Abstract
Fistulifera sp. JPCC DA0580 is an oleaginous marine diatom and hence promising strain for application to biodiesel production. In this study we investigated growth characteristics of this alga in ca. 1-liter culture scale. Culture medium was first modified and algal biomass productivity increased more than 10-fold in comparison with previous result. This alga showed optimum growth temperature between 25-30οC and tolerance against higher temperature up to 35οC. The algal growth was hardly affected by pH of culture medium between 7 to 9. The cells could grow in 2 to 8-fold diluted seawater. Optimum CO2 concentration for growth was 0.5 % (v/v). Under optimized culture conditions, 6.6 g dry weight/liter/week was finally obtained and thus project's target productivity (4.0 g dry weight/liter) was achieved at laboratory culture scale. This alga seems to be applicable for cultivation with using alkaline wastewater-seawater mixture. High-temperature tolerance of this strain is advantageous in outdoor cultivation. Requirement of relatively low CO2 concentration for growth can bring about reduction of CO2 cost. [This study is supported by JST/CREST]
