Algal Resources
Online ISSN : 2423-8473
Print ISSN : 1883-3284
15 巻, 1 号
  • 喜多 郁弥, 岡本 裕太, 團 昭紀, 浜野 龍夫, 岡 直宏
    2022 年 15 巻 1 号 p. 1-7
    発行日: 2022年
    公開日: 2023/06/10
    ジャーナル フリー
    In the seedling production method using Solution Extracted from Homogenized Thalli (SEHT), tissue culture conditions for increasing branch formation from Ulva prolifera subfragments have not been completely optimized yet for land-based cultivation. Thus, we examined the tissue culture conditions of temperature, nutrients and salinity for increasing branch formation from U. prolifera subfragments in the seedling production method using SEHT. For temperature, the average rate of branch formation was 0 % at 5 ℃, 2.8% at 10 °C, increasing to 28.4 % at 15 °C and reached a maximum of 64.0 % at 20 °C. Subsequently, it decreased to 40.0 % at 25 °C. For nutrients, the average of branch formation was 67.2 % when PES as nutrients was not added. When PES was added, the average rate was 72 %, 65.6 %, 65.6 %, 70.4 %, 70.4 %, and 70.8 % at a PES concentration of 0.0125 %, 0.025 %, 0.05%, 0.1% and 0.2 %, respectively. The average rate of branch formation was almost constant regardless of the different PES concentrations. For salinity, the average rate of branch formation was 29.2 to 31.6 % in salinities of 4.8 to 10.6 psu being almost constant, but 38.0 % in salinity of 16.0 psu and 54.0 % in salinity of 27.9 psu indicating increased branch formation in more saline conditions. In the seedling production method using SEHT, we recommend culture conditions for increased branch formation of U. prolifera subfragments as culturing temperature of 20 ℃, salinity of 27.9 psu and without adding nutrients.
Research note
  • Hiroko Tomoyori, Shoji Kondo, Makio Asakawa
    2022 年 15 巻 1 号 p. 9-13
    発行日: 2022年
    公開日: 2023/06/10
    ジャーナル フリー
    Pyropia spp. (Nori) contain nutritional compounds and functional constituents. We previously reported the suppressive effect of the Nori fraction on blood glucose in normal rats. This fraction was 75 % ethanol soluble fraction (NS) and separated using an ultrafiltration membrane with a molecular weight of 1000 Da. The obtained fraction had a molecular weight of less than 1000 Da (NS < 1000) and was used for administration. Patients with diabetes use subcutaneous injections of insulin; however, we would like to develop new orally available functional foods to relieve patients' pain and increase adherence. We assessed the antidiabetic effect of the NS < 1000 fraction orally administered to diabetic/obese KK-Ay mice. The three animal groups (control, 0.5 g/kg B. W., and 2.0 g/kg B. W.) were orally administered the fraction once daily for 7 weeks. Although the NS< 1000 fraction had no significant effect on body and organ weight, the serum insulin levels in the NS < 1000 groups were significantly lower than those in the control group after 4 weeks of administration and a glucose tolerance test. In conclusion, we discovered that the NS < 1000 fraction has constituents that may improve glucose metabolism by saving insulin.