Effects of butanol on high value product production in Schizochytrium limacinum B4D1

•Butanol treatment altered the lipid content.•Cells accumulated more C16:0 and less DHA in the presence of butanol.•Butanol treatment triggered squalene and sterol accumulation.•The carotenoid content was increased upon butanol treatment.•The antagonism between the formation of DHA and terpenoids was observed. Schizochytrium is a microalgae-like fungus and is widely used for producing docosahexaenoic acid (DHA). It is also a promising source of squalene and carotenoids. However, few fermentation strategies are available in enhancing squalene and carotenoid content in Schizochytrium. This study showed that butanol addition had multiple effects on Schizochytrium limacinum B4D1. First, butanol addition altered the lipid content of cells. Second, 6g/L of butanol decreased the proportion of DHA by nearly 40%. Third, the squalene content increased 31-fold in the presence of 6g/L butanol. Finally, cells accumulated more carotenoids upon butanol addition. Specifically, when cells were treated with 8g/L butanol, the astaxanthin content increased to 245 times than that of the untreated control. These results are helpful for the commercial exploitation of Schizochytrium in producing squalene and carotenoids.