Intertidal marine sediment harbours Actinobacteria with promising bioactive and biosynthetic potential

Abstract

Actinobacteria are the major source of bioactive natural products that find their value in research and drug discovery programmes. Antimicrobial resistance and the resulting high demand for novel antibiotics underscore the need for exploring novel sources of these bacteria endowed with biosynthetic potential. Intertidal ecosystems endure regular periods of immersion and emersion, and represent an untapped source of Actinobacteria. In this study, we studied the diversity and biosynthetic potential of cultivable Actinobacteria from intertidal sediments of Diu Island in the Arabian Sea. A total of 148 Actinobacteria were selectively isolated using a stamping method with eight isolation media. Isolates were grouped into OTUs based on their 16S rRNA gene sequence, and categorized within actinobacterial families such as Glycomycetaceae, Micromonosporaceae, Nocardiaceae, Nocardiopsaceae, Pseudonocardiaceae, Streptomycetaceae, and Thermomonosporaceae. The biosynthetic potential of the Actinobacteria, necessary for secondary metabolite biosynthesis, was screened and confirmed by extensive fingerprinting approaches based on genes coding for polyketide synthases and nonribosomal peptide synthetases. The observed biosynthetic potential was correlated with the antibacterial activity exhibited by these isolates in laboratory conditions. Ultimately, the results demonstrate that intertidal sediment is a rich source of diverse cultivable Actinobacteria with high potential to synthesize novel bioactive compounds in their genomes.

Diversity of culturable actinobacteria producing protease inhibitors isolated from the intertidal zones of Maharashtra, India

“…and Micromonispora sp . The observations coincided with observations of (Jose and Jha, 2017) who worked on the samples obtained from coast of Gujarat which is situated at north of Maharashtra. These findings might suggest that members of above three genera have adapted well to live in marine environments and show a widespread distribution along the western coast of India.…”

“…Many of them also produce external spores which are resistant to dehydration (Trujillo, 2016). Various reports say that marine actinobacteria have a high potential for production of biomolecules (Jose and Jha, 2017; Solanki et al, 2008) however, the number of actinobacterial compounds discovered so far are limited not by the number of compounds produced by them but by the amount of screening efforts put in (Watve et al, 2001). Many reports have highlighted the need for studying marine actinomycete diversity and their potential use for obtaining novel metabolites (Dharmaraj, 2010; Jensen et al, 2005; Lam, 2006; Subramani and Aalbersberg, 2012).…”

“…Many reports have highlighted the need for studying marine actinomycete diversity and their potential use for obtaining novel metabolites (Dharmaraj, 2010; Jensen et al, 2005; Lam, 2006; Subramani and Aalbersberg, 2012). Researchers from India have also isolated actinobacteria from coastal regions of West Bengal (Peela et al, 2005; Ramesh and Mathivanan, 2009), Gujarat (Jose and Jha, 2017), Tamil Nadu (Raja et al, 2010; Valli et al, 2012) and Andaman and Nicobar (Karthik et al, 2014) to name a few for bioprospecting studies. However, there are very few reports of isolation of actinobacteria and still fewer reports on PI producing actinobacteria from the coast of Maharashtra.…”

Freshwater transitions and symbioses shaped the evolution and extant diversity of caridean shrimps

“…Although there are mechanisms that can promote allopatric speciation in marine settings—notably the fragmentation of shallow water environments by marine regressions 11 and tectonic fragmentation 41 —freshwater habitats typically have much lower connectivity and far greater habitat isolation than found in the oceans. This lower connectivity in freshwater environments may also result in higher extinction rates 42 .…”

Whole genome sequence of Streptomyces humi strain MUSC 119T isolated from intertidal soil

“…Owing to their ability in synthesizing bioactive compounds of various structures, members of Streptomyces have always been in the limelight for the search of pharmaceutically important compounds [1][2][3][4][5][6] . Coupled with their ability to synthesize various bioactive compounds, their unique life cycle and spore formation has allowed these filamentous bacteria to survive and colonize various habitats, covering both terrestrial and marine region [7][8][9][10][11][12][13][14][15][16][17][18] . Streptomyces humi MUSC 119 T was recovered from mangrove soil in east coast of Peninsular Malaysia [19] .…”