Viabilidade técnica e análise de custos de diferentes meios para o cultivo de Arthrospira platensis

Abstract

The cyanobacteria Arthrospira platensis (A. platensis) is a rich source of essential amino acids, has a high concentration of vitamins and can be used as a feedstock for energy sources such as biofuels. In this sense, the aim of this study was to analyze the technical viability and raise the costs of different means for the cultivation of microalgae A. platensis. Therefore, we used strain of A. platensis, courtesy of the Universidade Federal de Santa Catarina (UFSC). Cultures were grown in 9-day process, ± 30 ° C temperature in shaker, fitted with artificial light, with initial concentration of 50 mg.L-1 in the bioprocess laboratory of Federal University of Triângulo Mineiro (UFTM). Three means were used: T1 - middle standard for cultivation (PAOLETTI et al., 1975), T2 - modified medium for cultivation without trace ( PAOLETTI et al., 1975) and T3 - alternative mean replacing some elements. Growth were analyzed, the maximum concentration (Xmax), Productivity (Px), the maximum specific rate (μmax) and rose the cost of production of 1 kg of biomass by the three proposed treatments. The results were statistically analyzed by analysis of variance with Tukey test (p <0.05). The growth media of the three treatments presented a microbial process with characteristic phases. Xmax ranged from 373.29 ± 100.62 mg.L-1 and 436.17 ± 107.48 mg.L-1, with no significant difference between treatments. The Px ranged from 40.39 ± 12.57 mg.L-1.d-1 and 48.22 ± 13.43 mg.L-1.d-1, and showed also no significant difference between treatments. The μmax ranged from 0,2662 d-1 and 0,3074 d-1 and showed also no significant difference between treatments. The initial investment cost of T1 was R$ 3,117.84, the initial cost of investment in T2 was R$ 2,667.04 represents a cost 14.46% less than the value of T1. The cost in T3 was R$ 1.628,85, the lowest among the three treatments analyzed, representing a cost about 47,76% less than the T1 and 38,93% lower than T2. According to the experimental conditions under which this thesis was researched, it can be concluded that the growth of microalgae showed good technical feasibility for microbial growth followed normality, showing no difference between the treatments. The kinetic parameters and productivity were satisfactory showing no difference between the treatments and the lower initial investment cost was T3, becoming therefore the treatment for use.