Growth kinetics of the microalga Pseudokirchneriella subcapitata (Korshikov) Hindak (Chlorophyceae) in natural water enriched with NPK fertilizer

Abstract

Microalgae can have multiple functions in biotechnological studies, but it is necessary to encourage research to bioprospect and know the intrinsic characteristics of these microorganisms. Thus, the aim of this study was to evaluate the growth kinetics of Pseudokirchneriella subcapitata in an alternative culture medium prepared with natural water that was enriched with the chemical fertilizer NPK (20-5-20). Three treatments were designed to evaluate growth kinetics: (T1) 200 mL of autoclaved distilled water, (T2) 200 mL of autoclaved natural water, and (T3) 200 mL of natural water that was notautoclaved. All of the treatments were performed in triplicate and 200 mL of NPK and 100 mL of P. subcapitata culture were added. With this design, we expected to observedifferences in the population growth of the microalga that were a function of thecompetition with the native species present in the test treatments. However, this was not observed, and the treatments did not result in significant differences in algal density (analysis of covariance [ANCOVA] F2,50 = 1.43, p = 0.25). Instead, all cultures displayed high productivity, tolerance to fluctuations in the pH of the medium, and growth in analternative low-cost medium (NPK). Thus, it was possible to conclude that microalgae have great potential for biotechnological studies, both in bench and industrial scales