CAJ | 학술논문

为了确定不同初始氮供应水平对产油微藻——魏氏真眼点藻(Eustigmatos vischeri)生长、形态和油脂积累的影响, 本研究通过在改良的 BG-11 培养基中设置 4 种不同的初始硝酸钠浓度(17.6、11.7、5.9 和3.0 mmol/L)对魏氏真眼点藻(E. vischeri)进行培养.观察结果表明,魏氏真眼点藻(E. vischeri)的营养细胞为一具裂叶状叶绿体、细胞质中有一红色素体和许多振动颗粒及光滑细胞壁的球形单细胞; 细胞繁殖方式主要是形成二分裂和四分裂的似亲孢子.在低氮条件下, 随着培养时间的延长, 细胞内油体逐步形成, 至培养末期占据细胞的大部分空间, 同时培养物的颜色也由绿色向黄绿色转变, 最终呈橙黄色.实验结果表明, 魏氏真眼点藻(E. vischeri)生物质浓度在17.6 mmol/L组获得最大值为9.14 g/L;总脂、中性脂和总脂肪酸三者占干重的含量随着初始硝酸钠浓度的降低而升高,在3.0 mmol/L组获得最高值,分别为60.81%、56.59%和53.47%;三者的单位体积产率均在5.9 mmol/L组获得最高值,分别为0.24、0.21和0.20 g/(L·d);主要脂肪酸组成为棕榈酸(C16:0)、棕榈油酸(C16:1)、油酸(C18:1)和二十碳五烯酸(C20:5ω3, EPA),其中棕榈油酸的含量最高.上述研究表明,魏氏真眼点藻(E. vischeri)是一株适合于生产生物柴油和长链不饱和脂肪酸EPA的高产油微藻.
위료학정불동초시담공응수평대산유미조——위씨진안점조(Eustigmatos vischeri)생장、형태화유지적루적영향, 본연구통과재개량적 BG-11 배양기중설치 4 충불동적초시초산납농도(17.6、11.7、5.9 화3.0 mmol/L)대위씨진안점조(E. vischeri)진행배양.관찰결과표명,위씨진안점조(E. vischeri)적영양세포위일구렬협상협록체、세포질중유일홍색소체화허다진동과립급광활세포벽적구형단세포; 세포번식방식주요시형성이분렬화사분렬적사친포자.재저담조건하, 수착배양시간적연장, 세포내유체축보형성, 지배양말기점거세포적대부분공간, 동시배양물적안색야유록색향황록색전변, 최종정등황색.실험결과표명, 위씨진안점조(E. vischeri)생물질농도재17.6 mmol/L조획득최대치위9.14 g/L;총지、중성지화총지방산삼자점간중적함량수착초시초산납농도적강저이승고,재3.0 mmol/L조획득최고치,분별위60.81%、56.59%화53.47%;삼자적단위체적산솔균재5.9 mmol/L조획득최고치,분별위0.24、0.21화0.20 g/(L·d);주요지방산조성위종려산(C16:0)、종려유산(C16:1)、유산(C18:1)화이십탄오희산(C20:5ω3, EPA),기중종려유산적함량최고.상술연구표명,위씨진안점조(E. vischeri)시일주괄합우생산생물시유화장련불포화지방산EPA적고산유미조.
This research aimed at analysing the effects of initial nitrogen supply on the growth, morphology and lipids accumulation of an oleaginous microalga of Eustigmatophyceae,Eustigmatos vischeri.E. vischeri was grown in modi-fied BG-11 medium containing four different initial concentrations of sodium nitrate (17.6 mmol/L, 11.7 mmol/L, 5.9 mmol/L and 3.0 mmol/L). The cell morphology and oil droplets formation process ofE.vischeri were observed un-der microscope. It was found that the vegetative cells ofE.vischeri were spherical unicellular with smooth cell wall and containing a lobed chloroplast, a red pigment body and many vibrating ganules in cytoplasm. The main reproduction way is by forming autospore such as binary or quadripartition division. With the prolongation of cultivation time, the oil droplets formed gradually under nitrogen depletion. Then, the oil droplets became larger and mutual fusion into larger and larger oil bodies, eventually occupied the main part of the cell. Moreover, the color of cultures changed from green to yellow-green, finally to orange-yellow. The physiological results showed that the highest biomass concentration was occurred at the initial sodium nitrate concentration of 17.6 mmol/L, up to 9.14 g/L. The contents oftotallipid (TLs), neutral lipids (NLs) and total fatty acids (TFAs) increased following the reduction of nitrogen concentration. Their maximum contents reached to 60.81%, 56.59% and 53.47% at the basis of dry cell weight, respectively. However, the highest volumetric productivity of TLs, NLs and TFAs were up to 0.24, 0.21 and 0.20 g/(L·d) at 5.9 mmol/L of sodium nitrate, respectively. In addition, the main components of fatty acid were palmic acid,palmitoleic acid, oleic acid and eicosapentaenoic acid, among them, the content ofpalmitoleic acid was highest one. As a whole,E. vischeriwas an oleaginous microalga, suitable for the production of biodiesel and high value-adding of long-chain polyunsaturated fatty acid EPA.