Insights into toxic Prymnesium parvum blooms: the role of sugars and algal viruses

Abstract

Prymnesium parvum is a toxin-producing microalga that causes harmful algal blooms globally, which often result in large-scale fish kills that have severe ecological and economic implications. Although many toxins have previously been isolated from P. parvum, ambiguity still surrounds the responsible ichthyotoxins in P. parvum blooms and the biotic and abiotic factors that promote bloom toxicity. A major fish kill attributed to P. parvum occurred in Spring 2015 on the Norfolk Broads, a low-lying set of channels and lakes (Broads) found on the East of England. Here, we discuss how water samples taken during this bloom have led to diverse scientific advances ranging from toxin analysis to discovery of a new lytic virus of P. parvum, P. parvum DNA virus (PpDNAV-BW1). Taking recent literature into account, we propose key roles for sialic acids in this type of viral infection. Finally, we discuss recent practical detection and management strategies for controlling these devastating blooms.

CuAAC click chemistry for the enhanced detection of novel alkyne-based natural product toxins

“… 1 We recently reported upon our efforts to tackle blooms of this microalga on the Norfolk Broads in the East of England. 2 – 4 Although several toxic compounds have been reported from P. parvum , 5 – 7 the toxins responsible for fish kills are believed to be the ichthyotoxic prymnesins-potent ladder-frame polyethers decorated with uncommon structural features, such as chlorine and alkynes ( Fig. 1 ).…”

Identification of a Kdn biosynthesis pathway in the haptophyte Prymnesium parvum suggests widespread sialic acid biosynthesis among microalgae

“…In connection with our work on the devastating impact of harmful algal blooms in the waterways of the East of England ( e.g. the Norfolk Broads) ( 24 – 26 ), we have cause to investigate sialic acids in the toxin-producing haptophyte Prymnesium parvum . The haptophytes are a widespread division of microalgae that play crucial roles in the oceanic carbon and sulfur cycles ( 27 , 28 ); they also form blooms that are toxic to fish ( 29 , 30 ).…”

“…The haptophytes are a widespread division of microalgae that play crucial roles in the oceanic carbon and sulfur cycles ( 27 , 28 ); they also form blooms that are toxic to fish ( 29 , 30 ). The toxin-producing species in this family mainly belong to the Prymnesium and Chrysochromulina genera, of which the most studied species is P. parvum , which is known to cause harmful blooms that result in mass fish mortalities because of the release of natural product toxins ( 23 – 34 ). P. parvum is cosmopolitan, with blooms causing economic disaster on all continents except Antarctica ( 35 ).…”

Synthesis of glyceryl glycosides related to A-type prymnesin toxins

“…One of the problems associated with detection of the prymnesin toxins is that current methods rely on detection of the parent organism [ 12 , 13 ]. None of these methods can provide quantification of toxin levels in water samples.…”