优化营养方式强化蛋白核小球藻生物量及蛋白质和叶绿素生产

Optimization of Trophic Modes for Enhancing the Production of Biomass, Protein, and Chlorophyll from Chlorella pyrenoidosa

本文通过优化营养方式和培养条件,提高了蛋白核小球藻生物量及细胞内蛋白质和叶绿素含量。结果表明,葡萄糖浓度能显著影响蛋白核小球藻混养和异养生长的生物量浓度(p<0.05),但不同硝酸钠浓度影响不显著。在葡萄糖浓度50 g/L、硝酸钠浓度3.75 g/L条件下,小球藻异养培养4 d,即可达到最高生物量浓度为21.31 g/L,显著高于盐度15‰条件下混养所得最高生物量浓度(14.32 g/L)(p<0.05)。当葡萄糖耗尽,将小球藻细胞经含氮且不含糖的培养基适当稀释后进行光诱导培养,并优化硝酸钠浓度。发现在高异养细胞密度(11.09 g/L)下,采用硝酸钠浓度(3.75 g/L)和低光强(6,411±532 Lux)诱导培养藻细胞48 h,即可获得高蛋白质含量(54.10%)和高叶绿素含量(3.14%)的小球藻,相对于光诱导培养前,分别提高了207.74%和342.25%,蛋白质和叶绿素产率也显著高于单独混养或异养培养的最高值,分别达到1.32 g/(L·d)和0.09 g/(L·d)。

The biomass of Chlorella pyrenoidosa and its cellular protein and chlorophyll contents were enhanced by optimizing trophic modes and culture conditions. The results showed that glucose concentration could significantly influence the biomass concentration of C. pyrenoidosa under mixotrophic and heterotrophic conditions（p〈0.05）, but no significant effect was found with different nitrate concentrations. The highest biomass concentration（21.31 g/L） was obtained when C. pyrenoidosa was cultivated in heterotrophic culture for four days with medium containing 50 g/L glucose and 3.75 g/L nitrate, and was significantly higher than the highest biomass concentration obtained in mixotrophic culture（14.32 g/L） with a salinity of 15‰（p〈0.05）. After glucose depletion, the heterotrophic C. pyrenoidosa strain was diluted with a nitrate-containing medium without glucose for photon-induced cultivation, and the concentration of nitrate was optimized. The results showed that 48-hour photon-induced cultivation under a low light intensity（6,411±532 Lux） in a medium containing 3.75 g/L nitrate produced high contents of protein（54.1%） and chlorophyll（3.14%） in C. pyrenoidosa; these values were increased by 207.74% and 342.25%, respectively, compared with those obtained before photon-induced cultivation. Additionally, the yields of protein and chlorophyll reached 1.32 g/（L·d） and 0.09 g/（L·d）, respectively, significantly higher than the peak values from mixotrophic or heterotrophic culture（p〈0.05）.