Wild ruminants are an interesting topic for research because only limited information exists regarding their microbiota. They could also be an environmental reservoir of undesirable bacteria for other animals or humans. In this study faeces of the 21 free-living animals was sampled (9 Cervus elaphus-red deer, adult females, 12 Capreolus capreolus-roe deer, young females). They were culled by selective-reductive shooting during the winter season of 2014/2015 in the Strzałowo Forest District-Piska Primeval Forest (53° 36 min 43.56 sec N, 21° 30 min 58.68 sec E) in Poland. Buttiauxella sp. is a psychrotolerant, facultatively anaerobic, Gram-negative rod anaerobic bacte- rial species belonging to the Phylum Proteobacteria, Class Gammaproteobacteria, Order Entero- bacteriales, Family Enterobacteriacae and to Genus Buttiauxella. Buttiauxella sp. has never previ- ously been reported in wild ruminants. In this study, identification, antimicrobial profile and sensitivity to enterocins of Buttiauxella strains were studied as a contribution to the microbiota of wild animals, but also to extend knowledge regarding the antimicrobial spectrum of enterocins. Five strains were identified using the MALDI-TOF identification system (evaluation score value was up to 2.224) and allotted to the genus Buttiauxella including the species Buttiauxella gaviniae,

B. ferragutiae, B. agrestis. Strains were DNase negative, and they hydrolysed esculin; fermentation of L-arabinose, D-mannitol and D-mannose was positive. Dulcitol, inositol reaction, urea and indol were negative. Buttiauxella strains did not form biofilm. They were resistant to at least one of the 13 antibiotics tested. B. agrestis 2/109/1 was resistant to amdinocillin, clindamycin and pen- icillin. However, Buttiauxella strains were sensitive to the enterocins used (inhibition activity ranged from 100 to 25 600 AU/ml).