Aida, Taku Michael; Maruta, Ryouma; Tanabe, Yuuhiko; Oshima, Minori; Nonaka, Toshiyuki; Kujiraoka, Hiroki; Kumagai, Yasuaki; Ota, Masaki; Suzuki, Iwane; Watanabe, Makoto M.; Inomata, Hiroshi; Smith Jr, Richard L.
초록
<P><B>Abstract</B></P> <P>Defatted heterotrophic microalgae (<I>Aurantiochytrium limacinum</I> SR21) was treated with high temperature water (175–350°C, 10–90min) to obtain nitrogen and phosphorous nutrients as a water soluble fraction (WS). Yields of nitrogen and phosphorous recovered in WS varied from 38 to 100% and from 57 to 99%, respectively. Maximum yields of nitrogen containing compounds in WS were proteins (43%), amino acids (12%) and ammonia (60%) at treatment temperatures of 175, 250 and 350°C, respectively. Maximum yield of phosphorous in WS was 99% at a treatment temperature of 250°C. Cultivation experiments of microalgae (<I>A. limacinum</I> SR21) using WS obtained at 200 and 250°C showed positive growth. Water soluble fractions from hydrothermal treatment of defatted microalgae are effective nitrogen and phosphorous nutrient sources for microalgae cultivation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nutrient recycle from defatted microalgae for microalgae cultivation is evaluated. </LI> <LI> N and P can be recovered from defatted microalgae by hydrothermal treatment. </LI> <LI> Nutrient efficiency depends on reaction conditions of the hydrothermal treatment. </LI> <LI> Hydrothermal treatment at high temperature conditions produce anti-growth agents. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>