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.

中文翻译：

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潮间带海洋沉积物具有放线菌，具有广阔的生物活性和生物合成潜力。

放线菌是生物活性天然产物的主要来源，在研究和药物发现计划中发现它们的价值。抗菌素耐药性以及由此产生的对新型抗生素的大量需求，凸显了对探索具有生物合成潜力的这些细菌的新型来源的需求。潮间带生态系统可以承受一定的浸没和浸没时期，并代表放线菌的未开发来源。在这项研究中，我们研究了阿拉伯海迪乌岛潮间带沉积物中可培养的放线菌的多样性和生物合成潜力。使用带有八种分离培养基的压印方法，选择性地分离出总共148株放线菌。根据分离株的16S rRNA基因序列将其分为OTU，并归类于放线菌科（如糖科）中。Micromonosporaceae，Nocardiaceae，Nocardiopsaceae，Pseudonocardiaceae，Streptomycetaceae和Thermomonosporaceae。通过基于编码聚酮化合物合成酶和非核糖体肽合成酶的基因的广泛指纹图谱方法，筛选并确认了次级代谢产物生物合成所必需的放线菌的生物合成潜力。在实验室条件下，观察到的生物合成潜能与这些分离物表现出的抗菌活性相关。最终，结果表明潮间带沉积物是多种可培养放线菌的丰富来源，具有在其基因组中合成新型生物活性化合物的高潜力。根据广泛的指纹图谱方法，基于编码聚酮化合物合酶和非核糖体肽合成酶的基因，筛选和确认了次级代谢产物生物合成所必需的物质。在实验室条件下，观察到的生物合成潜能与这些分离物表现出的抗菌活性相关。最终，结果表明潮间带沉积物是多种可培养放线菌的丰富来源，具有在其基因组中合成新型生物活性化合物的高潜力。根据广泛的指纹图谱方法，基于编码聚酮化合物合酶和非核糖体肽合成酶的基因，筛选和确认了次级代谢产物生物合成所必需的物质。在实验室条件下，观察到的生物合成潜能与这些分离物表现出的抗菌活性相关。最终，结果表明潮间带沉积物是多种可培养放线菌的丰富来源，具有在其基因组中合成新型生物活性化合物的高潜力。