Digestibilidade e Parâmetros Ruminais de Bovinos Consumindo Brachiaria Brizantha Cv. Marandu

This experiment aimed to evaluate nutrient intake, total and partial digestibility of dry matter (DM), organic matter (OM), crude protein (CP), neutral (NDF) and acid (ADF) detergent fiber and ruminal parameters, ammonia concentration and volatile fatty acids, in beef cattle fed palisade grass (Brachiaria brizantha cv. marandu) at two regrowth ages, 30 and 60 days, at two times of year (January and February). The intake of DM, OM and CP was influenced by forage age of regrowth with high values for 30 days; this was influenced by time of year, being observed in February the higher intake by animals. DM digestibility average was 60.7 and 59.4% for 30 and 60 days of forage regrowth, respectively, however, was observed effect of interaction between regrowth and time of year, the same comportment was observed for OM, averages were 63.9 and 63% for respective ages of regrowth. CP digestibility was higher for 30 days, 70.8%, than for 60 days of regrowth, 57%. The NDF and ADF digestibilities were influenced by the interaction between regrowth and time of year; their average for 60 days of regrowth in January were respectively 54.8 and 48.5%, being the lower values and, in February, the higher values: 64.9 and 60.4%. The ruminal average digestibility was 79.5, 86.2, 99.4 and 96.7% of the total degradable for DM, OM, NDF and ADF, respectively. Effects of regrowth and time of year there were not recorded. Two hours after the morning meal was observed the ammonia ruminal concentration peak. The acetate:propionate: butirate ruminal ratio observed was 74:18:8(%).

Structural insights into selectivity and cofactor binding in snake venom l-amino acid oxidases

l-Amino acid oxidases (LAAOs) are flavoenzymes that catalytically deaminate l-amino acids to corresponding α-keto acids with the concomitant production of ammonia (NH 3) and hydrogen peroxide (H 2O 2). Particularly, snake venom LAAOs have been attracted much attention due to their diverse clinical and biological effects, interfering on human coagulation factors and being cytotoxic against some pathogenic bacteria and Leishmania ssp. In this work, a new LAAO from Bothrops jararacussu venom (BjsuLAAO) was purified, functionally characterized and its structure determined by X-ray crystallography at 3.1å resolution. BjsuLAAO showed high catalytic specificity for aromatic and aliphatic large side-chain amino acids. Comparative structural analysis with prokaryotic LAAOs, which exhibit low specificity, indicates the importance of the active-site volume in modulating enzyme selectivity. Surprisingly, the flavin adenine dinucleotide (FAD) cofactor was found in a different orientation canonically described for both prokaryotic and eukaryotic LAAOs. In this new conformational state, the adenosyl group is flipped towards the 62-71 loop, being stabilized by several hydrogen-bond interactions, which is equally stable to the classical binding mode. © 2012 Elsevier Inc.

Efeitos do extrato de parede de levedura em dieta seca sobre a Microbiologia, ácidos graxos de cadeia curta e redução do odor das fezes de gatos adultos

The aim of this study was to evaluate the effects of yeast cell wall extract (YCW) in dry diet on the fecal microbiota, concentration of short-chain fatty acids (SCFA) and on the odor reduction of cats feces. We used 20 animals of both sexes, randomly assigned to four treatments and five repetitions totaling 20 experimental units: 1) dry commercial diet (control); 2) control + 0.2%, 3) control + 0.4%, and 4) control + 0.6% of YCW in dry matter. Enterobacteriaceae and lactic acid bacteria, fecal concentration of acetic, propionic and butyric acids, ammonia nitrogen and sensory panel were performed. There were no significant differences (p> 0.05) for bacterial counts and the concentration of SCFA and ammonia, but in sensory panel a reduction in the odor of feces could be noted with the use of 0.2% of YCW. We concluded that the addition of up to 0.6% YCW had no effect on the microbiology and the concentration of fatty acids, but there is potential for its use as an additive because of the improvement in the odor of feces. However, further studies are needed to understand the mechanisms of action and the effects of prebiotics for domestic cats.

Influence of carbon and nitrogen sources on lipase production by a newly isolated Candida viswanathii strain

Microorganisms can produce lipases with different biochemical characteristics making necessary the screening of new lipase-producing strains for different industrial applications. In this study, 90 microbial strains were screened as potential lipase producers using a sensitive agar plate method with a suitable medium supplemented with Tween 20 and also a liquid culture supplemented with olive oil. The highest cell growth and lipase production for Candida viswanathii were observed in triolein and oleic acid when used as the only pure carbon source. Renewable low-cost triacylglycerols supported the best cell growth, and olive oil was found to be the best inducer for lipase production (19.50 g/L and 58.50 U). The selected conditions for enzyme production were found with yeast extract as nitrogen source and 1.5 % (w/v) olive oil (85.70 U) that resulted in a good cell growth yield (YX/S = 1.234 g/g) and lipase productivity (1.204 U/h) after 72 h of shake-flask cultivation. C. viswanathii lipase presented high hydrolytic activity on esters bonds of triacylglycerols of long-chain, and this strain can be considered an important candidate for future applications in chemical industries. © 2012 Springer-Verlag Berlin Heidelberg and the University of Milan.

