**1. Introduction**

This research is in a pilot's plant phase and with the same one it is sought to interpret the behavior of the growth, carotenogenesis and protein contain of the microalga *Dunaliella salina* cultivated in synthetic medium with addition of a source of inorganic or organic carbon. The growth was measured with the purpose of evaluating its development under different culture conditions, since this can facilitate the decrease of the production costs in a climbed bigger. With the same principle the carotenogenosis was evaluated, to look for that fertilizer or which are those that increase the concentration of this pigment so important for the human health for its high nutritious value. If one wants to achieve a quick growth and development of this algae is an indispensable requirement the employment of near areas to salines,

fundamentally those that are not subjected to the commercial exploitation of the salt, to have bigger area readiness, what represented a bigger net production. The culture medium that intends with this work is since of novel character, until the moment it has been planted in the existent bibliography that this microalgae species is not able to grow in a nutritive medium that its base of carbon is organic, reason because it is the first time that is cultivated in this way.

Among their perspectives uses, the culture in areas near natural saline, is the best option for commercial exploitation, also as high rate ponds. The lack of vitamins in the human feeding is a problem of world character, for what is indispensable to increase the sources of these, to achieve the man's bigger survival. A way of achieving this end is with the culture of *D. salina*, which is able to accumulate a great quantity of Beta-carotene, a biological precursor of the vitamin "A", which transforms it in this when are being ingested by the man and it is not toxic to the human organism like in the case of the ingest of synthetic vitamin "A" pills; for what that biological practice is of fundamental importance.

In the current world, the microalgae cultivation is of great interest, due to the uses but diverse that one makes of these, since they can be used in the production of food animal and human, as aide of high value, as chemical and biochemical products, as fertilizer and in the purification of polluted waters, among others [1, 2].

The microalgae *D. salina* that belong to the class Chlorophyceae and to the order Dunaliellales is of great importance for the man, since it is the fundamental natural source of the ß-carotene or provitamin "A". The ß-carotene is recognized by its high one to be able to as antioxidant, what is the same thing an anti-carcinogenic of having proven effectiveness that can be used also as coloring [3], in the alimentary industry (mayonnaise's, pastry, bakery, soups, juices, jells, etc.).

At the present time several countries are devoted to the commercial exploitation of the *D. salina*, among them the main ones are Australia and Israel, both although they use different technologies, they have been able to obtain a sustained production of this microalga.

Australia, the main producer of natural ß-carotene, not uses salt lakes dedicated to the exploitation of the salt, with very little energy expense but with use of big extensions of lands of which they prepare with easiness in this country. Israel uses high-speed lagoons with land saving but with more energy expense. Other countries have also attempted new cultivation technologies to increase the production of this microalga with the smallest possible cost.

In Cuba we have been carried out several studies to find the solutions, as culture medium, but economic and offer a high yield, for this in the Fisheries Industry Ministry (MIP) the work has been guided in two ways: one with a medium of where the source of carbon is organic and it comes from the residual waters of the fishing industry and another with a inorganic carbon that tries to substitute the conventional nutrients for its use in the salines. This in turn can use a source of inorganic or organic carbon, in dependence of the requirements of the cultivation.
