Culturable Diversity and Enzyme Production Survey of Halophilic Prokaryotes from a Solar Saltern on the Shore of the Oman Sea

Abstract

The prokaryotic residents of the Tis solar saltern in the southeast of Iran on the shore of Oman Sea were investigated by the culture-dependent methods. Sequencing of the PCR-amplified fragments of <em>16S rRNA</em> genes revealed that bacterial populations were related to <em>Actinobacteria</em>,<em> Bacteroidetes</em>, <em>Balneolaeota</em>, <em>Firmicutes</em>, and <em>Proteobacteria</em>. They were phylogenetically identified as members of <em>Bacillus </em>(35%),<em> Aliifodinibius </em>(15%),<em> Longibacter </em>(10%),<em> Halomonas </em>(10%), <em>Arthrobacter </em>(5%),<em> Luteimonas </em>(5%),<em> Ornithinibacillus </em>(5%), <em>Rhodovibrio </em>(5%),<em> Staphylococcus </em>(5%),and <em>Tamilnaduibacter </em>(5%). All archaeal isolates were belonged to the order <em>Halobacteriales</em> in the following genera: <em>Haloferax </em>(33%),<em> Haloarcula </em>(27%),<em> Halogeometricum </em>(11%),<em> Halococcus </em>(5%),<em> Halomicroarcula </em>(5%),<em> Halorubrum </em>(5%),<em> Halostagnicola </em>(5%), and<em> Natronoarchaeum </em>(5%). Semi-quantitative evaluation of six hydrolytic enzymes, including amylase, cellulase, lipase, pectinase, protease, and urease among these strains, revealed that urease (47%) and amylase (41%) had the highest production frequency. The average production rates were observed for lipase (25%) and protease (30%), while the pectinase (12%) and cellulase (4%) productions were rare among these halophiles. The most potent bacterial/archaeal strains for the enzymes production were as: <em>Longibacter/Natronoarchaeum</em> (amylase), <em>Bacillus/ non archaeum</em> (cellulase), <em>Tamilnaduibacter/ Haloferax</em> (lipase), <em>Bacillus/ Haloferax</em> (pectinase), <em>Bacillus/ Haloferax</em> (protease), and<em> Staphylococcus/ Halococcus</em> (urease). This first report about the prokaryote populations of the solar salterns in Iran demonstrated its high microbial diversity and potentials for the production of industrially interesting enzymes.