Isolation and verification of anatoxin-a producing clones of Anabaena flos-aquae (Lyngb.) de Breb. from a eutrophic lake

Abstract

We present a technique to isolate and confirm anatoxin‐a producing clones (single trichome‐isolates) of Anabaena flos‐aquae (Lyngb.) de Breb. from blooms of this cyanobacterium. A single trichome is isolated from a field sample and grown in ASM medium. Single trichomes are then isolated from this culture and grown in ASM medium to produce single clone cultures. Mouse bioassay, and thin‐layer chromatography (TLC) using purified anatoxin‐a as reference is then used to confirm the anatoxin‐a producing clones. Using this methodology, Anabaena flos‐aquae samples collected during July 1991 from Hebgen Lake, Montana, were found to contain only 8.7% anatoxin‐a producing clones. This minor proportion of anatoxin‐a producing clones apparently accounts for the anatoxin‐a produced by the entire population of A. flos‐aquae. Our technique is simple and reproducible. A selected clone of A. flos‐aquae that produces anatoxin‐a and one that does not produce anatoxin‐a were deposited in the UTEX culture collection, University of Texas at Austin.

Anatoxin‐a occurrence and potential cyanobacterial anatoxin‐a producers in Spanish reservoirs1

“…When we compared the number of the samples in which Ana. flos‐aquae occurred and the percentage of such samples in which ANA was detected (4.3%), we found that this value was similar to that obtained by Kangatharalingam and Priscu (1993) (8.7%). This point reinforces the concept that this species is the most probable producer of ANA in the Spanish freshwaters.…”

Seasonal variations in microcystin contents of danish cyanobacteria

“…In Hastings Lake, different toxicities were often associated with species composition differences between sampling sites, demonstrating the heterogeneity of the cyanobacterial community. Genetic heterogeneity may, however, also be expected in cases of monospecific blooms because several studies have described toxic and nontoxic laboratory cultures of the same species, even when isolated from the same natural population [Carmichael and Gorham, 1977;Kangatharalingam and Priscu, 1993;Henriksen et al, 1997]. Temporal and spatial dynamics of such infraspecific differences and their effect on the overall toxicity of the population should be considered as a possible explanation for observed differences in toxicity.…”

GENETIC DIVERSITY WITHIN BALTIC SEA POPULATIONS OF NODULARIA (CYANOBACTERIA)1

“…1995 and in the diameter of their gas vesicles (Smarda et al 1988 Independent clonal isolates of single species from the Baltic Sea, or other cyanobacterial populations, differ in their physiologic characteristics (e.g. Kan-gatharlingham 8c Priscu 1993, Rouhiainen et al 1995, Walsby et al 1995. This indicates that populations may not be clonal, but there have been no descriptions of their genetic structure.…”