bioRxiv preprint doi: https://doi.org/10.1101/2021.03.20.434239; this version posted March 20, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 1 Internal microbial zonation assists in the massive growth of marimo, a lake ball of 2 Aegagropila linnaei in Lake Akan 3 Ryosuke Nakai,1,* Isamu Wakana,2 Hironori Niki1,3,¶ 4 1 Microbial Physiology Laboratory, Department of Gene Function and Phenomics, National 5 Institute of Genetics, 1111, Yata, Mishima, Shizuoka 411-8540 Japan 6 2 Kushiro International Wetland Center, 7-5 Kuroganecho, Kushiro, Hokkaido 085-8505, Japan 7 3 Department of Genetics, SOKENDAI (The Graduate University for Advanced Studies), 1111, 8 Yata, Mishima, Shizuoka 411-8540 Japan 9 * Present address: Microbial Ecology and Technology Research Group, Bioproduction Research 10 Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1, 11 Tsukisamu-higashi, Toyohira-ku, Sapporo, Hokkaido 062-8517 Japan 12 ¶ Correspondence to: Hironori Niki, Microbial Physiology Laboratory, Department of Gene 13 Function and Phenomics, National Institute of Genetics, 1111, Yata, Mishima, Shizuoka 411- 14 8540 Japan; E-mail:
[email protected]; Tel: +81-55-981-6827; Fax: +81-55-981-6870 bioRxiv preprint doi: https://doi.org/10.1101/2021.03.20.434239; this version posted March 20, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 15 Abstract 16 Marimo (lake ball) is an uncommon ball-like aggregation of the green alga, Aegagropila linnaei.