scholarly journals Production and characterization of Aspergillus niger GH29 family α-fucosidase and production of a novel non-reducing 1-fucosyllactose

2019 ◽  
Vol 37 (2) ◽  
pp. 221-229 ◽  
Author(s):  
Anne Usvalampi ◽  
Marcela Ruvalcaba Medrano ◽  
Hannu Maaheimo ◽  
Heidi Salminen ◽  
Olli Tossavainen ◽  
...  

AbstractFucosylated oligosaccharides are interesting molecules due to their bioactive properties. In particular, their application as active ingredient in milk powders is attractive for dairy industries. The objective of this study was to characterize the glycosyl hydrolase family 29 α-fucosidase produced by Aspergillus niger and test its ability to transfucosylate lactose with a view towards potential industrial applications such as the valorization of the lactose side stream produced by dairy industry. In order to reduce costs and toxicity the use of free fucose instead of environmentally questionable fucose derivatives was studied. In contrast to earlier studies, a recombinantly produced A. niger α-fucosidase was utilized. Using pNP-fucose as substrate, the optimal pH for hydrolytic activity was determined to be 3.8. The optimal temperature for a 30-min reaction was 60 °C, and considering temperature stability, the optimal temperature for a 24-h reaction was defined as 45 °C For the same hydrolysis reaction, the kinetic values were calculated to be 0.385 mM for the KM and 2.8 mmol/(mg*h) for the Vmax. Transfucosylation of lactose occurred at high substrate concentrations when reaction time was elongated to several days. The structure of the product trisaccharide was defined as 1-fucosyllactose, where fucose is α-linked to the anomeric carbon of the β-glucose moiety of lactose. Furthermore, the enzyme was able to hydrolyze its own transfucosylation product and 2′-fucosyllactose but only poorly 3-fucosyllactose. As a conclusion, α-fucosidase from A. niger can transfucosylate lactose using free fucose as substrate producing a novel non-reducing 1-fucosyllactose.

2008 ◽  
Vol 75 (4) ◽  
pp. 1135-1143 ◽  
Author(s):  
Karina Pokusaeva ◽  
Mary O'Connell-Motherway ◽  
Aldert Zomer ◽  
Gerald F. Fitzgerald ◽  
Douwe van Sinderen

ABSTRACT Two α-glucosidase-encoding genes (agl1 and agl2) from Bifidobacterium breve UCC2003 were identified and characterized. Based on their similarity to characterized carbohydrate hydrolases, the Agl1 and Agl2 enzymes are both assigned to a subgroup of the glycosyl hydrolase family 13, the α-1,6-glucosidases (EC 3.2.1.10). Recombinant Agl1 and Agl2 into which a His12 sequence was incorporated (Agl1His and Agl2His, respectively) exhibited hydrolytic activity towards panose, isomaltose, isomaltotriose, and four sucrose isomers—palatinose, trehalulose, turanose, and maltulose—while also degrading trehalose and, to a lesser extent, nigerose. The preferred substrates for both enzymes were panose, isomaltose, and trehalulose. Furthermore, the pH and temperature optima for both enzymes were determined, showing that Agl1His exhibits higher thermo and pH optima than Agl2His. The two purified α-1,6-glucosidases were also shown to have transglycosylation activity, synthesizing oligosaccharides from palatinose, trehalulose, trehalose, panose, and isomaltotriose.


2021 ◽  
Author(s):  
Gregory S Bulmer ◽  
Fang Wei Yuen ◽  
Naimah Begum ◽  
Bethan S Jones ◽  
Sabine S Flitsch ◽  
...  

β-D-Galactofuranose (Galf) and its polysaccharides are found in bacteria, fungi and protozoa but do not occur in mammalian tissues, and thus represent a specific target for anti-pathogenic drugs. Understanding the enzymatic degradation of these polysaccharides is therefore of great interest, but the identity of fungal enzymes with exclusively galactofuranosidase activity has so far remained elusive. Here we describe the identification and characterization of a galactofuranosidase from the industrially important fungus Aspergillus niger. Phylogenetic analysis of glycoside hydrolase family 43 subfamily 34 (GH43_34) members revealed the occurrence of three distinct clusters and, by comparison with specificities of characterized bacterial members, suggested a basis for prediction of enzyme specificity. Using this rationale, in tandem with molecular docking, we identified a putative β-D-galactofuranosidase from A. niger which was recombinantly expressed in Escherichia coli. The Galf-specific hydrolase, encoded by xynD demonstrates maximum activity at pH 5, 25 °C towards 4-Nitrophenyl-β-galactofuranoside (pNP-βGalf), with a Km of 17.9 ± 1.9 mM and Vmax of 70.6 ± 5.3 μmol min-1. The characterization of this first fungal GH43 galactofuranosidase offers further molecular insight into the degradation of Galf-containing structures and may inform clinical treatments against fungal pathogens.


