Estratégias para recuperação de xilooligossacarídeos do licor de resíduos de eucalipto para avaliação do seu efeito estimulante em Staphylococcus xylosus / Strategies for xylooligosaccharides recovery from eucalyptus waste liquor to evaluate their stimulatory effect on Staphylococcus xylosus

Xilooligossacarídeos (XOS) são reconhecidos pelo seu potencial prebiótico relevante para diversos setores industriais e foram obtidos após o pré-tratamento hidrotérmico da biomassa lignocelulósica residual de galhos de eucalipto. Subprodutos inibitórios são gerados durante o processo de solubilização dos oligossacarídeos e acabam comprometendo a utilização do licor em microrganismos. Neste trabalho, o processo de destoxificação, hidrólise enzimática e atividade estimulantes de crescimento da bactéria Staphylococcus xylosus foram estabelecidos. Os resultados mostraram que a adsorção com carvão ativado em pó removeu cerca de 55% do ácido acético e mais de 90% do ácido fórmico, compostos fenólicos, lignina solúvel, furfural e 5-hidroximetilfurfural, e que a soma dos oligossacarídeos xilobiose (X2) e xilotriose (X3) foram maximizadas de 0,57 g/L para 1,21 g/L com 110 U/gXOS da enzima endoxilanase e 6,3% do licor destoxificado na hidrólise enzimática. O consumo de cerca de 63% de X2 e de 46% de X3 pela bactéria em meio basal deficiente em fontes de carbono, mas acrescido com os oligômeros, proporcionou maior crescimento celular em relação aos meios basais com alta composição de carbono, com e sem XOS, revelando seu potencial prebiótico pelo efeito estimulante de crescimento. (AU)

Xylooligosaccharides (XOS) are recognized for their prebiotic potential relevant to several industrial sectors and were obtained after hydrothermal pretreatment of residual lignocellulosic biomass from eucalyptus branches. Inhibitory by-products are generated during the solubilization process of oligosaccharides and end up compromising the utilization of the liquor in microorganisms. In this work, the detoxification process, enzymatic hydrolysis and growth stimulating activity of Staphylococcus xylosus bacteria were established. The results showed that adsorption with powdered activated carbon removed about 55% of acetic acid and more than 90% of formic acid, phenolic compounds, soluble lignin, furfural, and 5-hydroxymethyl furfural and the sum of the oligosaccharides xylobiose (X2) and xylotriose (X3) were maximized from 0.57 g/L to 1.21 g/L with 110 U/gXOS of the enzyme endoxylanase and 6.3% of the detoxified liquor in the enzymatic hydrolysis. The consumption of X2 and X3 were about 63% and 46%, respectively, by the bacteria in basal medium deficient in carbon sources, but in medium added with the oligomers, provided higher cell growth compared to basal medium with high carbon composition, with and without XOS, revealing its prebiotic potential by its growth-stimulating effect. (AU)

Fast saccharide mapping method for quality consistency evaluation of commercial xylooligosaccharides collected in China / 药物分析学报

Due to the extensive use of xylooligosaccharides (XOS) as functional food ingredients,many inferior goods and even adulterants are generally found in the market,which may pose a health hazard to certain populations.Chromatography method such as high-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC) is traditionally applied for the quality analysis of XOS.However,it is time consuming due to the prolonged separation and pre-or post-derivatization procedure.In this study,a fast saccharide mapping method based on matrix-assisted laser desorption/time-of-flight mass spectrometry (MALDI-TOF-MS) was developed for the quality consistency analysis of 22 batches of XOS collected from different manufacturers in China.The time needed for saccharides analysis using MALDI-MS was less than 30 min for one plate,at least 6 times faster than that by the traditional HPTLC chromatography method.In addition,MALDI-MS possessed higher resolution for XOS with DP4-DP7 based on the difference of m/z,which is hardly separated using HPTLC.The results showed that XOS were present only in samples XY01-XY11,samples XY12-XY14 only consisted of hex oligo-saccharides,and samples XY15-XY22 were free of oligosaccharides.These indicate that the quality consistency of XOS products in the China market was poor,which should be carefully investigated.

Xylanase and beta-xylosidase from Penicillium janczewskii: Purification, characterization and hydrolysis of substrates

Background: Xylanases and β-D-xylosidases are the most important enzymes responsible for the degradation of xylan, the second main constituent of plant cell walls. Results: In this study, the main extracellular xylanase (XYL I) and p-xylosidase (BXYL I) from the fungus Penicillium janczewskii were purified, characterized and applied for the hydrolysis of different substrates. Their molecular weights under denaturing and non-denaturing conditions were, respectively, 30.4 and 23.6 kDa for XYL I, and 100 and 200 kDa for BXYL I, indicating that the latter is homodimeric. XYL I is highly glycosylated (78%) with optimal activity in pH 6.0 at 65°C, while BXYL I presented lower sugar content (10.5%) and optimal activity in pH 5.0 at 75°C. The half-lives of XYL I at 55, 60 and 65°C were 125,16 and 6 min, respectively. At 60°C, BXYL I retained almost 100% of the activity after 6 h. NH4+,Na+, DTT and β-mercaptoethanol stimulated XYL I, while activation of BXYL I was not observed. Interestingly, XYL I was only partially inhibited by Hg2+, while BXYL I was completely inhibited. Xylobiose, xylotriose and larger xylooligosaccharides were the main products from xylan hydrolysis by XYL I. BXYL I hydrolyzed xylobiose and larger xylooligosaccharides with no activity against xylans. Conclusion: The enzymes act synergistically in the degradation of xylans, and present industrial characteristics especially in relation to optimal activity at high temperatures, prolonged stability of BXYL I at 60°C, and stability of XYL I in wide pH range.

