Eldrin tells us how an invasive freshwater diatom is transforming river ecosystems across Japan.

The fish gastrointestinal microbiome is a valuable source of microorganisms with potential applications in aquaculture. In this study, strain LAB20 was isolated from the gut of silver therapon (Leiopotherapon plumbeus), an endemic freshwater fish in the Philippines. Wild-caught juveniles obtained from the Bureau of Fisheries and Aquatic Resources Regional Office No. 5 (Fabrica, Bula, Camarines Sur, Philippines; 13.49836°N, 123.30441°E) were dissected aseptically, and excised gut samples were homogenized in sterile phosphate-buffered saline, serially diluted, and plated on de Man, Rogosa, and Sharpe (MRS) agar supplemented with 1% calcium carbonate. Plates were incubated at 37°C for 48 h in a candle jar. Colonies exhibiting calcium carbonate dissolution halos were purified by repeated streaking on MRS agar and screened for antagonistic activity against Vibrio parahaemolyticus by agar well diffusion assay as previously described (1). For preliminary taxonomic identification, strain LAB20 was cultured in MRS broth at 37°C for 24 h under static conditions in screw-capped tubes. Genomic DNA was extracted using InstaGene Matrix (Bio-Rad Laboratories, USA), and the nearly full-length 16S rRNA gene was amplified using primers 27F (5′-AGAGTTTGATCMTGGCTCAG-3′) and 1492R (5′-TACGGYTACCTTGTTACGACTT-3′). Amplicons were bidirectionally Sanger sequenced on an ABI PRISM 3730XL DNA Analyzer (Applied Biosystems, Foster City, CA, USA). BLASTn analysis of the 16S rRNA gene sequence showed the highest similarity to Lactiplantibacillus plantarum JCM 1149 (GenBank accession no. NR_115605.1) and high similarity to Lactiplantibacillus pentosus 124-2 (GenBank accession no. NR_029133.1). Given their high sequence similarity, whole-genome sequencing was performed for definitive species-level identification.

The diatom Cymbella janischii is an invasive species in Japan, causing nuisance blooms by forming thick mats in rivers. To date, there are no documented studies on the microbiome associations in C. j...

Tannins are plant polyphenols that reduce aquafeed digestibility by binding proteins and digestive enzymes (1). Because these antinutritional compounds are common in plant-derived feed ingredients, there is increasing interest in isolating tannin-degrading microorganisms for potential application in sustainable aquafeed bioprocessing. Silver therapon (Leiopotherapon plumbeus), locally known as ayungin, is a Philippine endemic freshwater fish valued as a food fish (2). Strain BCA501 was isolated from the gut of wild-caught juvenile silver therapon obtained from the Bureau of Fisheries and Aquatic Resources Regional Office No. 5 (Fabrica, Bula, Camarines Sur, Philippines) by enrichment in a defined medium containing tannic acid as the sole carbon source, followed by heat treatment at 65°C for 20 min to select for spore-forming bacteria, and repeated streaking on Luria-Bertani agar until a pure culture was obtained, as previously described (3).

Abstract. From its earliest beginnings, life’s expansion into new habitats has been profoundly shaped by its reciprocal interactions with Earth’s changing

Phycology Journal recently sponsored prizes for Best Oral Presentation and Best Poster at the 13th International Phycological Congress. The winner of Best Oral Presentation, Eldrin DLR. Arguelles, wri...

Special Symposia Topics: Algae and their Microbial Symbionts: from Mutualists to Pathogens Chairs/Co-chairs: Suhelen Egan, Simon Dittami Speakers: Suhelen

Abstract. Small subunit (SSU) ribosomal RNA (rRNA) gene amplicon sequencing is a foundational method in microbial ecology. Currently, short-read platforms

Microbial communities in freshwater ecosystems drive critical biogeochemical cycles, nutrient transf

Discoveries and genome-wide understanding of Pseudogracilibacillus and related genera are key to resolving the taxonomic ambiguities of the polyphyletic and highly functional bacterial family Bacillac...

One Million Species on the Brink of Extinction? Why Biodiversity Matters

Eukaryotic Argonaute proteins participate in RNA-guided RNA silencing pathways and are divided into AGO and PIWI clades, with functional and mechanistic differences. Here, the authors show that a deep...

Background. Epigenetic regulation of gene expression and host defense is well established in microbi

The International Phycological Society (IPS), established in 1960, is committed to advancing the field of phycology by fostering the dissemination of

Introduction Short-read amplicon sequencing studies have typically focused on 1-2 variable regions o

This Review summarizes the computational strategies for microbiome analysis using long-read sequencing data.

Diatoms (Bacillariophyta) are a major source of primary production on Earth, generating between 1⁄4 to 1⁄2 of all oxygen. They are found in almost all bodies of water, the ice of mountains, the ar...