Tazi Karima, Jamai Latifa, Seddouk Loubna, Ettayebi Mohamed, Mohammed Alaoui-Mhamdi, Aleya Lotfi, Idrissi Abdellatif Janati
Laboratory of Biotechnology, Conservation and Valorization of Natural Resources, Faculty of Sciences DM, Sidi Mohammed Ben Abdellah, University of Fez, P.O. Box 1796, Atlas-Fez, Morocco.
Biodiversity-Bioenergy-Environment (BBE) Research Group, Faculty of Sciences, SMBA University of Fez, Fez, Morocco.
Environ Sci Pollut Res Int. 2022 Apr;29(16):23949-23962. doi: 10.1007/s11356-021-17583-3. Epub 2021 Nov 24.
Most methods that promote carbohydrate production negatively affect cell growth and microalgal biomass production. This study explores, in a two-stage cultivation strategy, in Chlamydomonas debaryana the optimization of certain culture conditions for high carbohydrate production without loss of biomass. In the first stage, the interaction between sodium bicarbonate supplementation, aeration, and different growth periods was optimized using the response surface methodology (RMS). The 3-factor Box-Behnken design (BBD) was applied, and a second-order polynomial regression analysis was used to analyze the experimental data. The results showed that 0.45 g L of sodium bicarbonate combined with a good aerated agitation (0.6 L min) and a cultivation period of 18 days are optimal to produce 5.02 g L of biomass containing 43% of carbohydrates.Under these optimized growth conditions, accumulation of carbohydrates was studied using different modes of nutritional stress. The results indicated that carbohydrate content was improved and the maximum accumulation (about 60% of the dry weight) was recorded under sulfur starvation with only a 14% reduction in biomass as compared to control. This study showed promising results as to biomass production and carbohydrate yield by the microalgae C. debaryana in view of production of third-generation biofuels.
大多数促进碳水化合物生成的方法都会对细胞生长和微藻生物量的产生产生负面影响。本研究采用两阶段培养策略，探索在德巴衣藻中优化特定培养条件以实现高碳水化合物产量且不损失生物量的方法。在第一阶段，使用响应面法（RMS）优化碳酸氢钠添加量、通气量和不同生长阶段之间的相互作用。采用三因素Box-Behnken设计（BBD），并使用二阶多项式回归分析来分析实验数据。结果表明，0.45 g/L的碳酸氢钠与良好的通气搅拌（0.6 L/min）以及18天的培养期相结合，是产生5.02 g/L含43%碳水化合物的生物量的最佳条件。在这些优化的生长条件下，使用不同的营养胁迫模式研究了碳水化合物的积累情况。结果表明，在硫饥饿条件下，碳水化合物含量得到提高，最大积累量（约占干重的60%），与对照相比生物量仅减少14%。鉴于第三代生物燃料的生产，本研究在德巴衣藻的生物量生产和碳水化合物产量方面显示出了有前景的结果。
