Nutrients Recovery on the Growth of Nitrogen and Phosphorus Starved Microcystis aeruginosa

Abstract

Microcystis in natural water bodies may frequently go through periods of nutrient limitation and then may recover when the limited nutrient becomes available. We investigated changes in cell physiology and expression of photosynthesis-related genes during the recovery of Microcystis aeruginosa from nitrogen starvation and phosphorus starvation with the method of 14C isotope and fluorescent quantitative PCR. Our results suggested that Microcystis cells relieved from N starvation and P starvation resumed growth within 24 h and displayed significantly higher growth rates than not-starved-cells in the first 48 h. Carbon production rates and the expression levels of photosynthesis-related genes all increased rapidly after relieving from N starvation and P starvation in different degrees, enabling the rapid recovery from nutrient starvation. However, N-starved cells can not resume their cellular activity to full capacity when N became available and the damage of N deficiency to M. aeruginosa was unrecoverable, whereas cellular activity of P-starved cells could recover to normal properties.