Characterization of a bacteriocin produced by a newly isolated Bacillus sp. Strain 8 A.
OBJECTIVE
The aim of this research was to investigate the production of bacteriocins by Bacillus spp. isolated from native soils of south of Brazil.


RESULTS
A bacteriocin produced by the bacterium Bacillus cereus 8 A was identified. The antimicrobial activity was produced starting at the exponential growth phase, although maximum activity was at stationary growth phase. A crude bacteriocin obtained from culture supernatant fluid was inhibitory to a broad range of indicator strains, including Listeria monocytogenes, Clostridium perfringens, and several species of Bacillus. Clinically relevant bacteria such as Streptococcus bovis and Micrococcus luteus were also inhibited. Bacteriocin was stable at 80 degrees C, but the activity was lost when the temperature reached 87 degrees C. It was resistant to the proteolytic action of trypsin and papain, but sensitive to proteinase K and pronase E. Bacteriocin activity was observed in the pH range of 6.0-9.0.


CONCLUSIONS
A bacteriocin produced by Bacillus cereus 8 A was characterized, presenting a broad spectrum of activity and potential for use as biopreservative in food.


CONCLUSIONS
The identification of a bacteriocin with large activity spectrum, including pathogens and spoilage microorganisms, addresses an important aspect of food safety.
Bizani
D
D
Departamento de Ciência de Alimentos, ICTA, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre, Brazil.
Brandelli
A
A
D001407:Bacillus / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism; D001430:Bacteriocins / Q000096:biosynthesis* / Q000494:pharmacology*; D001938:Brazil; D010450:Endopeptidases / Q000378:metabolism; D006094:Gram-Positive Bacteria / Q000145:classification / Q000187:drug effects*; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D016978:Mannheimia haemolytica / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D012988:Soil Microbiology
D001430:Bacteriocins; D010450:Endopeptidases