Ảnh hưởng của tốc độ dòng chảy lên sinh trưởng của vi tảo biển (Nannochloropsis oculata & Isochrysis galbana) nuôi trong hệ thống ống

Study on the effect of liquid velocities on growth of Nannochloropsis oculata and Isochrysis galbana cultured in tubular photobioreactor were carried out in National Breeding Center for Southern Marine Aquaculture, Research Institute for aquaculture No.2. Six identical systems were designed by acrylic pipe, have a cultured volume of 85 litters, 60 cm in light-path and 34 meters in length. Each experiment consisted of three treatments are liquid velocities at 0,2-0,3 m.s-1,  0,4-0,5  m.s-1 and  0,6-0,7  m.s-1;  two  replicates,  the  experiment  was  repeated  in  two times. The results pointed up this parameter effect the growth of both microalgal species. At liquid  velocity  of  0,6-0,7  m.s-1,  N.  oculata  reached  maximal  density  at  520,31  milllion cells.ml-1 higher than those at 0,4-0,5 m.s-1 was 427,50 million cells.ml-1, but the difference was not significant. The population was not able to reach maximal density and collapsed at 0,2-0,3 m.s-1. In case of I. galbana, there was no difference between liquid velocities at 0,4-0,5 and at 0,6-0,7 m.s-1, the population reached maximal at 32,38 and 33,38 million cells.ml-1, respectively; at 0,2-0,3 m.s-1, I. galbana cell was not able to multiplied. The obtained results demonstrated that  novel  tubular  photobioreactor can  improve the  technology  of  microalgal culture but optimising the designed system is one of the necessary steps before applying on each species.