State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, PR China.
University of Chinese Academy of Sciences, Beijing 100049, PR China.
Int J Syst Evol Microbiol. 2022 Mar;72(3). doi: 10.1099/ijsem.0.005285.
Two acidophilic strains, designated as ALEF1 and S30H14, were isolated from acid mine drainage sediment. Cells of both strains were Gram-stain-positive, aerobic, endospore-forming rods. Strains ALEF1 and S30H14 were acidophilic and mesophilic, the former grew at 20-40 °C (optimum, 30 °C) and pH 2.5-4.5 (optimum, pH 3.5), while the latter grew at 20-45 °C (optimum, 30 °C) and pH 2.0-5.5 (optimum, pH 4.5). The 16S rRNA gene-based sequence analysis revealed that strains ALEF1 and S30H14 belonged to the genus , and were phylogenetically close to TC-34 with 97.1 and 97.4% similarity, respectively. The similarity between the two novel strains was 98.6 %. The average nucleotide identity value between the genome sequences of ALEF1 and S30H14 was 79.5 %, and that between each of the two isolates and TC-34 were 72.0 and 74.3 %. In addition, the digital DNA-DNA hybridization value between ALEF1 and S30H14 was 24.9 %, between strain ALEF1 and TC-34 was 21.7 %, and between S30H14 and TC-34 was 26.3 %, far below the interspecies threshold. Both strains could utilize diverse carbon sources for heterotrophic growth; strain ALEF1 could utilize ferrous iron as the energy source for autotrophic growth. Menaquinone 7 was the only quinone detected in either strain. Both strains contained anteiso-C and anteiso-C, while -alicyclic fatty acids were not detected. Based on their phylogenetic positions, as well as phenotypic and genomic data, it is considered that strains ALEF1 and S30H14 represent two novel species within the genus , for which the names sp. nov. (type strain ALEF1=CGMCC 1.17055=KCTC 43124) and sp. nov. (S30H14=CGMCC 1.17050=KCTC 43125) are proposed.
两株嗜酸菌，分别命名为 ALEF1 和 S30H14，从酸性矿山排水沉积物中分离得到。两株菌的细胞均为革兰氏阳性、需氧、产芽孢的杆菌。菌株 ALEF1 和 S30H14 均为嗜酸菌和嗜温菌，前者在 20-40°C（最佳温度为 30°C）和 pH 2.5-4.5（最佳 pH 值为 3.5）下生长，而后者在 20-45°C（最佳温度为 30°C）和 pH 2.0-5.5（最佳 pH 值为 4.5）下生长。基于 16S rRNA 基因序列分析，菌株 ALEF1 和 S30H14 属于 属，与 TC-34 的相似度分别为 97.1%和 97.4%。这两个新菌株之间的相似度为 98.6%。ALEF1 和 S30H14 的基因组序列之间的平均核苷酸同一性值为 79.5%，每个菌株与 TC-34 的平均核苷酸同一性值分别为 72.0%和 74.3%。此外，ALEF1 和 S30H14 之间的数字 DNA-DNA 杂交值为 24.9%，菌株 ALEF1 与 TC-34 之间的数字 DNA-DNA 杂交值为 21.7%，S30H14 与 TC-34 之间的数字 DNA-DNA 杂交值为 26.3%，均远低于种间阈值。两株菌均能利用多种碳源进行异养生长；菌株 ALEF1 可以利用亚铁离子作为自养生长的能源。两种菌均检测到menaquinone 7。两株菌均含有anteiso-C 和anteiso-C，而未检测到 -alicyclic 脂肪酸。基于其系统发育位置以及表型和基因组数据，认为菌株 ALEF1 和 S30H14 代表 属中的两个新种，分别命名为 sp. nov.（模式菌株 ALEF1=CGMCC 1.17055=KCTC 43124）和 sp. nov.（S30H14=CGMCC 1.17050=KCTC 43125）。
