Effect of pH on growth and lipid accumulation kinetics of the microalga Chlorella vulgaris grown heterotrophically under sulfur limitation. (November 2016)

• Record Type: Journal Article
• Authors: Sakarika, Myrsini; Kornaros, Michael
• Is Part Of: Bioresource technology. Volume 219(2016)
• Page Start: 694
• Page End: 701
• Publication Date: 2016-11
• Subjects: C. vulgaris -- pH -- FAMEs -- Heterotrophic growth -- Sulfur limitation; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2016.08.033
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: C. vulgaris can grow heterotrophically on a wide pH range (5.0–8.0). pH 3.0, 4.0 and 11.0 are extreme for this strain and pH 9.5 causes cell aggregation. Fatty acid profile mainly composed of MUFAs with C18:1 being the dominant one. The optimal pH was found to be 7.5 for both growth and lipid accumulation. The SPV method underestimates intracellular lipids compared to FAME analysis. Abstract: The goal of the present study was to investigate the pH range that can support the growth of C. vulgaris, and, more specifically, to identify the optimal pH for the microalga's growth, under heterotrophic conditions. Furthermore, the effect of pH on the accumulation of intracellular lipids was studied. A wide range of pH values was tested using the respective buffer solutions. The optimal pH for biomass growth and lipid accumulation under sulfur limitation was found to be 7.5, resulting in maximum specific growth rate of 0.541 days −1 and maximum total lipid content of 53.43% g gDW −1 . The fatty acid composition of C. vulgaris was found to be unrelated to pH, as the lipid content did not present significant variations in the pH values tested. The fatty acid profile was mainly composed of monounsaturated fatty acids (MUFAs) with the dominant one being oleic acid (C18:1).