volatile-fatty acid (VFA). After incubation, feed bags were recovered and used for estimation of degradability of DMD, NDF, and OMD. Statistical analysis was carried out using the MIXED procedure of SAS, with carbohydrate profile, protein source, assay, and its interactions as fixed effects, with run and bottle as random effects. Orthogonal contrasts were used to compare carbohydrate profile, algae species, carbohydrate profile × algae interaction, and linear and quadratic effects of SBM replacement with CHL or SPI. There was no interaction effect between carbohydrate profile and algae source. LF-HS improved gas production, degradability of nutrients, and VFA, mainly increasing the production of butyrate and propionate. When compared with CHL, SPI had a greater degradability of nutrients and branched VFA, along with reduction in total gas production and tended to reduce total CH4 yield. The replacement of SBM with algae linearly reduced the degradability of nutrients, along with a linear reduction in gas production. When replacement of SBM with only SPI was evaluated, SPI slightly reduced the degradability of nutrients; however, it promoted a linear reduction in CH4 yield, as well as reduction in CH4 yield by unit of degraded DM, NDF, and OM. In summary, there was no interaction of carbohydrate profile and protein source, which means that SBM replacement had a similar effect, regardless of dietary carbohydrate profile. Spirulina may be a more suitable algae source when compared with Chlorella due to the potential to reduce CH4.

2.
J Dairy Sci ; 107(3): 1460-1471, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37944802

RESUMO

The objective of this study was to evaluate the effects of partially replacing soybean meal (SBM) with algal sources on in vitro ruminal fermentation. Using 6 fermenters in a 3 × 3 replicated Latin square with 3 periods of 10 d each, we tested 3 treatments: a control diet (CRT) with SBM at 17.8% of the diet dry matter (DM); and 50% SBM biomass replacement with either Chlorella pyrenoidosa (CHL); or Spirulina platensis (SPI). The basal diet was formulated to meet the requirements of a 680-kg Holstein dairy cow producing 45 kg/d of milk with 3.5% fat and 3% protein. All diets had a similar nutritional composition (16.0% CP; 34.9% NDF; 31.0% starch, DM basis) and fermenters were provided with 106 g DM/d split into 2 portions. After 7 d of adaptation, samples were collected for 3 d of each period for analyses of ruminal fermentation at 0, 1, 2, 4, 6, and 8 h after morning feeding for evaluation of the ruminal fermentation kinetics. For the evaluation of the daily production of total metabolites and for the evaluation of nutrient degradability, samples from the effluent containers were collected daily. Statistical analysis was performed with the MIXED procedure of SAS with treatment, time, and their interactions considered as fixed effects; day, square, and fermenter were considered as random effects. Orthogonal contrasts (CRT vs. algae; and CHL vs. SPI) were used to depict the treatment effect, and significance was declared when P ≤ 0.05. Fermenters that received algae-based diets had a greater propionate molar concentration and molar proportion when compared with the fermenters fed CRT diets. In addition, those algae-fed fermenters had lower branched short-chain fatty acids (BSCFA) and isoacids (IA), which are biomarkers of ruminal protein degradation, along with lower ammonia (NH3-N) concentration and greater nonammonia nitrogen (NAN). When contrasting with fermenters fed SPI-diets, fermenters fed based CHL-diets had a lower molar concentration of BSCFA and IA, along with lower NH3-N concentration and flow, and greater NAN, bacterial nitrogen flow, and efficiency of nitrogen utilization. Those results indicate that CHL protein may be more resistant to ruminal degradation, which would increase efficiency of nitrogen utilization. In summary, partially replacing SBM with algae biomass, especially with CHL, is a promising strategy to improve the efficiency of nitrogen utilization, due to the fact that fermenters fed CHL-based diets resulted in a reduction in BSCFA and IA, which are markers of protein degradation, and it would improve the efficiency of nitrogen utilization. However, further validation using in vivo models are required.


