Biotechnological conversions of bio-diesel derived waste glycerol into added-value compounds by higher fungi: production of biomass, single cell oil and oxalic acid

Agricultural University of Athens, Department of Food Science and Technology, 75 Iera Odos, 11855 Athens, Greece
Industrial Crops and Products (Impact Factor: 3.21). 03/2010; DOI: 10.1016/j.indcrop.2009.12.011

ABSTRACT Waste bio-diesel derived glycerol was used as the sole carbon source by higher fungi; two Lentinula edodes strains were flask cultured in carbon-limited conditions and displayed satisfactory growth in media presenting weak agitation, pH 4.0 and temperature 25 °C. Maximum biomass of 5.2 g/l was produced. Mycelia were synthesized, containing around 0.1 g of fat per g of biomass, with linoleic acid (Δ9,12C18:2) being the principal cellular fatty acid produced. Two Aspergillus niger strains were grown in nitrogen-limited flask cultures with constant nitrogen and two different initial glycerol concentrations into the medium. In 250-ml flask cultures, large-sized pellets were developed, in contrast with the trials performed in 2-l flasks. Nitrogen limitation led to oxalic acid secretion and intra-cellular lipid accumulation; in any case, sequential production of lipid and oxalic acid was observed. Initially, nitrogen limitation led to lipid accumulation. Thereafter, accumulated lipid was re-consumed and oxalic acid, in significant quantities, was secreted into the medium. In large-sized pellets, higher quantities of intra-cellular total lipid and lower quantities of oxalic acid were produced and vice versa. Maximum quantities of oxalic acid up to 20.5–21.5 g/l and lipid up to 3.1–3.5 g/l (corresponding to 0.41–0.57 g of fat per g of biomass) were produced. Lipid was mainly composed of oleic (Δ9C18:1) and linoleic (Δ9,12C18:2) acids.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this research was to evaluate the production and properties of polyhydroxyalcanoates (PHAs)obtained from crude glycerin (CG), a byproduct of the biodiesel industry, by Cupriavidus necator IPT 026.Experiments were carried out in shake flasks to determine the optimum CG (X1) and nitrogen (X2) concen-trations to maximize biomass accumulation and biopolymer production. The highest PHA and biomassproduction (2.81 g L−1and 4.34 g L−1, respectively) occurred at 15 g L−1of CG and 10 g L−1of nitrogenwith approximately 65% (w/v) cell accumulation (cell dry weight). Experiment 7 yielded the PHA withthe optimum properties (15 g L−1of CG and 3 g L−1of nitrogen), which showed a melting temperature of184.3◦C, crystallinity of 52.23%, thermal degradation occurring between 306.8◦C and 334.1◦C with a peakat 327.4◦C, and its molecular weight was 780 kDa. All experiments PHA production showed FTIR spectrasimilar to those reported in the literature. The monomeric profile of the produced PHAs showed a compo-sition similar to that of the PHA standard, showing evidence of 3-hydroxybutyrate (3HB) monomer in theanalyzed samples. Bacteria can use CG as an inexpensive substrate to produce value-added biodegradableproducts, such as PHA.
    Industrial Crops and Products 11/2013; 52:338-346. · 3.21 Impact Factor
  • Kinetics and Catalysis 07/2014; 55(4):434-445. · 0.67 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Clostridium pasteurianum cells immobilized on silica were used as biocatalysts for bioconversion of both pure and biodiesel-derived crude glycerol to butanol, 1,3-propanediol (PDO) and ethanol. Among five concentrations (1, 2, 3, 5, 10 % w/v) of cell immobilized support studied, 3 % w/v cell immobilized support performed the best and was chosen for further studies. The cross-linked cells produced higher amount of solvents than non-cross linked cells. The flow cytometric results revealed that presence of pure as well as crude glycerol had no adverse effect on cellular morphology of C. pasteurianum. The maximum yields of butanol, ethanol and 1,3-PDO obtained with immobilized cells were 0.36 (25 g/L pure glycerol), 0.11 (10 g/L pure glycerol) and 0.54 g/g (10 g/L pure glycerol), respectively. Among the three crude glycerol concentrations studied, 25 g/L crude glycerol gave maximum yield of n-butanol (0.23 g/g), and 5 g/L crude glycerol formed maximum 1,3-PDO (0.61 g/g). Only traces of ethanol were detected at all concentrations of crude glycerol studied. A comparison of free and immobilized cells revealed that immobilized cells performed better than free cells for mixed alcohols production at higher concentrations of both pure and crude glycerol. Thus, the use of immobilized cells is a viable option for converting high concentrations of biodiesel derived crude glycerol into alternate energy sources.
    Waste and Biomass Valorization. 10/2014; 5(5).


Available from
May 22, 2014