Abstract

PURIFICATION AND PHYSIOCHEMICAL CHARACTERIZATION OF PYOMELANIN PIGMENT PRODUCED FROM LOCAL PSEUDOMONAS AERUGINOSA ISOLATES

Huda M. Mahmood*, Alaa K. Mohammed, May T. A Flayyih

Abstract

Pyomelanins are pigment of high molecular weight formed by oxidative polymerization of phenolic or indolic compounds and usually are dark brown or black produced by all organisms from microorganisms to human. At the moment pyomelanins are still enigmatic bio-pigments with structure and determination methods not clearly understood. Among biopolymers, pyomelanins are unique in many aspects. This study was designed to screen and characterizes pyomelanogenic local pseudomonas aeruginosa isolates with extraction and characterization of pyomelanin pigment. Eight pyomelanoenic isolates were identified out of 143 specimens from burns, urine and sputum were collected from Iraqi patients hospitalizedinto eleven hospitals which are located in Baghdad, Al-Anbar and Karbala provinces during the period of July 2013 to April 2014. All isolates were identified as P. aeruginosa according to morphological, cultural, biochemical characteristics, VITEK-2 and 16S rRNA. The results were showed that the isolate of sputum from cystic fibrosis (CF) was greatest in production of pyomelanin. Pyomelanogenic isolates were 5.6% which produced pyomelanin pigment on pyomelanin production medium. The black pigment was confirmed as pyomelanin based on the solubility in organic solvents, UV-Vis, FT-IR and XRD spectra analysis. This is the first report on screening of pyomelanogenic local P. aeruginosa isolates and characterization of the produced pyomelanin pigment.

Keywords: Pseudomonas aeruginosa, pyomelanin pigment, physico-chemical characterization.