초록
<P><B>Highlights</B></P><P>► A novel strategy was developed for efficient algal biomass and lipid production. ► High biomass productivity and high biomass quality could be achieved. ► Cellular lipid content could be accumulated to high levels within several hours. ► Indoor and outdoor results showed consistent patterns by three chlorella species. ► It’s scale-up feasible for microalgal mass culture process.</P> <P><B>Abstract</B></P><P>A novel cultivation strategy called “sequential heterotrophy–dilution–photoinduction” was developed for efficient algal biomass and lipid production. Three <I>Chlorella</I> species were first cultivated heterotrophically to achieve high cell density, then the broth was diluted to suitable concentration (2–5g/L) and transferred to light environment for photoinduction. With this strategy, the <I>Chlorella</I> intracellular protein and chlorophyll increased rapidly to 50.87% and 32.97mg/g by a 12-h illumination, which were close to the level of cells cultivated photoautotrophically. Moreover, the lipid contents were increased by 84.57%, 70.65% and 121.59% within 24-h photoinduction for <I>C. vulgaris</I>, <I>C. pyrenoidosa</I> and <I>C. ellipsoidea</I>, respectively. Maximum lipid content as 26.11% of biomass and maximum lipid productivity of 89.89mg/L/d was both accomplished by <I>C. pyrenoidosa</I>. Further outdoor experiments showed consistent patterns. Therefore, the proposed strategy provided an effective approach for microalgal biomass production to meet the urgent need for both health food and biodiesel.</P>