Enterococci isolated from the crop and caecum of Japanese quails exposed to 7 day conditions of microgravity were re-vitalized after their dry-freezing long storage. Originally, the strains were isolated from Japanese quails after their landing from flight onboard the orbital station Mir during the experiment in August 1990. Because taxonomy as well as the studies concerning the bacteriocins, especially those produced by enterococci, have been continually developed for years, the aim of this study was to confirm species identification, stability of the properties of enterococci as well as to test new properties after their long storage. Genotyping allotted the strains to the species E. faecium. Lactic acid production was detected in similar amounts in the strains before and after their long-storage in dry-frozen form. The strains were vancomycinsensitive and kanamycin-resistant before as well as after their long-time storage. Variability in sensitivity to different antibiotics was found among the strains tested even before and after longtime storage. Each of the strains possessed at least one structural enterocin gene. The structural genes for enterocin A, P, B, L50B were detected in E. faecium EP7. E. faecium EP2, EEP4 have the genes for ent A, B, L50B. The gene for ent P was detected only in the strain EP7. The most often detected was ent A gene followed by ent genes B, L50B. All strains inhibited growth of at least 4 out of 15 indicators. The stability of the enterococcal properties determined before as well as after their dry-freezing was not influenced during their long-term storage; moreover, new properties were determined.
Enterococci, storage, enterocin gene, properties, stabilityJapanese quails represent suitable animal laboratory model for several reasons: their small size, low husbandry costs, short generation interval and adaptability to a wide range of husbandry conditions. Therefore, in past they were an object of the scientific space research programme (Boďa 1979) called Interkozmos that was finished in 1990s. In this programme many research issues were investigated and solved; e.g. the effect of microgravity on endocrine functions and adaptation processes (Juráni et al. 1988), embryonic development (Boďa et al. 1992) and/or morphological changes in the small intestine under space-flight conditions (Cigánková et al. 2000). Moreover, in the framework of the Interkozmos programme-Incubator 2, firstly also microflora of Japanese quails exposed to microgravity conditions was analysed in comparison to conventional Japanese quails with an impact on lactic acid bacteria such as lactobacilli, enterococci and staphylococci (Lauková et al. , 1993a(Lauková et al. , 1995. The most studied were enterococci that were also found to produce antimicrobial substances -bacteriocins (Lauková et al. 1993bc). The studied isolates were dry-frozen and stored for a long period for other tests. Because taxonomy as well as the studies concerning bacteriocins, especially those produced by enterococci, were continuall...