Production of antioxidant xylooligosaccharides from lignocellulosic materials using Bacillus amyloliquifaciens NRRL B-14393 xylanase.

The present study aimed to evaluate the enzymatic production of XOS, antioxidant activities together with total phenolic contents from different lignocellulosic materials and birchwoodxylan using both crude and pure forms of Bacillus amyloliquifaciens NRRL B-14393 xylanase respectively. The mode of action of the pure xylanase was studied by HPLC and the end products analysis of birchwoodxylan revealed that xylose, xylobiose and xylotriose were the only end products. The resulted XOS mixture exhibited potent antioxidant activity of 87.36 % and high total phenolic content of 182.88 mg GAE/ liter of extract. XOS were obtained from different alkali pretreated agricultural residues by the crude xylanase action with a yield in a range from 54.4% to85.5%.Maximum scavenging abilities and total phenolic contents of XOS mixtures of all the tested materials were determined. XOS mixtures of orange and mango peels revealed relatively higher antioxidant activities (96% and 76.84%, respectively) and total phenolic acid contents (156.32 and 133.74 mg GAE/ liter of extract, respectively) compared to the other XOS mixtures. In conclusion, Bacillus amyloliquifaciens NRRL B-14393 xylanase could be a promising source for production of XOS with high phenolic contents and antioxidant activities.

Xylanases–from Microbial Origin to Industrial Application.

Xylanases are in the focus of research due to their potential to replace many current polluting chemical technologies by biochemical conversion. The field of application for xylanases is vast; it comprises industrial applications like wood pulp bio-bleaching, papermaking and bioethanol production. In addition, these enzymes can be applied as additives in food and beverage industry, and animal nutrition. However, considering the potential applications for these enzymes, the market share of xylanases is still low. Thus, the search for promising xylanases which tolerate relevant processing conditions and therefore can be used in industrial settings is an ongoing task. This review provides an overview of the enzymes reported from 2012 to mid 2014. Further, legal restrictions for the use of (genetically modified) organisms and enzymes are considered. This review provides an integrated perspective on the potential of specific xylanases for industrial applications.

Xylanases: An Overview.

Endo-1, 4-β-xylanase (Endo-β-1, 4-xylan, xylanohydrolase; EC. 3.2.1.8, commonly called xylanase) is an industrially important enzyme which degrades xylan randomly and produces xylooligosaccharides, xylobiose and xylose. It is mainly present in microbes and plants but not in animals. Xylanases from fungal and bacterial sources have been extensively studied and produced commercially. Its potential use in paper industries has been discussed which is directly related to reduction in environmental pollution. It has role in bio-bleaching paper pulp and increasing pulp brightness. Besides, it can be exploited for ethanol production and as an additive in animal feedstock to improve its nutritional value. Endo-1, 4-β-xylanase can also be exploited in baking and fruit juice industries. Here, we reviewed its distribution, structural aspects and industrial/ biotechnological applications. Besides, we also discussed studies related to cloning of the gene encoding endo-1, 4-β-xylanase with the objectives of overproducing the enzyme and altering its properties to suit commercial applications.

Xilooligossacarídeos: produção, aplicações e efeitos na saúde humana / Xylooligosaccharides: production, applications and effects on human health

Os xilooligossacarídeos são açúcares não-convencionais (oligômeros formados por unidades de xilose), não-calóricos e não são metabolizados pelo organismo humano. São considerados prebióticos, uma vez que promovem seletivamente o crescimento de probióticos como Lactobacillus sp. e Bifidobacterium bifidum, promovendo uma série de benefícios à saúde humana, como a redução da constipação intestinal, a promoção da digestão e a absorção de nutrientes, a prevenção de infecções gastrintestinais e a inibição do crescimento de microrganismos patogênicos. Este artigo de revisão demonstra a produção de xilooligossacarídeos, tendo como fonte materiais lignocelulósicos, através de métodos químicos e enzimáticos, e também a sua aplicação como ingredientes em alimentos, salientando os efeitos benéficos à saúde provindos desses tipos de compostos.

Xylooligosaccharides are non-conventional sugars (sugar oligomers made of xylose units), non-calorics and non-digestible by humans. They are recognyzed as prebiotics once there are non digestible food ingredient that stimulate selectively probiotic growth like Lactobacillus sp. and Bifidobacterium bifidum, promoting several benefices to the human health as the reduction of the gut constipation, the increase of the digestion and nutrient absorption, prevention of gastrointestinal infections, and the inhibition of pathogenic microorganisms. This article reviews the production of xylooligosaccharides from lignocellulosic materials (by chemical or enzymatic methods) and its end products, as well as their application as food ingredients, with special attention to the beneficial effects caused on health by these types of compounds.