Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P.R. China.
University of Chinese Academy of Sciences, Beijing 100049, P.R. China.
J Microbiol Biotechnol. 2020 Jul 28;30(7):1072-1081. doi: 10.4014/jmb.2002.02053.
Screening suitable strains with high temperature adaptability is of great importance for reducing the cost of temperature control in microalgae cultivation, especially in summer. To obtain high temperature-tolerant diatoms, water samples were collected in summer from 7 different regions of China across the Northeast, North and East. A total of 731 water samples was collected and from them 131 diatom strains were isolated and identified based on the 18S rRNA sequences. Forty-nine strains out of the 131 diatoms could survive at 30°C, and 6 strains with relatively high biomass and lipid content at high temperature were selected and were found to be able to grow at 35°C. sp. HB162 had the highest dry biomass of 0.46 g/l and relatively high triacylglycerol (TAG) content of 237.4 mg/g dry biomass. The highest TAG content of 246.4 mg/g dry biomass was obtained in sp. HB236, while HB170 had high dry biomass (0.33 g/l) but relatively low TAG content (105.9 mg/g dry biomass). HB170 and sp. HB236 presented relatively stable growth rates and lipid yields under fluctuating temperatures ranging from 28 to 35°C, while HB162 maintained high lipid yield at temperatures below 25°C. The percentage of saturated fatty acids and monounsaturated fatty acids in all the 6 strains was 84-91% in total lipids and 90-94% in TAGs, which makes them the ideal feedstock for biodiesel.
筛选具有高温适应性的合适菌株对于降低微藻培养过程中的温度控制成本非常重要，尤其是在夏季。为了获得耐高温的硅藻，我们于夏季从中国东北、华北和华东的 7 个不同地区采集水样。共采集了 731 个水样，从中分离并鉴定了 131 株硅藻，基于 18S rRNA 序列。在 131 株硅藻中，有 49 株能在 30°C 下存活，有 6 株在高温下具有相对较高的生物量和脂质含量，被选择出来并发现能在 35°C 下生长。 sp. HB162 的干生物量最高，为 0.46 g/L，相对较高的三酰基甘油(TAG)含量为 237.4 mg/g 干生物量。在 sp. HB236 中获得了最高的 TAG 含量 246.4 mg/g 干生物量，而 HB170 具有较高的干生物量（0.33 g/L）但相对较低的 TAG 含量（105.9 mg/g 干生物量）。在 28 至 35°C 波动温度下，HB170 和 sp. HB236 的生长率和脂质产率相对稳定，而 HB162 在温度低于 25°C 时仍保持较高的脂质产率。在所有 6 株菌中，饱和脂肪酸和单不饱和脂肪酸在总脂质中的百分比为 84-91%，在 TAG 中的百分比为 90-94%，这使它们成为生物柴油的理想原料。
