Effects of nitrogen and phosphate in medium for Pyropia tenuipedalis thalli

Abstract

We investigated the relationship between the nutrients (nitrogen and phosphorus) in the medium and the total amino acid of in Pyropia tenupedalis thallus. The aim of this study is finding a new medium that will increase the total amino acid content in P. tenuipedalis thallus. First, we investigated the relationship between the total amino acid content and Nitrogen and Phosphorus content in P. tenuipedalis thallus. As a result, a positive correlation was found between total amino acid content and N content. Next, we examined the relationship between the presence and absence of nitrogen and phosphorus in the medium and the N and P contents in P. tenuipedalis thallus. In this study, modified 1/2 SWM-III medium was used as the reference medium. As the result, in the medium supplemented with no phosphorus, although the P content decreased, the N content was the highest. Finally, based on the above results, we newly prepared mediums with 50% and 10% phosphorus to the reference medium. We measured the growth, the effective quantum yields (Φ_II) and dry weight of cultured with them, analyzed N and P contents. In the medium with the 10% phosphorus to the reference medium, the N content in P. tenuipedalis increased and the P content in was retained. In addition, the growth of the thallus cultured in the medium was also maintained. From the above results, it is considered that a medium in which the amount of phosphorus contained in modified 1/2 SWM-III medium is reduced to 10% is suitable for land cultivation of P. tenuipedalis.