de Paula Rayan Silva, E Souza Clara Carvalho, Gonçalves Carlos Alberto Xavier, de Holanda Moura Marcelo Victor, Guañabens Anna Carolina Paganini, Andrade Gabriela Rabelo, Nascimento Andréa Maria Amaral, Cardoso Antonio Valadão, de Paula Reis Mariana, Jorge Erika Cristina
Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil.
Centro de Bioengenharia de Espécies Invasoras de Hidrelétricas (CBEIH), Avenida José Cândido da Silveira, 2100 - Cidade Nova, Belo Horizonte, MG, 31035-536, Brazil.
Braz J Microbiol. 2024 Mar;55(1):639-646. doi: 10.1007/s42770-024-01245-w. Epub 2024 Jan 12.
Iron (Fe) is the fourth most abundant element on the planet, and iron-oxidising bacteria (FeOB) play an important role in the biogeochemical cycle of this metal in nature. FeOB stands out as Fe oxidisers in microaerophilic environments, and new members of this group have been increasingly discussed in the literature, even though their isolation can still be challenging. Among these bacteria is the Gallionellaceae family, mainly composed of neutrophilic FeOB, highlighting Gallionella ferruginea, and nitrite-oxidiser genera. In the previous metagenomic study of the biofilm and sediments of the cooling system from the Irapé hydroelectric power plant (HPP-Irapé), 5% of the total bacteria sequences were related to Gallionellaceae, being 99% unclassified at genus level. Thus, in the present study, a phylogenetic tree based on this family was constructed, in order to search for shared and unique Gallionellaceae signatures in a deep phylogenetic level affiliation and correlated them with geomorphologic characteristics. The results revealed that Gallionella and Ferrigenium were ubiquitous reflecting their ability to adapt to various locations in the power plant. The cave was considered a hotspot for neutrophilic FeOB since it harboured most of the Gallionellaceae diversity. Microscopic biosignatures were detected only in the CS1 sample, which presented abundance of the stalk-forming Ferriphaselus and of the sheath-forming Crenothrix. Further studies are required to provide more detailed insights on Gallionellaceae distribution and diversity patterns in hydroelectric power plants, particularly its biotechnological potential in this industry.
铁（Fe）是地球上含量第四丰富的元素，铁氧化细菌（FeOB）在这种金属的自然生物地球化学循环中发挥着重要作用。在微需氧环境中，FeOB作为铁氧化剂脱颖而出，尽管它们的分离仍然具有挑战性，但该类群的新成员在文献中越来越受到讨论。这些细菌中有嘉利翁菌科，主要由嗜中性FeOB组成，其中突出的是铁锈嘉利翁菌，以及亚硝酸盐氧化菌属。在之前对伊拉佩水电站（HPP - 伊拉佩）冷却系统生物膜和沉积物的宏基因组研究中，总细菌序列的5%与嘉利翁菌科相关，在属水平上99%未分类。因此，在本研究中，基于该科构建了系统发育树，以便在深度系统发育水平归属中寻找嘉利翁菌科共有的和独特的特征，并将它们与地貌特征相关联。结果表明，嘉利翁菌属和铁生菌属无处不在，反映了它们适应发电厂不同位置的能力。该洞穴被认为是嗜中性FeOB的热点区域，因为它拥有大部分的嘉利翁菌科多样性。仅在CS1样本中检测到微观生物特征，该样本中存在大量形成柄的铁杆菌属和形成鞘的纤发菌属。需要进一步的研究来更详细地了解水电厂中嘉利翁菌科的分布和多样性模式，特别是其在该行业中的生物技术潜力。
