Growth and Metabolite Production in Chlorella sp.: Analysis of Cultivation System and Nutrient Reduction

Author(s)

Estevam, Bianca Ramos ; Rios Pinto, Luisa Fernanda ; Filho, Rubens Maciel ; Fregolente, Leonardo Vasconcelos

• Document type: Journal article
• Source: BioEnergy Research; v. N/A, p. 12-pg., 2022-10-25.

Abstract

Microalgae are a sustainable source for many bioproduct syntheses. This study shows how different cultivation systems and nutrient concentrations affect Chlorella sp. development. The cultivation was performed in open and closed lab-scale systems. A Tukey test was used to evaluate the significant differences between the microalgae growth and composition under the two systems analyzed. The effect of nitrogen and phosphorus concentration was analyzed with a 2(2) full factorial design. Lipids, carbohydrates, proteins, and pigments were extracted and quantified. The highest specific growth rate (0.52 1/day) was obtained in the open pond, with a cell density of 5.06 x 10(7) cells/mL and a biomass concentration of 1.30 mg/mL. In this condition, the higher concentration of pigments was obtained: 13 mu g/mg of chlorophyll-a, 15 mu g/mg of chlorophyll-b, and 2 mu g/mg of carotenoids. An expressive increase in the lipid (from 17 to 35%) was obtained in low nitrogen and high phosphorus. Protein percentage increases with both nutrients at a higher level, reaching up to 60%. The percentage of carbohydrates decreases from 32 to 13% with phosphorus reduction. Thus, this study points out the conditions that benefit the accumulation of each Chlorella sp. metabolite, contributing to the decision-making for the cultivation and applications of this microalgae. (AU)

• FAPESP's process: 15/20630-4 - Biorefinery development integrated to a bioethanol sugar cane plant with zero CO2 emission: routes to convert renewable resources to bio-products and bio-electricity
• Grantee: Rubens Maciel Filho
• Support Opportunities: Research Projects - Thematic Grants