title: Animal bone char solubilization with itaconic acid produced by free and immobilized Aspergillus terreus grown on glycerol-based medium.
abstract: Cells of Aspergillus terreus, free and immobilized in polyurethane foam, were employed in itaconic acid fermentation processes on glycerol-based media. The purpose was to assess their suitability for animal bone char solubilization and the development of a biotechnological alternative to P fertilizers chemically produced from rock phosphate. Animal bones constitute a renewable source of P that can replace the traditionally used finite, nonrenewable rock phosphate as a P source. Glycerol was an excellent substrate for growth (10.2 g biomass L(-1)) and itaconic acid production (26.9 g L(-1)) by free fungal cells after 120-h fermentation. Simultaneously, A. terreus solubilized the insoluble phosphate to a yield of 23 to 50 %, depending on the particle size and concentration. Polyurethane foam cut into cubes of 0.5-0.6 cm per side, with 0.3 mm pore size and applied at 2.0 g L(-1) proved to be an excellent cell carrier. In repeated batch fermentation, the immobilized mycelium showed a high capacity to solubilize animal bone char, which resulted on average in 168.8 mg L(-1) soluble phosphate per 48-h cycle and 59.4 % yield (percent of total phosphate) registered in the fourth batch.
authors.affiliation: Department of Chemical Engineering, Faculty of Sciences, University of Granada, c/Fuentenueva s/n, Granada, Spain. nbvass@yahoo.com
authors.forename: Nikolay
authors.initials: N
authors.lastname: Vassilev
authors.forename: Almudena
authors.initials: A
authors.lastname: Medina
authors.forename: Bettina
authors.initials: B
authors.lastname: Eichler-Löbermann
authors.forename: Elena
authors.initials: E
authors.lastname: Flor-Peregrín
authors.forename: Maria
authors.initials: M
authors.lastname: Vassileva
mesh_terms: D000818:Animals; D001230:Aspergillus / Q000737:chemistry / Q000166:cytology / Q000254:growth & development; D001842:Bone and Bones / Q000737:chemistry; D018914:Cells, Immobilized / Q000737:chemistry / Q000378:metabolism; D003470:Culture Media; D005285:Fermentation; D005308:Fertilizers; D005990:Glycerol / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry / Q000378:metabolism; D010758:Phosphorus / Q000737:chemistry / Q000378:metabolism; D011140:Polyurethanes / Q000737:chemistry; D013386:Succinates / Q000737:chemistry / Q000378:metabolism
chemical_list: D003470:Culture Media; D005308:Fertilizers; D010710:Phosphates; D011140:Polyurethanes; D013386:Succinates; D010758:Phosphorus; C028279:polyurethane foam; D005990:Glycerol; C005229:itaconic acid