Zarandi-Miandoab Leila, Hejazi Mohammad-Amin, Bagherieh-Najjar Mohammad-Bagher, Chaparzadeh Nader
Department of Biology, Azarbaijan Shahid Madani University, Tabriz, Iran.
Department of Biology, Faculty of Sciences, Golestan University, Gorgan, Iran.
Iran J Pharm Res. 2019 Summer;18(3):1566-1579. doi: 10.22037/ijpr.2019.1100752.
During recent years, there was growing demand in using microalga valuable products such as β-carotene in health care. β-Carotene has anti-cancer and anti-aging properties for human. In cells, β-carotene has a major protecting role for biomolecules, when the production of reactive oxygen species is elevated. In the present study, we investigated the influence of the four most effective factors (light intensity, temperature, nitrate and salinity concentration) and their interactions on the β-carotene production and the total chlorophyll/β-carotene ratio in low light adapted cells. Box-Benken design and response surface methodology (RSM) were used for this purpose and optimization of the factor levels. Two models were developed to explain how β-carotene productivity and the total chlorophyll/β-carotene ratio may depend on the stress factors. Among the four stress variables for β-carotene production, light intensity was stronger than the others. Meanwhile, interaction between light intensity and salt concentration exhibited the most important effect on the total chlorophyll/ β-carotene ratio. The predicted optimal conditions for maximum β-carotene productivity and minimum total chlorophyll/β-carotene ratio were derived from the fitted model in 200 µmol photons ms light intensity, 25 ºC, 0.9 mM nitrate and 3.8 M NaCl. When the predicted condition was tested experimentally, the expected results were observed. This suggests that overproduction of β-carotene in under certain conditions depends on used light intensity for preadaptation. The step-wise manner applying of stresses may act as a beneficial strategy to β-carotene overproduction.
近年来，在医疗保健领域对使用微藻的宝贵产品（如β-胡萝卜素）的需求不断增长。β-胡萝卜素对人类具有抗癌和抗衰老特性。在细胞中，当活性氧的产生增加时，β-胡萝卜素对生物分子具有主要的保护作用。在本研究中，我们研究了四个最有效的因素（光照强度、温度、硝酸盐和盐度浓度）及其相互作用对低光适应细胞中β-胡萝卜素产量和总叶绿素/β-胡萝卜素比率的影响。为此使用了Box-Benken设计和响应面方法（RSM）以及因素水平的优化。开发了两个模型来解释β-胡萝卜素生产力和总叶绿素/β-胡萝卜素比率如何可能取决于胁迫因素。在影响β-胡萝卜素产生的四个胁迫变量中，光照强度的影响比其他因素更强。同时，光照强度和盐浓度之间的相互作用对总叶绿素/β-胡萝卜素比率表现出最重要的影响。从拟合模型得出了β-胡萝卜素生产力最高和总叶绿素/β-胡萝卜素比率最低的预测最佳条件，即光照强度为200 μmol光子·m⁻²·s⁻¹、温度为25 ºC、硝酸盐浓度为0.9 mM和氯化钠浓度为3.8 M。当对预测条件进行实验测试时，观察到了预期结果。这表明在某些条件下微藻中β-胡萝卜素的过量生产取决于用于预适应的光照强度。逐步施加胁迫可能是β-胡萝卜素过量生产的有益策略。
