The apramycin-resistant mutants of E. coli were isolated spontaneously. Mutations, uprA and aprB,... more The apramycin-resistant mutants of E. coli were isolated spontaneously. Mutations, uprA and aprB, conferring resistance to apramycin were located at 72 min on the E. coli genetic map where most of ribosomal genes were mapped. One of the mutants, carrying the uprB mutation, has an altered translational fidelity expressed as severe restriction of amber suppressor activity in uivo. The chromosome location and altered translational fidelity indicate that the apramycin-resistant phenotype could be a consequence of an alteration of the ribosomal structure.
Five bacteriocin-producing lactococci isolates from traditionally prepared kefir were determined ... more Five bacteriocin-producing lactococci isolates from traditionally prepared kefir were determined as Lactococcus lactis subsp. lactis. The analyzed isolates showed different plasmid profiles and no cross inhibition between them was detected. Moreover, natural isolate BGKF26 was resistant to the antimicrobial activity of nisin producing strain NP45. Plasmid curing experiments revealed that the genes encoding bacteriocin and proteinase production are located on
The strain Lactobacillus paracasei subsp. paracasei BGBUK2-16. which was isolated from traditiona... more The strain Lactobacillus paracasei subsp. paracasei BGBUK2-16. which was isolated from traditionally homemade white-pickled cheese, produces bacteriocin 217 (Bac217; approximately 7 kDa). The onset of Bac217 biosynthesis was observed in the logarithmic phase of growth, and the production plateau was reached after 9 or 12 h of incubation at 37 and 30 degrees C, respectively, when culture entered the early stationary phase. Biochemical characterization showed that Bac217 retained antimicrobial activity within the range of pH 3 to 12 or after treatment at 100 degrees C for 15 min. Bac217 antimicrobial activity also remained unchanged after storage at 4 degrees C for 6 months or -20 degrees C for up to 12 months. However, Bac217 activity was completely lost after treatment with different proteolytic enzymes. BGBUK2-16 contains only one plasmid about 80 kb in size. Plasmid curing indicated that genes coding for Bac217 synthesis and immunity seem to be located on this plasmid. Bac217 exhi...
... JELENA BEGOVIC1, JB BRANDSMA2, B. JOVCIC1, MAJA TOLINACKI1, KATARINA VELJOVIC1, WC MEIJER2 an... more ... JELENA BEGOVIC1, JB BRANDSMA2, B. JOVCIC1, MAJA TOLINACKI1, KATARINA VELJOVIC1, WC MEIJER2 and L. TOPISIROVIC1 ... Genus Streptococcus Rosenbach 1884 In: Sneath, PHA, Mair, NS, Sharpe, ME, Holt, JG (Eds), Bergey's Manual of Systematic Bacteriology ...
The apramycin-resistant mutants of E. coli were isolated spontaneously. Mutations, uprA and aprB,... more The apramycin-resistant mutants of E. coli were isolated spontaneously. Mutations, uprA and aprB, conferring resistance to apramycin were located at 72 min on the E. coli genetic map where most of ribosomal genes were mapped. One of the mutants, carrying the uprB mutation, has an altered translational fidelity expressed as severe restriction of amber suppressor activity in uivo. The chromosome location and altered translational fidelity indicate that the apramycin-resistant phenotype could be a consequence of an alteration of the ribosomal structure.
Five bacteriocin-producing lactococci isolates from traditionally prepared kefir were determined ... more Five bacteriocin-producing lactococci isolates from traditionally prepared kefir were determined as Lactococcus lactis subsp. lactis. The analyzed isolates showed different plasmid profiles and no cross inhibition between them was detected. Moreover, natural isolate BGKF26 was resistant to the antimicrobial activity of nisin producing strain NP45. Plasmid curing experiments revealed that the genes encoding bacteriocin and proteinase production are located on
The strain Lactobacillus paracasei subsp. paracasei BGBUK2-16. which was isolated from traditiona... more The strain Lactobacillus paracasei subsp. paracasei BGBUK2-16. which was isolated from traditionally homemade white-pickled cheese, produces bacteriocin 217 (Bac217; approximately 7 kDa). The onset of Bac217 biosynthesis was observed in the logarithmic phase of growth, and the production plateau was reached after 9 or 12 h of incubation at 37 and 30 degrees C, respectively, when culture entered the early stationary phase. Biochemical characterization showed that Bac217 retained antimicrobial activity within the range of pH 3 to 12 or after treatment at 100 degrees C for 15 min. Bac217 antimicrobial activity also remained unchanged after storage at 4 degrees C for 6 months or -20 degrees C for up to 12 months. However, Bac217 activity was completely lost after treatment with different proteolytic enzymes. BGBUK2-16 contains only one plasmid about 80 kb in size. Plasmid curing indicated that genes coding for Bac217 synthesis and immunity seem to be located on this plasmid. Bac217 exhi...
... JELENA BEGOVIC1, JB BRANDSMA2, B. JOVCIC1, MAJA TOLINACKI1, KATARINA VELJOVIC1, WC MEIJER2 an... more ... JELENA BEGOVIC1, JB BRANDSMA2, B. JOVCIC1, MAJA TOLINACKI1, KATARINA VELJOVIC1, WC MEIJER2 and L. TOPISIROVIC1 ... Genus Streptococcus Rosenbach 1884 In: Sneath, PHA, Mair, NS, Sharpe, ME, Holt, JG (Eds), Bergey's Manual of Systematic Bacteriology ...
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