Is halophiles archaebacteria or eubacteria?

I've been wondering about this for a while.

I have read in many papers that Halophiles are bacteria or archaebacteria. I have also read that they are eubacteria.

In fact, halophiles are archaea (see article from the NIH page you referred to) and also bacteria. However, many species of bacteria also prefer high salt concentrations. For example, Bacillus halodurans can grow at very high salt concentrations (3 M NaCl). The Wikipedia page on Halophiles lists a number of bacteria that thrive in high-salt environments. Halophiles are both Archaea and Bacteria. Archaea, like Eubacteria, have a cell membrane and grow in a similar way. However, the main difference between the two is that Archaea don't have the genes needed for glycolysis. They use an alternate way of generating ATP by utilizing the chemical energy of sodium ions. The major difference is that they are not oxygen dependent.

Bacteria, on the other hand, have a cell membrane and grow using the same pathway as Eubacteria. They also generate ATP in a similar manner. The main difference is that they are oxygen dependent.

Is Halophile an Archaea?

Halophiles are extremophiles living in extreme conditions.

So they are considered as the most primitive group of organisms on earth. Their basic metabolism and cellular structures are more similar to Archaea than bacteria. They may be one of the oldest group of organisms. For more details see Archaea and Halophiles.

What do Halophiles look like? Halophiles are filamentous, motile bacteria. Their morphology is quite different from bacteria. They grow in clusters of millions. These clusters are referred as Halos.

The Halos are very large in size. The diameter of the Halos varies between 200-600 micrometers.

The Halos can be single or multi-celled. The multi-cellular Halos have a central rod-like structure called crown. It is composed of cells arranged in concentric circles.

The single-celled Halos have a central cell called sorus surrounded by a membrane. They live in water with salt concentrations higher than 25% NaCl. The optimal growth occurs at 55-60% salinity.

They have small cells (2.5-3.5 m), without any flagellum.

The cells are coccoid. They contain many vacuoles, which help them to withstand the high salinity. They have a unique cell wall. They do not have peptidoglycan. They contain polysaccharides.

Their cell walls are composed of a single unit. The genome of Halophiles is very small. They have a streamlined genome.

What do Halophiles eat? Halophiles are heterotrophs. They get their nutrition by taking up dissolved organic matter from the medium. They convert this matter into organic acids by the process of fermentation.

Some Halophiles can also metabolize ammonia. They can utilize various inorganic substances for growth and maintenance. They can also use sodium nitrite as an alternative electron acceptor. What are the different Halophiles? Halophiles are classified into two major groups based on their morphology, physiology and genomic data. They are called Gram-negative Halophiles and Gram-positive Halophiles.

What is the domain and kingdom of halophiles?

The domain of halophiles, or 'proteobacteria', is the domain Bacteria.

The superkingdom is Proteobacteria. The only kingdom within the domain Bacteria is the one called the domain, Proteobacteria. The name Proteobacteria refers to the presence of the bacteria with the property to secrete inorganic ions in the form of protons across their cell membranes.

Are there any other subphyla that would contain members of the domain Halobacteria? Yes, the domain Halobacteria is the subphylum Prodivision Halobacterium; it can be understood as a kind of subkingdom of Proteobacteria. Some authors also like to use the same name Halobacterium as a genus. But Halobacterium is only one of a large number of prokaryotes species from which new organisms are continuously being isolated, mainly from hypersaline environments. A more generic name should be chosen.

What does the name Halobacterium mean? According to the Oxford English Dictionary (OED), haloes are round disc-shaped haloes that are seen in the sky surrounding stars or planets, such as the Haloes of Saturn. Thus, the term Halobacterium means a microorganism that lives in the halos surrounding the stars. The word 'halorhabdus' ('halospore-forming') and 'halococcoid' ('halophilic') have been suggested as alternative names for Halobacterium, but these terms would be more widely used for non-halophilic members of Proteobacteria, such as Pseudomonas, Xanthomonas, etc.