Production and purification of proteins from plant sources for use as flocculents in potable and waste water treatment

• Research unit: INNOSUISSE
• Project number: 6764.3;5 LSPP-LS

Short description (English)

Production and purification of proteins from plant sources for use as flocculents in potable and waste water treatment

Short description (French)

Production and purification of proteins from plant sources for use as flocculents in potable and waste water treatment

Abstract (English)

In the first CTI-funded project, a process for the extraction of protein extracts from press-cakes of the sub- tropical shrub, Moringa oleifera at pilot scale was defined, and tests are currently underway to determine the flocculation activity of these extracts in two municipal waste-water treatment plants. In addition the active ingredients were partially isolated, sequenced and expressed in E. coli in order to determine structure/function relationships. During the course of this work proteins and nanocapsule structures were isolated at a small scale from a range of agricultural crops commonly found in Switzerland and Europe and were shown to exhibit potent flocculation activity. The present application builds on these findings through the isolation of different fractions and individual compounds from the seeds of a range of plants including (non- exhaustive list) rapeseed, sunflower, hemp, sesame, linseed and castor beans and testing their flocculation activity under different contions in the laboratory and in waste-water treatment facilities. The fractions will also be tested for the ability to remove heavy metals and recalcitrant organic compounds including pesticides, herbicides and chlorinated phenolics. The spectrum and dose of flocculating activity will also be defined in vitro and more powerful derivatives will be developed using recombinant DNA techniques. Press-cakes after extraction of the oil from the seeds of the different plants will be developed for use as biofilters for the removal of recalcitrant hydrophobic compounds from liquid and gas streams. The new bio-flocculating agents should offer improved flocculating activity compared with existing coagulants/ flocculants while being completely biodegradable and chemically non-toxic for water treatment.