2016年6月23日，國際代謝工程領(lǐng)域頂級研究期刊《Metabolic Engineering》在線發(fā)表了暨南大學(xué)生命科學(xué)技術(shù)學(xué)院李宏業(yè)教授發(fā)表的微藻脂類物質(zhì)代謝研究成果，李宏業(yè)教授為通訊作者。
微藻的脂類物質(zhì)含量及組成直接影響著微藻在水產(chǎn)、營養(yǎng)保健、生物能源等領(lǐng)域的應(yīng)用，是微藻資源高值化利用中的重要評價(jià)指標(biāo)。由于藻類獨(dú)特的生存環(huán)境造成其代謝途徑及代謝物成分與陸生生物有很大不同，基因組情況復(fù)雜，研究困難。對微藻脂類合成的調(diào)控機(jī)制的認(rèn)知不足，使得微藻藻株改良研究的進(jìn)展緩慢。
生科院李宏業(yè)教授課題組圍繞微藻脂類物質(zhì)合成與累積開展了研究，在IF：8.2)發(fā)表論文，報(bào)道了產(chǎn)油微藻代謝工程調(diào)控的關(guān)鍵節(jié)點(diǎn)。課題組構(gòu)建了典型產(chǎn)油微藻三角褐指藻的遺傳轉(zhuǎn)化體系，對其脂質(zhì)代謝網(wǎng)絡(luò)潛在關(guān)鍵節(jié)點(diǎn)進(jìn)行了挖掘，發(fā)現(xiàn)了一種新型的定位于線粒體的蘋果酸脫氫酶，具有很強(qiáng)的促NADPH生成的作用，可提供胞內(nèi)豐富的還原力，促進(jìn)脂肪酸的合成?；谶@一發(fā)現(xiàn)，成功獲得顯著上調(diào)表達(dá)該酶的工程藻株，工程藻株的生長速率與野生型藻類似，而藻細(xì)胞顯著增大，中性脂含量提高達(dá)2.5倍，從干重的23.3%提高到突破性的57%。工程藻株在保持高生物量的同時(shí)，獲得了高脂質(zhì)含量，綜合性狀優(yōu)于已報(bào)道的產(chǎn)油微藻。研究結(jié)果也表明了微藻的脂質(zhì)累積具有其獨(dú)特的機(jī)制，豐富了對脂類代謝的認(rèn)知。研究成果得到了國內(nèi)外同行的高度關(guān)注，文章發(fā)表后被scienceDirect評為當(dāng)季下載量最多文章之一“The most downloaded articles from ScienceDirect in the last 90 days”。
原文鏈接：
http://www.sciencedirect.com/science/article/pii/S1096717614001244
genetic improvement of the microalga Phaeodactylum tricornutum for boosting neutral lipid accumulation
原文摘要：
To obtain fast growing oil-rich microalgal strains has been urgently demanded for microalgal biofuel. Malic enzyme (ME), which is involved in pyruvate metabolism and carbon fixation, was first characterized in microalgae here. Overexpression of Phaeodactylum tricornutumME (PtME) significantly enhanced the expression of PtME and its enzymatic activity in transgenic P. tricornutum. The total lipid content in transgenic cells markedly increased by 2.5-fold and reached a record 57.8% of dry cell weight with a similar growth rate to wild type, thus keeping a high biomass. The neutral lipid content was further increased by 31% under nitrogen-deprivation treatment, still 66% higher than that of wild type. Transgenic microalgae cells exhibited obvious morphological changes, as the cells were shorter and thicker and contained larger oil bodies. Immuno-electron microscopy targeted PtME to the mitochondrion. This study markedly increased the oil content in microalgae, suggesting a new route for developing ideal microalgal strains for industrial biodiesel production.
