glucoamylase variant, methods for increasing the crude starch hydrolysis activity of a glucoamylase and for producing a glucoamylase variant, composition, use of a glucoamylase variant, processes for producing a fermentation product and for producing a syrup product, polynucleotide encoding the glucoamylase variant, nucleic acid construct, expression vector, and host cell

摘要

the present invention relates to variants of glucoamylase having an increase in crude starch activity compared to the glucoamylase disclosed as sequence 2, comprising one or more modifications in the catalytic domain and / or one or more modifications in the binding domain to starch selected from: a) at least one, preferably at least two, preferably at least three, preferably at least four from: v18m, t43k, n112l, t116r, a117q, g120s, a271f, y295w, q318y; and / or (b) introduction of at least three, preferably at least four, substitutions selected from the group: s458c, s458scgg, s458sggc, a493v, a518k, e520q, n527m, s540k, r, s (g) 546p, t (v) 549w, n503r, n539r + i541y + t543v + a545s + s546gcgv + g547s + s548t + t549a. the present invention also relates to polynucleotides encoding the variants; nucleic acid constructs, vectors and host cells comprising polynucleotides; and methods of using the variants.