Blake Robert C, Painter Richard G, Pham Nghi, Griswold Olivia, White Brooke, White Richard A
Division of Basic Pharmaceutical Sciences, Xavier University of Louisiana, New Orleans, LA, United States.
NCRC, Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Kannapolis, NC, United States.
Front Microbiol. 2025 May 9;16:1455423. doi: 10.3389/fmicb.2025.1455423. eCollection 2025.
is a thermoacidophilic archaeon that obtains all of its energy for growth from aerobic respiration and oxidative phosphorylation at the expense of selected organic and inorganic sources of electrons. Initial velocities for the oxidation of soluble ferrous ions by intact cells at 60 °C and pH 1.5 were determined using an integrating cavity absorption meter that permitted accurate absorbance measurements to quantify the increase in soluble ferric iron in the presence of turbid suspensions of the live organisms. that was cultured on yeast extract either in the absence or the presence of 20 mM soluble ferrous iron exhibited turnover numbers for soluble iron oxidation of 304 ± 26 and 333 ± 31 attamoles/cell/min, respectively. These functional data were consistent with the transcriptomic evidence presented by others, that the proteins presumably responsible for aerobic respiration on soluble iron are expressed constitutively in . Intact cells of were characterized by electrical impedance, laser light diffraction, and transmission electron microscopic measurements. All three types of measurements were consistent with the surprising observation that cells cultured on yeast extract in the presence of soluble iron bifurcated into approximately equal numbers of coccoidal cells of two sizes, smaller cells with an average diameter of 0.6 μm and larger cells with an average diameter of 1.35 μm. Cells cultured on the same concentration of yeast extract but in the absence of soluble iron comprised a single cell size with an intermediate average diameter of 1.06 μm. This unexpected bifurcation of a clonal cell population into two demonstrably different sizes when the extracellular nutrient environment changes has not previously been reported for , or any other single-celled archaeon or eubacterium.
是一种嗜热嗜酸古菌，其生长所需的所有能量均来自有氧呼吸和氧化磷酸化，以选定的有机和无机电子源为代价。在60°C和pH 1.5条件下，使用积分腔吸收仪测定完整细胞氧化可溶性亚铁离子的初始速度，该仪器能够在活生物体的浑浊悬浮液存在下进行准确的吸光度测量，以量化可溶性三价铁的增加。在酵母提取物中培养的，无论有无20 mM可溶性亚铁离子，其可溶性铁氧化的周转数分别为304±26和333±31阿托摩尔/细胞/分钟。这些功能数据与其他人提供的转录组学证据一致，即推测负责可溶性铁有氧呼吸的蛋白质在中组成性表达。通过电阻抗、激光光衍射和透射电子显微镜测量对的完整细胞进行了表征。所有三种测量结果都与一个惊人的观察结果一致，即在酵母提取物中添加可溶性铁培养的细胞会分成数量大致相等的两种大小的球菌细胞，较小的细胞平均直径为0.6μm，较大的细胞平均直径为1.35μm。在相同浓度的酵母提取物中培养但没有可溶性铁的细胞只有一种单一的细胞大小，平均直径为1.06μm。当细胞外营养环境发生变化时，克隆细胞群体意外地分成两种明显不同的大小，这种情况在或任何其他单细胞古菌或真细菌中以前都没有报道过。
