Screening and selection of novel animal probiotics isolated from bovine chyme

• Published in: Annals of microbiology Vol. 63; no. 4; pp. 1291 - 1300
• Main Authors: Ozkan, Alper D., Han, Diren, Umu, Ozgun C. O., Angun, Pinar, Senturk, Berna, Yasa, Oncay, Tekinay, Turgay
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-12-2013
• Subjects: Applied Microbiology; Biomedical and Life Sciences; Life Sciences; Medical Microbiology; Microbial Ecology; Microbial Genetics and Genomics; Microbiology; Mycology; Original Article; Antimicrobial; Feed supplement; Probiotics; Isolation
• ISSN: 1590-4261; 1869-2044
• DOI: 10.1007/s13213-012-0588-3

Probiotics, gut-colonizing microorganisms capable of conferring a number of health benefits to their hosts, are highly desirable as animal feed supplements. Members of the Gram-positive genus
Bacillus
are often utilized as probiotics, since endospores formed by those bacteria render them highly resistant to environmental extremes and therefore capable of surviving gastrointestinal tract conditions. In this study, 84 distinct bacterial colonies were obtained from bovine chyme and 29 isolates were determined as
Bacillus
species. These isolates were principally screened for their antimicrobial activity against a group of two Gram-positive and four Gram-negative bacteria, including known human and animal pathogens such as
Salmonella enterica, Klebsiella pneumoniae, Pseudomonas aeruginosa
, and
Staphylococcus aureus.
Seven strains displaying strong antimicrobial activity against the test cohort were further evaluated for other properties desirable from animal probiotics, including high spore-forming capacity and adhesiveness, resistance to pH extremes and ability to form biofilms. The isolates were found to resist simulated gastrointestinal conditions and most of the antibiotics tested. In addition, plasmid presence was checked and cytotoxicity tests were performed to evaluate the potential risks of antibiotic resistance transfer and unintended pathogenic effects on host, respectively. We propose that the bacterial isolates are suitable for use as animal probiotics.