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1.
Biotechnol Appl Biochem ; 70(3): 1279-1290, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36580629

RESUMO

This work aimed to produce porous poly-hydroxybutyrate (PHB) pellets in order to evaluate the pellets as a support for immobilization of the metagenomic lipase, LipG9. Four types of pelletized PHB particles with different morphological characteristics were obtained using the double emulsion and solvent evaporation technique (DESE). The micropores of these PHB pellets had similar average diameters (about 3 nm), but the pellets had different specific surface areas: 11.7 m2 g-1 for the PHB powder, 8.4 m2  g-1 for the control pellets (Ø < 0.5 mm, produced without the pore forming agent), 10.0 m2  g-1 for the small pellets (Ø < 0.5 mm), 9.5 m2  g-1 for the medium pellets (0.5 < Ø < 0.8 mm) and 8.4 m2  g-1 for the large pellets (Ø > 1.4 mm). Purified LipG9 was immobilized by adsorption on these pellets, and the results were compared with those obtained with PHB powder. The highest immobilization yield (83%) was obtained for the medium PHB pellets, followed by large (76%) and small (55%) PHB pellets. The activity of LipG9 immobilized on the pellets, for the synthesis of ethyl oleate in n-hexane, was highest for the medium pellets (22 U g-1 ). The immobilization yield was high for PHB powder (99%) but the esterification activity was slightly lower (20 U g-1 ). These results show that pelletized PHB beads can be used for the immobilization of lipases, with the advantage that pelletized PHB will perform better than PHB powder in large-scale enzyme bioreactors.


Assuntos
Hidroxibutiratos , Lipase , Emulsões , Poliésteres , Porosidade , Pós , Solventes
2.
BMC Public Health ; 23(1): 1943, 2023 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-37805529

RESUMO

This study aimed to verify the association between the weekly frequency of physical education (PE) classes and leisure sitting time among adolescents. We analyzed data from 73 countries using the Global School-based Student Health Survey (283,233 adolescents between 11 and 18 years of age). Leisure sitting time and weekly frequency of PE classes were self-reported. Sex, age, and food insecurity were used as covariates and the analyses were stratified by world regions and country income level. Poisson regression models (random-effects meta-analysis) were used for the main analyses. In comparison with 1 PE class per week (reference group), those with no PE classes presented a lower prevalence of ≥ 3 h/d of leisure sitting time (PR [95%CI] = 0.94 [0.91; 0.98]). On the other hand, adolescents with 2 days (PR [95%CI] = 1.06 [1.02; 1.26]), 3-4 days (PR [95%CI] = 1.17 [1.12; 1.22]), and 5 days (PR [95%CI] = 1.08 [1.04; 1.11]) of PE classes presented a higher likelihood of ≥ 3 h/d of leisure sitting time. No clear differences were observed for the different world regions and country income levels. We conclude that a higher weekly frequency of PE classes is associated with increased leisure sitting time among adolescents worldwide.


Assuntos
Educação Física e Treinamento , Comportamento Sedentário , Adolescente , Humanos , Comportamentos Relacionados com a Saúde , Atividades de Lazer , Inquéritos e Questionários , Masculino , Feminino , Criança
3.
Appl Microbiol Biotechnol ; 106(11): 4075-4089, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35622124

RESUMO

Understanding the mechanisms involved in tolerance to inhibitors is the first step in developing robust yeasts for industrial second-generation ethanol (E2G) production. Here, we used ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) and MetaboAnalyst 4.0 for analysis of MS data to examine the changes in the metabolic profile of the yeast Spathaspora passalidarum during early fermentation of hemicellulosic hydrolysates containing high or low levels of inhibitors (referred to as control hydrolysate or CH and strategy hydrolysate or SH, respectively). During fermentation of SH, the maximum ethanol production was 16 g L-1 with a yield of 0.28 g g-1 and productivity of 0.22 g L-1 h-1, whereas maximum ethanol production in CH fermentation was 1.74 g L-1 with a yield of 0.11 g g-1 and productivity of 0.01 g L-1 h-1. The high level of inhibitors in CH induced complex physiological and biochemical responses related to stress tolerance in S. passalidarum. This yeast converted compounds with aldehyde groups (hydroxymethylfurfural, furfural, 4-hydroxybenzaldehyde, syringaldehyde, and vanillin) into less toxic compounds, and inhibitors were found to reduce cell viability and ethanol production. Intracellularly, high levels of inhibitors altered the energy homeostasis and redox balance, resulting in lower levels of ATP and NADPH, while that of glycolytic, pentose phosphate, and tricarboxylic acid (TCA) cycle pathways were the most affected, being the catabolism of glucogenic amino acids, the main cellular response to inhibitor-induced stress. This metabolomic investigation reveals interesting targets for metabolic engineering of ethanologenic yeast strains tolerant against multiple inhibitors for E2G production. KEY POINTS: • Inhibitors in the hydrolysates affected the yeast's redox balance and energy status. • Inhibitors altered the glycolytic, pentose phosphate, TCA cycle and amino acid pathways. • S. passalidarum converted aldehyde groups into less toxic compounds.


