Diversity and Phylogeny of Actinomycetes of Arabian Sea Along the Gujarat Coast

Abstract

The diversity and biotechnological potential of the haloalkaliphilic actinomycetes of the saline habitats are explored only in a limited sense. Albeit, they have been reported to produce various enzymes, organic acids, antibiotics, and other secondary metabolites. Therefore, we aimed to investigate marine actinomycetes with respect to their cultivation, morphology, biochemical properties, enzyme secretion, solvent tolerance, antibacterial activities and phylogeny. Further, the composition of cell wall and its sugar constituents and variation in multiple–antibiotic-resistance (MAR) suggested diversity of the actinomycetes of the studied habitats. In total, 20 haloalkaliphilic actinomycetes were identified and studied further. Based on the 16S rRNA gene sequences, most of these actinomycetes belong to the genus Nocardiopsis. However, Hae III restriction patterns of the 16S rRNA genes reveal eight main clusters, corresponding with the Jaccard’s similarity coefficient and phenograms based on the biochemical properties. The Canonical Correlation Analysis suggests that pH and temperature rather than salinity and conductivity of the saline habitat are determinants of the growth of actinomycetes. The polyphasic analysis was highly significant in judging the diversity and taxonomy of the marine actinomycetes. Besides, the evaluated phenetic attributes may help in the exploration of the biotechnological potential of these actinomycetes.

Keywords:

• Nocardiopsis sp.
• molecular phylogeny
• polyphasic taxonomy
• diversity indices
• canonical correlation analysis (CCA)

Acknowledgements

Authors greatly acknowledge the infrastructural support provided by the UGC, New Delhi under various programs including CAS, Saurashtra University, DST-FIST Program, MoES Net Working Project and DBT Multi-Institutional Project. AKS acknowledges the award of UGC-Research Fellowship in Sciences for Meritorious Students (RFSMS). International Travel Grants from DST-SERB, DBT and Centre for International Co-operation in Science (CICS) to AKS for presenting his research in the 16th ISME-2016 in Canada are also duly acknowledged. SPS acknowledges DST-SERB International Travel Support to present his work in ‘Extremophile 2016’, Kyoto, Japan. We are extremely grateful to Dr. Peter J. Rogers (Ex-Manager, New Technologies, Carlton United Breweries, Melbourne, Australia and Adjunct Professor, Griffith University, Brisbane, Australia) for his valuable suggestions and contributions in improving the manuscript. BAK acknowledges CSIR Direct-Senior Research Fellowship and International Travel Grants from DST and CSIR.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Authors greatly acknowledge the financial and infrastructural support provided by the UGC, New Delhi.