2026-03-13T10:50:36Z https://fra.repo.nii.ac.jp/oai

oai:fra.repo.nii.ac.jp:02009838 2025-06-13T07:46:20Z 15

Effects of Hyphomonas Strains on the Growth of Red Algae Pyropia Species by Attaching Specifically to Their Rhizoids 40565561 Fukui, Yohei 福井, 洋平 フクイ, ヨウヘイ Fukui 福井 フクイ Yohei 洋平 ヨウヘイ 90470137 Abe, Mahiko 阿部, 真比古 アベ, マヒコ Abe 阿部 アベ Mahiko 真比古 マヒコ 80372027 Kobayashi, Masahiro 小林, 正裕 コバヤシ, マサヒロ Kobayashi 小林 コバヤシ Masahiro 正裕 マサヒロ Hyphomonas; Pyropia; Marine macroalgae; Rhizoids; Protoplasts; Thalli Bacteria and marine macroalgae form close associations, while various bacteria affect the morphogenesis and growth of macroalgae. Hyphomonas strains exhibit normal morphogenetic activity in protoplasts of the red alga Pyropia yezoensis (nori). However, the effects of the bacteria on the growth of Pyropia from protoplast cells to regenerated thalli remain unknown. Here, we assessed the growth of P. yezoensis and Pyropia tenera using combined cultures of three Hyphomonas strains (LNM10-16, SCM-2, and LNM-9) and three algal media (artificial seawater with vitamins, artificial seawater, and natural seawater) over 7 weeks. Third week after culture, the three Hyphomonas strains showed almost similar levels of normal growth activity for both Pyropia species. However, at 7 weeks, significant differences were observed among the three Hyphomonas strains in terms of length, length-to-width ratio, and normal morphology of Pyropia thalli. LNM10-16 significantly promoted the thalli length and length-to-width ratios of both Pyropia species in artificial seawater without vitamins and natural seawater, compared with the other two Hyphomonas strains. P. yezoensis cultured in artificial seawater with vitamins showed a much higher demand for LNM10-16 in development of the thalli length than P. tenera. These results may be explained by differences in the growth activities of Hyphomonas strains and the nutrient requirements of Pyropia species. Furthermore, the bacteria were more specifically attached to the rhizoid surfaces of both species. This study is the first to reveal that Hyphomonas strains affect the growth of Pyropia species by attaching to their rhizoids. Springer 2023-06-27 eng journal article VoR https://fra.repo.nii.ac.jp/records/2009838 10.1007/s00248-023-02257-z 23332039 水産技術研究所 養殖部門 シラスウナギ生産部 https://link.springer.com/article/10.1007/s00248-023-02257-z SPRINGER LINK 1432-184X 0095-3628 Microbial Ecology 86 13 2502 2514 https://fra.repo.nii.ac.jp/record/2009838/files/Fukui et al. Effects of Hyphomonas strains on the growth of red algae.pdf application/pdf 8 MB 2025-06-13