title: [Fingerprinting analysis of photopigments in purple bacteria].
abstract: OBJECTIVE
  Photopigments, including carotenoid and bacteriochlorophyll a, are the most important functional units of photosynthesis in purple bacteria. We developed rapid qualitative and quantitative methods to determine photopigments.
  
  
  METHODS
  Using Rhodopesudomonas palustris CQV97 as a reference, we used image gray intensity analysis, absorption spectrophotometry, thin layer chromatography (TLC), HPLC and mass spectrometry (MS) for photopigment analysis.
  
  
  RESULTS
  The total amount of photopigments increased by 13.5% by using modified acetone-methanol extraction. We developed two types of photopigment fingerprintings by TLC and HPLC, estimated the apparent relative content of each photopigment of fingerprintings, and determined the corresponding relationships between R(f) value of each photopigment on TLC fingerprinting and retention time of each photopigment elution in HPLC fingerprinting. Based on the data from the absorption spectra, MS and related photopigment biosynthetic pathway analysis, we identified 11 photopigments in CQV97 strain. Using this strain as a standard, we analyzed photopigments of the tested samples by TLC or HPLC. It was shown that (1) the relative standard deviation (RSD) of the two methods was less than 5%; (2) the compositions and contents of the theory sample were consistent with that of the standard sample; (3) the photopigment compositions of the real sample was the same as the standard sample, but the photopigment content was different.
  
  
  CONCLUSIONS
  Both of TLC and HPLC analyses for photopigment determination have good stability and repeatability. The fingerprintings analyses are suitable for rapid determination of photopigments of purple bacteria and have important application in control of regulation mechanism for photopigment synthesis.
authors.affiliation: Department of Bioengineering and Biotechnology, Huaqiao University, Xiamen 361021, China.
authors.forename: Minquan
authors.initials: M
authors.lastname: Zhuo
authors.forename: Chungui
authors.initials: C
authors.lastname: Zhao
authors.forename: Qianru
authors.initials: Q
authors.lastname: Cheng
authors.forename: Suping
authors.initials: S
authors.lastname: Yang
authors.forename: Yinbo
authors.initials: Y
authors.lastname: Qu
mesh_terms: D025541:Bacteriochlorophyll A / Q000032:analysis* / Q000302:isolation & purification; D002138:Calibration; D002338:Carotenoids / Q000032:analysis* / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002855:Chromatography, Thin Layer / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods; D020560:Proteobacteria / Q000737:chemistry* / Q000378:metabolism; D012015:Reference Standards; D015203:Reproducibility of Results
chemical_list: D025541:Bacteriochlorophyll A; D002338:Carotenoids