Datensatz

Zusammenfassung

Klebsiella oxytoca was stressed by incubation in seawater microcosms for ten years. Despite being introduced into sterile seawater, the added Klebsiella oxytoca declined to levels undetectable by plate counts on nutrient agar. After two years of starvation, no culturable strain was observed. Incubation of samples in nutrient-rich broth medium not supplemented with growth factors, however, allowed resuscitation of viable but non culturable (VBNC) cells so that subsequent plating yielded observable colonies for significantly extended periods of time. Recovery of VBNC Klebsiella oxytoca was obtained by incubation in nutrient broth even after ten years of starvation. To see whether the samples contain the same strain of Klebsiella oxytoca inoculated 10 years ago, the complete 16S rDNA gene was PCR amplified and sequenced from initial, stressed and revived strains of Klebsiella oxytoca. The 16S rDNA gene sequences from ten-year stressed strains were homologous in a high degree of similarity to the GenBank reference strain and were identical to each other.