混养模式和营养条件优化对斜生四链藻生物量积累和脂质含量的影响

Effects of mixed cultivation mode and nutrient condition optimization on biomass accumulation and lipid content of Tetradesmus obliquus

微藻被认为是具有发展潜力的生物柴油原料,在光合效率、生长速率和脂质积累速率等方面具有优势,能够减轻化石能源带来的环境污染问题。为了提高微藻的生物量、脂质含量和高价值产物含量,需要优化其培养模式和营养条件。探究了在自养、混养和异养条件下培育斜生四链藻的最佳培养模式,并使用响应面法优化培育时的营养条件,以提高微藻的生物量和脂质含量。研究结果表明,混合营养培育是最适合斜生四链藻生长发育的培育模式。进入稳定期后,在混养24 h的培养条件下,微藻的生物量和脂质含量分别是自养培养条件的3.82倍和2.49倍,而在混养8 h∶16 h组合中,对数生长期产生的蛋白质含量最高,达到了554.87 mg·L^(−1)。通过响应面法优化营养物质,在混养条件下,最佳参数设置:碳氮比为10,微量元素投加量为0.1 mL,维生素投加量为1.0 mL。实际测量的生物量和预测值分别为2.45 g·L^(−1)和2.43 g·L^(−1)。优化混养模式和营养条件可以提高微藻的生物量和利用效率。

Microalgae are considered to be the most promising feedstock for biodiesel production due to their advantages in high photosynthetic efficiency,growth rate,and lipid accumulation rate,which can alleviate the environmental pollution caused by fossil fuels.To increase the biomass,lipid content,and high-value product yield of microalgae,it is necessary to optimize their cultivation modes and nutritional conditions.This study investigated the optimal cultivation mode for the growth of Tetradesmus obliquus under three conditions:autotrophic,mixotrophic,and heterotrophic.Additionally,response surface methodology was employed to optimize the nutrient conditions for cultivation,with the goal of improving the biomass and lipid content of microalgae.The results showed that mixotrophic cultivation was the most suitable mode for the growth and development of Tetradesmus obliquus.Under mixotrophic cultivation conditions for 24 hours,the biomass and lipid content of microalgae were 3.82 times and 2.49 times higher,respectively,compared to autotrophic cultivation conditions.Moreover,the highest protein production during the logarithmic growth phase was the highest in the 8-hour mixotrophic and 16-hour autotrophic combination,reaching 554.87 mg·L^(−1).By optimizing the nutritional substances using response surface methodology,the optimal parameters under mixotrophic conditions were as follows:Carbon-to-nitrogen ratio of 10,trace element addition of 0.1 mL,and vitamin addition of 1.0 mL.The measured biomass and predicted values were 2.45 g·L^(−1) and 2.43 g·L^(−1),respectively.The optimization of mixotrophic cultivation mode and nutritional conditions could enhance microalgae biomass and utilization efficiency.