Assuntos
Saccharomyces cerevisiae , Xilose , Etanol/metabolismo , Fermentação , Fosfatos , Polissacarídeos , Saccharomyces cerevisiae/metabolismo , Saccharomycetales , Espectrometria de Massas em Tandem , Xilose/metabolismo
4.
J Aging Phys Act ; 30(6): 1101-1117, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-35385825

RESUMO

We aimed to systematically analyze reviews of randomized clinical trials that investigate the overall effect of exercise and of different types of exercise on sleep in older adults. Meta-analysis was performed to obtain the standardized mean difference of the effect of the different types of exercise. Twenty systematic reviews published between 2012 and 2020 met the inclusion criteria of this overview. Moderate significant effects of exercise were observed on overall sleep quality and its subjective components (quality, duration, latency, habitual efficiency, medication use, and daytime dysfunction). Among the types of exercise, sensitivity analysis revealed significant effects of Pilates, Tai Chi, and Baduanjin Qigong on sleep quality. Exercise has a positive effect on sleep quality in older people. Our findings are extremely important, especially for decision makers in the health area, permitting the planning of actions and evidence-based decision making. PROSPERO registration number: CRD42020222469.


Assuntos
Sono , Tai Chi Chuan , Humanos , Idoso , Revisões Sistemáticas como Assunto , Exercício Físico , Terapia por Exercício
5.
FEMS Yeast Res ; 21(4)2021 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-33983370

RESUMO

In this work, we evaluated the fermentative performance and metabolism modifications of a second generation (2G) industrial yeast by comparing an industrial condition during laboratory and industrial scale fermentations. Fermentations were done using industrial lignocellulosic hydrolysate and a synthetic medium containing inhibitors and analyses were carried out through transcriptomics and proteomics of these experimental conditions. We found that fermentation profiles were very similar, but there was an increase in xylose consumption rate during fermentations using synthetic medium when compared to lignocellulosic hydrolysate, likely due to the presence of unknown growth inhibitors contained in the hydrolysate. We also evaluated the bacterial community composition of the industrial fermentation setting and found that the presence of homofermentative and heterofermentative bacteria did not significantly change the performance of yeast fermentation. In parallel, temporal differentially expressed genes (tDEG) showed differences in gene expression profiles between compared conditions, including heat shocks and the presence of up-regulated genes from the TCA cycle during anaerobic xylose fermentation. Thus, we indicate HMF as a possible electron acceptor in this rapid respiratory process performed by yeast, in addition to demonstrating the importance of culture medium for the performance of yeast within industrial fermentation processes, highlighting the uniquenesses according to scales.


Assuntos
Etanol/metabolismo , Fermentação , Saccharomyces cerevisiae/metabolismo , Xilose/metabolismo , Bactérias , Meios de Cultura , Regulação Fúngica da Expressão Gênica , Microbiologia Industrial , Lignina/metabolismo , Proteoma , RNA-Seq , Saccharomyces cerevisiae/genética , Transcriptoma
6.
J Aging Phys Act ; 29(2): 225-232, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32887851

RESUMO

This study aimed to compare the effects of resistance training performed with low versus moderate loads on systemic resting blood pressure (BP) in older women. A total of 29 women (72.6 ± 5.1 years) were randomized into two groups: low load (LOW, n = 15) and moderate load (MOD, n = 14). An 8-week whole-body resistance training program was carried out 3 days/week (eight exercises, three sets, 10 or 15 repetition maximum). The LOW and MOD groups trained with a relative load of 15 and 10 repetition maximum, respectively. Outcome measures included resting systolic and diastolic BP. After 8 weeks, both groups presented significant changes (p < .05) in systolic BP (LOW = -3.0%; MOD = -4.6%) and mean BP (LOW = -1.9%; MOD = -3.1%). There was no change for diastolic BP in the posttest in both groups. The results suggest that low and moderate loads are equally effective for promoting decreases in resting BP in older women.


