Avaliação do triticale (X triticosecale wittimack) para silagem

Silages from three cultivars of triticale (X Triticosecale wittimack) were evaluated at the UNESP, Jaboticabal, Brazil. The cultivars FCA VJ-CB-01, FCA VJ-CB-02, and FCA VJ-CB-03 were harvested for silage in three growing stages of maturity; beginning of flowering, (S1), milk stage (S2), and dough stages (S3). Data were analyzed by randomized complete block with three replications. The DM (%) values increased while the CP (%DM) and buffering capacity (me HCl/100 g DM) decreased with plant development. Silages of plants harvested at S3 stage had higher pH and N-NH3 values compared to the S1 and S2 silages. The soluble carbohydrates contents (%DM) were higher at the S2 stage (16.9%) and were not different at the S1 (8.7%) and S3 (9.2%) stages. The crude energy contents (Kcal/kg MS) increased while the ADF, NDF, cellulose, and hemicellulose (DM%) decreased due to the presence of dough grains. This was not observed with the lignin contents. The IVDMD values were 66.3, 60.1 and 58.9%, for plants harvested at the S1, S2, and S3 stages, respectively. The results showed that there was no difference among for chemical composition, crude energy, and for IVDMD.

Cassava bagasse as a dietary food product

Cassava bagasse, the solid residue of the starch industry, was studied as a potential ingredient in high-fibre dietary products. The bagasse contained 80% of starch, 11.5% fibre, 1.14% ash and 0.85% of protein, and it had a pH of 5.8. Glucose was the major sugar and the hemicellulose content was 22.31%. Microscopic analysis of the bagasse revealed a large number of starch granules inside the parenchyma cells and fibres, as well as outside the cells. The bagasse may be used in high-fibre products, and total or partial hydrolysis of its starch content might increase its commercial value.

Efeito do Tratamento com Hidróxido de Sódio sobre a Fração Fibrosa, Digestibilidade e Tanino do Feno de Jurema-Preta (Mimosa tenuiflora. Wild)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Metabolismo de carboidratos não-estruturais em ruminantes

The carbohydrates provide 50 to 80% of the dry matter of grain and roughage and can be divided into structural (cellulose, hemicellulose) and non-structural (starch, pectin and sugars). The non-structural carbohydrates are primarily digested in the rumen and its dynamic process is a sequence for the supply of nutrients to the intestine. The quality and quantity of products resulting from ruminal fermentation are dependent on the type and activity of microorganisms in the rumen influenced by the type of food processing and that are subject of cereal grains that make up the diet. The NSC escape of rumen fermentation to be digested into glucose in the small intestine by pancreatic enzymes of origin (α-amylase) and intestinal mucosa (maltase and isomaltase). Starch is the most important energy supplier of cereals, which are important components of diets for intensive production of milk and meat.

Perfil Fermentativo e Valor Nutritivo de Silagem de Capim-Elefante Inoculada com Streptococcus Bovis

The experiment was developed to evaluate the effect of strains of Streptococcus bovis (HC5 and JB1) on pH, ammonia production and nutritional value in elephant-grass silages (Pennisetum purpureum Schum). The experimental design was entirely randomized, with three treatments: T1 - elephant- grass, T2 - grass-elephant inoculated with Streptococcus bovis HC5, T3 - elephant grass inoculated with Streptococcus bovis JB1, totaling five replicates per treatment. The smallest value of ammonia was observed in the silage treated with inoculante the base Streptococcus bovis JB1 (5.90% N-total). Inoculation increased the levels of lactic acid and decreased levels of acetic, propionic and butyric acids, and the silages inoculated with Streptococcus bovis JB1 and HC5 were those with the highest values of lactic acid. There were not statistical differences for the tenors of dry matter (MS) and crude protein (PB). For the values of the fibers, the grass-elephant silage inoculated with Streptococcus bovis JB1, it presented the smallest value of neutral detergent fiber (59.77 %) and Hemicellulose (26.71 %). The largest value of in vitro dry matter digestibility (DIVMS) was observed in the silage with Streptococcus bovis JB1, showing superiority of four percentile points (64.23 %) in relation to the treatment without bacterial inoculante (60.35 %). The use Streptococcus bovis JB1 was efficient in the process fermentativo besides promoting would get better in the quality of the fiber and DIVMS in the studied silage.

