β-Galactosidase activity of Escherichia coli under long-term starvation, alterations in temperature, and different nutrient conditions in lake water

Autores/as

  • R. Özkanca Ondokuz Mayıs University, Faculty of Science and Arts, Department of Biological Sciences, Kurupelit, Samsun, Turkey

Palabras clave:

Escherichia coli, β-galactosidase activity, long-term starvation, nutrient sources effect

Resumen

β-Galactosidase activity of Escherichia coli was investigated in response to long-term starvation, changes in temperature and the presence of certain nutrient sources in lake water. β-Galactosidase activity decreased markedly in filtered-autoclaved lake water at 25°C and 37°C, whereas it remained almost constant at 4°C and 15°C for 60 days. Increases in β-galactosidase activity were observed in response to the following nutrient sources: glycine, serine, methionine and ammonium sulfate at 4°C; glycine and ammonium sulfate at 15°C; glycine, serine, methionine and ammonium sulfate at 30°C. Glycine addition led to an increase in β-galactosidase activity of almost five and seven orders of magnitude at 15°C and 30°C, respectively. In addition, L-methionine had the strongest influence on b-galactosidase activity, which was detected as an increase of seven and eleven ordersof magnitude at 4°C and 30°C, respectively. The effect of several amino acids and other nitrogen sources depended on the concentration of the nutrient source and the temperature. The results showed that, in lake water, long-term starvation, temperature change, and variationsin nitrogen sourcesalter β-galactosidase activity. Those effects should be taken into account when monitoring coliformsfrom the environment.

Biografía del autor/a

R. Özkanca, Ondokuz Mayıs University, Faculty of Science and Arts, Department of Biological Sciences, Kurupelit, Samsun, Turkey

Ondokuz Mayıs University, Faculty of Science and Arts, Department of Biological Sciences, Kurupelit, Samsun, Turkey

Descargas

Publicado

2010-09-21

Número

Sección

Research Articles