Aarhus Institute of Advanced Studies, Aarhus University, Aarhus, Denmark.
J Basic Microbiol. 2023 Aug;63(8):944-956. doi: 10.1002/jobm.202300107. Epub 2023 May 25.
The ecological niche of the recently described limnic microalga Limnomonas gaiensis (Chlamydomonadales) in Northern Europe remains unknown. To decipher the species tolerance capacity to pH, the effects of hydrogen ions on the physiological response of L. gaiensis were investigated. Results showed that L. gaiensis could tolerate exposure from pH 3 up to pH 11, with an optimal survival at pH 5-8. Its physiological response to pH was strain specific. Globally the southernmost strain was more alkaliphilic, had a slightly rounder shape, a slowest growth rate, and a lowest carrying capacity. Despite strain discrepancies among lakes, Swedish strains exhibited similar growth rates, faster at more acidic conditions. The extreme pH conditions affected its morphological features such as the eye spot and papilla shape, especially at acidic pH, and the cell wall integrity, at more alkaline pH. The wide range tolerance of L. gaiensis to pH would not be a hindrance to its dispersal in Swedish lakes (pH 4-8). Notably, the storage of high-energetic reserves over a wide range of pH conditions, as numerous starch grains and oil droplets, makes L. gaiensis a good candidate for bioethanol/fuel industrial production and a key resource to sustain aquatic food chain and microbial loop.
最近在北欧发现的淡水微藻 Limnomonas gaiensis（Chlamydomonadales）的生态位仍不清楚。为了解析该物种对 pH 值的耐受能力，研究了氢离子对 L. gaiensis 生理反应的影响。结果表明，L. gaiensis 可耐受 pH 3 至 pH 11 的暴露，最适生存 pH 值为 5-8。其对 pH 值的生理反应具有菌株特异性。总体而言，最南端的菌株更偏碱性，形状略呈圆形，生长速度最慢，承载能力最低。尽管各湖泊之间的菌株存在差异，但瑞典的菌株表现出相似的生长速度，在酸性条件下更快。极端的 pH 值条件会影响其形态特征，如眼点和乳突形状，尤其是在酸性 pH 值条件下，以及细胞壁完整性，在碱性 pH 值条件下。L. gaiensis 对 pH 值的广泛耐受不会阻碍其在瑞典湖泊中的扩散（pH 值 4-8）。值得注意的是，L. gaiensis 在广泛的 pH 值条件下储存大量高能储备，如大量淀粉粒和油滴，使其成为生物乙醇/燃料工业生产的良好候选者，也是维持水生食物链和微生物环的关键资源。
