Identification and toxigenic potential of a Nostoc sp.

doi:2012.27.4.303

Algae > Volume 27(4); 2012 > Article

Algae 2012;27(4): 303-313. doi: https://doi.org/10.4490/algae.2012.27.4.303

Bahareh Nowruzi, Ramezan-Ali Khavari-Nejad, Karina Sivonen, Bahram Kazemi, Farzaneh Najafi, Taher Nejadsattari

¹Faculty of Biological Sciences, Kharazmi University, Tehran 15614, Iran
²Department of Biology, Science and Research Branch, Islamic Azad University, Tehran 14778, Iran
³Department of Applied Chemistry and Microbiology, University of Helsinki, Helsinki 248, Finland
⁴Department of Biotechnology, Shahid Beheshti University of Medical Sciences, Tehran 1983963113, Iran
⁵Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran 1983963113, Iran

*Corresponding Author

Email: bahare77biol@yahoo.com

ABSTRACT

Cyanobacteria are well known for their production of a multitude of highly toxic and / or allelopathic compounds. Among the photosynthetic microorganisms, cyanobacteria, belonging to the genus Nostoc are regarded as good candidate for producing biologically active secondary metabolites which are highly toxic to humans and other animals. Since so many reports have been published on the poisoning of different animals from drinking water contaminated with cyanobacteria toxins, it might be assumed that bioactive compounds are found only in aquatic species causes toxicity. However, the discovery of several dead dogs, mice, ducks, and fish around paddy fields, prompted us to study the toxic compounds in a strain of Nostoc which is most abundant in the paddy fields of Iran, using polymerase chain reaction and liquid chromatography coupled with a diode array detector and mass spectrophotometer. Results of molecular analysis demonstrated that the ASN_M strain contains the nosF gene. Also, the result of ion chromatograms and MS2 fragmentation patterns showed that while there were three different peptidic compound classes (anabaenopeptin, cryptophycin, and nostocyclopeptides), there were no signs of the presence of anatoxin-a, homoanatoxin-a, hassallidin or microcystins. Moreover, a remarkable antifungal activity was identified in the methanolic extracts. Based on the results, this study suggests that three diverse groups of potentially bioactive compounds might account for the death of these animals. This case is the first documented incident of toxicity from aquatic cyanobacteria related intoxication in dogs, mice, and aquatic organisms in Iran.

Key words: cyanobacteria; natural bioactive compound; Nostoc; toxicity