title: A simple purification and activity assay of the coagulant protein from Moringa oleifera seed.
abstract: Use of extracts from Moringa oleifera (MO) is of great interest for low-cost water treatment. This paper discusses water and salt extraction of a coagulant protein from the seed, purification using ion exchange, its chemical characteristics, coagulation and antimicrobial properties. The coagulant from both extracts is a cationic protein with pI greater than 9.6 and molecular mass less than 6.5 kDa. Mass spectrometric analysis of the purified water extract indicated that it contained at least four homologous proteins, based on MS/MS peptide sequence data. The protein is thermoresistant and remained active after 5h heat treatment at 95 degrees C. The coagulant protein showed both flocculating and antibacterial effects of 1.1--4 log reduction. With samples of high turbidity, the MO extract showed similar coagulation activity as alum. Cecropin A and MO extract were found to have similar flocculation effects for clay and microorganisms. Simple methods for both the purification and assay of MO coagulating proteins are presented, which are necessary for large-scale water treatment applications.
authors.affiliation: Department of Land and Water Resources Engineering, Brinellvägen 32, Royal Institute of Technology (KTH), 100 44 Stockholm, Sweden.
authors.forename: Kebreab A
authors.initials: KA
authors.lastname: Ghebremichael
authors.forename: K R
authors.initials: KR
authors.lastname: Gunaratna
authors.forename: Hongbin
authors.initials: H
authors.lastname: Henriksson
authors.forename: Harry
authors.initials: H
authors.lastname: Brumer
authors.forename: Gunnel
authors.initials: G
authors.lastname: Dalhammar
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D001413:Bacillus thuringiensis / Q000187:drug effects; D002845:Chromatography; D004926:Escherichia coli / Q000187:drug effects; D007474:Ion Exchange; D013058:Mass Spectrometry; D029588:Moringa oleifera / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry*; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D012639:Seeds / Q000737:chemistry*; D012965:Sodium Chloride; D014867:Water
chemical_list: D000900:Anti-Bacterial Agents; D010940:Plant Proteins; D014867:Water; D012965:Sodium Chloride