Statistical Optimization and Characterization of Prodigiosin from a Marine Serratia rubidaeaRAM_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.

Abstract

This research sought to determine optimal conditions to maximize prodigiosin production byan indigenous Egyptian marine bacterial strain Serratiarubidaea RAM_Alex.Serratiaru-bidaea 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 andfurther purified by organic solvents.The pigment extract showed absorbance with a UV-Vis spectrophotometer at 535 nm andfurther 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 thatpeptone, 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 μlinoculum size and incubation statically for 48 h at 30^oC.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, Serratiarubidaea.