Using of Some Agro-industrial Wastes for Improving Carotenoids Production from Yeast Rhodotorula glutinis 32 and Bacteria Erwinia uredovora DSMZ 30080

Abstract

Some agro-industrial wastes such as clarified cane molasses, high test molasses, sweet whey, potato starch and corn steep liquor were tested as carbon sources or nitrogen source for growth and carotenoid accumulation using bacteria Erwinia uredovora DSMZ 30080 and yeast Rhodotorula glutinis number 32. Erlenmeyer flasks containing 100 ml of production media, the flasks were inoculated with 1 ml of standard inoculum and incubated at 150 rpm for 4 days at 30°C. Samples were collected periodical every 24h, cell dry weight and carotenoids concentration were determined. Sweet whey and highest molasses gave the highest growth being 2.85 and 7.34 gl-1, respectively and scored the same layout on carotenoids conc. which reach the peak during stationary phase (72 h of fermentation). Using of high test molasses and sweet whey as carotenoid production media were incremented carotenoid conc. about 1.7 and 2 fold (with respect to reference media). Increasing high test molasses conc. to give 5% initial sugar led to up great growth, carotenoids conc., productivity, yield and Yc/x from Rhodo. glutinis 32 to be 7.31 gl-1, 2.67 mgl-1, 0.037 mgl-1h-1, 0.067% and 0.365, respectively. Furthermore, using corn steep liquor (30%) as nitrogen sources augmented carotenoids concentration about 3.8 and 4fold for incomplete and complete production media using Rhodo. glutinis32. Also, a negligible effect on growth was observed with dark incubation with both strains which dropped about 75 and 48% with regard to control for E. uredovora DSMZ 30080 and Rhod. glutinis 32, respectively, whereas, carotenoids conc. was increased about 21% for E. uredovora DSMZ 30080 in dark condition.