Use of low pH active alpha-1,4;/1,6-glycoside hydrolases (GLCH) as a feed additive for ruminants to enhance starch digestion
Disclosed are uses of at least one alpha-1,4/1,6-glycoside hydrolase (GLCH) as a feed additive for a ruminant wherein said hydrolase: (a) has at least 20% activity at pH less than or equal to 3 in the presence of pepsin as compared to activity of the hydrolase at pH 6 in the presence of pepsin, (b) said hydrolase is active in at least two of three digestive chambers of a ruminant comprising a rumen, an abomasum and a small intestine and (c) the hydrolase works with pancreatic amylase to increase glucose yield.
1 . A method for increasing starch digestibility and glucose yield in a ruminant which comprises:
(a) adding at least one fungal glucoamylase as a feed additive to feed for a ruminant,
wherein the at least one fungal glucoamylase is an EC 3.2.1.3 enzyme derived from Trichoderma reesei and:
(i) has at least 20% activity at pH less than or equal to 3 in the presence of pepsin as compared to activity of the hydrolase at pH 6 in the presence of pepsin;
(ii) is active in at least two of the three digestive chambers of a ruminant comprising a rumen, an abomasum, and a small intestine;
(iii) works with digestive enzymes present in the digestive chambers of the ruminant to increase starch digestibility and glucose yield; and
(iv) has at least 20% catalytic activity on maltose; and
(b) administering said feed additive to the ruminant, wherein starch digestibility and glucose yield in the ruminant is increased by said addition.
2 . The method of claim 1 wherein the at least one glucoamylase enzyme is capable of hydrolyzing raw starch under conditions comparable to those found in the rumen or abomasum.
3 . The method of claim 1 , further comprising adding at least one EC 3.2.1.1 alpha-amylase to the feed.
4 . The method of claim 3 , further comprising adding at least one xylanase to the feed.
5 . The method of claim 1 , further comprising adding at least one protease to the feed.
6 . The method of claim 5 wherein the protease is selected from the group consisting of an acid protease and a neutral metalloprotease.
7 . The method of claim 6 wherein the protease is a fungal aspartic protease or a bacterial neutral metalloprotease.
8 . The method of claim 5 , further comprising adding at least one xylanase to the feed.
9 . The method of claim 1 , further comprising adding at least one xylanase to the feed.