Elevated production of carotenoids by a new isolate of Scenedesmus sp.

Abstract

A newly isolated strain of Scenedesmus sp. was tested for carotenoid production. In the laboratory, the strain accumulated total carotenoids to a relative cellular content of more than 2% DW. Very high carotenoid productivity (max. up to 20mgL−1d−1) of Scenedesmus sp. was achieved due to its high specific growth rate (μmax 2.7d−1) and biomass productivity (max. up to 2gL−1d−1). Moreover the strain showed a high tolerance to elevated temperatures with only a moderate decrease in the final biomass at 38°C and 40°C compared to 30°C; there were no statistical differences in maximal specific growth rates between temperatures. Scenedesmus sp. was successfully grown in an outdoor 150L thin-layer photobioreactor, achieving a maximal specific growth rate of 1.44d−1 and a maximal biomass productivity of 1.3gL−1d−1. After 16d it accumulated 1.86% DW of total carotenoids with an overall carotenoid productivity of 9mgL−1d−1. Excellent growth, high carotenoid production and thermotolerance make this strain a prospective candidate for biotechnological production of carotenoid-rich biomass. The possibility of using the genus Scenedesmus as an alternative to well-established carotenoid producing microalgae is discussed.