【摘要】 试验旨在探讨耐热单星藻（Coelastrella thermophila sp.nov. STS1,CTNS）新种的培养条件和梯度水杨酸胁迫条件下CTNS新种对虾青素积累的影响。将维生素B₆（VB₆）设置为6个浓度梯度，即0、60、120、180、360、720μg/L，每组添加10.0 mmol/L柠檬酸钠于中草药营养液BG11培养基中进行CTNS新种培养，通过测定细胞密度、生物量、细胞干重、虾青素含量等指标确定最优培养条件；设置4个水杨酸浓度，即0（对照组）、64、128、256 g/L，组合不同光照强度，观察CTNS新种细胞形态及虾青素含量变化。结果表明：与对照组相比，随着VB₆浓度从0增加到180μg/L，藻细胞密度、生物量和细胞干重均逐渐增加，促进CTNS新种生长的最佳VB₆浓度是720μg/L。此浓度下，细胞浓度、生物量、细胞干重达到最大（P>0.05），实现0.368 g/L的藻体生物量；经256 g/L超高浓度水杨酸和光线20 000 Lux组合诱导，藻细胞由椭圆形变为圆形，胞质由青绿色变为淡红色，促进了虾青素的积累，虾青素含量由0.29 mg/L提高到1.32 mg/L（P>0.05）；实时荧光定量PCR结果表明，20 000 Lux光照强度和256 g/L水杨酸浓度的组合胁迫诱导中，藻体的八氢番茄红素脱氢酶（pds）和番茄红素-β-环化酶（lyc）显著表达（P<0.05），虾青素含量提高不显著（P>0.05）。更多还原

【Abstract】 This study aimed to optimize the culture conditions and investigate the combined induction of astaxanthin in a new Coelastrella thermophila sp. nov. STS1（CTNS）. Vitamin B₆（VB₆） concentrations were divided into six groups（ 0, 60, 120, 180, 360 μg/L and 720 μg/L）, each group was added with 10.0 mmol/L sodium citrate in the Chinese herbal medicine nutrient solution BG11 medium for the cultivation of the new CTNS species. The optimal culture conditions were determined by measuring indicators such as cell density, biomass, cell dry weight, and astaxanthin content. Four salicylic acid concentrations were set, namely 0（control group）, 64, 128 g/L and 256 g/L, combined with different light intensities to observe the changes in cell morphology and astaxanthin content of the new CTNS species. The results showed that the addition of VB₆ concentrations which increased from 0 to 180 μg/L led to increase in cell density, cell dry weight and biomass gradually. The growth of CTNS was optimal at 720 μg/L VB₆. At this concentration, the cell density, biomass, and cell dry weight reached the maximum（P>0.05）, 0.368 g/L algae biomass was obtained.The combined stress induction using 256 g/L salicylic acid and 20 000 Lux light intensity, the algal cells changed from elliptical to round, and the cytoplasm turned from turquoise to light red, enhanced the accumulation of astaxanthin. The astaxanthin content was elevated from 0.29 mg/L cells to 1.32 mg/L cells（P>0.05）. The morphology of algal cells underwent significant changes during astaxanthin accumulation. qRT-PCR results demonstrated that after the combined induction of 20 000 Lux light intensity and 256 g/L salicylic acid, the expression levels of certain enzyme genes, such as the pds and the lyc genes, were significantly increased（P<0.05）. But the increase in astaxanthin content was not significant（P>0.05）.更多还原