Utilization of solid residue from shrimp culture biofloc system for microalgae Navicula sp. Production

Abstract

The objective of this study was to evaluate the growth of microalgae Navicula sp. using solid residue from a biofloc cultivation system as culture medium compared to Conway medium. Two experiments were conducted with and without the addition of trace metals, in which each experiment had five treatments with three replicates each: R0C100 (100% Conway); R25C75 (25% residue and 75% Conway); R50C50 (50% residue and 50% Conway), R75C25 (75% residue and 25% Conway) e R100C0 (100% residue). The cultures were performed in Erlenmeyer flasks of 1 L for 10 days, with full photoperiod and initial innoculum of 5x10⁴ cells ml^-1. Daily counts were carried out to monitor the maximum cell density, doubling time and growth rate. The pH and temperature were measured at the beginning and at the end of the experiments. For statistical analysis were used the Cochran, Shapiro Wilk, ANOVA and Tukey (P <0.05) tests. The pH and temperature remained within the cultivation patterns in the two experiments. The culture medium with shrimp culture biofloc residue had similar result to the Conway medium, and displayed satisfactory for the development of microalgae Navicula sp., highlighting that the presence of trace metals has encouraged the growth of the species.