The
arabidofuranosidase gene was amplified from theAspergillus nigergenome by PCR. The gene length was 1790 bp
containing a intron sequence with 50 bp. The corresponding protein sequence
contains 9 N-glycosylation sites and 5 O-glycosylationsites, the N-terminal
contains 18 amino acids of the signal peptide. Arabidofuranosidase gene was
ligated with the expression vector pPICZαA and induced inPichia pastorX-33. The recombinant enzyme was purified by Ni column affinity chromatography.
The molecular size of the recombinant enzyme is 70 kDa, and the optimum
reaction temperature and optimum pH of the recombinant enzyme were 50 ℃ and 5.5
respectively. Cu2+, Zn2+and Fe2+had inhibitory
effect on the activity of Arabidofuranosidase, Fe3+promoted the
enzyme activity of arabidofuranosidase. TheKmandVmaxvalues of
the enzymes were 0.78 mM and 2.57 μmol/min/mg respectively, using 4-Nitrophenyl
α-L-arabinofuranoside as the substrate.
Recombinant
α-L-arabinofuranosidase was added at the initial stage of mashing with an
amount of 31.2 mU/g, wort filtration rate was increased by 12.8%. α-L-arabinofuranosidase
and xylanase have synergistic effect with barley malt arabinoxylans as
substrate.
XIE Xi-zhu et al
. Expression of α-L-arabinofuranosidase in Pichia pastoris and its effect on flterability of barley malt[J]. Food and Fermentation Industries, 2018
, 44(2)
: 48
.
DOI: 10.13995/j.cnki.11-1802/ts.015687