| 研究実績の概要 |
In this study we focused on use of excess sludge discharged from a sewage treatment plant as a substrate for thraustochytrids such as Aurantiochytrium sp. producing valuable fatty acids. Here we investigated consumption of an activated sludge sample as a model excess sludge by Aurantiochytrium sp. strain L3W producing polyunsaturated fatty acids such as docosahexaenoic acid (DHA). The strain L3W could grow in the medium prepared by adding the sludge sample seawater as sole carbon and nitrogen sources, while hydrolysis was necessary as pretreatment for utilization as its substrates. Consumption of the carbon and nitrogen contents in the media to which the hydrolyzed sludge sample (HSS) was added showed that the availability of carbon contents in the HSS was lower than that of glucose for the strain L3W; however the addition of glucose to the HSS medium accelerated the growth of the strain L3W, thereby confirming that the HSS may be better as a nitrogen source rather than a carbon source to cultivate the strain L3W. As the additional carbon source to the HSS, the jam liquid waste generated from a jam factory demonstrated good acceleration of the growth of the strain L3W as glucose. Finally, production of the fatty acids including DHA by the strain L3W was confirmed in the HSS medium, while the carbon source addition such as the jam liquid waste greatly enhanced its fatty acids production.
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