Explore the vast range of titles available.

β-Glucosidases are enzymes with high importance for many industrial processes, catalyzing the last and limiting step of the conversion of lignocellulosic material into fermentable sugars for biofuel production. However, β-glucosidases are inhibited by high concentrations of the product (glucose), which limits the biofuel production on an industrial scale. For this reason, the structural mechanisms of tolerance to product inhibition have been the target of several studies. In this study, we performed in silico experiments, such as molecular dynamics (MD) simulations, free energy landscape (FEL) estimate, Poisson–Boltzmann surface area (PBSA), and grid inhomogeneous solvation theory (GIST) seeking a better understanding of the glucose tolerance and inhibition mechanisms of a representative GH1 β-glucosidase and a GH3 one. Our results suggest that the hydrophobic residues Y180, W350, and F349, as well the polar one D238 act in a mechanism for glucose releasing, herein called “slingshot mechanism”, dependent also on an allosteric channel (AC). In addition, water activity modulation and the protein loop motions suggest that GH1 β-Glucosidases present an active site more adapted to glucose withdrawal than GH3, in consonance with the GH1s lower product inhibition. The results presented here provide directions on the understanding of the molecular mechanisms governing inhibition and tolerance to the product in β-glucosidases and can be useful for the rational design of optimized enzymes for industrial interests.

Annual ryegrass seeds having low physiological quality can lead to the formation of pastures with undesirable plant stands for soil cover and forage utilization pastures. Thus, the objective of this study was proposing a vigor test to classify annual ryegrass seeds. For that, different sowing depths (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 cm) over three substrates (sand, coconut fiber, and carbonized rice husk) were tested to differentiate the physiological quality of four seed lots of annual ryegrass cv. BRS Ponteio having similarities in germination and moisture. The seed lots were classified according to vigor through the field seedling emergence (FSE), 1,000-seeds weight, saturated salt accelerated aging, and germination first count. The 2.5 cm of sand sowing depth and 3.0 cm of coconut fiber sowing depth provided separation of seed lots in similar groups of those reported to FSE test through the seedling emergence and speed of seedling emergence tests. Resumo: Sementes de azevém com baixa qualidade fisiológica têm resultado em pastagens com inadequado estande de plantas para a cobertura do solo e, sobretudo, para a exploração forrageira. Neste sentido, o presente trabalho teve como objetivo propor um teste de vigor para sementes de azevém anual. Foram testadas profundidades de semeadura (0,5; 1,0; 1,5; 2,0; 2,5 e 3 cm) em três substratos (areia, fibra de coco e casca de arroz carbonizada) para diferenciar a qualidade fisiológica de quatro lotes de sementes da cultivar BRS Ponteio que apresentaram semelhança no teste de germinação e umidade. Os lotes foram classificados quanto ao vigor pelos testes de emergência em campo, peso de mil sementes, envelhecimento acelerado e primeira contagem da germinação. A profundidade de semeadura em substratos de areia e fibra de coco permitiu a determinação do vigor em sementes de azevém anual (de maneira similar ao observado no teste de germinação no campo), pela porcentagem de emergência e pelo índice de velocidade de emergência de plântulas semeadas em areia a 2,5 e em fibra de coco a 3,0 cm de profundidade de semeadura.

Essential oils (EOs) are a promising source for novel environmentally safe insecticides. However, the structural diversity of their compounds poses challenges to accurately elucidate their biological mechanisms of action. We present a new chemoinformatics methodology aimed at predicting the impact of essential oil (EO) compounds on the molecular targets of commercial insecticides. Our approach merges virtual screening, chemoinformatics, and machine learning to identify custom signatures and reference molecule clusters. By assigning a molecule to a cluster, we can determine its most likely interaction targets. Our findings reveal that the main targets of EOs are juvenile hormone-specific proteins (JHBP and MET) and octopamine receptor agonists (OctpRago). Three of the twenty clusters show strong similarities to the juvenile hormone, steroids, and biogenic amines. For instance, the methodology successfully identified E-Nerolidol, for which literature points indications of disrupting insect metamorphosis and neurochemistry, as a potential insecticide in these pathways. We validated the predictions through experimental bioassays, observing symptoms in blowflies that were consistent with the computational results. This new approach sheds a higher light on the ways of action of EO compounds in nature and biotechnology. It also opens new possibilities for understanding how molecules can interfere with biological systems and has broad implications for areas such as drug design.

