Alteromonas infernus sp. nov., a new polysaccharide‐producing bacterium isolated from a deep‐sea hydrothermal vent

Abstract

A deep-sea, aerobic, mesophilic and heterotrophic new bacterium was isolated from a sample of fluid collected among a dense population of Riftia pachyptila, in the vicinity of an active hydrothermal vent of the Southern depression of the Guaymas basin (Gulf of California). On the basis of phenotypic and phylogenetic analyses and DNA/DNA relatedness, the strain GY785 was recognized as a new species of the genus Alteromonas and the name of Alteromonas infernus is proposed. During the stationary phase in batch cultures in the presence of glucose, this bacterium secreted two unusual polysaccharides. The water-soluble exopolysaccharide-1 produced contained glucose, galactose, galacturonic and glucuronic acids as monosaccharides. The gel-forming exopolysaccharide-2 was separated from the bacterial cells by dialysis against distilled water and partially characterized.

Increased bacterial growth efficiency with environmental variability: results from DOC degradation by bacteria in pure culture experiments

“…Using the oxygraph based respiration rates (0.25 mM O 2 h −1 ) we estimated that cultures should be oxygen depleted after 1 h (data not shown). However, the cultured bacteria (Alteromonas infernus) is strictly aerobic and does not have a fermentative metabolism (Raguénès et al, 1997). This means that, if cultures were indeed limited by O 2 after 1 h, growth (POC increase) would stop; we did not observe this in our results (Fig.…”

Idiomarina gen. nov., comprising novel indigenous deep-sea bacteria from the Pacific Ocean, including descriptions of two species, Idiomarina abyssalis sp. nov. and Idiomarina zobellii sp. nov.

“…Representatives of these microorganisms are interesting in terms of their metabolic characteristics, psychrophilic nature, halotolerance and ubiquitous distribution in the marine environment. The presence of as yet undescribed novel bacterial taxa in a variety of extreme marine environments is indicative of the fact that they represent a resource of microbial diversity (Deming et al, 1988 ;Irgens et al, 1996 ;Bowman et al, 1997a, b ;Bozal et al, 1997 ;Ra ' gue! nes et al, 1997).…”

Vibrio diabolicus sp. nov., a New Polysaccharide-Secreting Organism Isolated from a Deep-Sea Hydrothermal Vent Polychaete Annelid, Alvinella pompejana

“…Since the discovery and exploration of many deep-sea hydrothermal ecosystems known for their extreme conditions, the search for EPS-secreting bacteria has been systematic (11,23,29). However, only a few EPS-secreting bacteria have been described (21,22,29,30), and all strains isolated previously from deep-sea hydrothermal ecosystems have been assigned to the genus Alteromonas. In the present study we describe the first Vibrio strain isolated from a deepsea hydrothermal vent and show that it is a member of a new species.…”