Gas chromatographic-mass spectrometric study of the degradation of phenolic compounds in wastewater olive oil by Azotobacter Chroococcum.

Compounds present in wastewater olive oil (WWOO) which can be used in metabolic pathways of Azotobacter chroococcum (A. chroococcum) have been investigated. Some compounds such as syringic acid, p-coumaric acid and syringaldehyde do not favour microorganism growing up. However, it has been shown that in batch culture, polyphenolic compounds (PCs) such as protocatetic acid and p-hydroxybenzoic acid do facilitate the growing up of microorganism. What is more, the maximum concentration in which bacteria can grow was 0.3% (w/v) for both polyphenols. At higher concentrations, substrate inhibition was observed; which is characterized by decreasing growth rates. Therefore, A. chroococcum can grow up using PCs as an individual source of carbon and energy supply but it is also dependent on the type of the compound and on its concentration. A gas chromatography coupled mass spectrometry method has been used for the study of the degradation of simple phenolic compounds.

Determination of polyphenolic compounds in wastewater olive oil by gas chromatography-mass spectrometry.

A simple and sensitive method for the determination of 21 polyphenolic compounds in wastewater from olive oil production plants is proposed. The method involves a liquid-liquid microextraction (LLME) procedure with ethyl acetate followed by a silylation step. Identification and quantification have been performed by gas chromatography-mass spectrometry (GC-MS). MS measurements were carried out using selected ion monitoring mode (SIM). alpha-Naftol was used as internal standard. The proposed method was applied to the determination of these compounds in wastewater from an olive oil production factory in Jaén (Spain) at concentration levels ranging from 1.0 to 75.0mugml(-1) for each compound. The autodegradation process by own microbiota in samples collected in three different points of the factory was also studied. The method was validated by a recovery assay with spiked samples.