| 摘要: |
| 优质产油藻种是实现微藻油脂产业化生产的基础,蹄形藻可以积累高含量的储藏性三酰甘油,但其是否具有微藻油脂开发潜力,目前仍然缺少系统的评价。利用形态学和分子技术对分离自暨南大学南湖的一株微藻进行鉴定,通过设置4种硝酸钠浓度(3.6、9.0、18.0和36.0mmol/L),测定生物质浓度、总脂含量、脂肪酸组成、光合效率等指标,评价该藻株的产油能力,并利用现有模型,计算生物柴油的质量参数。经鉴定该藻株为蹄形藻JNU-3201(Kirchneriella sp. JNU-3201),在整个培养周期内,其碳水化合物含量(干重)均低于20%,蛋白质含量呈降低趋势,总脂含量逐渐增加,说明脂类是该藻的主要储能物质;主要脂肪酸包括油酸(C18:1)、棕榈酸(C16:0)和亚油酸(C18:2);该藻株的生长和油脂含量明显受氮素水平影响,在最低氮浓度条件下(3.6mmol/L),获得最高总脂含量(46.92%±1.52%,干重),在最高氮浓度条件下(36.0mmol/L),获得最高生物质浓度[(6.53±0.11)g/L],在18.0mmol/L条件下,获得最高总脂产量[(2.43±0.06)g/L];降低氮浓度,单不饱和脂肪酸相对含量显著增加,但藻细胞光合色素的含量明显降低,且热和荧光损失的能量比例增加,经模型预测该藻生物柴油的十六烷值、运动黏度、比重、密度、碘值等均符合BD 100(S10)和EN 14214标准。综上所述,蹄形藻JNU-3201(Kirchneriella sp. JNU-3201)是一株具有开发潜力的产油藻株,可以作为生物柴油的生产原料。 |
| 关键词: 蹄形藻JNU-3201 氮浓度 总脂 脂肪酸 生物柴油质量参数 |
| DOI：10.11693/hyhz20220500145 |
| 分类号:X703 |
| 基金项目:热带亚热带水生态工程教育部工程研究中心开放基金,2021B0402号;南方海洋科学与工程广东省实验室(广州)人才团队引进重大专项,GML2019ZD0406号。 |
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| EVALUATION OF GROWTH AND LIPID ACCUMULATION POTENTIAL OF KIRCHNERIELLA SP. |
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SHEN Hong-Xiao1, LI Tao2,3, LI Ai-Fen1
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1.Institute of Hydrobiology, Jinan University, Guangzhou 510632, China;2.Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangdong Provincial Key Laboratory of Marine Medicine, Guangzhou 510301, China;3.Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou), Guangzhou 511458, China
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| Abstract: |
| High-quality oleaginous microalgae are considered the foundation for large-scale production of microalgal lipid. Kirchneriella sp. can accumulate storage triacylglycerols, but whether they have the potential for the feedstock of biodiesel is still lacking a systematic evaluation. A freshwater microalga, strain Kirchneriella sp. was isolated from Nanhu Lake of Jinan University, Guangzhou, South China, and identified using morphological and molecular techniques. To evaluate the lipid production capacity of the microalgae, the biomass concentration, total lipid content, fatty acid composition, and photosynthetic efficiency were determined by culturing them under the four different sodium nitrate concentrations conditions (3.6, 9.0, 18.0, and 36.0 mmol/L). Finally, the quality parameters of biodiesel were predicted by using the theoretical mathematical model. The microalgal strain was identified as Kirchneriella sp. JNU-3201. During the culture period, carbohydrate content was lower than 20% (in dry weight). Protein content decreased and total lipid content gradually increased with the culture time, indicating that lipid were the major carbon storage for Kirchneriella sp. JNU-3201. The major fatty acids included oleic acid (C18:1), palmitic acid (C16:0), and linoleic acid (C18:2); the growth and lipid accumulation of the microalgae were significantly affected by nitrogen concentration. The highest total lipid content (46.92%±1.52%, in dry weight) was obtained at the lowest nitrogen concentration (3.6 mmol/L), the highest biomass concentration [(6.53±0.11) g/L] was obtained at the highest nitrogen concentration (36.0 mmol/L), and the highest total lipid yield [(2.43±0.06) g/L] was obtained at the middle nitrogen concentration (18.0 mmol/L). The percentage of monounsaturated fatty acids was increased significantly at low nitrogen concentrations. However, the content of photosynthetic pigments was decreased significantly, and the proportion of energy was lost in the form of heat and fluorescence was increased. The biodiesel parameters of cetane number, kinematic viscosity, density, iodine number, and oxidative stability all meet the Chinese biodiesel standard BD 100 (S10) and EU biodiesel standard EN 14214 standards. In conclusion, Kirchneriella sp. JNU-3201 could be used as a potential feedstock for the production of microalgal biodiesel. |
| Key words: Kirchneriella sp. JNU-3201 nitrogen concentration total lipid fatty acid biodiesel quality parameters |
