The potential of tannin degrading bacteria isolated from rumen of Iranian Urial ram as silage additives

Abstract

High-tannin forages and agricultural waste reduce feed digestibility while some rumen bacteria can degrade tannin easily. For the first time, this study was isolated 21 tannin-degrading strains from the rumen of Iranian Urial rams that had similarities (99.89 to 100%) to Escherichia coli, Escherichia fergusonii, Raoultella planticola, Raoultella ornithinolytica, Enterobacter asburiae, Enterobacter cloacae, Klebsiella pneumoniae, and Klebsiella oxytoca. The highest and lowest tannase activity was recorded for Escherichia fergusonii GHMGHE30 (8.5866 U ml−1) and Escherichia coli GHMGHE5 (1.3006 U ml−1). They had cellulase, protease and antibacterial activities. Escherichia coli GHMGHE5, Escherichia fergusonii GHMGHE34, and Escherichia fergusonii GHMGHE31 had shown the highest inhibitory effect against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, respectively. All isolates were grown in acidic media and thermal range from 25 to 40 °C. The findings suggest that Escherichia fergusonii GHMGHE30 and Raoultella ornithinolytica GHMGHE33 have potential to use as additive for green treating of animal feed silages.