The objective of this study was to evaluate the effect of corn plant harvested in diferente maturity stages on the chemical composition, digestibility and aerobic stability of silages. The corn used in the study was the hybrid BM3061 harvested after 114, 121, 126, 133 and 140 days of sowing at five maturity stages based on the advancement of the grain milk line (early dent (ED), 1/3 of milk line (ML), 1/2 ML, 2/3 ML and black layer (BL)). A variation from 242.7 to 377.4 g of dry matter (DM) kg-1as fed was observed between the ED and BL stages; however, the measurements performed in this study did not exhibited major changes in the composition of these silages. The silages produced with plants that were harvested at the 1/2 ML, 2/3 ML and BL stages showed lower DM loss during the fermentative process. The silages produced with plants that were harvested at the ED and 1/3 ML stages showed higher in vitro organic matter digestibility (IVOMD) (0.584 and 0.631 g g-1 of OM, respectively). The corn silages produced at the maturity stage of 2/3 ML showed a higher aerobic stability (104 hours) during the aerobic exposure. The 1/3 and 2/3 ML maturity stages seem to be the best harvest stages for the production of corn silage in tropical climates.

Olive cake (OC) is a wet by-product of olive processing that may be used as animal feedstuff. Our objective was to investigate the impact of adding OC on fermentation and aerobic stability of maize and grass silages. Whole-crop maize (326 g dry matter (DM)/kg as fed) and 4 h-wilted elephant grass (229 g DM/kg as fed) were ensiled without (untreated) or with fresh OC (5% as fed basis). Ensiling was performed in experimental silos (n = 3), which remained stored for 99 d. As results, fermentative losses were unaffected by OC (P = 0.17), while the lactic acid concentration decreased (P = 0.02) by 33.7% in silages with OC. The pH of grass silage increased (P < 0.001) by adding OC (4.43 vs. 4.01 in the control), but it did not change the pH in maize silage. The concentration of acetic acid (P = 0.01) decreased by 15.2% in maize silage with OC and increased by 19.4% in grass silage with OC. The ether extract concentration increased (P = 0.02) in maize silage with OC compared to the control, and it was similar between grass silage without and with OC. After feedout, silage aerobic stability was not altered (P ≥ 0.18) by the addition of OC in maize and grass silages. Therefore, a possible fate for OC is to ensile it together maize forage, because there is no impairment of fermentation and aerobic stability of silages. Ensiling OC with grass is not recommended as it worsened the fermentation pattern. RESUMO: A torta de oliva (TO) é um subproduto úmido oriundo do processamento da oliva para produção de azeite. O objetivo deste estudo foi investigar o efeito da adição de TO sobre a fermentação e estabilidade aeróbia das silagens de milho e capim. A planta inteira de milho (32,6% de matéria seca (MS)) e o capim elefante pré-emurchecido por 4 horas (22,9% de MS) foram ensilados sem (controle) ou com TO fresca (5% com base na matéria natural). A ensilagem foi realizada em silos experimentais de PVC (n = 3), os quais permaneceram fechados por 99 dias. O experimento foi conduzido em delineamento inteiramente casualizado sob arranjo fatorial 2 × 2, e os dados foram analisados pelo procedimento MIXED do SAS a P ≤ 0,05. As perdas fermentativas não foram influenciadas pela TO (P = 0,17). No entanto, a concentração de ácido lático diminuiu 33,7% em silagens com TO (P = 0,02). Houve uma interação entre TO e culturas para pH, ácido acético e extrato etéreo (EE). O pH da silagem de capim aumentou (P < 0,001) devido a adição de TO (4,43 vs. 4,01 para o controle), enquanto o pH da silagem de milho não foi alterado pela TO. A concentração de ácido acético diminuiu 15,2% na silagem de milho com TO e aumentou 19,4% na silagem de capim com TO (P = 0,01). O EE foi maior (P = 0,02) na silagem de milho com TO comparado ao controle e similar entre a silagem de capim (com e sem TO). A estabilidade aeróbia das silagens de milho e capim não foram alteradas pela TO (P ≥ 0,18). Portanto, um possível destino para a TO é utiliza-la na ensilagem do milho, pois não houve prejuízo sobre o padrão de fermentação e estabilidade aeróbia desta silagem. A ensilagem de capim com TO não é recomendada, pois piorou o padrão de fermentação desta silagem.

