A study on the halophilic archaeal diversity from the food grade iodised crystal salt from a saltern of India

Abstract

Present study aimed to evaluate culturable halophilic archaeal diversity of iodised crystal salt, obtained from the solar salterns of Vedaranyam, Tamil Nadu, India. Bright yellow-orange-red pigmented colonies were obtained, by surface spreading of the saturated salt crystal suspension, on complex media such as NTYE (NaCl Tryptone Yeast Extract) and EHM (Extremely Halophilic Medium), followed by incubating the plates for 30-45 days. The viable halophilic pigmented/non-pigmented microbial counts were determined as colony forming units (CFU/g), which were approx. 1.1 x 104 /5.5 x 103 and approx. 1.0 x 104 /4.0 x 103 on NTYE and EHM, respectively. Six morphologically distinct isolates were purified and identified. Morphological characteristics of the isolates revealed the cells to be cocci and involuted/cup shape, whereas chemotaxonomic characteristics revealed the presence of bacterioruberin pigment. Small subunit ribosomal RNA (16S rRNA) gene analysis revealed that, majority of the isolates belonged to genus Halococcus, except one belonged to genus Halorubrum. To the best of our knowledge, this is the first study reporting, prevalence of Halococcus in iodised crystal salt, of Vedaranyam, Tamil Nadu, India.