Tannase-producing bacteria isolated from the rumen of Fallow deer (Dama dama): Livestock potential feed additives

چکیده مقاله

Abstract Introduction: Tannins are a group of polyphenolic compounds that are widely present in plants as an anti-nutritional factor. The rumen of wild ruminants contains novel microbes that detoxify antinutrients and improve feed digestion. The present study evaluated tannase-producing bacteria isolated from the rumen of Fallow deer (Dama dama), livestock potential feed additives. Materials and Methods: Tannase-producer bacteria (TPBs) were isolated from the rumen using a 2% tannic acid- plate and tannase activity (TAA) assayed by the spectrophotometer method. The bacterial DNA was extracted through boiling and amplified using a PCR reaction. The Sanger technique and BLAST software were used to identify the strains. Antibacterial (ABA) and antibiogram tests were performed by the disc diffusion method, and the acid and bile resistance of isolates were examined using broth cultures. Results: The results indicated that TPBs belonged to Klebsiella, Enterobacter, and Escherichia genera. Escherichia fergusonii GHMGHE44 (9.39 Uml-1) and Enterobacter cloacae GHMGHE26 (1.79 Uml-1) were the strongest and weakest tannin degraders (p<0.01). Among the isolates, bile and acid resistance were insignificant (p>0.01) but E. fergusonii GHMGHE28 (9.48 CFU ml-1) had a significant survival rate compared to E. cloacae GHMGHE25 (9.07 CFU ml-1) at pH of 7 (p<0.01). Also, K. pneumoniae subsp. rhinoscleromatis GHMGHE27 (32.66 mm), E. coli GHMGHE47 (40.66 mm), and E. fergusonii GHMGHE48 (24.66 mm) were potently suppressed the pathogen E. Coli, S. aureus and P. aeruginosa, respectively (p<0.01). Against used antibiotics, E. asburiae GHMGHE22 was the most sensitive isolate while others showed diverse reactions (p<0.01). Discussion and Conclusion: The findings showed that TPBs have the potential to study as commercial animal feed additives (AFA).