Use of Residual Biomass from the Textile Industry as Carbon Source for Production of a Low-Molecular-Weight Xylanase from Aspergillus oryzae

Abstract

Pretreated dirty cotton residue (PDCR) from the textile industry was used as an alternative carbon source for the submerged cultivation of Aspergillus oryzae and the production of xylanases. The filtered culture supernatant was fractionated by ultrafiltration followed by three chromatographic steps, which resulted in the isolation of a homogeneous low-molecular-weight xylanase (Xyl-O1) with a mass of 21.5 kDa as determined by sodium dodecyl sulfate-polyacrilamide gel electrophoresis (SDS-PAGE) co-polymerized with 0.1% oat spelt xylan. Enzyme catalysis was the most efficient at 50 °C and pH 6.0. The Km values (mg·mL−1) for the soluble fraction of oat spelt and birchwood xylans were 10.05 and 3.34, respectively. Xyl-O1 was more stable in the presence of 5,5-dithio-bis-(2-nitrobenzoic acid) (DTNB), 1,4-dithiothreitol (DTT), l-cysteine or β-mercaptoethanol, which increased the rate of catalysis by 40%, 14%, 40% or 37%, respectively. The enzyme stability was improved at pH 7.0 in the presence of 20 mM l-cysteine, with the retention of nearly 100% of the activity after 6 h at 50 °C. Xyl-O1 catalyzed the cleavage of internal β-1,4 linkages of the soluble substrates containing d-xylose residues, with a maximum efficiency of 33% for the hydrolysis of birchwood xylan after 12 h of incubation. Identification of the hydrolysis products by high-performance anion exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD) indicated the predominance of the hydrolysis products X2-X6 during the first 12 h of incubation and the accumulation of higher xylooligomers after the elution of the last xylooligomer standard, xylohexaose

Analysis of the Transcriptome in Aspergillus tamarii During Enzymatic Degradation of Sugarcane Bagasse

“…Previous studies have also highlighted the potential in this species in depolymerization of xylan, through secretion of β-1,4-endoxylanases (Gouda and Abdel-Naby, 2002 ; da Silva et al, 2014 ). Efficient secretion of such xylanases has also been reported in the strain A. tamarii BLU37 (Duarte et al, 2012 ; Monclaro et al, 2016 ). Whilst the transcriptome in different Aspergillus species during degradation of plant biomass has been the subject of recent investigation (de Souza et al, 2011 ; Delmas et al, 2012 ; Pullan et al, 2014 ; van Munster et al, 2014 ; Miao et al, 2015 ; Borin et al, 2017 ), despite the clear potential of A. tamarii as a xylanolytic species, there has been no investigation, prior to the current study, of the transcriptome of this species during saccharification of plant biomass.…”

“…As plant pathogens or saprophytes, many filamentous fungi are efficient in hydrolytic extracellular enzyme secretion for plant biomass depolymerization. A number of species belonging to the genus Aspergillus are efficient in secretion of a large repertoire of glycosyl hydrolases appropriate for industrial application in lignocellulosic biomass degradation (Machida et al, 2005 ; Duarte et al, 2012 ; Jaramillo et al, 2013 ; Pirota et al, 2014 ). The strain examined in this study was originally isolated from composting cotton textile waste material (Siqueira et al, 2009 ).…”

Purificação e caracterização bioquímica e biofísica de uma xilanase de aspergillus foetidus

“…xilanase, no entanto, para Xyl apresentou um efeito inibitório nas concentrações de 1 e 10 mM promovendo uma redução de 36% e 55%, respectivamente comparado com o controle. Duarte et al (2012) (Duarte et al, 2012;Haq et al, 2012). Goluguri et al (2016) ; Kumar e Satyanarayana, 2011; Goluguri et al, 2016).…”

“…xilana foram observados por Ryan et al (2003) utilizando uma xilanase purificada de Penicillium capsulatum para a hidrólise da xilana de faia e por Duarte et al (2012) para uma xilanase purificada de Aspergillus oryzae para a hidrólise da xilana de bétula (Ryan et al, 2003;Duarte et al, 2012). (Ujiie, Roy e Yaguchi, 1991;Ximenes et al, 1999).…”

Conversion of Wheat Bran to Xylanases and Dye Adsorbent by Streptomyces thermocarboxydus

“…Microorganisms, such as bacteria [ 20 , 21 , 22 , 23 ], actinomycetes [ 24 , 25 ], and fungi [ 26 , 27 , 28 , 29 ] are the primary sources for xylanase production. Among these, xylanases are produced by various strains of Streptomyces [ 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ].…”