Development of Cheap and Simple Culture Medium for the Microalgae Nannochloropsis sp. Based on Agricultural Grade Fertilizers Available in the Local Market of Gaza Strip (Palestine).

The unicellular marine microalgae Nannochloropsis sp. is one of the most common live feed used in the field of aquaculture. The high cost of the culture medium which supports an optimal growth of the algae however is still one of the main problems related to the large scale culture of Nannochloropsis sp. In this study, an attempt was made to develop a cheap and simple medium for Nannochloropsis sp. based on agricultural grade fertilizers available in the local market of Gaza Strip. Five different culture media, “A”, “B”, “C”, “D”, and “E” were tested and compared to F/2 medium which is commonly used for microalgae cultivation in commercial aquaculture. Medium “A” which consists of a combination of agricultural fertilizers such as ammonium sulfate (150 mg^-l), urea (7.5 mg^-l), calcium superphospate (25 mg^-l), micronutrient solution (0.5 mg^-l) and vitamin solution (0.5 ml^-l) resulted in maximum average cell density of 69 ×10⁶ ml^-1. Medium “A” was also found to be highly economical, since it is about thirteen times cheaper than F/2 medium. The results of the present study suggest that agricultural fertilizers are an excellent substitute that can be used for the cultivation of microalgae.

Key words: Nannochloropsis sp.; cost; culture medium; agricultural fertilizer; Gaza Strip