Population dynamics within a microbial consortium during growth on diesel fuel in saline environments.

The diversity and dynamics of a bacterial community extracted from an exploited oil field with high natural soil salinity near Comodoro Rivadavia in Patagonia (Argentina) were investigated. Community shifts during long-term incubation with diesel fuel at four salinities between 0 and 20% NaCl were monitored by single-strand conformation polymorphism community fingerprinting of the PCR-amplified V4-V5 region of the 16S rRNA genes. Information obtained by this qualitative approach was extended by flow cytometric analysis to follow quantitatively the dynamics of community structures at different salinities.

Influence of high salinities on the degradation of diesel fuel by bacterial consortia.

Microbial communities from three Argentinean saline soils were extracted and tested for their ability to degrade diesel fuel in liquid culture at salinities between 0% and 25%. In each case, the degradation process was continuously monitored by measuring oxygen consumption. Two communities (CR1 and CR2) showed nearly equal degrees of degradation across a salinity range of 0%-10% (the former degrading about 63% of the diesel fuel and the latter about 70% after 53 and 80 d, respectively).

Highly sensitive determination of ectoine and other compatible solutes by anion-exchange chromatography and pulsed amperometric detection.

In saline media prokaryotes compensate for the osmotic pressure of the surrounding medium by producing osmolytes. Although these osmolytes or osmoprotectors have quite diverse structures, most of them can be determined by anion-exchange chromatography combined with integrated pulsed amperometric detection. This technique offers the advantages of very high sensitivity and new opportunities to determine ectoine and 5-hydroxyectoine-two important osmolytes -after hydrolytic cleavage of the pyrimidine ring.

Formate-stimulated oxidation of methanol by Pseudomonas putida 9816.

It has been reported that Pseudomonas putida 9816 is able to grow on methanol, but it does not have methanol dehydrogenase or oxidase activity. To utilize methanol it requires yeast extract. The utilization of methanol can be accelerated by adding formate, which obviously helps oxidize methanol and win biologically useful energy.

Influence of heavy metals on the microbial degradation of diesel fuel.

The degradation of diesel fuel by a microbial community from a soil polluted by heavy metals (h.m.) in the presence of Cu, Ni, Zn, Pb, Cd, Hg and Cr (as chromate) was investigated.