Cellular viability and growth of microalgae: effect of the culture medium

In Aquaculture, the use of microalgae is fundamental in the first feeding of native fish species, since their optimal nutritional level favors survival. Successful production of microalgae under laboratory conditions depends on the culture medium used during the cryopreservation stage of production. Agricultural fertilizers can be used as a low-cost alternative culture media that promotes cell growth and cryopreservation. The objective was to evaluate the effect of two culture media on population growth (PG) and post-thawing viability (PTV) of three microalgal species (Chlorella sp., Desmodesmus sp., and Ankistrodesmus sp.). The PG and PTV were evaluated for F/2 Guillard and Nutrifoliar® culture media. Instantaneous growth rate (K), doubling time (dt), yield (y), and maximum density (md) were evaluated for PG in both culture media. For VCP, 5 and 10 % methanol was used in six treatments. The PTV was classified as no cell damage (NCD), cell damage (CD), and marked lesions (ML). Population growth did not differ among microalgae (p >0.05). T1 resulted in the lowest dt for Desmodesmus sp., (p <0.05). T2 showed the highest y and md for the three microalgae (p <0.05). Regarding post-thawing cell viability, the highest NCD for Chlorella sp. at day (d) 0 was similar between T3 and T4, and at d 5 it occurred in T6; for Desmodesmus sp., at d 0 it occurred in T6, and at d 5 it was similar between T6 and T1; for Ankistrodesmus sp., at d 0 and d 5 it occurred in T3. It is concluded that the culture medium Nutrifoliar®, is a viable alternative and of low cost for the culture and the cryopreservation of microalgae of fresh water.