Boomer S M, Pierson B K, Austinhirst R, Castenholz R W
Department of Biology, University of Puget Sound, Tacoma, WA 98416, USA.
Arch Microbiol. 2000 Sep;174(3):152-61. doi: 10.1007/s002030000189.
Novel red, filamentous, gliding bacteria formed deep red layers in several alkaline hot springs in Yellowstone National Park. Filaments contained densely layered intracellular membranes and bacteriochlorophyll a. The in vivo absorption spectrum of the red layer filaments was distinct from other phototrophs, with unusual bacteriochlorophyll a signature peaks in the near-infrared (IR) region (807 nm and 911 nm). These absorption peaks were similar to the wavelengths penetrating to the red layer of the mats as measured with in situ spectroradiometry. The filaments also demonstrated maximal photosynthetic uptake of radiolabeled carbon sources at these wavelengths. The red layer filaments displayed anoxygenic photoheterotrophy, as evidenced by the specific incorporation of acetate, not bicarbonate, and by the absence of oxygen production. Photoheterotrophy was unaffected by sulfide and oxygen, but was diminished by high-intensity visible light. Near-IR radiation supported photoheterotrophy. Morphologically and spectrally similar filaments were observed in several springs in Yellowstone National Park, including Octopus Spring. Taken together, these data suggest that the red layer filaments are most similar to the photoheterotroph, Heliothrix oregonensis. Notable differences include mat position and coloration, absorption spectra, and prominent intracellular membranes.
新型红色丝状滑行细菌在黄石国家公园的几个碱性温泉中形成了深红色层。细丝含有密集排列的细胞内膜和细菌叶绿素a。红色层细丝的体内吸收光谱与其他光合生物不同，在近红外（IR）区域（807纳米和911纳米）有不寻常的细菌叶绿素a特征峰。这些吸收峰与通过原位光谱辐射测量法测得的穿透到垫层红色层的波长相似。细丝在这些波长下也表现出对放射性标记碳源的最大光合吸收。红色层细丝表现出无氧光异养，这通过乙酸盐而非碳酸氢盐的特异性掺入以及不产生氧气得到证明。光异养不受硫化物和氧气的影响，但会因高强度可见光而减弱。近红外辐射支持光异养。在黄石国家公园的几个温泉中，包括章鱼泉，都观察到了形态和光谱相似的细丝。综合这些数据表明，红色层细丝与光异养生物俄勒冈嗜光菌最为相似。显著差异包括垫层位置和颜色、吸收光谱以及突出的细胞内膜。
