A Comprehensive Investigation of Potential Novel Marine Psychrotolerant Actinomycetes sp. Isolated from the Bay-of-Bengal

Background: This study was carried out to classify the diversity of the deep marine psychrotolerant actinomycetes sp. nov., in the Bay of Bengal and exploit the production of cold-active industrial and pharmaceutical biomolecules. Objective: 1) Characterization, optimum the growth conditions and classify the diversity of the novel isolated deep marine psychrotolerant actinomycetes sp from the Bay-of-Bengal. 2) Screening for industrially important biocatalysts and determine the antimicrobial activities against the five dreadful pathogens. 3) The differential expression profiling of the candidate genes to regulate the biosynthesis of selected enzymes. Methods: The cold-adapted actinomycetes were isolated from the deep marine water collections at 1200 mts below the surface in Bay-of-Bengal. The phenotypic and genotypic characterizations have been carried out to understand the persistent diversity of this novel marine psychrotolerant actinomycetes species. The production of cold-active enzymes, such as amylase, cellulase, lipase, pectinase, and L-asparaginase, were screened and the expression profiling genes were determined by using qRT PCR. The antibacterial and antifungal activities have also been investigated. Results: A total number of 37 novel actinomycetes were isolated and the phenotypic and genotypic characterizations identified the genus, dominated by Streptomyces (17 distinct sub-groups) as the major group, followed by Micromonospora, Actinopolyspora, Actinosynnema, Streptoverticillium, Saccharopolyspora, Nocardiopsis, and Nocardia. The optimum growth and abundant mycelium formation are observed at 15°C to 20°C and also capability for thriving at 4°C. All the isolates exhibited a significant role in the production of biocatalysts, and the antagonistic activities were also noted against five major selected pathogens. Conclusion: The Streptomyces from the Bay-of-Bengal have high biosynthetic potential and can serve as a good resource for the exploration of bioactive natural products.