Isolation and identification of moderately halophilic bacterium and enhanced treatment of hypersaline tanning wastewater by the bacterium

In order to investigate the application of moderately halophilic bacterium to the treatment of hypersaline organic tanning wastewater, a halophilic bacterium YS-1 was isolated from the salt water of a salina. The atomic force microscopy (AFM) observation, the physiologic-biochemical index measurement, the whole-cell fatty acid analysis and the 16S rDNA sequence homology identification for the bacterium were then carried out. The results show that the closest relative of YS-1 strain is Halomonas sp. (AB167061), meaning that YS-1 strain is a novel moderately halophilic species of Halomonas sp.. Moreover, according to the results of hypersaline tanning wastewater treatment by the identified bacterium combined with the biological activated carbon (BAC) technology in a sequencing batch reactor (SBR), it is found that, for the wastewater with an initial salt content of 9.3% and an initial COD_Cr of 1378 mg/L, the COD_Cr removal reaches 86% after the treatment for 168 h, and rises to 98% after 216 h. It is thus concluded that YS-1 strain can enhance the treatment of hypersaline tanning wastewater, and that a 'halophilic-BAC technology' combining the screened bacterium and the BAC technology is feasible in the treatment of hypersaline tanning wastewater.