Enhancing algal biomass and lipid production through bacterial co-culture

• Published in: Biomass & bioenergy 2019-03, Vol.122, p.280-289
• Main Authors: Berthold, David Erwin, Shetty, Kateel G., Jayachandran, Krishnaswamy, Laughinghouse, H. Dail, Gantar, Miroslav
• Format: Article
• Language: English
• Subjects: Algae screening; Characium; Co-culture; Lipid productivity; Microalgae; Pseudomonas
• ISSN: 0961-9534; 1873-2909
• DOI: 10.1016/j.biombioe.2019.01.033

Renewable energies, such as biofuels from algae, are a promising approach to deviate from fossil fuels. Mass algae cultivation requires better control over algae culture including taking advantage of co-cultivation with growth and lipid-promoting microorganisms. Integrating co-cultures into algal biotechnology can be beneficial in achieving enhanced yields and reduced expenditures. This work uses the co-cultivation of an alga with bacteria to simultaneously increase biomass and lipid productivities in algal cultures. Growth and lipid-promoting microbial cell-free filtrates were used to test for possible effects of bacterial extracellular compounds. Our results show that both the presence of bacterial cell as well as cell-free filtrate from one particular strain of bacteria, Pseudomonas composti, promoted the increase in biomass yield and lipid within freshwater Characium sp. 46-4. These results indicate that unidentified extracellular compounds released by bacteria can affect the growth rate and lipid metabolism of algae. •Screening of green microalgae revealed low lipid and biomass productivities when rendered axenic.•Characium sp. 46-4 was selected as a moderate lipid producer with high biomass capabilities.•Screening of Characium sp.46-4 with 39 bacteria revealed a bacterium capable of stimulating both algal biomass and lipid content.•Algal-bacterial co-cultures success depends on cultivation parameters.