Identification and characterization of β-d-galactofuranosidases from Aspergillus nidulans and Aspergillus fumigatus

Biochemical characterization of a glycoside hydrolase family 43 β-D-galactofuranosidase from the fungus Aspergillus niger

“…XynD displays an optimum pH between pH 4 and pH 5, and concurs with previously described recombinant galacto-furanosidases with varying optimum pHs of 3-7 28,30,34,49,50 . Optimal temperature of characterized galactofuranosidases vary, for example, the Galf-ase derived from Streptomyces sp.…”

“…A. niger AbfA and AbfB both have dual activity against pNP-Gal f and pNP-Ara f yet do not degrade galactomannan 33 . More recently, A. nidulans exo-acting Gal- f ases GfgA and GfgB have been identified, and have been shown to hydrolyze both β-(1,5) and β-(1,6) linkages, whilst A. fumigatus Afu2g14520 demonstrates dual activity against pNP-Gal f and pNP-Ara f, with higher activity against the latter 34 . Here we demonstrated that XynD encodes an galactofuranosidase active against pNP-Gal f. The enzyme is not responsible for galactomannan degradation and lacks activity against β-(1,5), β-(1,6)- and α-(1,2) linked Gal f substrates.…”

“…A. niger α-L-arabinofuranosidases AbfA and AbfB from GH families 51 and 54 have a dual activity and can hydrolyse both pNp-α-Ara f and pNp-β-Gal f 33 but are not active on fungal galactomannan, indicating other β-galactofuranosidases remain un-characterized. While undertaking the work described here, discovery of GH2 family β-galactofuranosidases GfgA and GfgB in A. nidulans has been reported, thus identifying the first specific fungal β-galactofuranosidases 34 . The biological function of Gal f ase enzymes in situ remain unclear, however, it has been suggested that the breakdown of galactomannan and other Gal f epitopes may be utilised as a carbon source, via degradation by Gal f ase, during carbon limitation to produce a source of galactose 32 .…”

“…For example, members of GH43-34, comprised to our knowledge only 6 biochemically characterized bacterial proteins at the time of writing, which all showed either β-D-galactofuranosidase or α-ʟ-arabinofuranosidase activity 35–37 . As bi-functionality of Ara f ases and Gal f ases seems prevalent 28,33,34 and Ara f and Gal f are structurally similar we hypothesized that fungal Gal f ases were potentially harboured in GH families containing both Ara f ases and Gal f ases.…”

Heterologous Expression and Characterization of a Novel Exo-Polygalacturonase from Aspergillus fumigatus Af293 and Its Application in Juice Extraction

“…A. fumigatus has a strong capacity for producing glycoside hydrolases that are widely used in the food industry, such as β-D-galactofuranosidases [ 45 ], raw starch glucoamylase [ 46 ], lipase [ 47 ], xyloglucanase [ 48 ], and xylanases [ 49 ]; however, A. fumigatus is an airborne opportunistic pathogen [ 50 , 51 ]. Thus, cloning and heterologous expression is a highly efficient method for developing and utilizing these enzyme resources.…”