Submerged membrane photobioreactor for the cultivation of Haslea ostrearia and the continuous extraction of extracellular marennine

Abstract

Haslea ostrearia is a marine diatom known to produce and excrete the marenine blue pigment. Its controlled, continuous and intensified cultivation remains a challenge. Thus, a submerged membrane photobioreactor (MPBR) was implemented in order to simultaneously and continuously cultivate H. ostrearia and extract marennine. The MPBR was compared with a similar air-lift photobioreactor (without membrane), both working at a dilution rate equal to 0.1, 0.3 and 0.5 d-1. Contrary to the air-lift photobioreactor, the MPBR successfully operated at high dilution rate without biomass washout. The MPBR allowed continuously recovering marennine and reaching high cell density (555 ± 25 × 106 cells L-1 at D = 0.1 d-1), marennine concentration (36.00 ± 0.02 mg L-1 at D = 0.1 d-1) and marenine productivity (7.20 ± 0.01 mg L-1 d-1 at D = 0.5 d-1).