Abstract

Increased employment of microalgae for applications as food additives, biofuels, pharmaceuticals and waste treatment also increases effluent production. The aim of this work was to evaluate the effect of different media on Chlorella sorokiniana microalgae growth and of the obtained cultivation effluents on lettuce (Lactuca sativa) seeds germination. The microalgae were grown in different media during 27 days. The higher maximum specific growth rate (µmax) among the evaluated media was obtained in the mixotrophic growth phase with a novel medium composed of 50% NPK medium and 50% Bold Basal medium added of glucose (1 g L-1). Cells grew in Bold Basal and NPK media presents very close µmax values, which indicates that NPK may be a good option for low-cost microalgae productions. The effluents were separated and utilized for seeds germination. After 10 days of germination, the results did not show differences in the germination rate when comparing treatments to control. The effluent did not cause any toxicity in the germination of the lettuce. Thus, Chlorella sorokiniana cultivation combined to horticulture can be utilized as a feasible productive integrated system.

Key words: Growth parameters, Organic fertilizers, Horticulture; Plant development; Waste.