Assuntos
Chlorella , Microalgas , Feminino , Bovinos , Animais , Fermentação , Lactação , Proteólise , Ração Animal/análise , Biomassa , Chlorella/metabolismo , Farinha/análise , Glycine max , Nutrientes/análise , Nitrogênio/metabolismo
3.
Bioresour Technol ; 394: 130234, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38142906

RESUMO

A new alternative for hydrodynamic cavitation-assisted pretreatment of sugarcane bagasse was proposed, along with a simultaneous saccharification and co-fermentation (SSCF) process performed in interconnected columns. Influential variables in the pretreatment were evaluated using a statistical design, indicating that an ozone flow rate of 10 mg min-1 and a pH of 5.10 resulted in 86 % and 72 % glucan and xylan hydrolysis yields, respectively, in the subsequent enzymatic hydrolysis process. Under these optimized conditions, iron sulfate (15 mg L-1) was added to assess Fenton pretreatment, resulting in glucan and xylan hydrolysis yields of 92 % and 71 %, respectively, in a material pretreated for 10 min. In SSCF, ethanol volumetric productivities of 0.33 g L-1 h-1 and of 0.54 g L-1 h-1 were obtained in batch and fed-batch operation modes, achieving 26 g L-1 of ethanol in 48 h in the latter mode.


Assuntos
Celulose , Saccharomycetales , Saccharum , Celulose/metabolismo , Fermentação , Saccharum/metabolismo , Etanol , Hidrodinâmica , Células Imobilizadas/metabolismo , Xilanos , Hidrólise
4.
Braz J Biol ; 83: e274991, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37909589

RESUMO

The objective of this study was to evaluate the water status, photosynthetic pigments, and photochemical efficiency of mini watermelon plants under salt stress and phosphate fertilization. The experiment was conducted in pots under greenhouse conditions in Pombal, PB, Brazil. The experimental design used was randomized blocks in a 5 × 4 factorial scheme, with five levels of electrical conductivity of irrigation water - ECw (0.3, 1.3, 2.3, 3.3, and 4.3 dS m-1) and four doses of phosphorus (60, 80, 100, and 120% of the recommendation), with three replicates. The relative water content in the tissues decreased with the increase in ECw levels in all phosphorus doses, with decreases of 7.05, 7.81 and 8.83% per unit increase in ECw, in plants fertilized with 80, 100 and 120% P2O5. On the other hand, ECw levels increased electrolyte leakage, regardless of phosphorus doses of the recommendation. The synthesis of photosynthetic pigments and the quantum efficiency of photosystem II were inhibited by increasing water salinity from 0.3 dS m-1 in plants grown under phosphorus doses above 60% of the recommendation. Water salinity from 0.3 dS m-1 reduced chlorophyll b contents, initial, maximum, and variable fluorescence of mini watermelon plants, with a decrease of 11.86, 4.51, 4.53, and 4.54% per unit increment of ECw, respectively.


Assuntos
Citrullus , Fosfatos , Fotossíntese , Águas Salinas , Fósforo
5.
Bioresour Technol ; 362: 127781, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35973567

RESUMO

The effect of a non-ionic surfactant optimized formulation (SOF) obtained from an experimental design was evaluated for different influencing variables in the processing of sugarcane bagasse cellulignin to produce biopigments. The major findings in the saccharification stage using the SOF point that: at same enzyme loading, the highest glucan hydrolysis yield was 63 % (2-fold higher compared to control); the enzyme loading of 2.5 FPU/g resulted in similar yield compared to 10 FPU/g (control); 15 % (m/v) of total solids loading maintained the yield in fed-batch configuration; the hydrolysis yield is maintained at high shear force stress (800 rpm of stirring rate) and temperatures (50-70 °C). Besides, under separate and semi-simultaneous hydrolysis and fermentation, the maximum biopigments production were of 10 AU510nm/mL and 17.84 AU510nm/mL, respectively. The SOF used in this study was found to be a promising additive either in a single or sequential steps to produce biopigments in biorefineries.


Assuntos
Saccharum , Celulose/metabolismo , Fermentação , Hidrólise , Monascus , Saccharum/metabolismo , Tensoativos
6.
Bioresour Technol ; 345: 126458, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34863850

RESUMO

Environmental problems due to utilization of fossil-derived materials for energy and chemical generation has prompted the use of renewable alternative sources, such as lignocellulose biomass (LB). Indeed, the production of biomolecules and biofuels from LB is among the most important current research topics aiming to development a sustainable bioeconomy. Yet, the industrial use of LB is limited by the recalcitrance of biomass, which impairs the hydrolysis of the carbohydrate fractions. Hydrodynamic cavitation (HC) and Advanced Oxidative Processes (AOPs) has been proposed as innovative pretreatment strategies aiming to reduce process time and chemical inputs. Therefore, the underlying mechanisms, procedural strategies, influence on biomass structure, and research gaps were critically discussed in this review. The performed discussion can contribute to future developments, giving a wide overview of the main involved aspects.