A sample of 158 Brazilian males from São Paulo (SP), Brazilian southeast, was typed for 17 Y-STR loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, YGATA_H4.1, and DYS385ab). A total of 158 haplotypes were identified, of which all were unique. The haplotype diversity and discrimination capacity were calculated in 1.0 and the genetic diversity was 67.4%. Pairwise haplotype distances showed that the São Paulo population is not significantly different from Rio de Janeiro and Portugal, but is different from African and Native American.

The volume and diversity of biological data are increasing at very high rates. Vast amounts of protein sequences and structures, protein and genetic interactions and phenotype studies have been produced. The majority of data generated by high-throughput devices is automatically annotated because manually annotating them is not possible. Thus, efficient and precise automatic annotation methods are required to ensure the quality and reliability of both the biological data and associated annotations. We proposed ENZYMatic Annotation Predictor (ENZYMAP), a technique to characterize and predict EC number changes based on annotations from UniProt/Swiss-Prot using a supervised learning approach. We evaluated ENZYMAP experimentally, using test data sets from both UniProt/Swiss-Prot and UniProt/TrEMBL, and showed that predicting EC changes using selected types of annotation is possible. Finally, we compared ENZYMAP and DETECT with respect to their predictions and checked both against the UniProt/Swiss-Prot annotations. ENZYMAP was shown to be more accurate than DETECT, coming closer to the actual changes in UniProt/Swiss-Prot. Our proposal is intended to be an automatic complementary method (that can be used together with other techniques like the ones based on protein sequence and structure) that helps to improve the quality and reliability of enzyme annotations over time, suggesting possible corrections, anticipating annotation changes and propagating the implicit knowledge for the whole dataset.

The crop rotation is a practice to protect and improve the soil properties and an alternative to improve the quality of crop residues is the application of fertilizers at the planting of cover crops. Thus, we evaluated the effect of fertilization with nitrogen, phosphorus and potassium (NPK) on organic matter production and chemical composition of cover crops succeeding the corn crop. The treatments consisted of the cultivation of Avena sativa L., Lupinus albus L., Pennisetum glaucum L., Raphanus sativus L. and Sorghum bicolor L. with (200 kg ha−1 of NPK [08-28-16] applied by broadcast seeding) and without fertilization at planting. Organic matter production by all cover crops, as well as concentrations of neutral detergent fibre (NDF) in shoots and roots of A. sativa L. and R. sativus L. were higher when they were fertilized. L. albus L. showed higher NDF and acid detergent fibre (ADF) contents than the other cover crops, with and without fertilization. Nitrogen concentration increased, but the carbon/nitrogen ratio (C/N) in the shoots of L. albus L., R. sativus L. and S. bicolor L. decreased when fertilization was applied. The use of N by the A. sativa L. and P. glaucum L. and of P and K by S. bicolor L. was 16, 54, 82 and 20% more efficient, respectively, when fertilization was applied. The A. sativa L., P. glaucum L. and R. sativus L. showed higher NDF/N, ADF/N and hemicellulose/N ratios in the fertilized treatment. Although the results obtained in this study are highly satisfactory, more research should be conducted to evaluate the decomposition of crop residues from cover crops fertilized with NPK, and the effects of this strategy on corn crops in succession.

