[New species of Natronobacterium].

An extreme haloalkalophilic bacterium HAM-2 with pleomorphic rods was isolated from Hamatai soda lake in Inner Mongolia Autonomous Region. Growth occurs in 12%-30% NaCl, no growth below 12%, optimum 17.5%. pH range for good growth 7.8-10.4, optimum 9.0-9.5. The strain HAM-2 is non-motile, Gram-negative, pleomorphic, cell of which were 1.0-2.0 by 2.0-5.0 microns in size in liquid medium. The major polar lipids of the organisms are phosphatidylglycerol phosphate and phosphatidyglycerol and contains an unidentified phospholipid as a minor component PL4. G + C contant of DNA is 59.5 mol%. Based on the characteristics, the strain HAM-2 could be included in the genus Natronobacterium, but since HAM-2 differs from reported four species of this genus in cell shape, polar lipids and biochemical features. The name Natronobacterium innemongoliae sp. nov. is proposed. The type strain is designated HAM-2.