title: Culture media statistical optimization for biomass production of a ligninolytic fungus for future rice straw degradation.
abstract: The main objective of this study was to optimize a culture media for low scale biomass production of Pleurotus spp. Future applications of this optimization will be implemented for "in situ" rice straw degradation, increase soil nutrients availability, and lower residue and rice culture management costs. Soil samples were taken from different points in six important rice production cities in Colombia. For carbon and nitrogen source selection a factorial 4(2) design was carried out. The Plackett-Burman design permitted to detect carbon, nitrogen and inducer effects on fungus growth (response variable for all designs). This optimization was carried out by a Box-Behnken design. Finally a re-optimization assay for glucose concentration was performed by means of a One Factor design. Only 4/33 (12 %) isolates showed and important laccase or manganese peroxidase activity compared to Pleurotus ostreatus (HPB/P3). We obtained an increased biomass production in Pleurotus spp. (T1.1.) with glucose, followed by rice husk. Rice straw was considered an inducing agent for lignin degradation. Glucose was a significant component with positive effects, whereas Tween 80 and pH had negative effects. On the contrary, rice husk, yeast extract and CaCl2 were not significant components for increase the biomass production. Final media composition consisted of glucose 25 g L(-1), yeast extract 5 g L(-1), Tween 80 0.38 % (v/v), Rice husk 10 g L(-1), CaCl2 1 g L(-1), and pH 4.88 ± 0.2. The Box-Behnken polynomial prediction resulted to be lower than the experimental validation of the model (6.59 vs. 6.91 Log10 CFU ml(-1) respectively).
authors.affiliation: Departamento de Microbiología, Facultad de Ciencias, Laboratorio de Biotecnología Aplicada, Grupo de Biotecnología Ambiental e Industrial (GBAI), Pontificia Universidad Javeriana, Bogotá, D.C. Colombia.
authors.forename: Viviana
authors.initials: V
authors.lastname: Sarria-Alfonso
authors.affiliation: Departamento de Microbiología, Facultad de Ciencias, Laboratorio de Biotecnología Aplicada, Grupo de Biotecnología Ambiental e Industrial (GBAI), Pontificia Universidad Javeriana, Bogotá, D.C. Colombia.
authors.forename: John
authors.initials: J
authors.lastname: Sánchez-Sierra
authors.affiliation: Departamento de Microbiología, Facultad de Ciencias, Laboratorio de Biotecnología Aplicada, Grupo de Biotecnología Ambiental e Industrial (GBAI), Pontificia Universidad Javeriana, Bogotá, D.C. Colombia.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Aguirre-Morales
authors.affiliation: Departamento de Microbiología, Facultad de Ciencias, Laboratorio de Biotecnología Aplicada, Grupo de Biotecnología Ambiental e Industrial (GBAI), Pontificia Universidad Javeriana, Bogotá, D.C. Colombia.
authors.forename: Ivonne
authors.initials: I
authors.lastname: Gutiérrez-Rojas
authors.affiliation: Instituto de Biotecnología, Ciudad Universitaria, Edificio Manuel Ancizar, Universidad Nacional de Colombia, Bogotá, D.C. Colombia.
authors.forename: Nubia
authors.initials: N
authors.lastname: Moreno-Sarmiento
authors.affiliation: Departamento de Microbiología, Facultad de Ciencias, Laboratorio de Biotecnología Molecular, Grupo de Biotecnología Ambiental e Industrial (GBAI), Pontificia Universidad Javeriana, Bogotá, D.C. Colombia.
authors.forename: Raúl A
authors.initials: RA
authors.lastname: Poutou-Piñales
keywords: Box-Behnken; Factorial design; Ligninolytic fungi; Plackett-Burman; Response surface methodology; Rice straw