Xylooligosaccharides Production from Alkali-Pretreated Sugarcane Bagasse Using Xylanases from Thermoascus aurantiacus

Brienzo, Michel; Carvalho, Walter; Milagres, Adriane M. F.

doi:10.1007/s12010-009-8892-5

Cited by 133 publications

(43 citation statements)

References 23 publications

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“…XOSs with low degrees of polymerization (DP = 2 to 6), produced from xylans by endoxylanases, have been proven to be able to promote proliferation of bifidobacteria, the beneficial microorganisms in the human intestine. Demand for this functional food additive has shown a rapid growth over the last two decades [24]. …”

Section: Resultsmentioning

confidence: 99%

Determinants for the improved thermostability of a mesophilic family 11 xylanase predicted by computational methods

Zhang

Wang

et al. 2014

Biotechnol Biofuels

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BackgroundXylanases have drawn much attention owing to possessing great potential in various industrial applications. However, the applicability of xylanases, exemplified by the production of bioethanol and xylooligosaccharides (XOSs), was bottlenecked by their low stabilities at higher temperatures. The main purpose of this work was to improve the thermostability of AuXyn11A, a mesophilic glycoside hydrolase (GH) family 11 xylanase from Aspergillus usamii E001, by N-terminus replacement.ResultsA hybrid xylanase with high thermostability, named AEXynM, was predicted by computational methods, and constructed by substituting the N-terminal 33 amino acids of AuXyn11A with the corresponding 38 ones of EvXyn11TS, a hyperthermostable family 11 xylanase. Two AuXyn11A- and AEXynM-encoding genes, Auxyn11A and AExynM, were then highly expressed in Pichia pastoris GS115, respectively. The specific activities of two recombinant xylanases (reAuXyn11A and reAEXynM) were 10,437 and 9,529 U mg-1. The temperature optimum and stability of reAEXynM reached 70 and 75°C, respectively, much higher than those (50 and 45°C) of reAuXyn11A. The melting temperature (Tm) of reAEXynM, measured using the Protein Thermal Shift (PTS) method, increased by 34.0°C as compared with that of reAuXyn11A. Analyzed by HPLC, xylobiose and xylotriose as the major hydrolytic products were excised from corncob xylan by reAEXynM. Additionally, three single mutant genes from AExynM (AExynMC5T, AExynMP9S, and AExynMH14N) were constructed by site-directed mutagenesis as designed theoretically, and expressed in P. pastoris GS115, respectively. The thermostabilities of three recombinant mutants clearly decreased as compared with that of reAEXynM, which demonstrated that the three amino acids (Cys5, Pro9, and His14) in the replaced N-terminus contributed mainly to the high thermostability of AEXynM.ConclusionsThis work highly enhanced the thermostability of AuXyn11A by N-terminus replacement, and further verified, by site-directed mutagenesis, that Cys5, Pro9, and His14 contributed mainly to the improved thermostability. It will provide an effective strategy for improving the thermostabilities of other enzymes.

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Section: Resultsmentioning

confidence: 99%

Determinants for the improved thermostability of a mesophilic family 11 xylanase predicted by computational methods

Zhang

Wang

et al. 2014

Biotechnol Biofuels

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“…Sabina-Hanim et al [59] observed 25.6% of xylose in XOs production by xylanase from Trichoderma viride using pretreated palm oil. Brienzo et al [60], using xylanase from T. aurantiacus on sugarcane bagasse hemicellulose, observed a yield of 12.97% of xylan after 24 h.…”

Section: Xylan Hydrolysis By Soluble and Immobilized Xynamentioning

confidence: 99%

Immobilization and stabilization of an endoxylanase from Bacillus subtilis (XynA) for xylooligosaccharides (XOs) production

