Marine microalgae co-cultured with floc-forming bacterium: Insight into growth and lipid productivity
Chin Sze Yee, Victor Tosin Okomoda, Fakriah Hashim, Khor Waiho, Siti Rozaimah Sheikh Abdullah, Cosmas Chidiebere Alamanjo, Hassimi Abu Hasan, Emienour Muzalina Mustafa, Nor Azman Kasan
Abstract
This study investigated the effect of co-culturing microalgae with a floc-forming bacterium. Of the six microalgae isolated from a biofloc sample, only Thalassiosira weissflogii , Chlamydomonas sp. and Chlorella vulgaris were propagated successfully in Conway medium. Hence, these species were selected for the experiment comparing microalgae axenic culture and co-culture with the floc-forming bacterium, Bacillus infantis . Results obtained showed that the co-culture had higher microalgae biomass compared to the axenic culture. A similar trend was also observed concerning the lipid content of the microalgae-bacterium co-cultures. The cell number of B. infantis co-cultured with T. weissflogii increased during the exponential stage until the sixth day, but the other microalgae species experienced a significant early reduction in cell density of the bacteria at the exponential stage. This study represents the first attempt at co-culturing microalgae with B. infantis , a floc-forming bacterium, and observed increased biomass growth and lipid accumulation compared to the axenic culture.