Influence of Cd, Co, and Zn on inorganic carbon acquisition and carbon metabolism in Emiliania huxleyi.

Abstract:

Trace elements are essential micronutrients for primary producers; hence they influence the global carbon cycle and contribute to the regulation of Earth’s climate. Over the past 25 years, the influence of Fe concentration on phytoplankton production has been well studied and this research has been instrumental in our understanding of the influence that biology has on the sequestration of atmospheric CO₂. However, other trace elements that are directly involved in carbon metabolism by primary producers, such as Zn, Cd, and Co, have received less attention. We examined the physiological response of two strains of Emiliania huxleyi to a range of realistic trace element concentrations (Zn, Cd, Co) in the marine environment under batch, semi-continuous, and continuous culture conditions. In addition, the continuous culture system was maintained at a pH of 8.15 ±0.02 by a sensor and regulator-controlled CO₂­ injection system. The results from this study will highlight the influence that trace element composition of seawater has on the growth rate, elemental quota, inorganic carbon uptake, and carbon metabolism of Emiliania huxleyi. Potential limitations for the interpretation of paleo-productivity records will be discussed.