Assuntos
Treinamento Resistido , Idoso , Pressão Sanguínea , Exercício Físico , Terapia por Exercício , Feminino , Humanos , Descanso
7.
Int J Mol Sci ; 22(17)2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34502023

RESUMO

Biomarkers are valuable tools in clinical practice. In 2001, the National Institutes of Health (NIH) standardized the definition of a biomarker as a characteristic that is objectively measured and evaluated as an indicator of normal biological processes, pathogenic processes, or pharmacological responses to a therapeutic intervention. A biomarker has clinical relevance when it presents precision, standardization and reproducibility, suitability to the patient, straightforward interpretation by clinicians, and high sensitivity and/or specificity by the parameter it proposes to identify. Thus, serum biomarkers should have advantages related to the simplicity of the procedures and to the fact that venous blood collection is commonplace in clinical practice. We described the potentiality of cfDNA as a general clinical biomarker and focused on endothelial dysfunction. Circulating cell-free DNA (cfDNA) refers to extracellular DNA present in body fluid that may be derived from both normal and diseased cells. An increasing number of studies demonstrate the potential use of cfDNA as a noninvasive biomarker to determine physiologic and pathologic conditions. However, although still scarce, increasing evidence has been reported regarding using cfDNA in cardiovascular diseases. Here, we have reviewed the history of cfDNA, its source, molecular features, and release mechanism. We also show recent studies that have investigated cfDNA as a possible marker of endothelial damage in clinical settings. In the cardiovascular system, the studies are quite new, and although interesting, stronger evidence is still needed. However, some drawbacks in cfDNA methodologies should be overcome before its recommendation as a biomarker in the clinical setting.


Assuntos
Ácidos Nucleicos Livres/sangue , Endotélio Vascular/fisiopatologia , Envelhecimento , Biomarcadores/sangue , Diabetes Mellitus , Endotélio Vascular/metabolismo , Humanos , Hipertensão , Comportamento Sedentário , Fumar
8.
Arch Microbiol ; 202(3): 645-656, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31776586

RESUMO

This study aimed to evaluate the effects of seed inoculation with Bradyrhizobium sp. and co-inoculation with Azospirillum brasilense. The seed treatments were as follows: control (without inoculation); A. brasilense (2 mL per kg-1 of seed); A. brasilense (4 mL per kg-1 of seed); Bradyrhizobium sp. (2 mL per kg-1 of seed); Bradyrhizobium sp. (4 mL per kg-1 of seed); A. brasilense + Bradyrhizobium sp. (2 mL of each strain per kg-1 of seed); and A. brasilense + Bradyrhizobium sp. (4 mL of each strain per kg-1 of seed). Peanut plants from seeds inoculated with Bradyrhizobium sp. and A. brasilense exhibited highest leaf concentration of photosynthetic pigments, carotenoids, nitrate, ammonia and amino acids. The inoculation of seeds with Bradyrhizobium sp. resulted in plants with increased concentrations of total soluble sugars, and ureides compared to the untreated plants. In contrast, seeds treated with A. brasilense alone resulted in plants exhibiting highest concentration of amino acids, which represent the highest concentration of nitrogen compounds in peanut plants. Seed inoculation with Bradyrhizobium sp. at a rate of 2 mL kg-1 was identified as the best treatment to promote increased biological nitrogen fixation and generate higher peanut yields.


