Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis Pasteur Private, Ottawa, ON K1N 6N5, Canada; Department of Biochemistry, University of Western Ontario, London, ON N6A 5C1, Canada.
Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis Pasteur Private, Ottawa, ON K1N 6N5, Canada.
Biotechnol Adv. 2018 Jul-Aug;36(4):986-1002. doi: 10.1016/j.biotechadv.2018.03.001. Epub 2018 Mar 7.
Cultivation of microalgae requires consideration of shear stress, which is generated by operations such as mixing, circulation, aeration and pumping that are designed to facilitate mass and heat transfer as well as light distribution in cultures. Excessive shear stress can cause increased cell mortality, decreased growth rate and cell viability, or even cell lysis. This review examines the sources of shear stress in different cultivation systems, shear stress tolerance of different microalgal species and the physiological factors and environmental conditions that may affect shear sensitivity, and potential approaches to mitigate the detrimental effects of shear stress. In general, green algae have the greatest tolerance to shear stress, followed by cyanobacteria, haptophytes, red algae, and diatoms, with dinoflagellates comprising the most shear-sensitive species. The shear-sensitivity of microalgae is determined primarily by cell wall strength, cell morphology and the presence of flagella. Turbulence, eddy size, and viscosity are the most prominent parameters affecting shear stress to microalgal cells during cultivation.
微藻培养需要考虑剪切应力，这是由混合、循环、通气和泵送等操作产生的，这些操作旨在促进培养物中的质量和热传递以及光分布。过大的剪切应力会导致细胞死亡率增加、生长速度和细胞活力下降，甚至细胞裂解。本综述考察了不同培养系统中剪切应力的来源、不同微藻物种对剪切应力的耐受能力以及可能影响剪切敏感性的生理因素和环境条件，以及减轻剪切应力不利影响的潜在方法。一般来说，绿藻对剪切应力的耐受性最强，其次是蓝藻、甲藻、红藻和硅藻，而鞭毛藻则是最敏感的物种。微藻的剪切敏感性主要取决于细胞壁强度、细胞形态和鞭毛的存在。在培养过程中，湍流、涡尺寸和粘度是影响剪切应力的最突出参数。
