IBR   13079
INSTITUTO DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Regulation of cell to cell communication, adherence and social behaviors in Bacillus subtilis
Autor/es:
ROVETTO A., LOMBARDÍA E., SABAL E., SALVARREY M., PEDRIDO M.E., AND GRAU R.
Lugar:
Salve Regina University, New Port, R.D., USA
Reunión:
Congreso; Gordon Research Conference; 2007
Institución organizadora:
Gordon Research Conference
Resumen:
In nature, microbes are able to express sophisticate and elaborate social behaviors that allow adaptation, survival and evolution. Here we report the social behavior of the undomesticated and probiotic strain B. subtilis natto. We demonstrated that the three master developmental regulators Spo0A, AbrB and SinR are crucial for the expression of social behaviors in B. subtilis natto. Biofilm development and colony morphogenesis were under the positive and negative control of Spo0A and AbrB /SinR respectively. The requirement of Spo0A during colony differentiation was not only due to its known antagonistic effects on AbrB and SinR but also for its unique role in maintaining the structure of the aerial colony at late developmental stages. Sliding motility (a sort of surface-associatted motility independent of flagella) of the B. subtilis natto strain was under the positive control of Spo0A and to a lesser extent, under the positive control of AbrB and SinR. Single spo0A minus cells were completely unable to slide, while single abrB and sinR mutants were partially defective in motility, however sliding phenotype was completely abolished in a double abrB-sinR mutant strain.  Therefore, Spo0A was essential and AbrB and/or SinR were required for sliding motility. Interestingly, sliding motility was also under the strict control of Spo0A in the undomesticated Marburg-derived strain NCIB3610. This phenotype was clearly demonstrated by the inability of a NCIB 3610-derived hag mutant strain to slide in the absence of  Spo0A production. In addition, we demonstrated that the B. subtilis natto strain was able to adhere with high affinity and specificity to the extracellular matrix representative proteins fibronectin and collagen. This specific binding was under the negative control of AbrB and counteracted by Spo0A. The B. subtilis natto strain was able to compete and to inhibit the adherence of pathogenic Staphylococcus aureus and Pseudomonas aeruginose to immobilized-fibronectin, a property that it would be of importance for the expression of the anti-infective properties of B. subtilis natto. Finally, we present a working model summarizing how wild strains of B. subtilis could alternate between different communitarian styles of behaviors.