title: By-products from the biodiesel chain as a substrate to citric acid production by solid-state fermentation.
abstract: In this study, we propose the use of tung cake for the production of organic acids, with an emphasis on citric acid by solid-state fermentation. We evaluated the conditions of production and the by-products from the biodiesel chain as raw materials involved in this bioprocess. First, we standardized the conditions of solid-state fermentation in tung cake with and without residual fat and with different concentrations of glycerine using the fungus Aspergillus niger The solid-state fermentation process was monitored for 7 days considering the biomass growth and pH level. Citric acid production was determined by high-performance liquid chromatography. Fungal development was better in the crude tung cake, consisting of 20% glycerine. The highest citric acid yield was 350 g kg(-1) of biomass. Therefore, the solid-state fermentation of the tung cake with glycerine led to citric acid production using the Aspergillus niger fungus.
authors.affiliation: Industrial Chemistry Course, Universidade de Santa Cruz do Sul, Santa Cruz do Sul, Brasil manuellasch@hotmail.com.
authors.forename: Manuella
authors.initials: M
authors.lastname: Schneider
authors.affiliation: Industrial Chemistry Course, Universidade de Santa Cruz do Sul, Santa Cruz do Sul, Brasil.
authors.forename: Gabriela F
authors.initials: GF
authors.lastname: Zimmer
authors.affiliation: Environmental Technology Program, Universidade de Santa Cruz do Sul, Santa Cruz do Sul, Brasil.
authors.forename: Ezequiel B
authors.initials: EB
authors.lastname: Cremonese
authors.affiliation: Chemistry and Physics Department and Environmental Technology Program, Universidade de Santa Cruz do Sul, Brasil.
authors.forename: Rosana
authors.initials: R
authors.lastname: de C de S Schneider
authors.affiliation: Chemistry and Physics Department and Environmental Technology Program, Universidade de Santa Cruz do Sul, Brasil.
authors.forename: Valeriano A
authors.initials: VA
authors.lastname: Corbellini
mesh_terms: D001234:Aspergillus niger / Q000378:metabolism; D056804:Biofuels / Q000032:analysis*; D019149:Bioreactors; D019343:Citric Acid / Q000032:analysis*; D005285:Fermentation; D007220:Industrial Waste / Q000032:analysis*; D010938:Plant Oils / Q000737:chemistry*; D018505:Waste Management / Q000379:methods*
chemical_list: D056804:Biofuels; D007220:Industrial Waste; D010938:Plant Oils; D019343:Citric Acid; C009612:tung oil
keywords: Aspergillus niger; Citric acid; SSF; biodiesel; by-products; glycerine; solid-state fermentation; tung cake