The present investigation evaluates the potential of three cyanobacteria species Anabaena cylindrica, Nostoc commune and Synechococcus BDUSM-13 for photo-protecting mycosporine-like amino acids (MAAs) synthesis using bicarbonate-based culture system. Current investigations witnessed noteworthy bicarbonate tolerance of all species (NaHCO₃; 0.5, 1 and 2 g L^{− 1}) in terms of their growth rate, chlorophyll content, biomass productivity and carbon fixation ability. Among all strains, Synechococcus BDUSM-13 showed maximum surge in specific growth rate (i.e. 0.72 day⁻¹) at 1 g L⁻¹, productivity (i.e. 0.92 ± 0.06 g day⁻¹ L⁻¹) and chlorophyll content (i.e. 0.09 g L⁻¹) at 2 g day⁻¹ L⁻¹. Synechococcus cells were also has the 0.48 g dw⁻¹ carbon content with highest CO₂ fixation rate (i.e. 0.653 g.CO₂ mL⁻¹ day⁻¹) at 2 g L⁻¹. Though, they were not able to produce MAAs after long UV-B exposure (i.e. 24 and 48 h). A. cylindrica strain was the most competent species for the bicarbonate-based approach, produced UV-protecting iminomycosporine compound (i.e. shinorine, λ_max at 334 ± 2 nm) along with carbon fixation (i.e. 0.49 g CO₂ mL⁻¹ day⁻¹) at 2 g L⁻¹ NaHCO₃. This suggests the bicarbonate supplementation during cultivation is a promising strategy to increase cellular abundance, biomass productivity and carbon fixation in cyanobacteria. However, UV-B irradiation may cause species-specific differences in the MAAs synthesis to produce UV-protecting compounds.

本研究评估了三种蓝藻物种鱼腥藻、发菜和聚球藻BDUSM-13 使用基于碳酸氢盐的培养系统光保护类菌孢素氨基酸 (MAA) 合成的潜力。目前的研究表明，所有物种（NaHCO ₃；0.5、1 和 2 g L ^{- 1}）在生长速度、叶绿素含量、生物量生产力和碳固定能力方面都具有显着的碳酸氢盐耐受性。在所有菌株中，聚球藻BDUSM-13在 1 g L ^-1时表现出比生长率（即 0.72 天^-1 ） 、生产力（即 0.92 ± 0.06 g 天^-1  L ^-1）和叶绿素含量（即 0.09 g L ^-1 ) 在 2 g 天^-1  L ^-1。聚球藻细胞还具有0.48g dw ^-1碳含量，在2g L ^-1下具有最高CO ₂固定率（即0.653g.CO ₂  mL ^-1 天^-1 ） 。然而，在长时间 UV-B 暴露（即 24 和 48 小时）后，他们无法产生 MAA。A. cylindrica菌株是基于碳酸氢盐的方法中最有能力的物种，产生紫外线防护亚氨基菌孢素化合物（即 shinorine，λ _max为 334 ± 2 nm）以及碳固定（即 0.49 g CO ₂  mL ⁻¹  day ⁻¹ )在2g L ^-1 NaHCO ₃下。这表明在培养过程中补充碳酸氢盐是增加蓝藻细胞丰度、生物量生产力和碳固定的一种有前景的策略。然而，UV-B 照射可能会导致 MAA 合成中的物种特异性差异，从而产生紫外线防护化合物。