Enhanced Stress Resistance at Stationary Phase of Oligotrophic Bacteria, Chromobacterium sp. Y95 and Aeromonas sp. Z06

Oligotrophic bacteria, Chromobacterium sp. Y95 and Aeromonas sp. Z06, can grow in 104-diluted nutrient broth (1/104NB). In the two oligotrophic bacteria, the stationary phase cultures showed enhanced heat, oxidation, and osmotic resistance as compared with cultures at exponential phase, although resistance was less marked than that of Escherichia coli. On Southern bloting analysis, Chromobacterium sp. Y95 and Aeromonas sp. Z06 genomic DNA hybridized with the sigma factor probes, RpoN-X and RpoD-4.2, and RpoD-4.2, respectively.