Salt and Seawater Science & Technology
Online ISSN : 2435-4619
  • Masao Tokunaga, Tsutomu Arakawa, Yuhei Tokunaga, Matsujiro Ishibashi
    2021 年 2 巻 p. 1-2
    発行日: 2021年
    公開日: 2021/03/29
    ジャーナル オープンアクセス
    Soluble expression of halophilic starch-binding domain (SBD1) from Kocuria α-amylase was low due to its instability in recombinant host Escherichia coli cells. Here, the stable SBD1 protein was expressed efficiently with an aggregation-prone peptide tag in insoluble E. coli inclusion bodies (IBs). Insoluble SBD1 protein with the tag, thus obtained, was easily solubilized with 8 M urea and refolded into an active form by simple urea dilution. The yield of active SBD1 with the tag after the solubilization / dilution method was 15 ~ 30 times higher than that of direct expression of SBD1 in soluble fraction.
  • Ryota Kataoka
    2021 年 2 巻 p. 3-9
    発行日: 2021年
    公開日: 2021/06/11
    ジャーナル オープンアクセス
     The Piran region is famous for salt production in Slovenia. The salt produced in Piran is familiar for its good quality and taste. In the Piran saltern, the bottom of the crystallization ponds used in the salt production process is covered with a microbial mat (called “Petola”) and tends to be cultivated in order to prevent the mixing of mud underneath with precipitated crystals of salt (halite). Petola's microbiological ecology has been studied. However, although Piran salt is known to have a unique umami taste, the relationship between microbes and umami taste remains unknown. Therefore, the purpose of this study is to measure glutamic acid, a source of the umami taste, in various salt products and to investigate the microbial community in salt products. Results showed that glutamic acid was detected in eight of the 35 products measured in this study and all the salt products in which glutamic acid was detected were made in solar salterns. Moreover, this study revealed that Piran salts contain higher concentrations of glutamic acid, one source of the umami taste, than the other salt products. Besides, bacterial diversity in salt products was also relatively high in Piran traditional salt, suggesting that halophilic microorganisms may be produced by complex interactions with dissolved organic matter in seawater or salterns to generate the umami taste.