Yun Lisa, Zegarac Robert, Ducat Daniel C
Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, United States.
Department of Energy-Michigan State University Plant Research Laboratories, Michigan State University, East Lansing, MI, United States.
Front Plant Sci. 2024 Apr 8;15:1378573. doi: 10.3389/fpls.2024.1378573. eCollection 2024.
Cyanobacteria have been proposed as a potential alternative carbohydrate feedstock and multiple species have been successfully engineered to secrete fermentable sugars. To date, the most productive cyanobacterial strains are those designed to secrete sucrose, yet there exist considerable differences in reported productivities across different model species and laboratories. In this study, we investigate how cultivation conditions (specifically, irradiance, CO, and cultivator type) affect the productivity of sucrose-secreting PCC 7942. We find that produces the highest sucrose yield in irradiances far greater than what is often experimentally utilized, and that high light intensities are tolerated by , especially under higher density cultivation where turbidity may attenuate the effective light experienced in the culture. By increasing light and inorganic carbon availability, / produced a total of 3.8 g L of sucrose and the highest productivity within that period being 47.8 mg L h. This study provides quantitative description of the impact of culture conditions on cyanobacteria-derived sucrose that may assist to standardize cross-laboratory comparisons and demonstrates a significant capacity to improve productivity via optimizing cultivation conditions.
蓝藻已被提议作为一种潜在的替代碳水化合物原料，并且多个物种已被成功改造以分泌可发酵糖。迄今为止，产量最高的蓝藻菌株是那些被设计用来分泌蔗糖的菌株，然而，不同模式物种和实验室报道的产量存在相当大的差异。在本研究中，我们调查了培养条件（具体而言，光照、二氧化碳和培养器类型）如何影响分泌蔗糖的集胞藻PCC 7942的产量。我们发现，在远高于通常实验所用的光照强度下，集胞藻PCC 7942产生的蔗糖产量最高，并且该菌株能够耐受高光强，特别是在较高密度培养下，此时浊度可能会减弱培养物中实际经历的有效光照。通过增加光照和无机碳的可利用性，集胞藻PCC 7942总共产生了3.8 g/L的蔗糖，该时期内的最高产量为47.8 mg/(L·h)。本研究提供了培养条件对蓝藻来源蔗糖影响的定量描述，这可能有助于规范跨实验室比较，并证明了通过优化培养条件提高产量的巨大潜力。