Comparing submerged and solid-state fermentation of agro-industrial residues for the production and characterization of lipase by Trichoderma harzianum

Lipase production by Trichoderma harzianum was evaluated in submerged fermentation (SF) and solid-state fermentation (SSF) using a variety of agro-industrial residues. Cultures in SF showed the highest activity (1.4 U/mL) in medium containing 0.5 % (w/v) yeast extract, 1 % (v/v) olive oil and 2.5 C:N ratio. This paper is the first to report lipase production by T. harzianum in SSF. A 1:2 mixture of castor oil cake and sugarcane bagasse supplemented with 1 % (v/w) olive oil showed the best results among the cultures in SSF (4 U/g ds). Lipolytic activity was stable in a slightly acidic to neutral pH, maintaining 50 % activity after 30 min at 50 C. Eighty percent of the activity remained after 1 h in 25 % (v/v) methanol, ethanol, isopropanol or acetone. Activity was observed with vegetable oils (olive, soybean, corn and sunflower) and long-chain triacylglycerols (triolein), confirming the presence of a true lipase. The results of this study are promising because they demonstrate an enzyme with interesting properties for application in catalysis produced by fermentation at low cost. © 2012 Springer-Verlag and the University of Milan.

Structural and functional studies with mytoxin II from Bothrops moojeni reveal remarkable similarities and differences compared to other catalytically inactive phospholipases A2-like

Lys49-phospholipases A2 (Lys49-PLA2s) are proteins found in bothropic snake venoms (Viperidae family) and belong to a class of proteins which presents a phospholipase A2 scaffold but are catalytically inactive. These proteins (also known as PLA2s-like toxins) exert a pronounced local myotoxic effect and are not neutralized by antivenom, being their study relevant in terms of medical and scientific interest. Despite of the several studies reported in the literature for this class of proteins only a partial consensus has been achieved concerning their functional-structural relationships. In this work, we present a comprehensive structural and functional study with the MjTX-II, a dimeric Lys49-PLA2 from Bothrops moojeni venom which includes: (i) high-resolution crystal structure; (ii) dynamic light scattering and bioinformatics studies in order to confirm its biological assembly; (iii) myographic and electrophysiological studies and, (iv) comparative studies with other Lys49-PLA2s. These comparative analyses let us to get important insights into the role of Lys122 amino acid, previously indicated as responsible for Lys49-PLA2s catalytic inactivity and added important elements to establish the correct biological assembly for this class of proteins. Furthermore, we show two unique sequential features of MjTX-II (an amino acid insertion and a mutation) in comparison to all bothropic Lys49-PLA2s that lead to a distinct way of ligand binding at the toxin's hydrophobic channel and also, allowed the presence of an additional ligand molecule in this region. These facts suggest a possible particular mode of binding for long-chain ligands that interacts with MjTX-II hydrophobic channel, a feature that may directly affect the design of structure-based ligands for Lys49-PLA2s. © 2013 Elsevier Ltd.

Influência do treinamento físico de alta intensidade sobre o metabolismo de ratos espontaneamente hipertensos (SHR)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo da relação estrutura/atividade para as ações neurotóxica/neuroprotetora das acilpoliaminotoxinas NSTX-3 e JSTX-3 em sistema nervoso central de ratos

Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC

Metabolismo energético do camarão da amazonia, Macrobrachium amazonicum

Pós-graduação em Biologia Geral e Aplicada - IBB

Caracterização do óleo de frutos de tucumã (Astrocaryum aculeatum) para produção de biodiesel

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito da adição de parede celular de levedura sobre a digestibilidade, microbiota, ácidos graxos de cadeia curta e aminas fecais e parâmetros hematológicos e imunológicos de cães

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito de éster de sacarose sobre Bemisia tabaci biótipo B, sobre seu predador Chrysoperla externa e sobre o desenvolvimento de plantas de tomateiro e melão

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Produção de lipase pelo fungo Myceliophthora sp. F. 2.1.4, caracterização e imobilização da solução enzimática bruta

Pós-graduação em Microbiologia - IBILCE

Fontes lipídicas associadas à glicerina bruta na dieta de tourinhos Nelore

Pós-graduação em Zootecnia - FCAV

Efeito de diferentes dosagens do preparado de anticorpos policlonais específicos sobre as variáveis ruminais, degradabilidade in situ e digestibilidade in vivo de bovinos alimentados com dieta de alto concentrado

Pós-graduação em Zootecnia - FMVZ