Hentschke Guilherme Scotta, Semedo Miguel, Ciancas Jimmy, Hoepfner Claudia, Guzmán Daniel, Rivera Daniela S, Vasconcelos Vitor M
CIIMAR/CIMAR-LA-Terminal de Cruzeiros do Porto de Leixões, Matosinhos, Portugal.
Fundación PROINPA, Cochabamba, Bolivia.
Front Microbiol. 2025 Jul 23;16:1650455. doi: 10.3389/fmicb.2025.1650455. eCollection 2025.
The Bolivian Altiplano presents extreme environmental conditions, including high altitude, intense UV radiation, low precipitation, freezing temperatures, and saline to alkaline waters. Despite these harsh settings, cyanobacteria thrive in microbial mats, although their diversity remains poorly characterized. This study aimed to explore the morphological and molecular diversity of cyanobacterial mats and their associated microbiomes in saline and freshwater ecosystems of the Bolivian Altiplano. Morphological analyses revealed seven distinct cyanobacterial morphotypes affiliated with Nostocaceae, Coleofasciculaceae, Rivulariaceae, and Microcoleaceae. Amplicon-based analysis of the 16S rRNA gene identified 4.113 ASV for the bacterial community. Of these, 310 were identified as Cyanobacteria, with 134 classified as Cyanophyceae assigned to 32 genera. Phylogenetic reconstruction and sequence identity comparisons resolved 42 cyanobacterial genera across nine orders. Moreover, 30 ASVs grouped into 16 clades unrelated to any known genus, suggesting the presence of potentially novel cyanobacterial lineages. The microbiome associated with these mats was dominated by Alphaproteobacteria, Bacteroidia, Gammaproteobacteria, Clostridia, Cyanophyceae, and Campylobacteria. Functional predictions based on 16S rRNA gene profiles indicated a predominance of phototrophic and chemoheterotrophic metabolisms, along with sulfur respiration, nitrogen fixation, nitrate and nitrite reduction, and fermentation pathways. Notably, nitrogen-fixing cyanobacteria and bacterial groups with bioremediation potential were prevalent, highlighting the ecological importance and possible biotechnological applications of these microbial consortia. This is the first comprehensive metabarcoding analysis of cyanobacterial mats from Bolivia, including their associated microbiomes. Many new bacterial and cyanobacterial taxa remain to be described in these ecosystems. Based on the functional genomic analysis, this work also highlights the great unexplored biotechnological potential of Bolivia's extreme environments and the functional roles of microbial mats in biogeochemical cycling under polyextreme conditions.
玻利维亚高原呈现出极端的环境条件，包括高海拔、强烈的紫外线辐射、低降水量、低温以及盐碱化至碱性的水体。尽管环境恶劣，但蓝藻在微生物垫中却十分繁茂，不过其多样性仍未得到充分描述。本研究旨在探索玻利维亚高原盐碱和淡水生态系统中蓝藻微生物垫及其相关微生物群落的形态和分子多样性。形态学分析揭示了七种不同的蓝藻形态类型，它们隶属于念珠藻科、鞘丝藻科、胶须藻科和微鞘藻科。基于扩增子的16S rRNA基因分析确定了细菌群落的4113个扩增子序列变体（ASV）。其中，310个被鉴定为蓝藻，134个属于蓝藻纲，分属于32个属。系统发育重建和序列同一性比较解析了九个目内的42个蓝藻属。此外，30个ASV归入16个与任何已知属无关的分支，这表明可能存在潜在的新蓝藻谱系。与这些微生物垫相关的微生物群落主要由α-变形菌纲、拟杆菌纲、γ-变形菌纲、梭菌纲、蓝藻纲和弯曲杆菌纲组成。基于16S rRNA基因图谱的功能预测表明，光养和化学异养代谢占主导地位，同时还有硫呼吸、固氮、硝酸盐和亚硝酸盐还原以及发酵途径。值得注意的是，具有生物修复潜力的固氮蓝藻和细菌类群普遍存在，凸显了这些微生物群落的生态重要性和可能的生物技术应用。这是对来自玻利维亚的蓝藻微生物垫及其相关微生物群落的首次全面元条形码分析。在这些生态系统中，许多新的细菌和蓝藻分类单元仍有待描述。基于功能基因组分析，这项工作还突出了玻利维亚极端环境中尚未开发的巨大生物技术潜力以及微生物垫在多极端条件下生物地球化学循环中的功能作用。