Assuntos
Hidrodinâmica , Lignina , Biocombustíveis , Biomassa , Lignina/metabolismo , Estresse Oxidativo
7.
Sugar Tech ; 23(6): 1425-1431, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33976476

RESUMO

Lignocellulosic sugars are the major renewable building blocks for green fuels and chemicals production. However, the implication of an effective pretreatment process is an inevitable process to access the biomass sugars. Alkaline pretreatment is a viable pretreatment process, causing a selective removal of lignin, with a minimum degradation of carbohydrates, increasing porosity and surface area, eventually enhancing enzymatic hydrolysis. Here, we have assessed commercial cloth washing detergents as catalytic agents, for the lignin removal from sugarcane bagasse. Three different detergents (Brilhiante® (B), Omo® (O), Sabonito Flash® (F)) were tested using three different concentrations (5, 10 and 15%) with and without pH adjustment. Pretreatment with O5pH (5% Omo®, pH 12) showed the maximum lignin removal (81.14%) and retainment of cellulose (44.15%), and hemicellulose (29.71%) in the pretreated bagasse. The maximum sugars (26.62 g/L) were released from the O10pH-pretreated sugarcane bagasse. This study shows the potential of washing detergents as the new potential catalytic agents for the pretreatment of biomass for efficient sugars recovery and retaining maximum lignin in the pretreated substrate.

8.
Syst Rev ; 9(1): 220, 2020 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-32988410

RESUMO

BACKGROUND: Expenditure on driver-related behavioral interventions and road use policy is often justified by their impact on the frequency of fatal and serious injury crashes. Given the rarity of fatal and serious injury crashes, offense history, and crash history of drivers are sometimes used as an alternative measure of the impact of interventions and changes to policy. The primary purpose of this systematic review was to assess the rigor of statistical modeling used to predict fatal and serious crashes from offense history and crash history using a purpose-made quality assessment tool. A secondary purpose was to explore study outcomes. METHODS: Only studies that used observational data and presented a statistical model of crash prediction from offense history or crash history were included. A quality assessment tool was developed for the systematic evaluation of statistical quality indicators across studies. The search was conducted in June 2019. RESULTS: One thousand one hundred and five unique records were identified, 252 full texts were screened for inclusion, resulting in 20 studies being included in the review. The results indicate substantial and important limitations in the modeling methods used. Most studies demonstrated poor statistical rigor ranging from low to middle quality. There was a lack of confidence in published findings due to poor variable selection, poor adherence to statistical assumptions relating to multicollinearity, and lack of validation using new data. CONCLUSIONS: It was concluded that future research should consider machine learning to overcome correlations in the data, use rigorous vetting procedures to identify predictor variables, and validate statistical models using new data to improve utility and generalizability of models. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42019137081.


Assuntos
Acidentes de Trânsito , Envio de Mensagens de Texto , Humanos , Modelos Estatísticos , Políticas
9.
Bioresour Technol ; 290: 121777, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31319211

RESUMO

Development of new technologies for pretreatment of lignocellulosic biomass is a current research challenge. In this way, hydrodynamic cavitation (HC) was used to assist alkaline hydrogen peroxide pretreatment of sugarcane bagasse (SCB) in sequential batches (SB-HC), semi-continuous (SC-HC) and continuous (C-HC) processes. Pretreatment resulted in compositional modifications in the material, mainly regarding the cellulose and lignin contents. The released sugars after enzymatic hydrolysis resulted, on average, in 42 g and 32-35 g of glucose per 100 g of SCB for samples treated in B-HC (10 min of process) and SC-HC process (7.5 min residence time), respectively. In C-HC process, with an average residence time of 7.5 min and 3.75 min, 38-46 g and 32-38 g of glucose per 100 g of SCB were obtained respectively in enzymatic hydrolysis step. HC technology was shown as a promising alternative for pretreatment of lignocellulosic biomass in all evaluated configurations aiming to produce high value bioproducts.


Assuntos
Saccharum , Celulose , Hidrodinâmica , Hidrólise , Lignina
10.
Prep Biochem Biotechnol ; 49(4): 328-333, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30712449

RESUMO

L-asparaginase is an important enzyme used in the pharmaceutical and food industry, which can be produced by different microorganisms using low cost feedstocks. In this work, sugarcane bagasse (SCB) was used as support for enzyme production in solid-state fermentation (SSF) by A. terreus. Initially, the influence of the variables carbon and nitrogen sources on the enzyme production was studied following an experimental design carried out in Erlenmeyer flasks. Statistical analysis indicated the use of 0.54% of starch, 0% of maltose, 0.44% of asparagine, and 1.14% of glutamine in the medium, resulting in enzyme activity per volume of produced extract of 120.723 U/L. Then, these conditions were applied in a horizontal column reactor filled with SCB, producing 105.3 U/L of enzyme activity. Therefore, the potential of extracellular L-asparaginase enzyme production in the column reactor using sugarcane bagasse as support was demonstrated and it represents a system that can favor large scale production.


