Improvement of light to biomass conversion by de-regulation of light-harvesting protein translation in Chlamydomonas reinhardtii
Improvement of light to biomass conversion by de-regulation of light-harvesting protein translation in Chlamydomonas reinhardtii
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DOI：
10.1016/j.jbiotec.2009.02.015
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发表时间：
2009-06-01
影响因子：
4.1
通讯作者：
Kruse, O.
中科院分区：
文献类型：
--
作者：
Beckmann, J.;Lehr, F.;Kruse, O.
微藻将太阳光能转化为生物质的有效利用受到封闭生物反应器中密集细胞培养物高光照射期间损失的限制。通过使用具有较小天线尺寸的细胞培养物填充到高细胞密度培养物中可以克服不均匀的光分布，从而允许良好的光穿透到反应器的内部部分。我们设计了一种新的小 PSII 天线尺寸的莱茵衣藻菌株，该菌株具有更高的光子转换效率和高光照条件下的生长速率。我们通过改造 LHC 翻译抑制子 NAB1* 的永久活性变体 NAB1* 来实现这一目标，以通过翻译抑制来减小天线尺寸。 NAB1* 表达在 Stm6Glc477(T7) 中得到证实，导致 LHC 天线尺寸减小 10-17%。与亲本菌株相比，T7 在饱和光强度下显示出类似 50% 的光合效率 (Phi PSII) 增加。 T7 以更高的效率将光转化为生物质，对数生长期中期提高了约 50%。此外，T7 培养物在大型生物反应器中生长时达到了更高的密度。因此，菌株T7的表型可能对生物技术应用具有重要意义，其中光合微藻作为替代植物生物质来源用于大规模培养。 (C) 2009 Elsevier B.V. 保留所有权利。
The efficient use of microalgae to convert sun light energy into biomass is limited by losses during high light illumination of dense cell cultures in closed bioreactors. Uneven light distribution can be overcome by using cell cultures with smaller antenna sizes packed to high cell density cultures, thus allowing good light penetration into the inner sections of the reactor. We engineered a new small PSII antenna size Chlamydomonas reinhardtii strain with improved photon conversion efficiency and increased growth rates under high light conditions. We achieved this goal by transformation of a permanently active variant NAB1* of the LHC translation repressor NAB1* to reduce antenna size via translation repression. NAB1* expression was demonstrated in Stm6Glc477(T7), leading to a reduction of LHC antenna size by 10-17%. T7 showed a similar to 50% increase of photosynthetic efficiency (Phi PSII) at saturating light intensity compared to the parental strain. T7 converted light to biomass with much higher efficiencies with a similar to 50% improved mid log growth phase. Moreover, T7 cultures reached higher densities when grown in large-scale bioreactors. Thus, the phenotype of strain T7 may have important implications for biotechnological applications in which photosynthetic microalgae are used for large-scale culturing as an alternative plant biomass source. (C) 2009 Elsevier B.V. All rights reserved.