title: Valorization of By-Products from Palm Oil Mills for the Production of Generic Fermentation Media for Microbial Oil Synthesis.
abstract: This study demonstrates the production of a generic nutrient-rich feedstock using by-product streams from palm oil production that could be used as a substitute for commercial fermentation supplements. Solid-state fermentations of palm kernel cake (PKC) and palm-pressed fiber (PPF) were conducted in tray bioreactors and a rotating drum bioreactor by the fungal strain Aspergillus oryzae for the production of crude enzymes. The production of protease was optimized (319.3 U/g) at an initial moisture content of 55 %, when PKC was used as the sole substrate. The highest free amino nitrogen (FAN) production (5.6 mg/g) obtained via PKC hydrolysis using the crude enzymes produced via solid-state fermentation was achieved at 50 °C. Three initial PKC concentrations (48.7, 73.7, and 98.7 g/L) were tested in hydrolysis experiments, leading to total Kjeldahl nitrogen to FAN conversion yields up to 27.9 %. Sequential solid-state fermentation followed by hydrolysis was carried out in the same rotating drum bioreactor, leading to the production of 136.7 U/g of protease activity during fermentation and 196.5 mg/L of FAN during hydrolysis. Microbial oil production was successfully achieved with the oleaginous yeast strain Lipomyces starkeyi DSM 70296 cultivated on the produced PKC hydrolysate mixed with commercial carbon sources, including glucose, xylose, mannose, galactose, and arabinose.
authors: Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 118 55, Athens, Greece.
authors: Erminda
authors: E
authors: Tsouko
authors: Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 118 55, Athens, Greece.
authors: Vasiliki
authors: V
authors: Kachrimanidou
authors: Biochemistry Department, Chemistry Institute, Federal University of Rio de Janeiro, Cidade Universitária, Centro de Tecnologia, Bloco A, Lab 549, Rio de Janeiro, RJ, 21941-909, Brazil.
authors: Anderson Fragoso
authors: AF
authors: Dos Santos
authors: Biochemistry Department, Chemistry Institute, Federal University of Rio de Janeiro, Cidade Universitária, Centro de Tecnologia, Bloco A, Lab 549, Rio de Janeiro, RJ, 21941-909, Brazil.
authors: Maria Eduarda
authors: ME
authors: do Nascimento Vitorino Lima
authors: Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 118 55, Athens, Greece.
authors: Seraphim
authors: S
authors: Papanikolaou
authors: Biotechnology Division, Research and Development Center, PETROBRAS, Av. Horácio Macedo, 950. Ilha do Fundão, Rio de Janeiro, 21941-915, Brazil.
authors: Aline Machado
authors: AM
authors: de Castro
authors: Biochemistry Department, Chemistry Institute, Federal University of Rio de Janeiro, Cidade Universitária, Centro de Tecnologia, Bloco A, Lab 549, Rio de Janeiro, RJ, 21941-909, Brazil. freire@iq.ufrj.br.
authors: Denise Maria Guimarães
authors: DM
authors: Freire
authors: Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 118 55, Athens, Greece. akoutinas@aua.gr.
authors: Apostolis A
authors: AA
authors: Koutinas
mesh_terms: D001236:Aspergillus oryzae / Q000378:metabolism; D056804:Biofuels / Q000382:microbiology*; D019149:Bioreactors / Q000382:microbiology*; D001709:Biotechnology; D002244:Carbon / Q000378:metabolism; D005285:Fermentation; D006868:Hydrolysis; D000073878:Palm Oil; D010447:Peptide Hydrolases / Q000378:metabolism; D010938:Plant Oils / Q000737:chemistry*
chemical_list: D056804:Biofuels; D010938:Plant Oils; D000073878:Palm Oil; D002244:Carbon; D010447:Peptide Hydrolases
keywords: Enzyme production; Generic fermentation feedstock; Microbial oil; Palm oil residues; Solid-state fermentation