Simple 100-l-scale and long-term culture of Desmodesmus communis (Chlorophyceae) in Japan

Abstract

Microalgal biomass is attracting attention as a new biological resource in pharmaceuticals, as a source of vegetable proteins and industrial materials, and from the perspective of carbon cycling. Various specialized mass-culture systems have been developed to produce large-scale biomass. However, reducing the costs of microalgal biomass production is necessary. We conducted a long-term culture experiment using a simple mass-culture system for Desmodesmus, which has been extensively studied as a candidate species for microalgal biomass production in recent years. Compared to those on Chlorella and Haematococcus, only a few mass culture studies have been conducted on Desmodesmus, and no such studies have been conducted in Japan. We cultured the original strain of Desmodesmus communis (dSgDes-eco1), isolated from a lake in Saga City, Japan. A maximum biomass productivity of 0.040 ± 0.0017 g/l/day, which is comparable to that obtained in a previous study, was recorded in a simple 100-l culture system that was small in volume, open-culture, and easy to operate. A significant positive correlation was observed between biomass productivity and water temperature. Protein content remained almost constant throughout the incubation period, averaging 47.9%. A significant positive correlation was also observed between the protein content and daily average of accumulated photon flux density. Our culture system is expected to reduce the costs of microalgal biomass and vegetable protein production.