Assessment of New and Genome-Reduced Strains Regarding Their Robustness as in Biotechnological Applications.

Organic olvent-tolerant strains of the Gram-negative bacterial genus are discussed as potential biocatalysts for the biotechnological production of various chemicals. However, many current strains with the highest tolerance are belonging to the species and are classified as biosafety level 2 strains, which makes them uninteresting for the biotechnological industry. Therefore, it is necessary to identify other biosafety level 1 strains with high tolerance towards solvents and other forms of stress, which are suitable for establishing production platforms of biotechnological processes. In order to exploit the native potential of as a microbial cell factory, the biosafety level 1 strain VLB120 and its genome-reduced (GRC) variants as well as the plastic-degrading strain TDA1 were assessed regarding their tolerance towards different -alkanols (1-butanol, 1-hexanol, 1-octanol, 1-decanol). Toxicity of the solvents was investigated by their effects on bacterial growth rates given as the EC50 concentrations. Hereby, both toxicities as well as the adaptive responses of GRC3 and TDA1 showed EC50 values up to two-fold higher than those previously detected for DOT-T1E (biosafety level 2), one of the best described solvent-tolerant bacteria. Furthermore, in two-phase solvent systems, all the evaluated strains were adapted to 1-decanol as a second organic phase (i.e., OD was at least 0.5 after 24 h of incubation with 1% () 1-decanol), which shows the potential use of these strains as platforms for the bio-production of a wide variety of chemicals at industrial level.