Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50011-1061, USA.
Bioresour Technol. 2012 Dec;125:175-81. doi: 10.1016/j.biortech.2012.08.110. Epub 2012 Sep 5.
Microalgae are a promising feedstock for biofuels because of their capability to produce lipids. Cell disruption is necessary to maximize lipid extraction. Sonication conditions were evaluated for breaking heterotrophic (Schizochytrium limacinum) and autotrophic (Chlamydomonas reinhardtii) microalgae cells. Cell disruption was estimated by Nile red-lipids fluorescence quantification in S. limacinum and by the release of intracellular chlorophyll and carotenoids in green microalga C. reinhardtii. In both species, approximately 800 J/10 mL was the energy input necessary to maximize cell disruption, regardless of the cell concentrations studied. Increasing sonication time produced increasing amount of free radicals, quantified by the formation of hydroxyterephthalate. Sonication energy beyond the level needed for cell disruption induced oxidation of arachidonic acid, a polyunsaturated fatty acid typically found in marine lipids. Careful control of sonication conditions is necessary to maximize oil extraction at the lowest operational cost and to prevent oil from free radical-induced degradation.
微藻是生物燃料的有前途的原料，因为它们能够产生脂质。为了最大限度地提取脂质，需要进行细胞破碎。本文评价了超声破碎异养（裂殖壶藻）和自养（莱茵衣藻）微藻细胞的条件。通过尼罗红-脂质荧光定量法在裂殖壶藻中测定细胞破碎程度，通过绿色微藻莱茵衣藻中细胞内叶绿素和类胡萝卜素的释放来评估细胞破碎程度。在这两种生物中，无论研究的细胞浓度如何，大约 800 J/10 mL 的能量输入是实现细胞破碎最大化所需的能量。随着超声时间的增加，自由基的数量也随之增加，通过对羟基苯二甲酸的形成来定量。超过细胞破碎所需能量的超声能量会诱导花生四烯酸的氧化，花生四烯酸是一种通常存在于海洋脂质中的多不饱和脂肪酸。为了以最低的运营成本最大限度地提取油脂并防止油脂因自由基诱导而降解，需要仔细控制超声条件。