Assuntos
Arachis/microbiologia , Bradyrhizobium/fisiologia , Sementes/crescimento & desenvolvimento , Ureia/metabolismo , Inoculantes Agrícolas/fisiologia , Arachis/crescimento & desenvolvimento , Arachis/metabolismo , Azospirillum brasilense/fisiologia , Fixação de Nitrogênio , Fotossíntese , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Sementes/metabolismo , Sementes/microbiologia , Ureia/química
9.
J Strength Cond Res ; 34(10): 2996-3002, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30273288

RESUMO

Ribeiro, AS, Schoenfeld, BJ, dos Santos, L, Nunes, JP, Tomeleri, CM, Cunha, PM, Sardinha, LB, and Cyrino, ES. Resistance training improves a cellular health parameter in obese older women: a randomized controlled trial. J Strength Cond Res 34(10): 2996-3002, 2020-Phase angle (PhA) is a viable indicator of cellular health, with higher values reflecting better cellularity, cell membrane integrity, and cell function. Adaptive responses to resistance training (RT) on PhA may be important in obese older people. The main purpose of the present study was to investigate the effects of 8 weeks of RT on PhA in obese older women. Thirty-three obese older women (68.1 ± 5.7 years, 71.6 ± 10.1 kg, 154.5 ± 6.7 cm, 30.0 ± 4.1 kg·m, and 45.0 ± 6.0% body fat) were randomly allocated into 1 of 2 groups: a training group that performed the RT program (TG, n = 18) or a nonexercise control group (CG, n = 15). The whole-body RT consisted of an 8-week RT program involving 8 exercises performed for 3 sets of 8-12 repetitions 3 times a week. Anthropometric, body fat and fat-free mass, PhA, total body water (TBW), intracellular water (ICW), and extracellular water compartments were performed at before and after training. After the intervention period, the TG presented greater increases (p < 0.05) than CG for fat-free mass (TG = +1.3% and CG = -0.3%), TBW (TG = +2.0% and CG = -1.7%), ICW (TG = +3.1% and CG = -1.9%), and PhA (TG = +3.4% and CG = -1.4%), and lower values for percentage of body fat (TG = -1.3% and CG = +0.9%) and bioimpedance resistance (TG = -4.6% and CG = +2.3%). Our results suggest that 8 weeks of RT improves PhA-a cellular health parameter-in obese older women.


Assuntos
Composição Corporal/fisiologia , Obesidade/fisiopatologia , Treinamento Resistido/métodos , Idoso , Antropometria , Água Corporal , Feminino , Humanos , Pessoa de Meia-Idade , Força Muscular/fisiologia
10.
J Vasc Bras ; 19: e20190150, 2020 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34178073

RESUMO

Vitamin D (1,25-dihydroxycolecalciferol) is a prohormone that has attracted the interest of researchers since studies have shown that its effects are not restricted to bone metabolism. Thus, the present review summarizes the most recent findings and discusses the usefulness of prescribing vitamin D and its analogues for treatment and prevention of cardiovascular disorders and endothelial dysfunction. The paper constitutes a narrative review of the literature, selecting articles published from 2012 to 2019. Studies have shown that vitamin D3 and its analogues have beneficial effects on endothelial function, but these results are controversial, since research with larger samples and of longer duration found no reduction in morbidity and mortality or cardiovascular risk factors after use of these substances. Given the current state of the art, there is no clear scientific basis for supplementation with vitamin D or its analogues for treatment of endothelial dysfunction or cardiovascular disease.

11.
Mol Biol Rep ; 46(5): 5019-5024, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31290054

RESUMO

The microbial community present in forage peanut, a tropical legume, and its silages are unknown. For this reason, we used the Ion Torrent platform to study the bacterial community present in this legume during silage fermentation. Forage peanut was harvested at the start of flowering with a backpack mower and was chopped with a stationary ensilage cutter and then ensiled in bags measuring 25.40 cm × 35.56 cm, in triplicate. The bags were opened after 1, 3, 7, 14, 28 and 56 days of fermentation. Primers targeting the 16S rDNA gene were used, and the PCR products were used in library preparation and sequencing using the Ion Torrent platform. In total, 721,837 sequences were obtained and processed using the program MOTHUR v.23.0. The sequencing result revealed that the genus Weissella was present at the different periods of fermentation of peanut silage in greater amounts than the other genera (Bacillus, Rummeliibacillus, Enterococcus, Lactobacillus, Pediococcus). The six libraries constructed reached high coverage value (0.999). Comparison of the number of operational taxonomic units (OTUs) between the forage crop and the silages with 14 and 56 days of fermentation revealed that some sequences were exclusive to the plant and others to fermentation periods. The silage with 28 days of fermentation remained distant from the other fermentation periods in regard to microbial diversity. Knowledge of the diversity of different bacterial genera through sequence analysis can guide bioprospecting studies.


