Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1007/s00792-003-0372-1
Volltext Shareable Link
Titel (primär) Carbon and energy fluxes during haloadaptation of Halomonas sp. EF11 growing on phenol
Autor Maskow, T. ORCID logo ; Kleinsteuber, S. ORCID logo
Quelle Extremophiles
Erscheinungsjahr 2004
Department UMB
Band/Volume 8
Heft 2
Seite von 133
Seite bis 141
Sprache englisch
Abstract The haloalkaliphile Halomonas sp. EF11 can grow on phenol as sole source for carbon and energy, while maintaining an osmotic equilibrium predominantly by adjusting levels of a certain compatible solute. To determine the energy costs of haloadaptation and the fate of substrate-carbon, the strain was grown continuously in an isothermal compensation calorimeter, keeping all conditions constant except salinity. As salinity increased, slight linear reductions in exothermic heat flow and biomass formation occurred, and 1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid (ectoine) synthesis increased linearly. However, beyond a certain salinity threshold the stationary phenol concentration increased exponentially, while heat flow fell sharply, indicating intoxication or wash-out. The clear transition point between the phases, where ectoine formation peaked, suggests that calorimetric measurements could be used to control the conversion of growth-inhibiting substrates (like phenol) into ectoine and to optimize the process. Enthalpy balance and chemical determinations revealed acetate and formate were formed as side products when the C/N ratio in the feed was low, while 2-muconic acid semialdehyde and formate were produced when the ratio was high. These findings indicate that phenol assimilation occurs via the meta pathway. However, enzyme assays implied that assimilation occurs via the ortho and meta pathways at a low C/N ratio and exclusively via the meta pathway at a high C/N ratio.
dauerhafte UFZ-Verlinkung
Maskow, T., Kleinsteuber, S. (2004):
Carbon and energy fluxes during haloadaptation of Halomonas sp. EF11 growing on phenol
Extremophiles 8 (2), 133 - 141 10.1007/s00792-003-0372-1