NOVELTY - A protein (I) having an endo-arabinanase activity specific to arabinan, an optimum temperature of 20-40 degrees Centigrade and having 30% or more activity at 0 degrees Centigrade, is new.    USE - (I) is useful for removing sediments from fruit juice working liquid, which involves adding (I), allowing decomposition, and removing sediments. (I) and the above mentioned removal process is useful for producing fruit juice working liquid. (I) or (II) is useful for producing arabino oligosaccharide, which involves degrading arabinan into arabino oligosaccharide using (I) or (II). (I) or (II) is useful for producing manure from agricultural waste materials, which involves preprocessing the agricultural waste material using (I) or (II) and decomposing the polysaccharides containing arabinanase, that are contained in the agricultural waste materials. (VI) is useful for producing (I), which involves culturing (VI) (all claimed). (I) or (II) is useful for decomposing plant derived waste materials e.g. sugar beet pulp, soybean cake, apple fiber, rice bran and corn lees.    ADVANTAGE - (I) has excellent arbinanase activity even at very low temperatures (0 degrees Centigrade).    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) protein (II) having a sequence chosen from:    (a) protein having a fully defined sequence (S1) of 320 amino acids as given in the specification or comprising amino acids 20-320 of (S1);    (b) protein having a fully defined sequence (S2) of 692 amino acids as given in the specification;    (c) (I); and    (d) protein comprising one or more amino acid substitution, deletion, addition or insertion in sequence of (a) or (b);    (2) gene (III) encoding (I);    (3) polynucleotide (IV) having a base sequence chosen from:    (a) base sequence encoding (II);    (b) base sequence comprising a fully defined sequence (S3) of 963 base pairs as given in the specification or comprising nucleotides 58-963 of (S3);    (c) polynucleotide having a fully defined sequence (S4) of 2079 base pairs as given in the specification;    (d) gene encoding (I);    (e) base sequence comprising one or more substitution, addition, insertion or deletion in (b) or (c); and    (f) sequence complementary to (a)-(e);    (4) vector (V) containing (IV);    (5) transformed organism (VI) containing (V); and    (6) fruit juice working liquid produced using (I).