title: Microscopic examination of chitosan-polyphosphate beads with entrapped spores of the biocontrol agent, Streptomyces melanosporofaciens EF-76.
abstract: Spores of the biocontrol agent, Streptomyces melanosporofaciens EF-76, were entrapped by complex coacervation in beads composed of a macromolecular complex (MC) of chitosan and polyphosphate. A proportion of spores entrapped in beads survived the entrapment procedure as shown by treating spores from chitosan beads with a dye allowing the differentiation of live and dead cells. The spore-loaded chitosan beads could be digested by a chitosanase, suggesting that, once introduced in soil, the beads would be degraded to release the biocontrol agent. Spore-loaded beads were examined by optical and scanning electron microscopy because the release of the biological agent depends on the spore distribution in the chitosan beads. The microscopic examination revealed that the beads had a porous surface and contained a network of inner microfibrils. Spores were entrapped in both the chitosan microfibrils and the bead lacuna.
authors.affiliation: Centre d'Etude et de Valorisation de la Diversité Microbienne, Département de Biologie, Faculté des Sciences, Université de Sherbrooke, 2500, boul. Universitété Sherbrooke, Québec J1K 2R1, Canada.
authors.forename: Guy
authors.initials: G
authors.lastname: Jobin
authors.forename: Gilles
authors.initials: G
authors.lastname: Grondin
authors.forename: Geneviève
authors.initials: G
authors.lastname: Couture
authors.forename: Carole
authors.initials: C
authors.lastname: Beaulieu
mesh_terms: D048271:Chitosan; D046911:Macromolecular Substances; D008853:Microscopy; D010572:Pest Control, Biological / Q000592:standards*; D011122:Polyphosphates; D016062:Porosity; D013171:Spores, Bacterial / Q000302:isolation & purification / Q000502:physiology; D013194:Staining and Labeling; D013302:Streptomyces / Q000302:isolation & purification* / Q000502:physiology
chemical_list: D046911:Macromolecular Substances; D011122:Polyphosphates; D048271:Chitosan