Riesberg Grant, Bigelow Timothy A, Stessman Dan J, Spalding Martin H, Yao Linxing, Wang Tong, Xu Jin
Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011.
Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa 50011.
J Acoust Soc Am. 2014 Jun;135(6):3632-8. doi: 10.1121/1.4874627.
To consider microalgae lipid biofuel as a viable energy source, it is a necessity to maximize algal cell lysis, lipid harvest, and thus biofuel production versus the energy used to lyse the cells. Previous techniques have been to use energy consumptive ultrasound waves in the 10-40 kHz range in a stationary exposure environment. This study evaluated the potential of using 1.1 MHz ultrasound pulses in a new flow through type chamber on Chlamydomonas reinhardtii as a model organism for cell breakage. The ultrasound was generated using a spherically focused transducer with a focal length of 6.34 cm and an active diameter of 6.36 cm driven by 20 cycle sine-wave tone bursts at varied pulse repetition frequencies. First, variations in flow rate were examined at a constant duty cycle of 3.6%. After assessing flow rates, the duty cycle was varied to further explore the dependence on the tone burst parameters. Cell lysis was assessed by quantifying protein and chlorophyll release into the supernatant as well as by lipid extractability. Appropriate flow rates with higher duty cycles led to statistically significant increases in cell lysis relative to controls and other exposure conditions.
要将微藻脂质生物燃料视为一种可行的能源，有必要使藻类细胞裂解、脂质收获最大化，从而使生物燃料产量相对于用于裂解细胞的能量达到最大化。以往的技术是在固定暴露环境中使用10 - 40千赫兹范围内消耗能量的超声波。本研究评估了在一种新型流通式腔室中使用1.1兆赫兹超声脉冲对莱茵衣藻进行细胞破碎的潜力，莱茵衣藻作为细胞破碎的模式生物。超声由一个焦距为6.34厘米、有效直径为6.36厘米的球面聚焦换能器产生，该换能器由具有不同脉冲重复频率的20周期正弦波脉冲串驱动。首先，在3.6%的恒定占空比下检查流速变化。在评估流速之后，改变占空比以进一步探究对脉冲串参数的依赖性。通过量化释放到上清液中的蛋白质和叶绿素以及脂质提取率来评估细胞裂解情况。与对照和其他暴露条件相比，具有较高占空比的合适流速导致细胞裂解在统计学上显著增加。