Ultra-structural mapping of sugarcane bagasse after oxalic acid fiber expansion (OAFEX) and ethanol production by Candida shehatae and Saccharomyces cerevisiae

Background: Diminishing supplies of fossil fuels and oil spills are rousing to explore the alternative sources of energy that can be produced from non-food/feed-based substrates. Due to its abundance, sugarcane bagasse (SB) could be a model substrate for the second-generation biofuel cellulosic ethanol. However, the efficient bioconversion of SB remains a challenge for the commercial production of cellulosic ethanol. We hypothesized that oxalic-acid-mediated thermochemical pretreatment (OAFEX) would overcome the native recalcitrance of SB by enhancing the cellulase amenability toward the embedded cellulosic microfibrils. Results: OAFEX treatment revealed the solubilization of hemicellulose releasing sugars (12.56 g/l xylose and 1.85 g/l glucose), leaving cellulignin in an accessible form for enzymatic hydrolysis. The highest hydrolytic efficiency (66.51%) of cellulignin was achieved by enzymatic hydrolysis (Celluclast 1.5 L and Novozym 188). The ultrastructure characterization of SB using scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman spectroscopy, Fourier transform-near infrared spectroscopy (FT-NIR), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) revealed structural differences before and after OAFEX treatment with enzymatic hydrolysis. Furthermore, fermentation mediated by C. shehatae UFMG HM52.2 and S. cerevisiae 174 showed fuel ethanol production from detoxified acid (3.2 g/l, yield 0.353 g/g; 0.52 g/l, yield, 0.246 g/g) and enzymatic hydrolysates (4.83 g/l, yield, 0.28 g/g; 6.6 g/l, yield 0.46 g/g). Conclusions: OAFEX treatment revealed marked hemicellulose degradation, improving the cellulases ability to access the cellulignin and release fermentable sugars from the pretreated substrate. The ultrastructure of SB after OAFEX and enzymatic hydrolysis of cellulignin established thorough insights at the molecular level. © 2013 Chandel et al; licensee BioMed Central Ltd.

Xylo-oligosaccharides from lignocellulosic materials: Chemical structure, health benefits and production by chemical and enzymatic hydrolysis

Currently, there is worldwide interest in the technological use of agro-industrial residues as a renewable source of food and biofuels. Lignocellulosic materials (LCMs) are a rich source of cellulose and hemicellulose. Hemicellulose is rich in xylan, a polysaccharide used to develop technology for producing alcohol, xylose, xylitol and xylo-oligosaccharides (XOSs). The XOSs are unusual oligosaccharides whose main constituent is xylose linked by β 1-4 bonds. The XOS applications described in this paper highlight that they are considered soluble dietary fibers that have prebiotic activity, favoring the improvement of bowel functions and immune function and having antimicrobial and other health benefits. These effects open a new perspective on potential applications for animal production and human consumption. The raw materials that are rich in hemicellulose include sugar cane bagasse, corncobs, rice husks, olive pits, barley straw, tobacco stalk, cotton stalk, sunflower stalk and wheat straw. The XOS-yielding treatments that have been studied include acid hydrolysis, alkaline hydrolysis, auto-hydrolysis and enzymatic hydrolysis, but the breaking of bonds present in these compounds is relatively difficult and costly, thus limiting the production of XOS. To obviate this limitation, a thorough evaluation of the most convenient methods and the opportunities for innovation in this area is needed. Another challenge is the screening and taxonomy of microorganisms that produce the xylanolytic complex and enzymes and reaction mechanisms involved. Among the standing out microorganisms involved in lignocellulose degradation are Trichoderma harzianum, Cellulosimicrobium cellulans, Penicillium janczewskii, Penicillium echinulatu, Trichoderma reesei and Aspergillus awamori. The enzyme complex predominantly comprises endoxylanase and enzymes that remove hemicellulose side groups such as the acetyl group. The complex has low β-xylosidase activities because β-xylosidase stimulates the production of xylose instead of XOS; xylose, in turn, inhibits the enzymes that produce XOS. The enzymatic conversion of xylan in XOS is the preferred route for the food industries because of problems associated with chemical technologies (e.g., acid hydrolysis) due to the release of toxic and undesired products, such as furfural. The improvement of the bioprocess for XOS production and its benefits for several applications are discussed in this study. © 2012 Elsevier Ltd.

