Reduction of algal wall-growth biofilm for the cultivation of Chlorococcum in photobioreactors using commercial surfactants and floating plastic media

Abstract

During the cultivation of Chlorococcum humicola in photobioreactors (PBRs), significant biofilm formation occurred, leading to light limitation and lower productivity. This work presents the possibility of using commercial surfactants to reduce wall-growth biofilm in PBRs. Results confirm that sodium dodecyl sulfate (SDS) at 0.0082 mM can successfully control wall-growth biofilm in the cultivation of C. humicola more than CTAB and Triton X-100. The addition of SDS into 2-L PBRs, built from either acrylic or glass, results in 68–158 % and 28–43 % increases in algal biomass concentrations compared to those without SDS addition. PBRs applying with SDS at the start of the cultivation can be operated for 23 days without stopping aeration to remove biofilm. Both SDS and floating plastic media were effective in algal biofilm control when applying in 60-L PBRs. The addition of SDS is seen to offer a practical solution to reduce algal biofilm on both glass and acrylic surfaces and promote higher biomass concentration during the cultivation.