Microbiology Group, Sector of Botany, Department of Biology, National and Kapodistrian University of Athens, Zografou Campus, 15781, Athens, Greece.
Biotechnol Lett. 2019 May;41(4-5):533-545. doi: 10.1007/s10529-019-02658-6. Epub 2019 Apr 16.
Microalgae gained interest for potential use as biodiesel producers, since they synthesize and accumulate significant quantities of lipids. The aim of this work was to isolate indigenous microalgae strains from Greek habitats, study their physicochemical growth conditions and finally select the best ones with respect to overall lipid production and profile.
Two sampling sites of marine aquatic ecosystems were selected in Attica prefecture, Greece in order to screen for novel wild type strains with lipid production capacity. Microalgae isolates (59) were obtained from the selected areas and were morphologically and molecularly characterized. Fatty acids were estimated through Flow Cytometry combined with BODIPY staining method. Four isolates were selected for their lipid production properties and were cultivated in 15 L tank cultures. The four isolates were also identified by 18S rDNA gene sequencing. Two of them, Chlorella sp. ΑCΑ9 and ACA17, exhibited both maximum biomass and lipid productivity. Optimization of growth conditions with respect to pH and initial NaNO concentration was performed for the two microalgae in 15 L cultures. Finally, 20 L fed batch cultures were set up using the optimum culture conditions. Lipid profiles were stabilized for both strains at dry biomass levels over 1 g L and lipid content of 25% (w/w).
Two Chlorella strains (ACA9 and ACA17) were promising candidates for biodiesel production as they were easily grown in sea water in fed batch systems and produce lipids suitable for biodiesel-especially Chlorella sp. ACA9.
微藻因其能够合成和积累大量脂质而被认为是生物柴油生产的潜在原料，因此受到了关注。本研究的目的是从希腊生境中分离出土著微藻菌株，研究其理化生长条件，最后根据总脂质产量和特征选择最佳菌株。
为了筛选具有产脂能力的新型野生型菌株，在希腊阿提卡州选择了两个海洋水生生态系统的采样点。从选定区域获得了 59 个微藻分离株，并对其进行了形态学和分子特征鉴定。通过流式细胞术结合 BODIPY 染色法估算脂肪酸。选择了四个具有产脂特性的分离株进行 15 L 罐培养。通过 18S rDNA 基因测序对这四个分离株进行了鉴定。其中两个，Chlorella sp. ΑCΑ9 和 ACA17，表现出最大的生物量和脂质生产力。对这两种微藻在 15 L 培养物中的生长条件（pH 和初始 NaNO3 浓度）进行了优化。最后，根据最佳培养条件，建立了 20 L 补料分批培养。在干生物量水平超过 1 g/L 和脂质含量为 25%（w/w）时，两种菌株的脂质谱均得到稳定。
两种绿藻（ACA9 和 ACA17）是生物柴油生产的有前途的候选者，因为它们可以在海水-fed 分批系统中轻松生长，并且产生适合生物柴油的脂质，特别是绿藻 ACA9。
