Center Algatech, Institute of Microbiology CAS, 379 81, Třeboň, Czech Republic.
Folia Microbiol (Praha). 2019 Sep;64(5):705-710. doi: 10.1007/s12223-019-00735-x. Epub 2019 Nov 6.
Aerobic anoxygenic phototrophic (AAP) bacteria are a common component of freshwater microbial communities. They harvest light energy using bacteriochlorophyll a-containing reaction centers to supplement their predominantly heterotrophic metabolism. We used epifluorescence microscopy, HPLC, and infrared fluorometry to examine the dynamics of AAP bacteria in the mesotrophic lake Vlkov during the seasonal cycle. The mortality of AAP bacteria was estimated from diel changes of bacteriochlorophyll a fluorescence. The AAP abundance correlated with water temperature and DOC concentration. Its maximum was registered during late summer, when AAP bacteria made up 20% of total bacteria. The novel element of this study is the seasonal measurements of AAP mortality rates. The rates ranged between 1.15 and 4.56 per day with the maxima registered in early summer coinciding with the peak of primary production, which documents that AAP bacteria are a highly active component of freshwater microbial loop.
好氧厌氧型光合（AAP）细菌是淡水微生物群落的常见组成部分。它们利用含有细菌叶绿素 a 的反应中心来收获光能，以补充其主要的异养代谢。我们使用荧光显微镜、高效液相色谱法和红外荧光法来研究中营养湖泊 Vlkov 在季节性周期中 AAP 细菌的动态。通过细菌叶绿素 a 荧光的昼夜变化来估计 AAP 细菌的死亡率。AAP 丰度与水温及 DOC 浓度相关。其最大值出现在夏末，此时 AAP 细菌占总细菌的 20%。本研究的新颖之处在于对 AAP 死亡率的季节性测量。这些速率在每天 1.15 到 4.56 之间变化，最大值出现在初夏，与初级生产力的峰值相吻合，这证明了 AAP 细菌是淡水微生物环中非常活跃的组成部分。
