Query: NC_007426:205390 Natronomonas pharaonis DSM 2160, complete genome
Lineage: Natronomonas pharaonis; Natronomonas; Halobacteriaceae; Halobacteriales; Euryarchaeota; Archaea
General Information: Isolated from Lake Gabara in Egypt. Extreme haloalkaliphilic archeon. Natronomonas pharaonis is able to survive at high salt and pH conditions which results in limited nitrogen availability through ammonium. In order to compensate for this, Natronomonas pharaonis has developed three systems to promote nitrogen assimilation: direct uptake of ammonia, uptake of nitrate, and uptake of urea. Another problem with high pH environments is the use of a proton gradient for the generation of ATP, which other alkaliphiles have adapted to by substitution of sodium ions for protons. However, this organism utilizes protons for ATP generation as determined by experimental data.
Subject: NC_015709:1459838 Zymomonas mobilis subsp. pomaceae ATCC 29192 chromosome, complete
Lineage: Zymomonas mobilis; Zymomonas; Sphingomonadaceae; Sphingomonadales; Proteobacteria; Bacteria
General Information: Country: United Kingdom; Isolation: Sick cider; Temp: Mesophile. The natural habitat of this organism includes sugar-rich plant saps where the bacterium ferments sugar to ethanol. The high conversion of sugars to ethanol makes this organism useful in industrial production systems, particularly in production of bioethanol for fuel. A recombinant strain of this bacterium is utilized for the conversion of sugars, particularly xylose, which is not utilized by another common sugar-fermenting organism such as yeast, to ethanol. Since xylose is a common breakdown product of cellulose or a waste component of the agricultural industry, it is an attractive source for ethanol production. Zymomonas mobilis was chosen for this process as it is ethanol-tolerant (up to 120 grams of ethanol per litre) and productive (5-10% more ethanol than Saccharomyces). This bacterium ferments using the Enter-Doudoroff pathway, with the result that less carbon is used in cellular biomass production and more ends up as ethanol, another factor that favors this organism for ethanol production.