Haddix Pryce L, Shanks Robert M Q
Department of Biology, Auburn University Montgomery, Room 311B Goodwyn Hall, P. O. Box 244023, Montgomery, AL, 36124-4023, USA.
The Charles T. Campbell Laboratory, Department of Ophthalmology, University of Pittsburgh Eye Center and School of Medicine, 203 Lothrop St., Pittsburgh, PA, 15213, USA.
Arch Microbiol. 2018 Sep;200(7):989-999. doi: 10.1007/s00203-018-1508-0. Epub 2018 Apr 3.
Serratia marcescens is a gram-negative, facultatively-anaerobic bacterium and opportunistic pathogen which produces the red pigment prodigiosin. We employed both batch culture and chemostat growth methods to investigate prodigiosin function in the producing organism. Pigmentation correlated with an increased rate of ATP production during population lag phase. Results with a lacZ transcriptional fusion to the prodigiosin (pig) biosynthetic operon revealed that operon transcription is activated by low cellular levels of ATP at high cell density. Furthermore, these data enabled estimation of the ATP per cell minimum value at which the operon is induced. Pigmented cells were found to accumulate ATP more rapidly and to multiply more quickly than non-pigmented cells during the high density growth phase. Finally, results with both batch and chemostat culture revealed that pigmented cells grow to approximately twice the biomass yield as non-pigmented S. marcescens bacteria. Prodigiosin production may, therefore, provide a growth advantage at ambient temperatures.
粘质沙雷氏菌是一种革兰氏阴性、兼性厌氧细菌和机会致病菌，可产生红色色素灵菌红素。我们采用分批培养和恒化器生长方法来研究灵菌红素在产生菌中的功能。在群体延迟期，色素沉着与ATP产生速率的增加相关。用与灵菌红素（pig）生物合成操纵子的lacZ转录融合体进行的结果表明，在高细胞密度下，低细胞水平的ATP可激活操纵子转录。此外，这些数据能够估计操纵子被诱导时每个细胞的ATP最小值。发现在高密度生长阶段，有色素的细胞比无色素的细胞更快地积累ATP，并且繁殖得更快。最后，分批培养和恒化器培养的结果都表明，有色素的细胞生长至生物量产量约为无色素粘质沙雷氏菌细菌的两倍。因此，在环境温度下，灵菌红素的产生可能提供生长优势。
