Thepsuthammarat Kamolwan, Imai Tsuyoshi, Plangklang Pensri, Sittijunda Sureewan, Reungsang Alissara
Faculty of Environment and Resource Studies, Mahidol University, Nakhon Pathom, 73170, Thailand.
Division of Environmental Science and Engineering, Graduate School of Science and Engineering, Yamaguchi University, Yamaguchi, 755-8611, Japan.
Heliyon. 2024 Sep 3;10(17):e37261. doi: 10.1016/j.heliyon.2024.e37261. eCollection 2024 Sep 15.
This study aimed to produce PHB using hydrogenic effluent discharged from the biohydrogen production process with freshwater microalgae including sp. KKU-P1, and sp. KKU-P2. Batch experiments explored the influence of initial pH and hydrogenic effluent concentration, revealing optimal conditions at 10 % (v/v) effluent concentration and a pH of 6.5 for both KKU-P1 and KKU-P2. Subsequently, medium formulation and photoperiods were optimized to maximize biomass and PHB accumulation. The results showed that the optimal condition for PHB accumulation with KKU-P1 and KKU-P2 was nitrogen phosphorus (NP)-limited Bold's Basal Medium (BBM) under dark conditions. A two-step PHB accumulation in the upscale bioreactor was investigated under optimal conditions. The results showed that KKU-P1 achieved maximum PHB, protein, carbohydrate, and lipid contents of 4.57 %, 29.37 %, 24.76 %, and 13.21 %, respectively, whereas KKU-P2 achieved 6.35 %, 31.53 %, 16.16 %, and 4.77 %, respectively. Based on these findings, it appears that a mixotrophic approach under nutrient-limiting conditions is effective for PHB production in both KKU-P1 and KKU-P2 strains.
本研究旨在利用淡水微藻（包括KKU-P1菌株和KKU-P2菌株）生物制氢过程中排放的含氢废水来生产聚羟基丁酸酯（PHB）。批次实验探究了初始pH值和含氢废水浓度的影响，结果表明，对于KKU-P1和KKU-P2菌株，废水浓度为10%（v/v）、pH值为6.5时为最优条件。随后，对培养基配方和光照周期进行了优化，以实现生物量和PHB积累的最大化。结果表明，对于KKU-P1和KKU-P2菌株，在黑暗条件下，聚羟基丁酸酯积累的最优条件是氮磷（NP）限制的Bold基础培养基（BBM）。在最优条件下，对放大规模生物反应器中的两步聚羟基丁酸酯积累进行了研究。结果表明，KKU-P1的聚羟基丁酸酯、蛋白质、碳水化合物和脂质的最大含量分别为4.57%、29.37%、24.76%和13.21%，而KKU-P2的相应含量分别为6.35%、31.53%、16.16%和4.77%。基于这些发现，在营养限制条件下的混合营养方法对于KKU-P1和KKU-P2菌株生产聚羟基丁酸酯似乎是有效的。
