FEMS Microbiology Letters, 367, 2020, fnaa078 https://doi.org/10.1093/femsle/fnaa078 Advance Access Publication Date: 14 May 2020 Research Letter R E S E A R C H L E T T E R – Biotechnology & Synthetic Biology Exploration and profling of hidden endophytic mycota of marine macroalgae with potential drug leads Manomi Sarasan 1 , Neema Job 1 , Jayesh Puthumana 2 , Ravinesh R. 3 , Prabhakaran M. P. 4 , Lathika Cicily Thomas 1 and Rosamma Philip 1, * 1 Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology, Fine Arts Avenue, Kochi, Kerala 682016, India, 2 National Centre for Aquatic Animal Health, Cochin University of Science and Technology, Fine Arts Avenue, Kochi, Kerala 682016, India, 3 Department of Aquatic Biology and Fisheries, University of Kerala, Kariavattom Campus, Trivandrum, Kerala 695034, India and 4 Department of Fishery Hydrography, Kerala University of Fisheries and Ocean Studies, Cochin, Kerala 682506, India ∗ Corresponding author: Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Faculty of Marine Sciences, Cochin University of Science and Technology,Fine Arts Avenue, Kochi, Kerala 682 016, India. Tel: +91-9447620009; E-mail: rosammap@gmail.com; rose@cusat.ac.in One sentence summary: Hidden mycota of marine macroalgae. Editor: Michael Sauer ABSTRACT Diversity studies of endophytic assemblages are emerging challenges, which unveil novel phenotypes producing interesting chemical entities and a better understanding of their ecological signifcance. In the present investigation, we selected an extremely complex and unique environment supporting unexplored endophytes, ‘Macroalgae of Kerala coast, India’. Unlike terrestrial fora and mangroves, reports displaying endophytic assemblages of marine fora remain limited, especially from India. The main goal of this study was to expose hidden endophytic fungi from macroalgae and examination of their bioactive potential. An ecological investigation of four red, four green and three brown algae resulted in 133 fungal taxa with 29 distinct morphospecies. Aspergillus and Penicillium were found to be the dominant genera. Penicillium chrysogenum was the sole fungi that contributed 11% of the entire endophytic community. Antimicrobial activity against various aquaculture/human pathogens revealed that around 59% of endophytes inhibited at least one of the pathogens screened. The maximum number of isolates (37%) inhibited Escherichia coli tailed by Aspergillus fumigatus (27%). Antimicrobial profle of fungal endophytes endorses them as a potential source of bioactive molecules that can be explored to fnd a solution for drug resistance in microbial pathogens. Keywords: endophytic fungi; macroalgae; fungal diversity; antimicrobial; bioactive compound INTRODUCTION Researchers world over are deeply involved in the search for novel molecules as alternatives to combat the enduring drug resistance among microbes. In this context, the importance of endophytes, an unexplored microbial community, with very high potential for rare metabolite production emerges as a signifcant resource yet to be explored (Sarasan et al. 2017). Endophytes are microorganisms, may be fungus, bacteria, yeast or mycoplasma that inhabits the internal tissue of healthy plants without causing any disease in the host. Among the prominent ones, fungal endophytes can have profound effects on the stimulation of plant growth, disease resistance, improve- ment in plant’s ftness to harsh environmental stresses, insecti- cidal property and recycling of nutrients (Sturz and Nowak 2000), Received: 2 November 2019; Accepted: 12 May 2020 C  The Author(s) 2020. Published by Oxford University Press on behalf of FEMS. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com 1 Downloaded from https://academic.oup.com/femsle/article/367/11/fnaa078/5837081 by guest on 25 October 2022