Comparison of growth and toxicity responses between non-toxic and toxic strains of Prorocentrum hoffmannianum

Tch Lee,Sjl Xu,Fwf Lee,Pl Chan

doi:10.3354/ab00725

Abstract

We aimed to study the growth and toxicity responses of non-toxic (CCMP683) and toxic (CCMP2804) strains of Prorocentrum hoffmannianum under various nitrate and phosphate concentrations. The 2 strains were cultured in L1-Si medium with standard, depleted or 10-fold repleted nitrate or phosphate. CCMP683 cultured in standard L1-Si medium exhibited delayed growth. Nitrate or phosphate depletion decreased the cell density of both strains. Repletion of nitrate slightly increased the cell density of both strains. Repletion of phosphate also slightly increased the cell density of CCMP2804 but surprisingly decreased the cell density of CCMP683. Okadaic acid (OA) and its derivatives were not detected in CCMP683. OA was detected only in CCMP2804. Depletion of nitrate or phosphate increased the cellular concentration of OA, and repletion of nitrate or phosphate had no effect on the cellular concentration of OA. Correlation analysis indicated that the cellular concentration of OA was negatively correlated with cell density. Differences in the growth response to phosphate repletion and in the ability to produce OA suggest that the 2 strains may be good candidates for comparative studies related to phosphate metabolism and OA toxicity.

Highlights

Harmful algal blooms (HABs) have recently become a major global concern, as their incidence has increased dramatically over the last few decades (Van Dolah 2000)
Recent findings indicated that diarrhetic shellfish poisoning (DSP) toxins are implicated in carcinogenesis (Valdiglesias et al 2013), and it was shown in a number of studies that long-term, low-dose exposure of okadaic acid (OA) resulted in increased DNA damage in several human and marine cell types (Traoré et al 2001, Valdiglesias et al 2011, McCarthy et al 2014)
These findings highlight the importance of investigating DSP toxins and the related harmful algae species to control HABs and the associated adverse health effects due to DSP toxins (Valdiglesias et al 2013)

Summary

Introduction

Harmful algal blooms (HABs) have recently become a major global concern, as their incidence has increased dramatically over the last few decades (Van Dolah 2000). Recent findings indicated that DSP toxins are implicated in carcinogenesis (Valdiglesias et al 2013), and it was shown in a number of studies that long-term, low-dose exposure of OA resulted in increased DNA damage in several human and marine cell types (Traoré et al 2001, Valdiglesias et al 2011, McCarthy et al 2014) These findings highlight the importance of investigating DSP toxins and the related harmful algae species to control HABs and the associated adverse health effects due to DSP toxins (Valdiglesias et al 2013)

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