RESUMO
Endophytic fungi, isolated from a number of different species of tropical plants, were investigated for lipid biodiesel precursor production. The extracts produced from liquid cultures of these fungi were subjected to acidcatalyzed transesterification reactions with methanol producing methyl esters and then analyzed through chromatographic (GC-FID) and spectrometric techniques (MS, NMR ¹H). The European Standard Method, EN 14103, was used for the quantification of methyl esters extracted from the fungi of the species and genera studied. Xylariaceous fungi exhibited the highest concentrations of methyl esters (91%), and hence may be a promising source for biofuel.
Assuntos
Biocombustíveis , Fungos/crescimento & desenvolvimento , Fungos/metabolismo , Metabolismo dos Lipídeos , Plantas/microbiologia , Cromatografia , Meios de Cultura/química , Fungos/isolamento & purificação , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Metanol/metabolismoRESUMO
In this work, the use of (1)H NMR spectroscopy and statistical approach to the evaluation of biodiesel-diesel blends quality is described. Forty-six mixtures of oil-diesel, biodiesel-diesel, and oil-biodiesel-diesel were analyzed by (1)H NMR and such data were employed to design four predictive models. Thirty-six mixtures were used in the calibration set and the others in the validation. The PCR and PLS models were evaluated through statistical parameters. Briefly, PLS and PCR models were suitable for the prediction of biodiesel and oil concentration in mineral diesel. Specially, in higher concentration the predicted values were quite similar to the real ones. This fact was evidenced by the low relative errors of high concentrated samples; this means that the prediction of low concentrated samples will probably show high deviation. Therefore, (1)H NMR-PLS and (1)H NMR-PCR methods are fairly useful for the quality control of biodiesel-diesel blends, particularly they are suitable for prediction of concentrations greater than 2%.