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.

Estudo e transformação química de biopolímeros a base de quitina e quitosana para preparação de materiais com diversas propriedades

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação de suportes para a imobilização de Zymomonas mobilis CCT 4494 visando à produção de etanol e levana

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The Identification and Biochemical Properties of the Catalytic Specificity of a Serine Peptidase Secreted by Aspergillus fumigatus Fresenius

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

Chemical characteristics and fractionation of proteins from Moringa oleifera Lam. leaves

Moringa oleifera Lam, is a leguminous plant, originally from Asia, which is cultivated in Brazil because of its low production cost. Although some people have used this plant as food, there is little information about its chemical and nutritional characteristics. The objective of this study was to characterise the leaves of M. oleifera in terms of their chemical composition, protein fractions obtained by solubility in different systems and also to assess their nutritional quality and presence of bioactive substances. The whole leaf flour contained 28.7% crude protein, 7.1% fat, 10.9% ashes, 44.4% carbohydrate and 3.0 mg 100 g(-1) calcium and 103.1 mg 100 g(-1) iron. The protein profile revealed levels of 3.1% albumin, 0.3% globulins, 2.2% prolamin, 3.5% glutelin and 70.1% insoluble proteins. The hydrolysis of the protein from leaf flour employing sodium dodecyl sulfate (SDS) and 2-mercaptoethanol (ME) resulted in 39.5% and 29.5%, respectively. The total protein showed low in vitro digestibility (31.8%). The antinutritional substances tested were tannins (20.7 mg g(-1)), trypsin inhibitor (1.45 TIU mg g(-1)), nitrate (17 mg g(-1)) and oxalic acid (10.5 mg g(-1)), besides the absence of cyanogenic compounds. beta-Carotene and lutein stood out as major carotenoids, with concentrations of 161.0 and 47.0 mu g g(-1) leaf, respectively. Although M. oleifera leaves contain considerable amount of crude protein, this is mostly insoluble and has low in vitro digestibility, even after heat treatment and chemical attack. In vivo studies are needed to better assess the use of this leaf as a protein source in human feed. (C) 2013 Elsevier Ltd. All rights reserved.

Chitosan and alginate biopolymer membranes for remediation of contaminated water with herbicides

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

Acid Lipase from Candida viswanathii: Production, Biochemical Properties, and Potential Application

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Nanocomposites of natural rubber and polyaniline-modified cellulose nanofibrils

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Transport of amino acids from milk whey by Caco-2 cell monolayer after hydrolytic action of gastrointestinal enzymes

The bioavailability of amino adds from milk whey protein hydrolysates was evaluated using diffusion of the substances through semi-permeable membranes (dialyzability) and transport by Caco-2 cell cultures. The hydrolysates with low degree of hydrolysis (LDH) and high degree of hydrolysis (HDH) were obtained after 120 min of reaction time at 50 degrees C after the initial addition of pepsin, followed by the addition of trypsin, chymotrypsin and carboxypeptidase-A. The proteins and hydrolysates were further subjected to in vitro digestion with pepsin plus pancreatin. HPLC was used to determine the concentrations of dialyzable amino adds (48.4% of the non-hydrolyzed proteins, 63.2% of the LDH sample and 58.3% of the HDH sample), demonstrating the greater dialyzability of the hydrolysates. The LDH and HDH whey protein hydrolysates prepared with pepsin, trypsin, chymotrypsin and carboxypeptidase-A showed only 14.7% and 20.8% of dialyzable small peptides and amino acids, respectively. The efficiency of absorption was demonstrated by the preferential transport of Ile, Lou and Arg through a layer of cells. In the LDH hydrolysate, Tyr was also transported. Prior high- and low-degree hydrolysis of the whey provided transport by 5.7% and 6.6%, respectively, in comparison with 23% for non-hydrolyzed proteins, considering the total amount of these amino adds that was applied to the cells. (C) 2014 Elsevier Ltd. All rights reserved.

Influence of cellulose nanofibrils on soft and hard segments of polyurethane/cellulose nanocomposites and effect of humidity on their mechanical properties

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

Crystallization and preliminary X-ray diffraction analysis of a novel sphingomyelinase D from Loxosceles gaucho venom

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Biochemical characterisation and application of lipases produced by Aspergillus sp on solid-state fermentation using three substrates

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

Effects of Locally Administered Tiludronic Acid on Experimental Periodontitis in Rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Chitosan-collagen scaffolds can regulate the biological activities of adipose mesenchymal stem cells for tissue engineering

Scaffolds of chitosan and collagen can offer a biological niche for the growth of adipose derived stem cells (ADSC). The objective of this work was to characterize the physico-chemical properties of the scaffolds and the ADSC, as well as their interactions to direct influences of the scaffolds on the behavior of ADSC. The methodology included an enzymatic treatment of fat obtained by liposuction by collagenase, ASDC immunophenotyping, cell growth kinetics, biocompatibility studies of the scaffolds analyzed by the activity of alkaline phosphatase (AP), nitric oxide (NO) determination by the Griess-Saltzman reaction, and images of both optical and scanning electron microscopy of the matrices. The extent of the crosslinking of genipin and glutaraldehyde was evaluated by ninhydrin assays, solubility tests and degradation of the matrices. The results showed that the matrices are biocompatible, exhibit physical and chemical properties needed to house cells in vivo and are strong stimulators of signaling proteins (AP) and other molecules (NO) which are important in tissue healing. Therefore, the matrices provide a biological niche for ADSC adhesion, proliferation and cells activities.

Stability of a Lipase Extracted from Seeds of Pachira aquatica in Commercial Detergents and Application Tests in Poultry Wastewater Pretreatment and Fat Particle Hydrolysis

A protein extract containing a plant lipase from oleaginous seeds of Pachira aquatica was tested using soybean oil, wastewater from a poultry processing plant, and beef fat particles as substrate. The hydrolysis experiments were carried out at a temperature of 40°C, an incubation time of 90 minutes, and pH 8.0-9.0. The enzyme had the best stability at pH 9.0 and showed good stability in the alkaline range. It was found that P. aquatica lipase was stable in the presence of some commercial laundry detergent formulations, and it retained full activity up to 0.35% in hydrogen peroxide, despite losing activity at higher concentrations. Concerning wastewater, the lipase increased free fatty acids release by 7.4 times and promoted the hydrolysis of approximately 10% of the fats, suggesting that it could be included in a pretreatment stage, especially for vegetable oil degradation.