Assuntos
Asparaginase/biossíntese , Aspergillus/enzimologia , Reatores Biológicos , Celulose/química , Fermentação , Saccharum/química , Asparaginase/isolamento & purificação
11.
Arq. bras. med. vet. zootec. (Online) ; 71(1): 281-290, jan.-fev. 2019. tab, graf
Artigo em Português | LILACS, VETINDEX | ID: biblio-989354

RESUMO

O enriquecimento ambiental é uma ferramenta importante dentro dos sistemas de produção, a fim de promover o bem-estar e favorecer a saúde dos animais. Portanto, o objetivo deste trabalho foi avaliar o efeito do enriquecimento ambiental sobre o estresse de suínos na fase de creche. Foram utilizados 32 leitões, alojados em granja experimental, distribuídos em quatro grupos (n= 8): corda, corrente, garrafa PET e controle negativo. Amostras de sangue foram coletadas no início e no final do experimento para contagem de leucócitos circulantes e determinação de antioxidantes não enzimáticos, óxido nítrico, malondialdeído, e de saliva para avaliação do cortisol. Foi aplicado etograma e fez-a ganho médio de peso diário e a conversão alimentar. Os parâmetros avaliados no primeiro dia do experimento não variaram entre os grupos (P>0,05). No último dia do experimento, os valores de neutrófilos e da relação neutrófilo/linfócito foram mais elevados nos leitões do grupo corrente, assim como os valores de cortisol salivar (P<0,05). O ácido úrico apresentou-se mais elevado nos leitões do grupo corrente e o malondialdeído (MDA) nos do grupo garrafa (P< 0,05). Os enriquecimentos ambientais estimularam comportamentos positivos nos leitões, tendo a corda se destacado como o mais atrativo. Por outro lado, a corrente apresentou efeito negativo sobre a fisiologia dos animais, gerando estresse, assim como a garrafa, que induziu a peroxidação lipídica e um menor ganho de peso nos leitões.(AU)


Environmental enrichment is an important tool within production systems to promote welfare and animal health. The aim of this study was to evaluate the effect of enrichment objects on stress of piglets in nursery phase. 32 piglets housed in experimental farm were distributed in 4 groups (n= 8): rope, chain, pet bottle and negative control. Blood samples were collected at the beginning and end of the experiment to count circulating leukocytes and determine non-enzymatic antioxidants, nitric oxide, malondialdehyde, and saliva to evaluate cortisol. At the same time, an etogram and evaluation of mean daily gain and feed conversion were applied. The evaluated parameters on first day of the experiment did not vary between groups (P> 0.05). On the last day, neutrophil and neutrophil /lymphocyte ratios were higher in chain group piglets, as were salivary cortisol values (P< 0.05). Uric acid was higher in chain group and MDA in bottle group (P< 0.05). Environmental enrichment stimulated positive behaviors in piglets, where the rope stood out as the most attractive. On the other hand, chain had a negative effect on animal physiology, generating stress, as well as the bottle that induced lipid peroxidation and a lower weight gain in piglets.(AU)


Assuntos
Animais , Suínos/anormalidades , Suínos/crescimento & desenvolvimento , Estresse Fisiológico , Comportamento Animal
12.
Int J Biol Macromol ; 127: 169-177, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30639656

RESUMO

Pullulan is a biopolymer used in food industry produced by Aureobasidium pullulans from starch. In the present work, sugarcane bagasse (SCB) hydrolysate was evaluated as an alternative substrate in fermentation process assisted by blue LED lights. The best fermentation conditions in Erlenmeyer flasks were 25.3 °C, stirring speed of 232 rpm and yeast extract concentration of 1.88 g/L, yielding 25.19 g/L of pullulan, that corresponded to yield of 0.48 g/g and 0.28 g/(L·h) of volumetric productivity. By using a column bubble photobioreactor, similar yield values were obtained. Thermal properties of the produced pullulan as glass transition (Tg) and melting (Tm) temperatures were 38 °C and 160 °C, respectively, which were similar to the corresponding values of commercial food grade pullulan. Therefore, SCB hydrolysate is a promising substrate to produce good quality pullulan (86% of purity) with application in food industry, besides to represent a new alternative for biorefineries.