Olive cake (OC) is a wet by-product of olive processing that may be used as animal feedstuff. Our objective was to investigate the impact or adding OC on fermentation and aerobic stability or maize and grass silages. Whole-crop maize (326 g dry matter (DM)/kg as red) and 4 h-wilted elephant grass (229 g DM/kg as red) were ensiled without (untreated) or with fresh OC (5% as red basis). Ensiling was performed in experimental silos (n = 3), which remained stored for 99 d. As results, fermentative losses were unaffected by OC (P = 0.17), while the lactic acid concentration decreased (P = 0.02) by 33.7% in silages with OC. The pH of grass silage increased (P < 0.001) by adding OC (4.43 vs. 4.01 in the control), but it did not change the pH in maize silage. The concentration of acetic acid (P = 0.01) decreased by 15.2% in maize silage with OC and increased by 19.4% in grass silage with OC. The ether extract concentration increased (P = 0.02) in maize silage with OC compared to the control, and it was similar between grass silage without and with OC. After feedout, silage aerobic stability was not altered (P [greater than or equal to] 0.18) by the addition of OC in maize and grass silages. Therefore, a possible fate for OC is to ensile it together maize forage, because there is no impairment of fermentation and aerobic stability of silages. Ensiling OC with grass is not recommended as it worsened the fermentation pattern. Key words: by-product, corn silage, olive cake, fermentation, grass silage. A torta de oliva (TO) e um subproduto umido oriundo do processamento da oliva para producao de azeite. O objetivo deste estudo foi investigar o efeito da adicao de TO sobre a fermentacao e estabilidade aerobia das silagens de milho e capim. A planta inteira de milho (32,6% de materia seca (MS)) e o capim elefante pre-emurchecido por 4 horas (22,9% de MS) foram ensilados sem (controle) ou com TO fresca (5% com base na materia natural). A ensilagem foi realizada em silos experimentais de PVC (n = 3), os quais permaneceram fechados por 99 dias. O experimento foi conduzido em delineamento inteiramente casualizado sob arranjo fatorial 2 * 2, e os dados foram analisados pelo procedimento MIXED do SAS a P [less than or equal to] 0,05. As perdas fermentativas nao foram influenciadas pela TO (P = 0,17). No entanto, a concentracao de acido latico diminuiu 33,7% em silagens com TO (P = 0,02). Houve uma interacao entre TO e culturas para pH, acido acetico e extrato etereo (EE). O pH da silagem de capim aumentou (P < 0,001) devido a adicao de TO (4,43 vs. 4,01 para o controle), enquanto o pH da silagem de milho nao foi alterado pela TO. A concentracao de acido acetico diminuiu 15,2% na silagem de milho com TO e aumentou 19,4% na silagem de capim com TO (P = 0,01). O EE foi maior (P = 0,02) na silagem de milho com TO comparado ao controle e similar entre a silagem de capim (com e sem TO). A estabilidade aerobia das silagens de milho e capim nao foram alteradas pela TO (P [greater than or equal to] 0,18). Portanto, um possivel destino para a TO e utiliza-la na ensilagem do milho, pois nao houve prejuizo sobre o padrao de fermentacao e estabilidade aerobia desta silagem. A ensilagem de capim com TO nao e recomendada, pois piorou o padrao de fermentacao desta silagem. Palavras-chave: fermentacao, silagem de capim, silagem de milho, subproduto, torta de oliva.

Objetivou-se avaliar a composição bromatológica e digestibilidade in vitro da matéria seca de cana-de-açúcar hidrolisada em diferentes tempos de estocagem. O experimento foi conduzido no setor de Forragicultura da UNIFENAS, campus de Alfenas (MG) em 2010. Utilizou-se o delineamento inteiramente casualizado em esquema fatorial 2 x 6, sendo testados dois tratamentos (cana-de-açúcar in natura e hidrolisada com 1,0% de cal virgem) em seis tempos de estocagem (0, 24, 48, 72, 96 e 120 horas), com três repetições. A cana-de-açúcar armazenada no estado in natura apresentou menores teores de MS, PB, FDN e FDA em relação à hidrolisada, no entanto, apresentou maiores porcentagens de MO e NDT. Os maiores coeficientes de digestibilidade in vitro da MS e MO foram observados na cana-de-açúcar que permaneceu no estado in natura, devido a melhor composição bromatológica apresentado por este tratamento. O armazenamento da cana-de-açúcar no estado integral (in natura) apresenta melhor composição bromatológica quando comparado à cana-de-açúcar hidrolisada, não sendo recomendado utilizar cal virgem, pois não atua positivamente nas características químico-bromatológicas dessa gramínea. A cana-de-açúcar in natura pode ser armazenada por até 96 horas após o corte, sem comprometimento da composição bromatológica.