Submitted to: Applied Biochemistry and Biotechnology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/10/2011
Publication Date: 3/1/2012
Publication URL: http://handle.nal.usda.gov/10113/55231
Citation: Piazza, G.J., Nunez, A., Garcia, R.A. 2012. Identification of highly active flocculant proteins in bovine blood. Applied Biochemistry and Biotechnology. 166(5):1203-1214. Interpretive Summary: Blood meal is prepared from animal blood produced in slaughterhouses. Due to concerns related to bovine spongiform encephalopathy (BSE), also known as mad cow disease, there has been less worldwide demand for animal proteins, such as blood meal. We are conducting research to find nonfood uses for animal by-products, such as blood, to help the animal processing industry supplement its income. A flocculant is a substance that causes particles suspended in a fluid to aggregate and form discrete flocs. We have found that beef blood and its components are excellent renewable flocculants, with potential use in a variety of industrial processes as well as waste water treatment facilities. We have indentified some of the key protein components in blood that are responsible for its flocculating activity. By concentrating the flocculant proteins, a more effective renewable flocculant can be prepared, and the remainder of blood components can be applied to other uses.
Technical Abstract: Bovine blood is an excellent flocculating agent, faster acting and as effective on a mass basis as polyacrylamide, the most widely utilized polymeric flocculant. To determine the molecular basis of flocculation activity, whole bovine blood (BB) and BB plasma were fractionated by size exclusion chromatography. The BB fraction with highest flocculation potential (FP) was subjected to preparative electrophoresis, and the tryptic peptides of the major protein component were examined by matrix assisted laser desorption/ionization with automated tandem time of flight measurement of selected ions (MALDI-TOF/TOF) mass spectrometry. Hemoglobin dimer (subunits alpha and beta) was identified as the major protein; its high FP was confirmed by testing a commercial sample of hemoglobin. Thus hemoglobin dimer is the most active flocculant in BB, but three plasma proteins were also found to have flocculation activity.