Alkalibacillus halophilus subsp. hitensis subsp. nov. A new subspecies of moderately halophilic bacterium isolated from a chemical plant in China

In order to develop halophilic microorganism resources to improve environment, a Gram-positive, strictly aerobic and moderately halophilic bacterial strain JSA1 was obtained from the waste water sample collected from Jinhong Chemical Plant at Weihai city, by the methods of quick isolation and screening of halophilic bacteria. Systematic studies on it were carried out. Results show that the strain JSA1 is bacillus. The temperature range most suitable for its growth is 29-35°C and the most suitable pH is 6.5-9.0. It can grow well at the salt mass concentration of 30-150 g/L. The C + G mole fraction of its DNA is 37.5%. The analytical result of 16S rRNA gene sequence reveals that this strain has the closest relationship with Alkalibacillus halophilus (DQ359731) of Alkalibacillus. Their similarities are as high as 99%. However, they have obvious differences in aspects of whole-cell main fatty acid components, cell size, cell morphology, motility, oxidase, gelatine liquefication, NaCl tolerance range, pH tolerance range, G + C mole fraction, sole carbon source, sole nitrogen source, antibiotic sensitivity and strain source. Comparing with other species of the same genus, differences of this strain are even more obvious. In view of multiple identification results, we believe this strain is a new subspecies of Alkalibacillus halophilus and name it Alkalibacillus halophilus subsp. hitensis subsp. nov.