Cost-Effective and Efficient Production of Carbohydrates from an Alkalihalophilic Leptolyngbya sp. in a Photobioreactor with Periodical Mixing

Abstract

Using sodium bicarbonate (NaHCO3) as the carbon source makes it possible to decouple mixing and carbon supply in microalgae cultivation, and a periodical mixing may be sufficient to support rapid microalgae growth. To test this idea, growth of a screened Leptolyngbya sp. DUT 001 cultured with NaHCO3 was evaluated in a bubbling column photobioreactor. First, the culture medium of this strain was optimized as 25.2 g L–1 NaHCO3 and 0.5 g L–1 NaNO3, in which condition the achieved highest biomass productivity and carbohydrate content were 0.74 g L–1 d–1 and 75.7 ± 1.3%, respectively. Second, the effect of four periodical mixing modes of 6:2, 6:4, 6:6, and 6:10 (bubbling/stopping, s) on microalgae growth was investigated, and these cultures resulted in the highest biomass concentrations of 1.76 ± 0.03, 1.75 ± 0.04, 1.72 ± 0.05, and 1.66 ± 0.04 g L–1, respectively. Correspondingly, the highest carbohydrate contents were 56.5 ± 1.2, 63.0 ± 2.5, 64.7 ± 2.1, and 60.6 ± 2.5%, respectively. However, there was no significant difference between these values and those achieved in the control group with continuous mixing (P > 0.05), which was 1.82 ± 0.06 g L–1 and 59.3 ± 1.3%, respectively. These results showed that it is feasible to use periodical mixing in microalgae cultivation, which may significantly reduce the microalgae biomass production cost.

Effect of DACH-K2CO3 Mixed Absorbent on the Performance of a CO2 Absorption and Microalgae Conversion (CAMC) System

“…40 The production of biofuels such as bioethanol is increasing due to high demand in the transportation sector. 41,42 The improvement of photosynthetic activity in the CAMC coupling system is associated with increased carbohydrate synthesis, aligning with the previously observed boost in photosynthetic pigment content. Carbohydrate synthesis is closely related to the carbon fixation stage, further reaffirming the positive influence of carbon source optimization on photosynthetic carbon fixation within the coupled system.…”

“…Microalgal carbohydrates offer a cost-effective substrate for the production of various biofuels, including bioethanol, biobutanol, biomethane, and biohydrogen 40. The production of biofuels such as bioethanol is increasing due to high demand in the transportation sector 41,42. The improvement of photosynthetic activity in the CAMC coupling system is associated with increased…”

Optimization of Industrial-Scale Cultivation Conditions to Enhance the Nutritional Composition of Nontoxic Cyanobacterium Leptolyngbya sp. KIOST-1

“…Such cell death has also been observed in other Leptolyngbya sp. and Arthrospira cultures [50,51]. This sharp increase in pH was related to bicarbonate consumption.…”

Ecological response of Rotaria rotatoria (Bdelloid Rotifera) to unbalanced nitrogen in food: experimental insights from life history strategy and feeding behavior

“…As the foundation of aquatic food webs, algae play an important role in energy transfer and nutrient cycles (Bi et al 2018). Generally, a lack of N leads to a direct decrease in both algal biomass and population density in aquatic ecosystems (Zhu et al 2014(Zhu et al , 2020Zhou and Wang 2022). Although N limitation in the environment inhibits algal growth, it also enhances lipid content (Rodolfi et al 2009;Van Vooren et al 2012;Pancha et al 2014).…”