2018 ◽  
Vol 81 (1) ◽  
Author(s):  
Halifah Pagarra ◽  
Roshanida A. Rahman ◽  
Nur Izyan Wan Azelee ◽  
Rosli Md Illias

Polygalacturonases represent an important member of pectinases group of enzymes with immense industrial applications. The activity of exo-polygalacturonase produced by Aspergillus niger was studied in solid state fermentation (SSF) using Nephrolepis biserrata leaves as substrate. Central composite design (CCD) was used to optimize four significant variables resulted from the screening process that has been initially analyzed for the production of exo-polygalacturonase which are incubation time, temperature, concentration of pectin and moisture content. The optimum exo-polygalacturonase production obtained was 54.64 U/g at 120 hours of incubation time, temperature at 340C, 5.0 g/L of pectin concentration and 75.26% of moisture content. For partial characterization of exo-polygalacturonase, the optimum temperature and pH were obtained at 50°C and pH 4.0, respectively. SDS-PAGE analysis showed that molecular weight of exo-polygalacturonase were 35 and 71 kDa. This study has revealed a significant production of exo-polygalacturonase by A. niger under SSF using cheap and easily available substrate and thus could found immense potential application in industrial sectors and biotechnology


2012 ◽  
Vol 393 (8) ◽  
pp. 767-775 ◽  
Author(s):  
Boris Tefsen ◽  
Ellen L. Lagendijk ◽  
Joohae Park ◽  
Michiel Akeroyd ◽  
Doreen Schachtschabel ◽  
...  

Abstract Aspergillus niger possesses a galactofuranosidase activity, however, the corresponding enzyme or gene encoding this enzyme has never been identified. As evidence is mounting that enzymes exist with affinity for both arabinofuranose and galactofuranose, we investigated the possibility that α-l-arabinofuranosidases, encoded by the abfA and abfB genes, are responsible for the galactofuranosidase activity of A. niger. Characterization of the recombinant AbfA and AbfB proteins revealed that both enzymes do not only hydrolyze p-nitrophenyl-α-l-arabinofuranoside (pNp-α-Araf) but are also capable of hydrolyzing p-nitrophenyl-β-d-galactofuranoside (pNp-β-Galf). Molecular modeling of the AbfB protein with pNp-β-Galf confirmed the possibility for AbfB to interact with this substrate, similarly as with pNp-α-Araf. We also show that galactomannan, a cell wall compound of A. niger, containing β-linked terminal and internal galactofuranosyl moieties, can be degraded by an enzyme activity that is present in the supernatant of inulin-grown A. niger. Interestingly, purified AbfA and AbfB did not show this hydrolyzing activity toward A. nigergalactomannan. In summary, our studies demonstrate that AbfA and AbfB, α-l-arabinofuranosidases from different families, both contain a galactofuranose (Galf)-hydrolyzing activity. In addition, our data support the presence of a Galf-hydrolase activity expressed by A. niger that is capable of degrading fungal galactomannan.


2017 ◽  
Vol 89 (4) ◽  
pp. 463-472 ◽  
Author(s):  
Ruijun Wang ◽  
Zhengchu Liu ◽  
Lifeng Cheng ◽  
Shengwen Duan ◽  
Xiangyuan Feng ◽  
...  

Xylanase plays an important role in the hydrolysis of hemicellulose and has gained much attention in the field of biological degumming. The research for xylanases with cellulase-free and high activity for biological degumming has intensified in recent years. In the present research, heterologous expression of a novel endo-β-1,4-xylanase (GH30) from Dickeya dadantii DCE-01 in Escherichia coli BL21 (DE3) was reported. Biochemical characterization of the enzyme and a potential application in ramie biological degumming was discussed. The results showed that the xylanase gene consists of 1251 nucleotides, belonging to glycoside hydrolase family 30 (GH30). The optimal activity of the xylanase was observed at 50℃ and a pH value of 6.4. The Km and Vmax values for beechwood xylan were 14.25 mg/mL and 296.6 μmol/mg, respectively. The catalytic activity was enhanced by addition of 1 mM Cu2+, Ca2+, Mg2+, and K+. The recombinant enzyme was specific for xylan substrates. The enzyme exhibited hydrolytic activity toward ramie hemicellulose. The recombinant xylanase could be effectively applied to ramie degumming.


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