一般注記Chromochloris zofingiensis is an emerging alternative for the commercial production of astaxanthin, to Haematococcus pluvialis, due to its high productivity and ability to grow in multiple nutritional modes namely, autotrophic, mixotrophic and heterotrophic. The cultivation of microalgae in multiple culture steps (stock, preculture, and biomass production phase) in different nutritional modes can contribute to the enhancement of cell biomass and has hardly been performed. Moreover, it’s effect on cell growth and biomass productivity is still unknown. Therefore, in this study, we firstly observed the cell growth in different nutritional modes in preculture phase (Chapter II, Study 1). Later, the effect of preculture on the biomass production via combination of nutritional modes for determining the optimum conditions (stock, preculture and biomass production phase) was evaluated (Chapter III, Study 2). As a result, heterotrophically precultured cells showed higher biomass productivities than with auto- and mixotrophically precultured cells in autotrophic and mixotrophic in biomass production phase. The increase in productivity was due to the stored cellular materials such as lipids, starch and nuclei in heterotrophically precultured cells (Study 2). In the three-phase culture, a highest biomass productivity was obtained in mixotrophic condition (Chapter IV). This study suggested that the optimum combinations of nutritional modes for higher biomass and astaxanthin productivity are autotrophic for stock (to maintain the following heterotrophic growth), heterotrophic for preculture (to store growth-promoting factors), mixotrophic for biomass production phase (to achieve high productivity), and autotrophic (for astaxanthin induction), respectively.
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受理日（W3CDTF）2023-10-11T15:41:07+09:00
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