Assunção Joana, Pagels Fernando, Tavares Tânia, Malcata F Xavier, Guedes A Catarina
CIIMAR /CIMAR-LA-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos, s/n, 4450-208 Matosinhos, Portugal.
LEPABE-Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal.
Bioengineering (Basel). 2022 Jul 21;9(7):331. doi: 10.3390/bioengineering9070331.
Cyanobacteria are microorganisms that are well-adapted to sudden changes in their environment, namely to light conditions. This has allowed them to develop mechanisms for photoprotection, which encompass alteration in pigment composition. Therefore, light modulation appears to be a suitable strategy to enhance the synthesis of specific pigments (e.g., phycocyanin) with commercial interest, in addition to conveying a more fundamental perspective on the mechanisms of acclimatization of cyanobacterium species. In this study, was accordingly cultivated in two light phase stages: (i) white LED, and (ii) shift to distinct light treatments, including white, green, and red LEDs. The type of LED lighting was combined with two intensities (50 and 150 µmol·m·s). The effects on biomass production, photosynthetic efficiency, chlorophyll (chl ) content, total carotenoids (and profile thereof), and phycobiliproteins (including phycocyanin, allophycocyanin, and phycoerythrin) were assessed. White light (under high intensity) led to higher biomass production, growth, and productivity; this is consistent with higher photosynthetic efficiency. However, chl underwent a deeper impact under green light (high intensity); total carotenoids were influenced by white light (high intensity); whilst red treatment had a higher effect upon total and individual phycobiliproteins. Enhanced PC productivities were found under modulation with red light (low intensities), and could be achieved 7 days earlier than in white LED (over 22 days); this finding is quite interesting from a sustainability and economic point of view. Light modulation accordingly appears to be a useful tool for supplementary studies pertaining to optimization of pigment production with biotechnological interest.
蓝藻是一类非常适应其环境中突然变化，即光照条件变化的微生物。这使它们能够形成光保护机制，其中包括色素组成的改变。因此，除了能从更基本的角度了解蓝藻物种的适应机制外，光调制似乎是一种合适的策略，可用于提高具有商业价值的特定色素（如藻蓝蛋白）的合成。在本研究中，相应地在两个光照阶段培养：（i）白色发光二极管（LED），以及（ii）转换为不同的光照处理，包括白色、绿色和红色LED。LED照明类型与两种强度（50和150 μmol·m·s）相结合。评估了其对生物量生产、光合效率、叶绿素（chl）含量、总类胡萝卜素（及其分布）和藻胆蛋白（包括藻蓝蛋白、别藻蓝蛋白和藻红蛋白）的影响。白光（高强度下）导致更高的生物量生产、生长和生产力；这与更高的光合效率一致。然而，叶绿素在绿光（高强度）下受到的影响更深；总类胡萝卜素受白光（高强度）影响；而红色处理对总藻胆蛋白和单个藻胆蛋白的影响更大。在红光（低强度）调制下发现藻蓝蛋白的生产力提高，并且比在白色LED下（超过22天）可提前7天实现；从可持续性和经济角度来看，这一发现非常有趣。因此，光调制似乎是用于与生物技术相关的色素生产优化补充研究的有用工具。
