Journal of Environmental Science and Technology1994-78872077-2181Asian Network for Scientific Information10.3923/jest.2019.17.25SuzukiYoshihiro NakadaKoki NukazawaKei YamanishiHiroyuki 12019121Background and Objective: Treated sewage (TS) has great potential as a nutrient resource for seaweed cultivation. However, there is little information on using the nutrients in the treated sewage for seaweed cultivation because seaweed cannot live in freshwater, such as TS. In this study, the optimum salinity with mixing seawater and TS for the growth of the valuable seaweed Pyropia yezoensis (seaweed laver "nori") was determined using a micro-well plate bioassay. Materials and Methods:Pyropia yezoensis conchospores were released from the mature conchocelis in the filtered and sterilized natural sea water. To carry out a bioassay using juvenile sporophytes, the spores were cultivated in a micro-well plate. The maximum fluorescence intensity of chlorophyll was determined to reflect response in the bioassay using a micro-well plate. The effects of salinity on spore and sporophytes were tested over a range of salinity concentrations (0-60 per-mil, %). The effect of TS addition on spore growth was examined using the spore bioassay, varying the mix ratio of TS and artificial seawater. The nutrient requirement for the early development stage of P. yezoensis was investigated using the spore bioassay. The concentration of the nutrients in the enriched seawater was prepared by adjusting the concentration of PES medium. Results: An appropriate ratio of treated sewage: Seawater kept the salinity at 20%, which was optimum for spore germination and sporophyte growth. In addition, the nutritional requirement at the early stage of P. yezoensis growth and development was investigated. The nutrients contained in 100% TS were insufficient for maximum growth of P. yezoensis. Conclusion: Since the TS is useful to promote growth of the variable seaweed as a fertilizer, lowering of salinity becomes the limit factor of the growth. Mixing TS with seawater to keep the salinity at 20% and to maintain as high a nutrient concentration in the culture environment as possible, could promote P. yezoensis production.]]>Verstraete, W. and S.E. Vlaeminck,201118253264Aznar-Sanchez, J.A., L.J. Belmonte-Urena, J.F. Velasco-Munoz and F. Manzano-Agugliaro,201819811201132Mo, W. and Q. Zhang,2013127255267Zijp, M.C., S.L. Waaijers-van Der Loop, R. Heijungs, M.L.M. Broeren and R. Peeters et al.,2017197221230Ryther, J.H., J.C. Goldman, C.E. Gifford, J.E. Huguenin and A.S. Wing et al.,19755163177Fang, L.L., B. Valverde-Perez, A. Damgaard, B.G. Plosz and M. Rygaard,201688538549Taube, N., J. He, M.C. Ryan and C. Valeo,20162016Tomita, A., Y. Nakura and T. Ishikawa,201519393404Diez, I., A. Santolaria, N. Muguerza and J.M. Gorostiaga,2013843142Murayama, F., Y. Shimizu and S. Takagi,201581107114Troell, M., P. Ronnback, C. Halling, N. Kautsky and A. Buschmann,19991999pp: 603-611pp: 603-611Chopin, T., A.H. Buschmann, C. Halling, M. Troell and N. Kautsky et al.,200137975986Hernandez, I., M.A. Fernandez-Engo, J.L. Perez-Llorens and J.J. Vergara,2005Sparus auratus waste waters.]]>17557567Cahill, P.L., C.L. Hurd and M. Lokman,2010306153159Wang, X., L.M. Olsen, K.I. Reitan and Y. Olsen,20122267283Anibal, J., H.T. Madeira, L.F. Carvalho, E. Esteves, C. Veiga-Pires and C. Rocha,2014Ulva rigida and Enteromorpha clathrata.]]>211332413334Kevekordes, K.,2000Hormosira banksii (Phaeophyceae).]]>35365371Anderson, B.S. and J.W. Hunt,1988Macrocystis pyrifera (Agardh): A preliminary report.]]>26113134De Barreda Ferraz, D.G., C. Sabater and J.M. Carrasco,200456315320Paixao, S.M., L. Silva, A. Fernandes, K. O'Rourke, E. Mendonca and A. Picado,200817165171Vendrell, E., D.G.B. Ferraz, C. Sabater and J.M. Carrasco,200982538542Provasoli, L.,19681968pp: 47-74pp: 47-74Takami, T., T. Maruyama, Y. Suzuki and A. Miura,1997Porphyra yezoensis.]]>5667180Weber, C.I.,19934th Edn.,Japanese Industrial Standards Committee,19981998Yamauchi, K.,197339489496Pereira, D.T., C. Simioni, E.P. Filipin, F. Bouvie and F. Ramlov et al.,2017Acanthophora spicifera (Rhodophyta, Ceramiales).]]>31555565Bollen, M., C.A. Pilditch, C.N. Battershill and K. Bischof,2016Undaria pinnatifida and native New Zealand kelps: Implications for competition.]]>2016Doblin, M.A. and M.N. Clayton,1995122689698Pereira, R., G. Kraemer, C. Yarish and I. Sousa-Pinto,2008Porphyra dioica (Bangiales, Rhodophyta) under controlled-culture conditions.]]>43107118Ueki, C., A. Murakami, T. Katoh, N. Saga and T. Motomura,2010Porphyra yezoensis.]]>76375382Niwa, K. and K. Harada,2013Pyropia yezoensis f. narawaensis (Bangiales, Rhodophyta).]]>439113118Purnama, A., H.H. Al-Barwani and M. Al-Lawatia,20031554147Lattemann, S. and T. Hopner,2008220115Nwoba, E.G., N.R. Moheimani, B.E. Ubi, J.C. Ogbonna, A. Vadiveloo, J.R. Pluske and J.M. Huisman,20172271523Yang, L., B. Si, X. Tan, H. Chu and X. Zhou et al.,2018266349356