Super life--how and why 'cell selection' leads to the fastest-growing eukaryote.

What is the highest possible replication rate for living organisms? The cellular growth rate is controlled by a variety of processes. Therefore, it is unclear which metabolic process or group of processes should be activated to increase growth rate. An organism that is already growing fast may already have optimized through evolution all processes that could be optimized readily, but may be confronted with a more generic limitation.

Oxygen protection of nitrogen fixation in free-living Azorhizobium caulinodans: the role of cytochrome aa.

The growth properties of Azorhizobium caulinodans wild-type and a cytochrome aa mutant strain, both growing with N as N source at fixed dissolved partial oxygen pressures in the range 0.5--4.0 kPa, were studied by making use of continuous cultures (chemostats and pH-auxostats) and transient cultures.

Expression of the mau gene cluster of Paracoccus denitrificans is controlled by MauR and a second transcription regulator.

The mau gene cluster of Paracoccus denitrificans constitutes 11 genes (10 are located in the transcriptional order mauFBEDACJGMN; the 11th, mauR, is located upstream and divergently transcribed from these genes) that encode a functional methylamine-oxidizing electron transport branch. The mauR gene encodes a LysR-type transcriptional activator essential for induction of the mau operon. In this study, the characteristics of that process were established.