CO2 Removal from Biogas by Cyanobacterium Leptolyngbya sp. CChF1 Isolated from the Lake Chapala, Mexico: Optimization of the Temperature and Light Intensity

Abstract

In the present study, the capacity of the cyanobacterium Leptolyngbya sp. CChF1 to remove CO from real and synthetic biogas was evaluated. The identification of the cyanobacterium, isolated from the lake Chapala, was carried out by means of morphological and molecular analyses, while its potential for CO removal from biogas streams was evaluated by kinetic experiments and optimized by a central composite design coupled to a response surface methodology. Results demonstrated that Leptolyngbya sp. CChF1 is able to remove CO and grow indistinctly in real or synthetic biogas streams, showing tolerance to high concentrations of CO and CH, 25 and 75%, respectively. The characterization of the biomass composition at the end of the kinetic assays revealed that the main accumulated by-products under both biogas streams were lipids, followed by proteins and carbohydrates. Regarding the optimization experiments, light intensity and temperature were the studied variables, while synthetic biogas was the carbon source. Results showed that light intensity was significant for CO capture efficiency (p = 0.0290), while temperature was significant for biomass production (p = 0.0024). The predicted CO capture efficiency under optimal conditions (27.1 °C and 920 lx) was 93.48%. Overall, the results of the present study suggest that Leptolyngbya sp. CChF1 is a suitable candidate for biogas upgrading.

Potential of novel desert microalgae and cyanobacteria for commercial applications and CO2 sequestration

“…QUCCCM 56 showed the second-best carbon capture potential with 186.8 ± 16.0 mg CO 2 L −1 d −1 at 40°C. This is higher than the carbon capture rate found by Choix et al (2017) for Leptolyngbya sp. CChF1 of 159 ± 40 mg CO 2 L −1 d −1 .…”

“…CChF1 of 159 ± 40 mg CO 2 L −1 d −1 . Besides, Choix et al (2017) based the carbon capture rate on the hypothetical carbon content of 51.4% (Chisti 2007) which is an overestimation according to the findings of the current study, where total carbon values of 44-47% were found for Leptolyngbya sp. QUCCCM 56.…”

“…Singh et al (2014) reported a Leptolyngbya strain which was capable of growing at temperatures up to 45°C; however, 30°C was reported as the optimum temperature. Regardless, the biomass productivity of QUCCCM 56 was found to be 35% higher at 40°C, as compared to the highest productivities found by Singh et al (2014) at 30°C, and 18% higher compared to Choix et al (2017) at 28°C. One consideration which should also be taken into account is that in non-temperature controlled cultivation systems (open and closed), the temperature will fluctuate over the course of a diurnal cycle, and even under extreme conditions, continuous temperatures of 45°C are not expected.…”

“…described in literature, differences were found especially in regard to protein contents. Choix et al (2017) and Kim et al (2015) found protein values of 11.4 and 52.6% for Leptolyngbya sp. CChF1 and Leptolyngbya sp.…”

Advances in the biological fixation of carbon dioxide by microalgae

“…observered that Leptolyngbya sp. CChF1 can accumulate biopolymer and has the potential to convert CO 2 from biogas to high value‐added products 116 . However, there are many impacts on microalgae capturing CO 2 in the biogas such as mixing wavelengths and light cycles, but microalgae upgrading biogas is an attractive approach 117 …”