Molecular Characterization and Significance of Salt‐Tolerant Alkaliphilic Actinomycetes of the Saline Habitats of Mithapur, Coastal Gujarat, India

Soil salinization and alkalinization threaten agriculture and microbial diversity, driving the need for salt-tolerant and alkaliphilic microorganisms in biotechnology. The present study aimed to isolate, characterize, and assess the molecular diversity of such actinomycetes from coastal Gujarat, India, to identify candidates for biotechnological applications. Eight salt-tolerant and alkaliphilic actinomycetes were isolated from Mithapur, Gujarat (India), and confirmed to grow at 5% salt and pH 9. Their colony characteristics, in situ growth, biochemical properties, and antibiotic susceptibility were examined. To extend the study further, the genomic DNA was extracted from the cell mass to assess the molecular diversity of the actinobacteria. The quality, purity, and yield of the extracted DNA were assessed by spectroscopic analysis and agarose gel electrophoresis. The 16S rRNA genes were then amplified using five different primer sets, including two universal (U1 and U2), two Streptomyces-specific (StrepB/StrepE and StrepB/StrepF), and one Nesterenkonia-specific (NF/R) primer set. The varying number of isolates yielded expected amplicons with U1 (1500 bp), U2 (1000 bp), StrepB/StrepE (500 bp), StrepB/StrepF (1170 bp), and NF/R (1120 bp) primer sets. DGGE with the amplified 16S rRNA gene was used as a fingerprinting tool to further differentiate the actinomycetes and assess their molecular diversity, highlighting their potential for bioremediation, agriculture, and biotechnology.