Abstract

LOPEZ O., José C.; HERNANDEZ C., Luz M.; QI, Meng  and  MCALLISTER, Tim. Evaluation of a feluric acid esterase (Fae1A) isolated from rumen fungus Anaeromyces mucronatus on the degradation of the cell wall of alfalfa hay and wheat straw: In vitro assay. Nova scientia [online]. 2015, vol.7, n.14, pp.45-56. ISSN 2007-0705.

Ferulic acid esterases are capable of releasing phenolic compounds of the plant cell wall, increasing access to polysaccharides. In vitro determinations were performed in order to estimate the potential for ferulic acid esterase (Fae1A) isolated from rumen fungus Mucronatus Anaeromyces. This esterase was obtained from a previous study conducted in the Lethbridge Research Center, Alberta Canada, through cloning processes and hetero-expression of Fae1A gene in a strain of E. coli BL21. Three levels (0, 9 and 18 mg) of protein contained in the enzyme were combined with rumen fluid and incubated in 2 different fiber sources (alfalfa hay and wheat straw) using 15 replicates per treatment. The inclusion of the enzyme increased (P <0.05) the disappearance of dry matter in alfalfa hay, releasing more quantity (P <0.01) of reducing sugars (AR) at 4 and 12 h. Fae1A released more phenolic compounds vs. alfalfa hay wheat straw. Total and individual phenolic compounds released from alfalfa were increased according to the level of enzyme added. In the wheat straw, ferulic acid was double compared to the p-coumaric acid. In conclusion, the addition of Fae1A improved the amount of reduced sugars and phenolic compounds were released into the alfalfa hay and wheat straw, indicating its potential for use as a fibrinolytic enzyme and improve the digestibility of the fiber in the ruminant.

Keywords : fibrolytic enzymes; Fermentation In vitro; phenols.