Ulva sp.

Noor, Sadia, Begum, Mst. Nadira, Rony, Satyajit Roy, Uddin, Mohammad Zashim, Sohrab, Md. Hossain & Mazid, Md. Abdul, 2024, Bioactivity and chemical screening of endophytic fungi associated with the seaweed Ulva sp. of the Bay of Bengal, Bangladesh, Botanica Marina (Warsaw, Poland) 67 (2), pp. 115-129 : 124

4.1 Endophytic fungi associated with Ulva sp.

Ulva sp. , the green seaweed found abundantly on the coastline, is also populated by endophytic fungal taxa, just like other seaweeds. The identification of Ulva sp. was carried out using morphological analysis. The present investigation revealed six different endophytic fungal isolates associated with Ulva sp. The identity of the isolates of Ulva sp. was established by definitive microscopic characteristics followed by macroscopic (phenotypic) observations. The most closely related species was selected more definitively using molecular (genotypic) analysis, such as by comparing the ITS sequence of fungal DNA ( Schoch et al. 2012). Table S 2 briefly describes the BLAST best hits of the isolates. Many fungi were misidentified previously due to phenotypic variations ( Sarwar et al. 2019; Weiss and Göker 2011). Thus, the phylogenetic analysis of DNA sequence data along with morphological characterization has been proved to be an appropriate way to identify fungi correctly ( Horiike 2016; Wang et al. 2022). The identification of six isolates derived from Ulva sp. revealed six different fungal species from five genera ( Chaetomium , Nigrospora , Curvularia , Aspergillus and Collariella ; Table 1) belonging to four classes, namely, Euascomycetes, Sordariomycetes , Dothideomycetes and Eurotiomycetes .

This is the first report of fungal endophytes in Ulva sp. collected from Saint Martin’ s Island in the Bay of Bengal, Bangladesh. However, very few reports are available on the diversity of endophytic fungi in green seaweeds. Chaetomium sp. , Phomopsis sp. , Acremonium sp. , Aspergillus niger and Cladosporium sp. were isolated from Ulva lactuca collected from Kovalam (covelong), Chennai ( Ahamed and Murugan 2019), whereas Fusarium semitectum , Paecilomyces lilacinus , Aspergillus fl avus, Penicillium expansum , P. roqueforti , Rhizopus sp. and Pythium sp. were isolated from the same seaweed species from Johor, Malaysia (Zainee et al. 2021). Other studies have also reported the fungal endophytes Acremonium fuci , Chaetomium globosum , Emericellopsis enteromorphae , E. phycophila , Monodictys putredinis , Parasarocladium alavariense , P. fusiforme and Penicillium sp. from marine green macroalgae ( Gonçalves et al. 2019; Singh et al. 2018). The fungal species isolated in this study have been reported previously from a diverse array of macroalgal hosts ( Flewelling et al. 2015), except that Nigrospora magnoliae was first isolated from Magnolia plants collected in China and Thailand ( de Silva et al. 2021), and this is the second report of an endophytic isolate characterised as N. magnoliae .