Biomass and pigments production of the mixed culture of microalgae (Hyaloraphidium contortum and Chlorella vulgaris) by cultivation in media based on commercial fertilizer

For the mixed culture of Chlorella vulgaris and Hyaloraphidium contortum, was determined the effect of different sources of nutrients (Nitrofoska ®, Poliverdol ® and Guillard) on the production of photosynthetic pigments and biomass. Bioassays were performed in quadruplicate in batch cultures maintained in aeration and continuous illumination. The growth was determined by cell counting and the production of pigment by spectrophotometry. The cell density increased with time of planting, obtaining maximum production at 24 days with an average of 1.38 104±5603.94; 1.09 104 ± 29.125 and 3.04 104± 8.900 cells mL-1 in Nitrofoska®, Poliverdol® and Guillard, respectively. The pigment (chlorophyll a and b and carotenoids) production was moderated (1.11 μg mL-1 at 24 days) in the medium Guillard during all-time research. Commercial agricultural fertilizers are an alternative source of nutrients for growth and pigment production in the mixed culture of microalgae

Influence of vitamin c and e enriched feeding on growth and chemical composition of red tilapia (Oreochromis spp.)

The objective of this study was determining the influence of enriched feeding with vitamin C and E on growth and chemical composition of red tilapia (Oreochromis spp.). A completely randomized design was used in this experiment. No statistically significant differences were observed for humidity, while all other parameters evaluated in this study showed differences. The results obtained showed enhanced growth in terms of size, weight and growth rate, and a 100% survival in the fish using the combination of vitamin C and E. The chemical characterization indicated that protein ranged from 20.36% to 21.56%, humidity from 73.04% to 76.52%, ash from 1.29% to 3.27% and ether extract from1.83% to 3.23% for treatments 1 and 4. The obtained results suggest that the fish growth increased and red tilapia steaks have high nutritional value using the fodder in combination with vitamin C and E