Silver nitrate imparts different functions on bacteria depending upon its concentration. At lower concentration it induced synthesis of nanoparticles, whereas at higher concentrations it induced cell death. Bacillus licheniformis was used as model system. The MIC was 5 mM, and it induced catalase production, apoptotic body formation and DNA fragmentation.

Os genes do sacB e do sacC que codificam o levansucrase e o sucrase extracellular respectivamente foram sub-clonados independentemente no pBluescript (número elevado de cópias) e no vetor ponte para Z. mobilis-E. coli, pZA22 (baixo número de cópias). A expressão destes genes foi comparada tanto em E. coli quanto em Z. mobilis. O nível da expressão do gene sacB em E. coli foi quase dez vezes menor do que a expressão do gene sacC, independente do meio de cultivo ou da linhagem hospedeira. Em Z. mobilis, a expressão dos genes sacB e sacC mostrou regulação dependente da fonte de carbono. Os níveis dos transcritos sacB e sacC estavam três vezes mais aumentados em células cultivadas em sacarose do que aquelas cultivadas em glicose/frutose. A análise por Northern blot revelou que o nível do transcrito sacC era 2-3 vezes maior do que aquele de sacB. Esses resultados sugerem que a expressão do gene sacC foi mais pronunciada do que sacB.

The sacB and sacC genes encoding levansucrase and extracellular sucrase respectively were independently subcloned in pBluescript (high copy number) and in Z. mobilis-E. coli shuttle vector, pZA22 (low copy number). The expression of these genes were compared under identical background of E. coli and Z. mobilis host. The level of sacB gene expression in E. coli was almost ten fold less than the expression of sacC gene, irrespective of the growth medium or the host strain. In Z. mobilis the expression of sacB and sacC genes was shown to be subject to carbon source dependent regulation. The transcript of sacB and sacC was three fold higher in cells grown on sucrose than in cells grown on glucose/fructose. Northern blot analysis revealed that the transcript levels of sacC was approximately 2-3 times higher than that of sacB. These results suggested that the expression of sacC gene was more pronounced than sacB.