Purification of β-xylosidase from Aspergillus tamarii using ground oats and a possible application on the fermented hydrolysate by Pichia stipitis

El-Gindy, A.A.; Saad, R. R.; Fawzi, Eman M.

doi:10.1007/s13213-014-0940-x

Cited by 12 publications

(5 citation statements)

References 40 publications

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“…The continued characterization of hydrolases, accessory proteins and the regulation of their expression in Aspergillus species that display efficiency in degradation of lignocellulose will further our understanding of their roles in saccharification. Given the importance of Aspergillus tamarii as an efficient producer of enzymes such as xylanases (El-Gindy et al, 2015 ; Monclaro et al, 2016 ), we utilized an Illumina RNA-seq approach to analyze the transcriptome in this fungus following semi-solid and liquid cultivation on steam-exploded bagasse (SB) compared gene expression following growth on glucose (G). Genes encoding cellulases and hemicellulases, transcription factors and transporters are characterized in relation to their differential expression following fungal growth on each carbon source.…”

Section: Introductionmentioning

confidence: 99%

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

Midorikawa

Corrêa

Noronha

et al. 2018

Front. Bioeng. Biotechnol.

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The production of bioethanol from non-food agricultural residues represents an alternative energy source to fossil fuels for incorporation into the world's economy. Within the context of bioconversion of plant biomass into renewable energy using improved enzymatic cocktails, Illumina RNA-seq transcriptome profiling was conducted on a strain of Aspergillus tamarii, efficient in biomass polysaccharide degradation, in order to identify genes encoding proteins involved in plant biomass saccharification. Enzyme production and gene expression was compared following growth in liquid and semi-solid culture with steam-exploded sugarcane bagasse (SB) (1% w/v) and glucose (1% w/v) employed as contrasting sole carbon sources. Enzyme production following growth in liquid minimum medium supplemented with SB resulted in 0.626 and 0.711 UI.mL−1 xylanases after 24 and 48 h incubation, respectively. Transcriptome profiling revealed expression of over 7120 genes, with groups of genes modulated according to solid or semi-solid culture, as well as according to carbon source. Gene ontology analysis of genes expressed following SB hydrolysis revealed enrichment in xyloglucan metabolic process and xylan, pectin and glucan catabolic process, indicating up-regulation of genes involved in xylanase secretion. According to carbohydrate-active enzyme (CAZy) classification, 209 CAZyme-encoding genes were identified with significant differential expression on liquid or semi-solid SB, in comparison to equivalent growth on glucose as carbon source. Up-regulated CAZyme-encoding genes related to cellulases (CelA, CelB, CelC, CelD) and hemicellulases (XynG1, XynG2, XynF1, XylA, AxeA, arabinofuranosidase) showed up to a 10-fold log2FoldChange in expression levels. Five genes from the AA9 (GH61) family, related to lytic polysaccharide monooxygenase (LPMO), were also identified with significant expression up-regulation. The transcription factor gene XlnR, involved in induction of hemicellulases, showed up-regulation on liquid and semi-solid SB culture. Similarly, the gene ClrA, responsible for regulation of cellulases, showed increased expression on liquid SB culture. Over 150 potential transporter genes were also identified with increased expression on liquid and semi-solid SB culture. This first comprehensive analysis of the transcriptome of A. tamarii contributes to our understanding of genes and regulatory systems involved in cellulose and hemicellulose degradation in this fungus, offering potential for application in improved enzymatic cocktail development for plant biomass degradation in biorefinery applications.

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Section: Introductionmentioning

confidence: 99%

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

Midorikawa

Corrêa

Noronha

et al. 2018

Front. Bioeng. Biotechnol.

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“…An improved yield of peptidase production, approximately 30 times higher, was obtained through SSF compared to SmF [115]. In another comparative study among SSF, slurry state fermentation (SlSF) and SmF, revealed that maximum β-xylosidase was obtained in SSF (33.7 U·mL −1 ) followed by SlSF (24.9 U·mL −1 ) and SmF (5.5 U·mL −1 ) [129].…”

Section: Enzymes Productionmentioning

confidence: 96%

Solid-State Fermentation as a Novel Paradigm for Organic Waste Valorization: A Review

et al. 2017

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Abstract:The abundance of organic solid waste throughout the world has become a common issue that needs complete management at every level. Also, the scarcity of fuel and the competition between food and substance as an alternative to a petroleum-based product has become a major problem that needs to be properly handled. An urge to find renewable substances for sustainable development results in a strategy to valorize organic solid waste using solid state fermentation (SSF) and to manage the issue of solid wastes in a green approach. This paper reviews management of solid wastes using SSF, with regard to its current application, advantages and challenges, downstream processing in SSF, economic viewpoint, and future perspectives.

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“…in enzyme production, biodegradation of agro-industrial wastes, and a variety of industrial fermentation processes for upgrading low-value feedstocks [18][19][20]. Among the frequently employed species within the genus Aspergillus, Aspergillus tamarii, a saprophyte fungus, is recognized as an efficient protease [21,22] and xylanase [23][24][25][26] producer. So far, the (putative) LPMOs of A. tamarii have not gained much attention.…”

Section: Introductionmentioning

confidence: 99%

Characterization of two family AA9 LPMOs from Aspergillus tamarii with distinct activities on xyloglucan reveals structural differences linked to cleavage specificity

et al. 2020

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Aspergillus tamarii grows abundantly in naturally composting waste fibers of the textile industry and has a great potential in biomass decomposition. Amongst the key (hemi)cellulose-active enzymes in the secretomes of biomass-degrading fungi are the lytic polysaccharide monooxygenases (LPMOs). By catalyzing oxidative cleavage of glycoside bonds, LPMOs promote the activity of other lignocellulose-degrading enzymes. Here, we analyzed the catalytic potential of two of the seven AA9-type LPMOs that were detected in recently published transcriptome data for A. tamarii, namely AtAA9A and AtAA9B. Analysis of products generated from cellulose revealed that AtAA9A is a C4-oxidizing enzyme, whereas AtAA9B yielded a mixture of C1-and C4-oxidized products. AtAA9A was also active on cellopentaose and cellohexaose. Both enzymes also cleaved the β-(1!4)-glucan backbone of tamarind xyloglucan, but with different cleavage patterns. AtAA9A cleaved the xyloglucan backbone only next to unsubstituted glucosyl units, whereas AtAA9B yielded product profiles indicating that it can cleave the xyloglucan backbone irrespective of substitutions. Building on these new results and on the expanding catalog of xyloglucan-and oligosaccharideactive AA9 LPMOs, we discuss possible structural properties that could underlie the observed functional differences. The results corroborate evidence that filamentous fungi have evolved AA9 LPMOs with distinct substrate specificities and regioselectivities, which likely have complementary functions during biomass degradation.

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Purification of β-xylosidase from Aspergillus tamarii using ground oats and a possible application on the fermented hydrolysate by Pichia stipitis

Cited by 12 publications

References 40 publications

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

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

Solid-State Fermentation as a Novel Paradigm for Organic Waste Valorization: A Review

Characterization of two family AA9 LPMOs from Aspergillus tamarii with distinct activities on xyloglucan reveals structural differences linked to cleavage specificity

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