Microbiologie appliquée: libre accès
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Abstrait

Fatty Acid Methyl Ester Analysis of Olive Oil Degraded by Candida parapsilosis

Bukola Margaret Popoola , Onilude Anthony Abiodun

Fatty acids are the major components of lipids; and the physical, chemical and physiological properties of a lipid class depend primarily on its fatty acid composition. Gas chromatography method can be used for the identification of microbiological degraded fatty acids in vegetable oils as methyl ester. The use of GC for FAME Quantification determination with flame ionization detectors has been effectively used for some time. It is highly sensitive, high accuracy and high reproducibility. It has advantages over Mass Spectrometry (MS) when analyzing n-6 and n-3 fatty acid metabolism as it is able to distinguish between structurally similar fatty acids as it uses retention time for labeling as opposed to atomic mass. MS is able to identify fatty acids within a sample but unable to distinguish double bond positions in stereoisomers and therefore unable to tell certain fatty acids apart.

Although GC/MS and other technical methods have been developed to quantitate C8-C26 chain-length FAs, the GC analysis of FAs with FID remains the most frequently used method (Jumat et al., 2006).

This study monitored the breakdown of olive oil by the lipase of Candida parapsilosis which was grown in two different mineral salt medium, one consisting of (g/L) of KH₂PO₄, 7.584; K₂HPO₄^-, 0.80; MgSO₄ .7H₂O, 0.80; CaCl₂, 0.16; (NH₄)₂NO₃, 0.80; FeSO₄¬, 0.16; and olive oil 2%, PH maintained at 7.0. The second one is also a modification of the first medium consisting (g/L) of KH₂PO₄, 7.584; K₂¬HPO₄¬, 0.80; MnSO₄.4H₂O,0.80; NaCl, 0.16; (NH₄)₂NO₃, 0.80; Fe₂(SO₄)₃, 0.08; and olive oil, 2%, pH maintained at 7.0 was studied over 25 days. The fatty acid profiles of the oils and methyl esters were determined by chromatography analyzer. The olive oil was analyzed for the fatty acids commonly present in it which are Myristic, Palmitic, Stearic, Oleic, Linoleic, Linolenic, Behenic and Lignoceric, having specific carbon number and their values in approximate percentage C14:0 (0.4), C16:0 (14.0), C18:0 (5.5), C18:1 (76.4), C18:2 (3.4), C18:3 (0.1), C22:0 (0.1) and C24:0 (0.1) respectively. Of all the fatty acid, oleic acid percentage is high in olive oil containing considerable amount of 76.4%.

The lipase of Candida parapsilosis reduced the fatty acid by 6.7% after 20 days in the media used. Hence the lipase from Candida parapsilosis had potential for degradation of fatty waste, a potential microbial isolate to be used for bioremediation processes.