Title: Determining the fate of virginiamycin in the fuel ethanol production process Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 7, 2012
Publication Date: June 7, 2012
Citation: Bischoff, K.M., Rich, J.O., Zhang, Y. 2012. Determining the fate of virginiamycin in the fuel ethanol production process [abstract]. Fuel Ethanol Workshop. Track 3. Paper 1. p. 23. Technical Abstract: Antibiotics are frequently used to prevent and treat bacterial contamination at commercial fuel ethanol facilities. A study to evaluate the fate of the antibiotic virginiamycin during the ethanol production process was conducted in the pilot plant facilities at the National Corn to Ethanol Research Center, Edwardsville, IL. Three 3,500 gallon fermentor runs were performed: one with no antibiotic (F1), one dosed with 2 ppm of a commercial virginiamycin product (F2), and one dosed at 20 ppm of virginiamycin product (F3). Fermentor samples, distillers grains (DDGS), and process intermediates (whole stillage, thin stillage, syrup, and wet-cake) were collected from each run and extracted with a citric acid:acetone solvent. Extracts were analyzed for antibiotic activity by bioassay against Kocuria rhizophila versus a virginiamycin standard curve. Antibiotic activity was detected in DDGS from both the F2 and F3 runs, with values of 0.7 ppm and 8.9 ppm respectively. Values in the process intermediates from the F3 run ranged from 0.9 ppm to 4.5 ppm. No antibiotic activity (< 0.6 ppm) was detected in any of the F1 samples or in the process intermediate samples from the F2 run. Analytical methods using liquid chromatography/mass spectrometry are under development for chemical quantification of virginiamycin M and S in sample extracts. These results demonstrate that biologically active antibiotic may persist in distillers grains coproducts produced from fermentations treated with virginiamycin.