Improving carbohydrate accumulation in Chlamydomonas debaryana induced by sulfur starvation using response surface methodology

• Published in: Environmental science and pollution research international 2022-04, Vol.29 (16), p.23949-23962
• Main Authors: Tazi, Karima, Jamai, Latifa, Seddouk, Loubna, Ettayebi, Mohamed, Mohammed, Alaoui-Mhamdi, Aleya, Lotfi, Idrissi, Abdellatif Janati
• Format: Article
• Language: English
• Subjects: Accumulation; Aeration; Algae; Aquatic microorganisms; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Biofuels; Biomass; Carbohydrates; Cell culture; Chlamydomonas; Cultivation; Design factors; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Growth conditions; Microalgae; Nutrient deficiency; Optimization; Polynomials; Production methods; Regression analysis; Research Article; Response surface methodology; Sodium; Sodium bicarbonate; Starvation; Sulfur; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-021-17583-3

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 −1 of sodium bicarbonate combined with a good aerated agitation (0.6 L min −1 ) and a cultivation period of 18 days are optimal to produce 5.02 g L −1 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.