et al. 2016

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a b s t r a c tXylooligosaccharides (XOs) are small oligomers constituted by 2−10 units of xylan monomers, with important nutraceutical properties. They can be produced through hydrolysis of xylan catalyzed by an endoxylanase. The use of immobilized and stabilized enzymes may decrease the industrial process costs. In this study, XynA, a recombinant enzyme from B. subtilis, was immobilized in three different supports: agarose and chitosan activated with glyoxal groups and chitosan activated with glutaraldehyde. High immobilization yields were obtained, 100% for agarose-glyoxal and chitosan-glutaraldehyde, 82% for chitosan-glyoxal, with recovered activities of 42.7 (±1.3), 10.7 ± 0.8 and 53.6% (± 1.7), respectively. A great increase in the thermal stability of the enzyme (at 56 • C, pH 5.5) was achieved for the glyoxal derivatives: 75-fold for chitosan and 8600-fold for agarose. The great thermal stability obtained to the derivative agarose-glyoxal can be explained by the enzyme immobilization through lysine residues located in unstable sites of the protein structure. The agarose-glyoxal derivative was tested in the production of XOs (X2, X3 and X4) from soluble and conventional birchwood xylan, reaching approximately 20% of conversion in 3 h and 23% in 24 h, without the undesirable xylose production. After 10 cycles of hydrolysis, the conversion remained almost unchanged.

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“…High quality XOS can be produced enzymatically using xylanases from a variety of microorganisms including: Aspergillus, Thermoascus, Trichoderma, Streptomycetes, Phanerochaetes, Chytridiomycetes, Ruminoccocus, Penicillium, Fibrobacter, Clostridium, Pichia and Bacillus (1,(10)(11)(12)(13). However, the search for more effi cient xylanase-producing strains is necessary considering the production costs and low yields of production.…”

Section: Introductionmentioning

confidence: 99%

Screening of Xylanolytic Aspergillus fumigatus for Prebiotic Xylooligosaccharide Production Using Bagasse

Carvalho

Neto

Almeida

et al. 2015

Food Technol. Biotechnol.

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Currently, lignocellulosic waste is a topic of global studies, given that fossil fuel reserves are diminishing, the new agricultural frontiers are limited and the demand for food and biofuels is increasing by the growing world population (1). For these reasons, technology must advance to improve the use of agricultural and agroindustrial residues to obtain food and biofuel.Xylans present in lignocellulosic materials have been studied for obtaining xylooligosaccharides (XOS) from waste materials such as corncobs, rice hulls, olive pits, barley straw (2), tobacco stalk, cott on stalk, sunfl ower stalk, wheat straw (3) and sugarcane bagasse (4-6). Sugarcane bagasse is inexpensive, renewable and abundant source of XOS especially in the countries that produce ethanol and sugar from sugarcane. However, more research is necessary to improve the use of this residue. SummarySugarcane bagasse is an important lignocellulosic material studied for the production of xylooligosaccharides (XOS). Some XOS are considered soluble dietary fi bre, with low caloric value and prebiotic eff ect, but they are expensive and not easily available. In a screening of 138 fungi, only nine were shortlisted, and just Aspergillus fumigatus M51 (35.6 U/mL) and A. fumigatus U2370 (28.5 U/mL) were selected as the most signifi cant producers of xylanases. These fungi had low β-xylosidase activity, which is desirable for the production of XOS. The xylanases from Trichoderma reesei CCT 2768, A. fumigatus M51 and A. fumigatus U2370 gave a signifi cantly higher XOS yield, 11.9, 14.7 and 7.9 % respectively, in a 3-hour reaction with hemicellulose from sugarcane bagasse. These enzymes are relatively thermostable at 40-50 °C and can be used in a wide range of pH values. Furthermore, these xylanases produced more prebiotic XOS (xylobiose and xylotriose) when compared with a commercial xylanase. The xylanases from A. fumigatus M51 reached a high level of XOS production (37.6 %) in 48-72 h using hemicellulose extracted from sugarcane bagasse. This yield represents 68.8 kg of prebiotic XOS per metric tonne of cane bagasse. In addition, in a biorefi nery, aft er hemicellulose extraction for XOS production, the residual cellulose could be used for the production of second-generation ethanol.

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Xylooligosaccharides Production from Alkali-Pretreated Sugarcane Bagasse Using Xylanases from Thermoascus aurantiacus

Cited by 133 publications

References 23 publications

Determinants for the improved thermostability of a mesophilic family 11 xylanase predicted by computational methods

Determinants for the improved thermostability of a mesophilic family 11 xylanase predicted by computational methods

Immobilization and stabilization of an endoxylanase from Bacillus subtilis (XynA) for xylooligosaccharides (XOs) production

Screening of Xylanolytic Aspergillus fumigatus for Prebiotic Xylooligosaccharide Production Using Bagasse

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