Assuntos
Ascomicetos/crescimento & desenvolvimento , Celulose/química , Glucanos , Saccharum/química , Glucanos/biossíntese , Glucanos/química , Glucanos/isolamento & purificação
13.
PLoS One ; 13(11): e0206763, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30388164

RESUMO

BACKGROUND: Physical activity reduces the risk of noncommunicable diseases and is therefore an essential component of a healthy lifestyle. Regular engagement in physical activity can produce immediate and long term health benefits. However, physical activity levels are not as high as might be expected. For example, according to the global World Health Organization (WHO) 2017 statistics, more than 80% of the world's adolescents are insufficiently physically active. In response to this problem, physical activity programs have become popular, with step counts commonly used to measure program performance. Analysing step count data and the statistical modeling of this data is therefore important for evaluating individual and program performance. This study reviews the statistical methods that are used to model and evaluate physical activity programs, using step counts. METHODS: Adhering to PRISMA guidelines, this review systematically searched for relevant journal articles which were published between January 2000 and August 2017 in any of three databases (PubMed, PsycINFO and Web of Science). Only the journal articles which used a statistical model in analysing step counts for a healthy sample of participants, enrolled in an intervention involving physical exercise or a physical activity program, were included in this study. In these programs the activities considered were natural elements of everyday life rather than special activity interventions. RESULTS: This systematic review was able to identify 78 unique articles describing statistical models for analysing step counts obtained through physical activity programs. General linear models and generalized linear models were the most popular methods used followed by multilevel models, while structural equation modeling was only used for measuring the personal and psychological factors related to step counts. Surprisingly no use was made of time series analysis for analysing step count data. The review also suggested several strategies for the personalisation of physical activity programs. CONCLUSIONS: Overall, it appears that the physical activity levels of people involved in such programs vary across individuals depending on psychosocial, demographic, weather and climatic factors. Statistical models can provide a better understanding of the impact of these factors, allowing for the provision of more personalised physical activity programs, which are expected to produce better immediate and long-term outcomes for participants. It is hoped that this review will identify the statistical methods which are most suitable for this purpose.


Assuntos
Acelerometria/métodos , Exercício Físico , Modelos Estatísticos , Interpretação Estatística de Dados , Promoção da Saúde/métodos , Humanos , Avaliação de Programas e Projetos de Saúde , Dispositivos Eletrônicos Vestíveis
14.
J Appl Microbiol ; 123(5): 1203-1213, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28799253

RESUMO

AIMS: This study aimed to evaluate new d-xylose-fermenting yeasts from Brazilian ecosystems for the production of second-generation ethanol. METHODS AND RESULTS: d-xylose-fermenting yeasts isolated from rotting wood and wood-boring insects were identified as the species Scheffersomyces parashehatae, Scheffersomyces illinoinensis, Spathaspora arborariae and Wickerhamomyces rabaulensis. Among the yeasts tested, those of Sc. parashehatae exhibited the highest ethanol production when cultivated on complex medium (Yp/set  = 0·437 g g-1 ). Sheffersomyces illinoinensis and Sp. arborariae showed similar ethanol production in this assay (Yp/set up to 0·295 g g-1 ). In contrast, in sugarcane bagasse hemicellulosic hydrolysate, Sc. parashehatae and Sc. illinoinensis exhibited similar ethanol production (Yp/set up to 0·254 g g-1 ), whereas Sp. arborariae showed the lowest results (peak Yp/set  = 0·160 g g-1 ). Wickerhamomyces rabaulensis exhibited a remarkable xylitol production (Yp/sxyl  = 0·681  g g-1 ), but producing low levels of ethanol (Yp/set  = 0·042 g g-1 ). CONCLUSIONS: The novel d-xylose-fermenting yeasts showed promising metabolic characteristics for use in fermentation processes for second-generation ethanol production, highlighting the importance of bioprospecting research of micro-organisms for biotechnological applications. SIGNIFICANCE AND IMPACT OF THE STUDY: This study widens the scope for future researches that may examine the native yeasts presented, as limited studies have investigated these species previously.


