FIRST REPORT OF THE CYANOTOXINS CYLINDROSPERMOPSIN AND DEOXYCYLINDROSPERMOPSIN FROM RAPHIDIOPSIS CURVATA (CYANOBACTERIA)

Abstract

A strain of Raphidiopsis (Cyanobacteria) isolated from a fish pond in Wuhan, P. R. China was examined for its taxonomy and production of the alkaloidal hepatotoxins cylindrospermopsin (CYN) and deoxy‐cylindrospermopsin (deoxy‐CYN). Strain HB1 was identified as R. curvata Fritsch et Rich based on morphological examination of the laboratory culture. HB1 produced mainly deoxy‐CYN at a concentration of 1.3 mg·g−1 (dry wt cells) by HPLC and HPLC‐MS/MS. CYN was also detected in trace amounts (0.56 μg·g−1). A mouse bioassay did not show lethal toxicity when tested at doses up to 1500 mg dry weight cells·kg−1 body weight within 96 h, demonstrating that production of primarily deoxy‐CYN does not lead to significant mouse toxicity by strain HB1. The presence of deoxy‐CYN and CYN in R. curvata suggests that Raphidiopsis belongs to the Nostocaceae, but this requires confirmation by molecular systematic studies. Production of these cyanotoxins by Raphidiopsis adds another genus, in addition to Cylindrospermopsis, Aphanizomenon, and Umezakia, now known to produce this group of hepatotoxic cyanotoxins. This is also the first report from China of a CYN and deoxy‐CYN producing cyanobacterium.

Bismuth oxybromide promoted detoxification of cylindrospermopsin under UV and visible light illumination

“…Cylindrospermopsin (CYN) is one of the common members of cyanotoxins which always cause human injury. CYN originates from several cyanobacteria, such as Cylindrospermopsis raciborskii [3], Umezakia natans [4], Aphanizomenon ovalisporum [5], Anabaena bergii [6], Raphidiopsis curvata [7], Aphanizomenon flos-aquae [8], Anabaena lapponica [9], Lyngbya wollei [10] and Aphanizomenon gracile [11]. CYN has neurotoxic effects (inhibition of protein synthesis by binding to liver DNA and forms single DNA adducts which results in liver damage), hepatotoxic effects (inhibition of glutathione synthesis in hepatocytes), and cytotoxic effects (inhibitor of cytochrome P450) [12].…”

Molecular separation of two long taxonomically debated cyanobacterial genera Cylindrospermopsis and Raphidiopsis (Nostocales) based on the ITS-L phylogeny

“…They mainly differ in terms of heterocytes, which are absent in Raphidiopsis strains. However, distinction between these two genera is difficult when heterocytes are not shown in Cylindrospermopsis strains (Li et al, 2001;Moustaka-Gouni et al, 2009;Alster et al, 2010). The coexistance of Cylindrospermopsis and Raphidiopsis in the same waters has been widely reported (McGregor and Fabbro, 2000;Moustaka-Gouni et al, 2009;Wu et al, 2011).…”

“…This genus morphologically resembles another cyanobacterial bloom-forming genus, Raphidiopsis Fritsch et Rich (Li et al, 2001;Moustaka-Gouni et al, 2009;Alster et al, 2010;Wu et al, 2011;Komá rek, 2013). These two genera mainly differ in terms of heterocytes, which are absent in Raphidiopsis.…”

“…These two heterocytous cyanobacterial genera Raphidiopsis and Cylindrospermopsis, are difficult to distinguish, especially in cases where heterocytes are not present in Cylindrospermopsis strains (Li et al, 2001;Moustaka-Gouni et al, 2009;Alster et al, 2010). They share similar ecological niches, in which Raphidiopsis species have been found to co-occur with Cylindrospermopsis raciborskii (Woloszyń ska) Seenayya et Subba Raju in a range of waters (Moustaka-Gouni et al, 2009;Wu et al, 2011;Hill, 1970).…”

Advances in solid phase extraction of the cyanobacterial toxin cylindrospermopsin

“…Among these species, the most widely distributed is Cylindrospermopsis raciborskii, which is now found in many countries (Briand et al 2004). Other species producing this cyanotoxin are Umezakia natans (Harada et al 1994), Anabaena bergii (Schembri et al 2001), Raphidiopsis curvata (Li et al 2001), Aphanizomenon ovalisporum (Banker et al 1997), Aphanizomenon flos-aquae (Preussel et al 2006), Anabaena lapponica (Spoof et al 2006), or Lyngbya wollei (Seifert et al 2007).…”