Bacteria have flourished within our community for many years, having thrived on the planet since even before the dawn of humans. They have established suitable mechanisms in order to overcome selection difficulties such as in the presence of antibiotics, bacteria create antibiotic resistance genes which is essential for their survival. This however is not a surprise to most people, as bacteria posses a system called the SOS response.
The SOS response is essential for regulating bacterial mutations which eventually leads to antibiotic resistance being produced. The SOS response is a type of DNA repair mechanism which is induced by the presence of single stranded DNA which is usually derived from DNA damage. The RecA protein, stimulated by the single stranded DNA is involved in the inactivation of the LexA repressor which therefore results in the induced response.
From a recent study conducted by Grzesiuk, E. et.al. (2002), the SOS system in Escherichia coli was induced in response to DNA damage and the arrest of DNA synthesis. It was also found that when the bacteria were starved for arginine, the LexA dependent SOS system was induced, but only occurred when growth was recommenced and when the glycerol was the source of carbon. This mechanism is just one of the ways in which bacteria survive, perhaps there are more to be found.
Student Number: 41193763
References:
- Grzesiuk, E., Janion, C., Nowosielska, A., Sikora, A. (2002) Induction of the SOS response in Starved Escherichia coli. Environmental and Molecular Mutagenensi, vol. 40, pp. 129-133
- Andes, D. R., Chin, J. K., Cirz, R. T., Craig, W. A., de Crecy-Lagard, V., Romesberg, F. E. (2005). Inhibition of Mutation and Combating the Evolution of Antibiotic Resistance. PLoS Biology, vol. 3, pp.1024-1033
