A total of 30 clones exhibiting activity on α-naphthyl acetate were isolated from an Anaeromyces mucronatus YE505 cDNA library. Sequence analysis revealed that these clones represented two esterase genes. One of these genes (axe6A) has 81% amino acid sequence identity to an acetylxylan esterase from Orpinomyces sp. that included a carbohydrate esterase (CE) family 6 catalytic domain. The second gene (fae1A) showed 34 to 42% amino acid sequence identity to CE family 1 esterases from Orpinomyces sp., Ruminococcus albus and Clostridium thermocellum. Gene fae1A comprises an 828-nt open reading frame encoding a polypeptide of 275 amino acids with a M_r of 31050 Da.  The fae1A coding sequence was cloned into the pET30a expression vector and overexpressed in Escherichia coli BL21 (DE3). Gene product Fae1A was found to exhibit activity against a number of substrates including naphthyl fatty acid esters, p-nitrophenyl fatty acid esters and hydroxylcinnamic acid esters. Fae1A exhibited a lower K_m and higher catalytic efficiency (k_cat/K_m) on ferulic acid esters than on α-naphthyl acetate or p-nitrophenyl acetate, suggesting that it has a higher affinity for ethyl and methyl ferulate than for the acetyl esters. Activity of Fae1A was inhibited by the serine specific protease inhibitor, phenylmethylsulfonyl fluoride, indicating that a serine residue plays a role in its activity. To our knowledge, this is the first report of carbohydrate esterase from Anaeromyces.