Assuntos
Arachis/microbiologia , Microbiota/genética , Silagem/microbiologia , Bactérias/genética , Fermentação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
12.
J Aging Phys Act ; 27(4): 515-520, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30507279

RESUMO

The aim of this study was to analyze the association between muscle quality index (MQI) and phase angle (PhA) after a program of progressive resistance training (RT) in older women. Sixty-six older women with previous RT experience (68.8 ± 4.6 years, 156.6 ± 5.3 cm, 66.0 ± 13.0 kg, and 26.7 ± 4.6 kg/m2) underwent 12 weeks of RT (3 ×/week, eight exercises, and 10-15 repetition maximum). Anthropometry, muscular strength (one-repetition maximum tests), and body composition (dual-energy X-ray absorptiometry and spectral bioimpedance) were measured pre- and posttraining. There were observed significant increases for PhA, MQI, muscular strength, muscle mass, and reactance, whereas no significant changes in body fat and resistance were found. A significant correlation was observed between the RT-induced relative changes in PhA and MQI (r = .620). We conclude that improvements in MQI induced by RT are associated with increases in PhA. Therefore, PhA may be a valid tool to track changes in MQI after 12 weeks of RT in older women.


Assuntos
Músculo Esquelético/fisiologia , Treinamento Resistido , Idoso , Idoso de 80 Anos ou mais , Composição Corporal , Feminino , Humanos , Estudos Longitudinais , Força Muscular/fisiologia
13.
Nutr Health ; 25(2): 103-112, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30909813

RESUMO

BACKGROUND: Aging is accompanied by progressive and accentuated decline in muscular strength and skeletal muscle mass, affecting health and functional autonomy. Both resistance training (RT) and diet are strategies that may contribute to improvement in the health of the elderly. AIM: The purpose of this study was to evaluate the effects of higher habitual protein intake on RT-induced changes in body composition and strength in untrained postmenopausal women. METHODS: Seventy older women were submitted to an RT program. Body composition, muscular strength, and dietary intake (24 h dietary recall) were performed pre- and post-intervention. To verify different intervention effects according to protein intake of the participants, the sample was separated into tertiles according to protein intake: low, moderate, and high protein intake. RESULTS: A time vs. group interaction ( p < 0.05) was observed, with high protein intake presenting greater increases compared with low protein intake, for skeletal muscle mass (5.3% vs. 1.3%), lower limb lean soft tissue (4.9% vs. 1.4%), upper lean soft tissue (4.9% vs. 1.2%), preacher curl (24% vs. 15.2%), and total strength (16.4% vs. 11.7%). A time vs. group interaction ( p < 0.05) was observed, with high protein intake presenting greater increases compared with moderate protein intake, for skeletal muscle mass (5.3% vs. 3.2%). In all groups, a main effect of time ( p < 0.05) was observed for knee extension and chest press. CONCLUSIONS: We conclude that intake of >1.0 g/kg/day of protein promotes gains in skeletal muscle mass and muscular strength after RT in untrained older women.


Assuntos
Composição Corporal , Proteínas Alimentares/administração & dosagem , Força Muscular , Treinamento Resistido , Idoso , Brasil , Dieta , Fenômenos Fisiológicos da Nutrição do Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Músculo Esquelético/fisiologia
14.
Int J Sports Med ; 39(8): 613-618, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29945272

RESUMO

This study aimed to analyze the effects of a pyramid system performed with two repetition zones on muscular strength and skeletal muscle mass (SMM) in older women. Thirty-nine physically independent older women (67.8±5.4 years) were randomly assigned into one of two of groups that performed an 8-week resistance training program in an ascending pyramid fashion. Both groups performed 3 sets: a narrow repetition zone (NPR, n=20) with 12/10/8 repetitions, and a wide repetition zone (WPR, n=19) with 15/10/5 repetitions. The program consisted of 8 whole-body exercises, performed 3 times a week. Dual-energy X-ray absorptiometry was used to measure SMM, and muscular strength was evaluated by one-repetition maximum (1RM). Both groups increased (P<0.05) SMM (NPR=+ 4.7%, effect size=+ 0.34; WPR=+ 8.4%, effect size=+ 0.77), and total strength (NPR=+ 11.3%, effect size=+ 0.80; WPR=+ 13.8%, effect size=0.84), without statistical differences between them. Results suggest that both zones of repetitions in a pyramid system are effective strategies to improve muscular strength and muscle growth in older women.


