Journal of Pure and Applied MicrobiologyVol. 11 No. 3

Statistical Optimization and Characterization of Prodigiosin from a Marine Serratia rubidaea RAM_Alex

Rasha A. Metwally*1, Nermeen A. El-Sersy1, Amany El Sikaily2, Hanan A. Ghozlan3 and Soraya A. Sabry3

1Microbiology Lab., National Institute of Oceanography and Fisheries, Alexandria, Egypt. 2Pollution Lab., National Institute of Oceanography and Fisheries, Alexandria, Egypt. 3Botany & Microbiology Department, Faculty of Science, Alexandria University, Egypt.

Received on 01 June 2017 and accepted on 16 July 2017



This research sought to determine optimal conditions to maximize prodigiosin production by an indigenous Egyptian marine bacterial strain Serratia rubidaea RAM_Alex. Serratia rubidaea RAM_Alex isolated from bivalve samples of Temsah Lake, Ismailia, Egypt was used to investigate the production of the natural red pigment prodigiosin. Pigment production was assayed in different growth conditions using Nutrient broth as production medium. The water insoluble red pigment was extracted using ethanol and further purified by organic solvents. The pigment extract showed absorbance with a UV-Vis spectrophotometer at 535 nm and further characterized using TLC, FTIR and 1H-NMR. A statistical screening procedure was adopted to select the main factors affecting production. Analyses of Plackett- Burman design results demonstrated that peptone, NaCl, and culture volume were the most important independent variables. The near optimum medium contained (g/L): peptone 7, beef extract 5, yeast extract 1, NaCl 10, pH 6, using 25 ml culture volume, 100 l inoculum size and incubation statically for 48 h at 30oC. When this condition was employed, a two fold increase in pigment yield was achieved reaching ~1600.511 mg/l.

Keywords : Biopigments, nutrient broth, Plackett-Burman design, prodigiosin, Serratia rubidaea.