Assuntos
Celulose/metabolismo , Etanol/metabolismo , Polissacarídeos/metabolismo , Saccharomycetales/metabolismo , Saccharum/metabolismo , Madeira/microbiologia , Brasil , Ecossistema , Fermentação , Saccharomycetales/classificação , Saccharomycetales/genética , Saccharomycetales/isolamento & purificação , Xilitol/biossíntese , Xilose/metabolismo
15.
J Dairy Sci ; 100(10): 7864-7873, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28822551

RESUMO

Staphylococcus aureus is an important pathogen that has shown ability to establish biofilm communities that can represent a source of contamination and resistance in food processing. Rhamnolipids (RL) have attracted attention as candidates to replace synthetic surfactants, exhibiting high surface activity combined with its microbial origin, biodegradability, and low toxicity. In this work, an RL biosurfactant was evaluated regarding its ability to disrupt or remove S. aureus biofilms established on polystyrene plates using nutrient broth and skim milk as the growth media. Rhamnolipid treatment was performed at different surfactant concentrations and temperatures. Rhamnolipid removes up to 88.9% of milk-based biofilms, whereas for nutrient medium 35% removal was attained. The RL concentration affects the disruption of nutrient medium-based biofilms. High carbohydrate content of milk-based biofilms favors disruption by RL and the organization of RL molecules in solution showed a predominance of aggregates from 1 to 10 and 100 to 1,000 nm in all conditions studied. Biofilm disruption activity of RL is nutrient-specific and dependent on biofilm matrix composition. Staphylococcus aureus biofilms established in milk were significantly reduced using RL at low concentrations and temperatures. These findings suggest potential application of RL in milk (dairy) processing industries where low temperatures are applied.


Assuntos
Biofilmes/efeitos dos fármacos , Glicolipídeos/farmacologia , Staphylococcus aureus/fisiologia , Tensoativos/farmacologia , Animais , Leite/microbiologia
16.
Interação psicol ; 20(2): 234-242, maio-ago. 2016. tab, ilus
Artigo em Português | Index Psicologia - Periódicos | ID: psi-69575

RESUMO

A eficácia coletiva docente é a percepção compartilhada pelos professores sobre a capacidade do corpodocentede organizar e executar ações necessárias a um efeito positivo no desempenho acadêmico dosalunos. Este artigo tem o objetivo de construir um panorama das pesquisas sobre eficácia coletiva deprofessores, analisando seus principais resultados. Para tanto, foram realizadas buscas de artigospublicados entre 2000 e 201 3, na base de dados Portal de Periódicos Capes. Os resultados indicam que aeficácia coletiva de professores está diretamente relacionada ao desempenho acadêmico dos alunos.Notou-se ainda que outras variáveis podem influenciar as crenças coletivas, tais como a autoeficácia e asituação socioeconômicada escola(AU)


Assuntos
Docentes , Eficácia , Literatura de Revisão como Assunto
17.
Bioresour Technol ; 203: 42-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26720138

RESUMO

A packed bed flow-through column reactor (PBFTCR) was used for pretreatment and subsequent enzymatic hydrolysis of sugarcane bagasse (SCB). Alkaline pretreatment was performed at 70 °C for 4h with fresh 0.3M NaOH solution or with liquor recycled from a previous pretreatment batch. Scheffersomyces stipitis NRRL-Y7124 was used for fermentation of sugars released after enzymatic hydrolysis (20 FPU g(-1) of dry SCB). The highest results for lignin removal were 61% and 52%, respectively, observed when using fresh NaOH or the first reuse of the liquor. About 50% of cellulosic and 57% of hemicellulosic fractions of pretreated SCBs were enzymatically hydrolyzed and the maximum ethanol production was 23.4 g L(-1) (ethanol yield of 0.4 gp gs(-1)), with near complete consumption of both pentoses and hexoses present in the hydrolysate during the fermentation. PBFTCR as a new alternative for SCB-biorefineries is presented, mainly considering its simple configuration and efficiency for operating with a high solid:liquid ratio.


Assuntos
Biocombustíveis , Celulose/metabolismo , Fermentação , Saccharomycetales/metabolismo , Celulose/ultraestrutura , Etanol/análise , Etanol/metabolismo , Hidrólise , Lignina/metabolismo , Saccharum
18.
Persoonia ; 37: 218-403, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-28232766