Assuntos
Força Muscular/fisiologia , Músculo Esquelético/anatomia & histologia , Treinamento Resistido/métodos , Adaptação Fisiológica , Idoso , Índice de Massa Corporal , Feminino , Humanos , Músculo Esquelético/fisiologia
15.
J Food Sci Technol ; 55(12): 4851-4858, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30482980

RESUMO

The objective of this study was to evaluate the characteristics of kefir beverages made from yam, sesame and bean extracts after fermentation of the extracts with water kefir grains. Formulations were prepared with raw and boiled yams. To the yam extract, sesame and different percentages of white bean extract were added. The fermentation kinetics, the chemical composition and color of the extracts were analyzed. To determine the fermentation kinetic parameters, pH and titratable acidity were evaluated. The chemical composition and color of all extracts were determined before and after fermentation process. The decrease in pH and increase in titratable acidity were affected both by raw or boiler yam. The addition of bean extract favored the decrease in pH of formulations containing extracts of raw or boiled yams. Chemical composition and color of the beverages were altered after fermentation. The kefir beverage made from yam and sesame enriched with 50% beans proved to be an excellent fermentation substrate. In addition, it is a new way of consuming vegetable products, especially fermented products, which have limited diversity to serve vegan consumers and also people with certain allergies to dairy products.

16.
Pak J Pharm Sci ; 31(1): 1-8, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29348077

RESUMO

Macrophages have been considered an elusive yet emerging therapeutic target in tumor development since they are an important component in tumor microenvironment. The purpose of the present study was to evaluate the effect of C. sinensis on macrophage function (a component of tumor microenvironment which can alter the virulence of cancer) in high-fat diet fed rats. IMR-32 human neuroblastoma cell cytotoxicity was also investigated. The following parameters were observed to evaluate macrophage function: superoxide anion, hydrogen peroxide, nitric oxide, lysosomal volume and phagocytic capacity. High fat diet (HFD) plus C. sinensis supplementation promoted a decreased superoxide anion and hydrogen peroxide levels as well as lysosomal volume and phagocytic capacity. Nitric oxide was increased in the same group. In summary, C. sinensis offered an important anti-tumoral perspective from the standpoint of the tumor microenvironment and in vitro IMR-32 cytotoxicity.


Assuntos
Antineoplásicos/farmacologia , Cordyceps , Dieta Hiperlipídica , Hiperlipidemias/fisiopatologia , Macrófagos Peritoneais/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Animais , Antineoplásicos/isolamento & purificação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cordyceps/química , Humanos , Peróxido de Hidrogênio/metabolismo , Hiperlipidemias/etiologia , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos Peritoneais/fisiologia , Masculino , Neuroblastoma/metabolismo , Neuroblastoma/patologia , Óxido Nítrico/metabolismo , Ratos Wistar , Superóxidos/metabolismo , Microambiente Tumoral/efeitos dos fármacos
17.
BMC Biotechnol ; 17(1): 71, 2017 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-28888227

