Effects of Oxygen Transfer Coefficient on Submerged Fermentation of Chromium Enriched Ganoderma lucidum.

Wei-Chih Kuan; Su-Der Chanh; Yong-Siang Cheng

Trivalent chromium (Cr3+) has been applied in type II diabetes patients to decrease blood glucose level and improve glucose tolerance. The objectives of this study were to modulate oxygen supply to improve organic chromium conversion in submerged fermentation of chromium enriched Ganoderma lucidum. The results showed that addition of 100 mg/L Cr34 in liquid medium enhanced higher biomass growth (1.78 g/L). Fermentation of G. lucidum with 150 mL of 5% cereal medium and 100 mg/L Cr in a 500 mL flask reached the highest biomass of 3.01 g/L and organic chromium of 40.1 mg/L production after 7-day cultivation. The organic chromium of G. lucidum was a primary metabolite and 92% of organic chromium was distributed in the extracellular products. The oxygen transfer coefficients (KLa) in 5-L air-lift and stirred fermentors with 5% cereal medium were analyzed. The KLa values in an air-lift fermentor increased with higher aeration rate and the KLa values were clearly improved from 11.3 to 111 .1 hr-1 with the same aeration rate when agitation rate increased in a stirred fermentor. Operation at 300 rpm with KLa = 88.3 (hr-1) proride the highest biomass (19.8 g/L) than the other agitation rate. The G. lucidum fermented in a medium containing 5% cereal and 100 m/L Cr3+ agitation at 300 rpm and 1 vvm aeration had the highest biomass (10.69 g/L) and organic chromium production (64.1 mg/L) after 7-days cultivation.

GANODERMA lucidum; PHYSIOLOGICAL transport of oxygen; CHROMIUM; FERMENTATION; PEOPLE with diabetes; BLOOD sugar; GLUCOSE tolerance tests; BIOMASS

Taiwanese Journal of Agricultural Chemistry & Food Science, 2011, Vol 49, Issue 5, p252

1605-2471

Academic Journal