RESUMO

Novel species of fungi described in this study include those from various countries as follows: Australia: Apiognomonia lasiopetali on Lasiopetalum sp., Blastacervulus eucalyptorum on Eucalyptus adesmophloia, Bullanockia australis (incl. Bullanockia gen. nov.) on Kingia australis, Caliciopsis eucalypti on Eucalyptus marginata, Celerioriella petrophiles on Petrophile teretifolia, Coleophoma xanthosiae on Xanthosia rotundifolia, Coniothyrium hakeae on Hakea sp., Diatrypella banksiae on Banksia formosa, Disculoides corymbiae on Corymbia calophylla, Elsinoë eelemani on Melaleuca alternifolia, Elsinoë eucalyptigena on Eucalyptus kingsmillii, Elsinoë preissianae on Eucalyptus preissiana, Eucasphaeria rustici on Eucalyptus creta, Hyweljonesia queenslandica (incl. Hyweljonesia gen. nov.) on the cocoon of an unidentified microlepidoptera, Mycodiella eucalypti (incl. Mycodiella gen. nov.) on Eucalyptus diversicolor, Myrtapenidiella sporadicae on Eucalyptus sporadica, Neocrinula xanthorrhoeae (incl. Neocrinula gen. nov.) on Xanthorrhoea sp., Ophiocordyceps nooreniae on dead ant, Phaeosphaeriopsis agavacearum on Agave sp., Phlogicylindrium mokarei on Eucalyptus sp., Phyllosticta acaciigena on Acacia suaveolens, Pleurophoma acaciae on Acacia glaucoptera, Pyrenochaeta hakeae on Hakea sp., Readeriella lehmannii on Eucalyptus lehmannii, Saccharata banksiae on Banksia grandis, Saccharata daviesiae on Daviesia pachyphylla, Saccharata eucalyptorum on Eucalyptus bigalerita, Saccharata hakeae on Hakea baxteri, Saccharata hakeicola on Hakea victoria, Saccharata lambertiae on Lambertia ericifolia, Saccharata petrophiles on Petrophile sp., Saccharata petrophilicola on Petrophile fastigiata, Sphaerellopsis hakeae on Hakea sp., and Teichospora kingiae on Kingia australis.Brazil: Adautomilanezia caesalpiniae (incl. Adautomilanezia gen. nov.) on Caesalpina echinata, Arthrophiala arthrospora (incl. Arthrophiala gen. nov.) on Sagittaria montevidensis, Diaporthe caatingaensis (endophyte from Tacinga inamoena), Geastrum ishikawae on sandy soil, Geastrum pusillipilosum on soil, Gymnopus pygmaeus on dead leaves and sticks, Inonotus hymenonitens on decayed angiosperm trunk, Pyricularia urashimae on Urochloa brizantha, and Synnemellisia aurantia on Passiflora edulis. Chile: Tubulicrinis australis on Lophosoria quadripinnata.France: Cercophora squamulosa from submerged wood, and Scedosporium cereisporum from fluids of a wastewater treatment plant. Hawaii: Beltraniella acaciae, Dactylaria acaciae, Rhexodenticula acaciae, Rubikia evansii and Torula acaciae (all on Acacia koa).India: Lepidoderma echinosporum on dead semi-woody stems, and Rhodocybe rubrobrunnea from soil. Iran: Talaromyces kabodanensis from hypersaline soil. La Réunion: Neocordana musarum from leaves of Musa sp. Malaysia: Anungitea eucalyptigena on Eucalyptus grandis × pellita, Camptomeriphila leucaenae (incl. Camptomeriphila gen. nov.) on Leucaena leucocephala, Castanediella communis on Eucalyptus pellita, Eucalyptostroma eucalypti (incl. Eucalyptostroma gen. nov.) on Eucalyptus pellita, Melanconiella syzygii on Syzygium sp., Mycophilomyces periconiae (incl. Mycophilomyces gen. nov.) as hyperparasite on Periconia on leaves of Albizia falcataria, Synnemadiella eucalypti (incl. Synnemadiella gen. nov.) on Eucalyptus pellita, and Teichospora nephelii on Nephelium lappaceum.Mexico: Aspergillus bicephalus from soil. New Zealand: Aplosporella sophorae on Sophora microphylla, Libertasomyces platani on Platanus sp., Neothyronectria sophorae (incl. Neothyronectria gen. nov.) on Sophora microphylla, Parastagonospora phoenicicola on Phoenix canariensis, Phaeoacremonium pseudopanacis on Pseudopanax crassifolius, Phlyctema phoenicis on Phoenix canariensis, and Pseudoascochyta novae-zelandiae on Cordyline australis.Panama: Chalara panamensis from needle litter of Pinus cf. caribaea. South Africa: Exophiala eucalypti on leaves of Eucalyptus sp., Fantasmomyces hyalinus (incl. Fantasmomyces gen. nov.) on Acacia exuvialis, Paracladophialophora carceris (incl. Paracladophialophora gen. nov.) on Aloe sp., and Umthunziomyces hagahagensis (incl. Umthunziomyces gen. nov.) on Mimusops caffra.Spain: Clavaria griseobrunnea on bare ground in Pteridium aquilinum field, Cyathus ibericus on small fallen branches of Pinus halepensis, Gyroporus pseudolacteus in humus of Pinus pinaster, and Pseudoascochyta pratensis (incl. Pseudoascochyta gen. nov.) from soil. Thailand: Neoascochyta adenii on Adenium obesum, and Ochroconis capsici on Capsicum annuum. UK: Fusicolla melogrammae from dead stromata of Melogramma campylosporum on bark of Carpinus betulus. Uruguay: Myrmecridium pulvericola from house dust. USA: Neoscolecobasidium agapanthi (incl. Neoscolecobasidium gen. nov.) on Agapanthus sp., Polyscytalum purgamentum on leaf litter, Pseudopithomyces diversisporus from human toenail, Saksenaea trapezispora from knee wound of a soldier, and Sirococcus quercus from Quercus sp. Morphological and culture characteristics along with DNA barcodes are provided.

