期刊名称：Journal of Environmental Science and Technology
印刷版ISSN：1994-7887
电子版ISSN：2077-2181
出版年度：2019
卷号：12
期号：1
页码：17-25
DOI：10.3923/jest.2019.17.25
出版社：Asian Network for Scientific Information
摘要：Background 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.
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