优化发酵条件促海鞘桔青霉Asc2-4生长与产油

Optimization of fermentation conditions to promote the growth and oilproduction of Penicillium citrinum Asc2-4 from Pyrosomella verticilliata

桔青霉(Penicillium citrinum)Asc2-4是一株分离自雷州海鞘(Pyrosomella verticilliata)的产油真菌,研究温度、pH值、接种量、转速、装液量等单因素对其生长和产油的影响,响应面优化高产油的显著因子,再通过气相色谱分析菌油组成。结果表明:单因素优化初步确定适宜生长的发酵条件并得到提高产油的显著因子(接种量、装液量和转速);响应面优化得出最优发酵条件为温度29℃、pH值5.5、接种量3.3%、装液量120 mL/250 mL和转速220 r/min;验证结果与模型预测值符合,生物量和油脂质量浓度高达19.19 g/L和8.80 g/L,比优化前提高了65.57%和224.72%;菌油的C16和C18系脂肪酸占总脂肪酸96.26%,其主要组分及含量为41.52%油酸(C18:1)、21.74%亚油酸(C18:2)、16.77%棕榈酸(C16:0)和15.61%硬脂酸(C18:0)。研究结果为开发利用桔青霉Asc2-4提供理论基础。

Penicillium citrinum Asc2-4 is the oleaginous fungus isolated from Pyrosomella verticilliata.In this study,the effects of single factors such as temperature,pH,inoculation amount,rotational speed and liquid volume on the growth and oil production of the fungus were investigated.The significant factors of high-yield oil were then optimized by response surface method,and lastly the composition of oil was analyzed by gas chromatography.The result showed that single factor optimization preliminarily determined the suitable fermentation conditions for fungal growth.The significant factors for the improvement of oil production included inoculation amount,liquid loading amount and rotational speed.The optimal fermentation conditions obtained by response surface method showed the temperature 29℃,pH 5.5,inoculation amount 3.3%,liquid volume 120 mL/250 mL,and rotational speed 220 r/min.The verification results were consistent with the predicted values of the model.Biomass and lipid mass concentration reached 19.19 g/L and 8.80 g/L,which were 65.57%and 224.72%higher than those before optimization,respectively.The C16 and C18 fatty acids in fungus oil accounted for 96.26%of the total fatty acids,and the components thereof,encompassing 41.52%oleic acid(C18:1),21.74%linoleic acid(C18:2),16.77%palmitic acid(C16:0)and 15.61%stearic acid(C18:0).This study provided theoretical basis for the development and utilization of Penicillium citrinum Asc2-4.