TITLE:
Isolation of Picocyanobacteria (Order Synechococcales) and Occurrence of the Cyanotoxin Anatoxin-A in a Shallow Mesotrophic Pond
AUTHORS:
Nancy J. Leland, Kimberley Crocker Pearson, Marty K. Burke, Jeffrey T. Miller, Alison Watts, James F. Haney
KEYWORDS:
Picocyanobacteria, Anatoxin-a, eDNA, Phycocyanin, Phycoerythrin
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.15 No.6,
June
28,
2023
ABSTRACT: We have verified the use of a serial filtration method to isolate picocyanobacteria for analysis. We used eDNA metabarcoding to confirm the picocyanobacteria as members of the Order Synechococcales, Genus Cyanobium, specifically Cyanobium 6307. Fluorometric analysis using accessory pigments phycocyanin and phycoerythrin described periods of excess biomass, where the net growth rate model confirmed these conditions. The total anatoxin-a concentrations in the picocyanobacterial sample ranged from 0.0074 - 6.41 μg·L-1 representing a 40-fold difference over the entire sampling season. Sampling frequency of every three days appeared to be an important factor in capturing these changes in anatoxin-a concentration. During a period of excess biomass, we were able to establish a linear correlation between cyanobacterial biomass and Anatoxin-a concentrations.