Effects of Fe fertilizer eluate on the growth of Sargassum horneri at the germling and immature stages

Abstract

To aid in the restoration of coastal barren ground areas, it is important to clarify the effects of chelated iron on the growth of seaweed. In particular, for the further development of practical methods to promote seaweed growth, Fe-binding organic ligands, such as humic substances (HSs) composed of humus materials, rather than Fe-binding inorganic ligands, such as ethylenediaminetetraacetic acid (EDTA), should be investigated. In this study, the effects of an Fe-fertilizer, made from HSs and steelmaking slag, on the growth of Sargassum horneri at the germling and immature stages were examined. The addition of the Fe-fertilizer eluate containing Fe-organic ligand complexes clearly promoted the growth of Sargassum horneri at the germling and immature stages. It was also clear that the effect of Fe concentration in the Fe-fertilizer eluate on the growth rate was almost the same as that of Fe-EDTA. Moreover, the addition of the Fe-fertilizer eluate had a great effect on the brown color of Sargassum horneri thalli and promoted the increased content of photosynthetic pigments, such as Chl. a. Based on these experimental results, the application of the Fe-fertilizer containing Fe-organic ligand complexes is expected to become an effective method for the restoration of the barren ground phenomenon in Fe-deficient coastal areas.

Contrasting effects of blue and red LED irradiations on the growth of Sargassum horneri during the germling and immature stages

“…Fertilized eggs of Myagropsis myagroides and S. patens were collected in the same nursery house for comparison. Fertilized eggs of each Sargassaceae species were rinsed with filtered seawater, poured into amber glass bottles (500 mL) filled with filtered seawater, and stored at 4°C (Nagai et al 2014;Miki et al 2016).…”

“…Immature S. horneri is attached to ropes or concrete blocks and cultured in coastal areas (Akimoto et al 2010). During the artificial cultivation of S. horneri at the early stage in indoor tanks, precisely controlling the environmental factors, such as temperature, nutrients, and light, is required (Hurd et al 2014;Nagai et al 2014;Miki et al 2016).…”

Toxicological study for phenol using germling growth of the brown macroalga Sargassum horneri

“…Fertilized eggs of female S. horneri were collected on May 9, 2016 in a nursery greenhouse of the Sakai Ovex Co., Fukui Prefecture, Japan. The eggs were rinsed with filtered seawater, poured into 500-ml amber glass bottles filled with filtered seawater, and stored without light illumination in a refrigerator at 4°C until use following protocols by the previous studies (Nagai et al 2014;Miki et al 2016a;Miki et al 2016b).…”

“…The basic culture medium was seawater pumped from the ocean at a depth of 320 m around the Noto Peninsula of the Ishikawa Prefecture in Japan. This seawater was filtered through a 0.45-μm-pore membrane, sterilized by autoclaving at 121°C for 20 min Yamato,Japan), and stored in a refrigerator at 4°C following protocols by the previous studies (Nagai et al 2014;Miki et al 2016a;Miki et al 2016b).…”

“…S. horneri is an ecologically-and economically-important seaweed that provides fishery products and food for human consumption. In addition, it is a potential bioenergy resource (Choi et al 2008;Pang et al 2009;Nagai et al 2014;Miki et al 2016a). Miki et al (2016b) reported that fertilized eggs of S. horneri stored in a refrigerator for approximately 170 days grew just as successfully as eggs stored for shorter periods.…”