Microcystis Chemotype Diversity in the Alimentary Tract of Bigheaded Carp

• Main Authors: Milán Riba, Attila Kiss-Szikszai, Sándor Gonda, Gergely Boros, Zoltán Vitál, Andrea Kériné Borsodi, Gergely Krett, Gábor Borics, Andrea Zsuzsanna Ujvárosi, Gábor Vasas
• Format: Article
• Language: English
• Published: MDPI AG 2019-05-01
• Series: Toxins
• Subjects: <i>Microcystis</i>; chemotype; bigheaded carp; anabaenopeptin; microginin; microcystin
• Online Access: https://www.mdpi.com/2072-6651/11/5/288

Most cyanobacterial organisms included in the genus <i>Microcystis</i> can produce a wide repertoire of secondary metabolites. In the mid-2010s, summer cyanobacterial blooms of <i>Microcystis</i> sp. occurred regularly in Lake Balaton. During this period, we investigated how the alimentary tract of filter-feeding bigheaded carps could deliver different chemotypes of viable cyanobacteria with specific peptide patterns. Twenty-five <i>Microcystis</i> strains were isolated from pelagic plankton samples (14 samples) and the hindguts of bigheaded carp (11 samples), and three bloom samples were collected from the scums of cyanobacterial blooms. An LC-MS/MS-based untargeted approach was used to analyze peptide patterns, which identified 36 anabaenopeptin, 17 microginin, and 13 microcystin variants. Heat map clustering visualization was used to compare the identified chemotypes. A lack of separation was observed in peptide patterns of <i>Microcystis</i> that originated from hindguts, water samples, and bloom-samples. Except for 13 peptides, all other congeners were detected from the viable and cultivated chemotypes of bigheaded carp. This finding suggests that the alimentary tract of bigheaded carps is not simply an extreme habitat, but may also supply the cyanobacterial strains that represent the pelagic chemotypes.