Naslov
Coexistence of Escherichia coli and Salmonella enterica serovar Typhimurium during prolonged starvation in stationary phase

Autori
Bačun-Družina, Višnja ; Čulić, Valentina ; Rosandić, Lucija ; Franekić Čolić, Jasna

Izvornik
Periodicum biologorum (0031-5362) 104 (2002), 4; 425-430

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Escherichia coli; Salmonella enterica serovar Typhimurium; growth advantage in stationary phase (GASP); carbon starvation stress; rpoS gene.

Sažetak
The natural selection could occur in cultures of Enterobacteriaceae mantained during prolonged stationary phase. The resulting mutants with increased fitness express GASP enabling them to grow and displace the parent as the majority population. The purpose of our investigation was to analyse mixed populations of Escherichia coli K12 and Salmonella enterica serovar Typhimurium, during the prolonged period of carbon starvation. The homogeneous or mixed cultures were incubated with aeration at 37°C in glass test tubes. We determined viable cell counts by making serial dilutions in PBS buffer and plating onto LB, and selective minimal lactose or Simmons citrate plates. The results showed that after ten days of growth of a single and mixed bacterial species in complete medium the growth rate considerably decreased compared to the growth in minimal medium. In the mixed cultures during eleven days of growth in minimal medium, the aged cells or the rpoS mutant of E. coli, do not have ability to overgrow the younger or the cells of the same age of another bacterial species. The mixture of one-day-old cultures of S. enterica and sixteen days old cells of E. coli as minority did not show the GASP phenomenon. The same results were obtained if the mixture consisted of the S. enterica as minority cells.

Izvorni jezik
Engleski

Znanstvena područja
Biotehnologija

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