RESUMO

BACKGROUND: Second-generation ethanol production is a clean bioenergy source with potential to mitigate fossil fuel emissions. The engineering of Saccharomyces cerevisiae for xylose utilization is an essential step towards the production of this biofuel. Though xylose isomerase (XI) is the key enzyme for xylose conversion, almost half of the XI genes are not functional when expressed in S. cerevisiae. To date, protein misfolding is the most plausible hypothesis to explain this phenomenon. RESULTS: This study demonstrated that XI from the bacterium Propionibacterium acidipropionici becomes functional in S. cerevisiae when co-expressed with GroEL-GroES chaperonin complex from Escherichia coli. The developed strain BTY34, harboring the chaperonin complex, is able to efficiently convert xylose to ethanol with a yield of 0.44 g ethanol/g xylose. Furthermore, the BTY34 strain presents a xylose consumption rate similar to those observed for strains carrying the widely used XI from the fungus Orpinomyces sp. In addition, the tetrameric XI structure from P. acidipropionici showed an elevated number of hydrophobic amino acid residues on the surface of protein when compared to XI commonly expressed in S. cerevisiae. CONCLUSIONS: Based on our results, we elaborate an extensive discussion concerning the uncertainties that surround heterologous expression of xylose isomerases in S. cerevisiae. Probably, a correct folding promoted by GroEL-GroES could solve some issues regarding a limited or absent XI activity in S. cerevisiae. The strains developed in this work have promising industrial characteristics, and the designed strategy could be an interesting approach to overcome the non-functionality of bacterial protein expression in yeasts.


Assuntos
Aldose-Cetose Isomerases/metabolismo , Chaperonina 60/genética , Proteínas de Escherichia coli/genética , Proteínas de Choque Térmico/genética , Engenharia de Proteínas/métodos , Saccharomyces cerevisiae/genética , Aldose-Cetose Isomerases/química , Aldose-Cetose Isomerases/genética , Chaperonina 60/metabolismo , Proteínas de Escherichia coli/metabolismo , Etanol/metabolismo , Proteínas de Choque Térmico/metabolismo , Modelos Moleculares , Propionibacterium/enzimologia , Conformação Proteica , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/metabolismo , Xilose/metabolismo
19.
Appl Microbiol Biotechnol ; 100(1): 9-16, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26476647

RESUMO

The lignocellulosic biomass, comprised mainly of cellulose, hemicellulose, and lignin, is a strong competitor for petroleum to obtain fuels and other products because of its renewable nature, low cost, and non-competitiveness with food production when obtained from agricultural waste. Due to its recalcitrance, lignocellulosic material requires an arsenal of enzymes for its deconstruction and the consequent release of fermentable sugars. In this context, enzymes currently classified as auxiliary activity 9 (AA9/formerly GH61) and 10 (AA10/formerly CBM 33) or lytic polysaccharide monooxygenases (LPMO) have emerged as cellulase boosting enzymes. AA9 and AA10 are the new paradigm for deconstruction of lignocellulosic biomass by enhancing the activity and decreasing the loading of classical enzymes to the reaction and, consequently, reducing costs of the hydrolysis step in the second-generation ethanol production chain. In view of that disclosed above, the goal of this work is to review experimental data that supports the relevance of AA9 and AA10 for the biomass deconstruction field.


Assuntos
Biocombustíveis , Biomassa , Glicosídeo Hidrolases/metabolismo , Lignina/metabolismo , Biotransformação
20.
RSC Adv ; 14(16): 10930-10941, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38577424

RESUMO

One of the challenges hindering the commercialization of perovskite solar cells (PSCs) is the presence of toxic metals such as lead in their composition. Simulation studies using SCAPS-1D have already been conducted on lead-free PSCs to find optimized solar cell parameters, having tin as the primary candidate for replacing lead in perovskites. Here, we used fullerene-C60 and its derivative PCBM as interlayers in a lead-free tin-based PSC between the ETL (ZnO) and the perovskite MASI in both regular and inverted configurations of PSCs using SCAPS-1D software. To the best of our knowledge, this is the first simulation study reporting the impact of using fullerene-C60 and PCBM as interlayers in lead-free PSCs. The defect density (Nt) of the perovskite material is varied, allowing us to observe its influence on the power conversion efficiency (PCE). Using an Nt value of 1017 cm-3 without the interlayer, the PCE was 6.90% and 3.72% for regular and inverted devices. Using PCBM as an interlayer improves the efficiency of both simulated PSCs, achieving a maximum PCE of 8.11% and 5.26% for the regular and inverted configurations, respectively. Decreasing the Nt from 1017 cm-3 to 1016 cm-3 caused a significant increase in efficiency, reaching 13.38% (n-i-p) and 10.00% (p-i-n). Finally, using the optimized parameters and an ideal Nt value (1013 cm-3), both PSCs achieved a PCE close to 30%.

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