Halomonas magadii sp. nov., a new member of the genus Halomonas , isolated from a soda lake of the East African Rift Valley

Alcalilimnicola halodurans gen. nov., sp. nov., an alkaliphilic, moderately halophilic and extremely halotolerant bacterium, isolated from sediments of soda-depositing Lake Natron, East Africa Rift Valley.

“…These soda lakes are supposed to be the habitats of relict microbial communities and are regarded as possible centres of the origin of microbial diversity (Zhilina & Zavarzin, 1994). The concentrated brines of the hypersaline Lake Magadi have been shown to support a dense and diverse population of aerobic, organotrophic, halophilic and alkaliphilic representatives of major bacterial and archaeal phyla (reviewed recently by Duckworth et al, 1996Duckworth et al, , 2000Jones et al, 1998 ;Grant et al, 1999). Anaerobic decomposition, which dominates in these lakes, is performed by the anaerobic, alkaliphilic microbial community that has not yet been studied in detail, in spite of its possible M. M. Yakimov and others biotechnological applications (Zhilina & Zavarzin, 1994).…”

Halomonas halocynthiae sp. nov., isolated from the marine ascidian Halocynthia aurantium.

“…We think it is, because it appears more important to provide the scientific community with information of a novel species (although based only on a single strain) combined with information on the tentative genus affiliation than to describe a new genus within the radiation of the genus Halomonas. The intrageneric diversity, demonstrated by the branching of Chromohalobacter (Ventosa et al, 1989) within the radiation of Halomonas (Duckworth et al, 2000 ; this paper), has been acknowledged. A dissection of Halomonas may lead to the description of two or more genera for Halomonas species and, because of the slightly divergent properties exhibited by Halomonas halocynthiae sp.…”

“…At the time of writing, the genus Halomonas contains 22 species, including the recently described Halomonas campisalis, a denitrifying, moderately haloalkaliphilic bacterium (Mormile et al, 1999), Halomonas magadiensis, an extremely halotolerant bacterium isolated from a soda lake of the East African Rift Valley (Duckworth et al, 2000), and Halomonas marisflavi, a halophilic bacterium from the Yellow Sea (Yoon et al, 2001).…”

“…Halomonas species have been isolated from salterns, marine environments, estuarine waters, salt lakes and ponds, Antarctic saline lakes and saline soils (Vreeland et al, 1980 ;Baumann et al, 1983 ;Franzmann et al, 1987 ;Quesada et al, 1984Quesada et al, , 1990Valderrama et al, 1991 ;Mellado et al, 1995 ;Mormile et al, 1999 ;Duckworth et al, 2000 ;Bouchotroch et al, 2001 from coastal sea water at a depth of 3 m in Troitsa Bay, Peter the Great Bay, The Sea of Japan, Russia, in October 1990. Aliquots of the gill-tissue homogenate, diluted in sterile sea water, were spread on agar plates of sea-water medium (SWM) containing (l −" ): 5n0 g peptone, 2n5 g yeast extract, 1n0 g glucose, 0n2 g K # HPO % , 0n05 g MgSO % , 500 ml sea water and 500 ml distilled water, solidified with 15n0 g agar.…”

“…The 16S rDNA sequence of strain KMM 1376 T was aligned manually with nucleotide sequences obtained from GenBank and EMBL. The method of Jukes & Cantor (1969) was Vreeland et al, 1980 ;James et al, 1990) ; 3, H. subglaciescola UQM 2926 T (Franzmann et al, 1987) ; 4, H. venusta DSM 4743 T (Baumann et al, 1972(Baumann et al, , 1983James et al, 1990) ; 5, H. aquamarina IAM 12550 T (Baumann et al, 1972(Baumann et al, , 1983Akagawa & Yamasoto, 1989 ;James et al, 1990) ; 6, H. meridiana DSM 5425 T (James et al, 1990 ;Duckworth et al, 2000) ; 7, H. magadiensis NCIMB 13595 T (Duckworth et al, 2000). All strains are positive for utilization of -proline.…”