ANTIMICROBIAL ACTIVITY OF BACTERIOCIN-LIKE SUBSTANCES PRODUCED BY BACTERIAL STRAINS ISOLATED FROM CROP AND CECUM OF JAPANESE-QUAIL UNDER MICROGRAVITY CONDITIONS

Antimicrobial activities of bacteriocin - like substances produced by enterococci and staphylococci isolated from the crop and caecum of Jap anese quail, exposed to 7-day microgravity conditions, are presented i n this study. Fifteen enterococcal and staphylococcal selected strains were allotted according to identification criteria to the species Ent erococcus gallinarum, E. faecium, E. faecalis, S. gallinarum and S. au reus. All strains isolated from the crop or caecum in the flight or co ntrol group produced bacteriocin substances which inhibited the growth of at least of three of ten indicator bacteria, reaching clear zones of inhibition of 2 to 10 mm in diameter. S. aureus S1 was found with n o bacteriocin production. Only bacteriocin substances produced by E. g allinarum EG12 and EG10 inhibited the growth of gram - negative E. col i. Heat treatment at 50 and 60 degrees C for 30 min did not lead to a loss of antagonistic activity, only of the substances produced by EG10 , EG12, LS1 and SG2 strains. Trypsin treatment did not affect the inhi bitory activity in strains EG12, EGH1, EGK1, EA7, EGH13, EGH9, S2, LS1 and SG2. Bacteriocin substances produced by enterococci EG12, EGH1, E KH1,EKH2, EGK1, EA7, EGH13 and S. aureus LS1 were resistant to chlorof orm vapours. For better determination of bacteriocins produced it is r equired to analyse the amino acid sequence. E. gallinarum EG10 and EG1 2 strains, due to the wider antimicrobial spectrum of bacteriocins pro duced, are suitable for use as probiotics for supressing enteritis or other enteropathogenic processes in the digestive tract.