Gigova Liliana, Ivanova Natalia, Gacheva Gergana, Andreeva Raina, Furnadzhieva Sevdalina
Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria.
J Phycol. 2012 Feb;48(1):85-93. doi: 10.1111/j.1529-8817.2011.01088.x. Epub 2011 Dec 7.
The effects of different temperatures and light intensities on growth, pigments, sugars, lipids, and proteins, as well as on some antioxidant and proteolytic enzymes of Trachydiscus minutus (Bourr.) H. Ettl, were investigated. The optimum growth temperature and light intensity were 25°C and 2 × 132 μmol photons · m(-2 ) · s(-1) , respectively. Under these conditions, proteins were the main biomass components (33.45% dry weight [dwt]), with high levels of carbohydrates (29% dwt) and lipids (21.77% dwt). T. minutus tolerated temperatures between 20°C and 32°C, with only moderate changes in cell growth and biochemical composition. Extremely low (15°C) and high (40°C) temperatures decreased chl and RUBISCO contents and inhibited cell growth. The biochemical response of the alga to both unfavorable conditions was an increase in lipid content (up to 35.19% dwt) and a decrease in carbohydrates (down to 13.64% dwt) with much less of a change in total protein content (in the range of 30.51%-38.13% dwt). At the same time, the defense system of T. minutus was regulated differently in response to heat or cold treatments. Generally, at 40°C, the activities of superoxide dismutase (SOD), catalase (CAT), and proteases were drastically elevated, and three polypeptides were overexpressed, whereas the glutathione reductase (GR) and peroxidase (POD) activities were reduced. In contrast, at 15°C, all these enzymes except GR were suppressed. The effect of light was to enhance or decrease the temperature stress responses, depending on intensity. Our studies demonstrate the broad temperature adaptability of T. minutus as well as the potential for the production of valuable algal biomass.
研究了不同温度和光照强度对微小 Trachydiscus minutus（布尔）H. Ettl 的生长、色素、糖类、脂质和蛋白质以及一些抗氧化酶和蛋白水解酶的影响。最佳生长温度和光照强度分别为 25°C 和 2×132 μmol 光子·m(-2)·s(-1)。在这些条件下，蛋白质是主要的生物量成分（干重的 33.45%），碳水化合物（干重的 29%）和脂质（干重的 21.77%）含量较高。微小 Trachydiscus minutus 能耐受 20°C 至 32°C 的温度，细胞生长和生化组成仅有适度变化。极低（15°C）和极高（40°C）温度会降低叶绿素和核酮糖-1,5-二磷酸羧化酶（RUBISCO）含量并抑制细胞生长。藻类对这两种不利条件的生化反应是脂质含量增加（高达干重的 35.19%），碳水化合物含量减少（低至干重的 13.64%），而总蛋白质含量变化较小（在干重的 30.51%-38.13%范围内）。同时，微小 Trachydiscus minutus 的防御系统在热或冷处理时的调节方式不同。一般来说，在 40°C 时，超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和蛋白酶的活性急剧升高，三种多肽过度表达，而谷胱甘肽还原酶（GR）和过氧化物酶（POD）的活性降低。相反，在 15°C 时，除 GR 外所有这些酶都受到抑制。光照的影响取决于强度，可增强或降低温度胁迫反应。我们的研究证明了微小 Trachydiscus minutus 具有广泛的温度适应性以及生产有价值藻类生物量的潜力。
