Evaluation of the effects of immobilization on Spirulina platensis cultures

Different studies are carried out to reduce the production costs of Spirulina platensis biomass, which is produced in liquid cultures and has a high commercial value. These studies are in the direction of determining the optimum production method by changing the nutrient medium content and culture conditions. Immobilization is a method that changes the culture conditions. In our study, Luffa cylindrica (luffa), a natural fiber, was used for the immobilization of S. platensis cells, and the growth parameters and pigment production of the cultures were investigated. In two-factor experiments, week (first and second weeks) and culture type (free and immobilized cultures), statistically significant week*culture type interactions were found in optical density, dry weight, pH, and chlorophyll-a content. Immobilization did not increase the optical density and biomass production of the cultures. The highest optical densities and biomass productions were obtained in two-week-old free cultures, where the pH value was also found to be the highest. The highest values of chlorophyll-a and total carotene content were obtained from one-week immobilized cultures (30.06 µg/ml and 48.35 µg/ml, respectively). The fact that immobilization increased pigment production in one-week-old cultures indicates that when pigment production is targeted in S. platensis cultures, two-stage cultures that increase pigment yield via one-week immobilization after biomass production is completed can be used.