Fontes de carbono de baixo custo para a produção de xilanase termoestável por aspergillus niger

A strain of the flamentous fungus Aspergillus niger was isolated and shown to possess extracellular xylanolytic activity. These enzymes have biotechnological potential and can be employed in various industries. This fungus produced its highest xylanase activity in a medium made up of 0.1% CaCO3, 0.5% NaCl, 0.1% NH4Cl, 0.5% corn steep liquor and 1% carbon source, at pH 8.0. A low-cost hemicellulose residue (powdered corncob) proved to be an excellent inducer of the A. niger xylanolytic complex. Filtration of the crude culture medium with suspended kaolin was ideal for to clarify the extract and led to partial purifcation of the xylanolytic activity. The apparent molecular mass of the xylanase was about 32.3 kDa. Maximum enzyme activity occurred at pH 5.0 and 55-60oC. Apparent Km was 10.41 ± 0.282 mg/mL and Vmax was 3.32 ± 0.053 U/mg protein, with birchwood xylan as the substrate. Activation energy was 4.55 kcal/mol and half-life of the crude enzyme at 60oC was 30 minutes. Addition of 2% glucose to the culture medium supplemented with xylan repressed xylanase production, but in the presence of xylose the enzyme production was not affected.

Biomass-to-bio-products application of feruloyl esterase from Aspergillus clavatus

The structural polysaccharides contained in plant cell walls have been pointed to as a promising renewable alternative to petroleum and natural gas. Ferulic acid is a ubiquitous component of plant polysaccharides, which is found in either monomeric or dimeric forms and is covalently linked to arabinosyl residues. Ferulic acid has several commercial applications in food and pharmaceutical industries. The study herein introduces a novel feruloyl esterase from Aspergillus clavatus (AcFAE). Along with a comprehensive functional and biophysical characterization, the low-resolution structure of this enzyme was also determined by small-angle X-ray scattering. In addition, we described the production of phenolic compounds with antioxidant capacity from wheat arabinoxylan and sugarcane bagasse using AcFAE. The ability to specifically cleave ester linkages in hemicellulose is useful in several biotechnological applications, including improved accessibility to lignocellulosic enzymes for biofuel production. © 2012 Springer-Verlag Berlin Heidelberg.

The enzymatic recalcitrance of internodes of sugar cane hybrids with contrasting lignin contents

The recalcitrance in grasses varies according to cell type and maturation. The origin of the recalcitrance in different regions from sugar cane internodes with varied lignin contents was evaluated. The efficiency of enzymatic hydrolysis was correlated with the chemical, micromorphological and microspectrophotometric characteristics of the samples. The internodes of three sugar cane hybrids were dissected into four different fractions. The outermost fraction and the rind were the most recalcitrant regions, whereas the pith-rind interface and the pith were less recalcitrant. Cellulose conversion reached 86% after 72h of enzymatic digestion of the pith from the hybrid with the lowest lignin content. There was an inversely proportional correlation between the area occupied by vascular bundles and the efficiency of cellulose hydrolysis. High cellulose and low lignin or hemicellulose contents enhanced the efficiency of enzymatic hydrolysis of the polysaccharides. The critical evaluation of the results permitted to propose an empirical parameter for predicting cellulose conversion levels that accounts for the positive effect of high cellulose and low lignin plus hemicellulose and the detrimental effect of abundant vascular bundles. The cellulose conversion levels fit well to this calculated parameter, following a second order polynomial with an r2 value of 0.96. © 2013 Elsevier B.V.

Produção de etanol a partir de mosto hidrolisado hemicelulósico de ponta e palha de cana-de-açúcar

Pós-graduação em Microbiologia Agropecuária - FCAV

Estudo das atividades xilanásicas produzidas pelo fungo Aspergillus caespitosus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo da hidrólise do bagaço de cana-de-açúcar por fungos filamentosos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Seleção de micro-organismos fermentadores de xilose em etanol a partir de diferentes variedades da casca de uvas (Vitis spp)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Caracterização de fibras de milho e sua incorporação em barras de cereais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)