19.
Curr Microbiol ; 72(2): 133-138, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26507335

RESUMO

The use of sugarcane bagasse hemicellulosic hydrolysates presents an interesting alternative to second generation (2G) ethanol production. Techniques to enhance the fermentation process, e.g., the use of immobilized cells, is one of the key factors for efficient production. Here, the effect of two important parameters (cell concentration in immobilized system and stirring rate) on the 2G ethanol production using the wild Brazilian yeast S. shehatae UFMG-HM 52.2 immobilized in calcium alginate matrix are presented. A 2(2) full factorial design of experiments was carried out to evaluate the effect of cell concentrations in sodium alginate solution for immobilized bead production (3.0, 6.0, and 9.0 g/L) and stirring rate (150, 200, and 250 rpm) for 2G ethanol production. Statistical analysis showed that the use of both variables at low levels enhanced ethanol yield (YP/S). Under these process conditions, YP/S of 0.31 g/g and ethanol productivity (Qp) of 0.12 g/L h were achieved. Results showed the potential of this immobilized yeast in 2G ethanol production from C5 sugars and demonstrate the importance of adequate cell concentration in immobilized systems, a finding that stands to increase bioprocesses yields and productivity.


Assuntos
Reatores Biológicos/microbiologia , Células Imobilizadas/metabolismo , Etanol/metabolismo , Glicosídeo Hidrolases/metabolismo , Saccharomycetales/metabolismo , Biotecnologia/métodos , Brasil
20.
Vet Parasitol ; 208(3-4): 231-7, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25648284

RESUMO

This study aimed to verify the influence of bovine genetic resistance on biological traits of the Rhipicephalus (Boophilus) microplus tick. Genetic resistance or susceptibility was determined according to breeding values for tick counts, predicted using a dataset of 9007 Hereford and Braford (Hereford×Zebu) bovines naturally infested and raised under extensive production systems in southern Brazil. From a total of 974 Braford heifers born in 2008, 20 were classified as genetically tick-resistant and 20 classified as genetically tick-susceptible, and used to obtain the ticks samples used in this study. The 40 heifers were exposed to four subsequent artificial infestations with approximately 20,000 larvae at 14-day intervals. From the 19th to 23rd day of each infestation tick counts were performed on the left body side of the heifers. Engorged ticks were manually collected on the day of highest observed burden after each infestation. Tick counts on susceptible heifers were 5.5, 10.5, 11.1 and 6.9 times larger than on resistant heifers, respectively, after the first, second, third and fourth artificial infestations. In the third infestation, ticks from resistant heifers showed lower egg production index (P<0.0001) than ticks from susceptible heifers. In the fourth infestation, ticks from susceptible group showed higher egg mass weight (P<0.05) and nutrient index (P<0.0001) than ticks from resistant heifers. Tick initial weights showed a positive association with egg production index in susceptible heifers (P<0.05) and a negative association in the resistant group (P<0.05), suggesting a host defense mechanism that reduces the conversion efficiency of ingested blood to eggs in engorged ticks from resistant cattle. This shows that bovine genetic tick resistance, in addition to affecting the number of ticks carried by the animals, also affected the egg mass weight, egg production and nutrient indexes of ticks. The results of the present study imply that the selection of resistant animals could be used as a strategic tool for tick control in production systems, reducing infestation levels on cattle and environment.


Assuntos
Doenças dos Bovinos/parasitologia , Predisposição Genética para Doença , Rhipicephalus/fisiologia , Infestações por Carrapato/veterinária , Animais , Bovinos , Doenças dos Bovinos/genética , Doenças dos Bovinos/prevenção & controle , Infestações por Carrapato/genética , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controle
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA