From Microalgae Growth Promotion to the Production of Secondary Metabolites

Funding Information: F.Q.-N. and P.R.B. acknowledge receiving a Ph.D. fellowship (2022.10633.BD; 2021.07927.BD514, respectively) funded by FCT/MCTES. Funding Information: This research was conducted in the scope of the project “PhycoµBiome: Understanding and harnessing the power of the microalgae microbiome aiming the maximization of marine microalgae productivity” funded by Fundação para a Ciência e Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior (FCT/MCTES, Portugal), grant number PTDC/BAA-BIO/1262/2020. The research was performed with the support of iNOVA4Health (UIDB/04462/2020 and UIDP/04462/2020) and the Associate Laboratory LS4FUTURE (LA/P/0087/2020) also funded by the FCT/MCTES. Publisher Copyright: © 2023 by the authors.Marine bacteria are a significant source of bioactive compounds for various biotechnological applications. Among these, actinomycetes have been found to produce a wide range of secondary metabolites of interest. Saccharopolyspora is one of the genera of actinomycetes that has been recognized as a potential source of these compounds. This study reports the characterization and genomic analysis of Saccharopolyspora sp. NFXS83, a marine bacterium isolated from seawater from the Sado estuary in Portugal. The NFXS83 strain produced multiple functional and stable extracellular enzymes under high-salt conditions, showed the ability to synthesize auxins such as indole-3-acetic acid, and produced diffusible secondary metabolites capable of inhibiting the growth of Staphylococcus aureus. Furthermore, when Phaeodactylum tricornutum was co-cultivated with strain NFXS83 a significant increase in microalgae cell count, cell size, auto-fluorescence, and fucoxanthin content was observed. Detailed analysis revealed the presence of clusters involved in the production of various secondary metabolites, including extracellular enzymes, antimicrobial compounds, terpenes, and carotenoids in the genome of strain NFXS83. Ultimately, these findings indicate that Saccharopolyspora sp. NFXS83 has a significant potential for a wide range of marine biotechnological applications.publishersversionpublishe