ABSTRACT
Biodegradation of dissolved fluorene (Flu), phenanthrene (Ph) and pyrene (Py), three polycyclic aromatic hydrocarbons (PAHs), singly or as a mixture of the three, by two bacterial strains, MEBIC 5140 (Mycobacterium flavescens) and MEBIC 5141 (Mycobacterium scrofulaceum), as well as the effects of low molecular weight organic acids (LMWOAs), e.g. malic acid, citric acid and butyric acid on biodegradation of the three PAHs in mineral salts medium aqueous solution were investigated using a newly established dual-wavelength fluorimetric method. The results showed that biodegradation processes can be monitored simultaneously, quickly and simply by dual-wavelength fluorimetry. Both co-metabolism and inhibitory effects were found during the biodegradation of the three PAHs by MEBIC 5140 and MEBIC 5141. Positive effects of butyric acid and negative effects of citric acid on biodegradation of the three PAHs in a mixture were observed.
Subject(s)
Acids/metabolism , Fluorometry/methods , Mycobacterium/metabolism , Polycyclic Aromatic Hydrocarbons/metabolism , Acids/chemistry , Biodegradation, Environmental , Fluorometry/instrumentation , Molecular Weight , Solutions/chemistryABSTRACT
A fluorimetric method for simultaneous determination of dissolved acenaphthylene (Ace) phenanthrene (Ph) and pyrene (Py), mixed in an aqueous mineral salts medium (MSM), was developed. The linear ranges for determination of Ace, Ph and Py dissolved in the mixture were 4.00 x 10(-6) to 3.00 x 10(-3)g/L, 2.00 x 10(-6) to 1.00 x 10(-3)g/L and 7.00 x 10(-7) to 1.00 x 10(-4)g/L. The limits of detection for Ace, Ph and Py were 8.53 x 10(-7), 4.98 x 10(-7) and 6.01 x 10(-8)g/L and the relative standard deviations 1.05%, 1.62% and 1.16% (n=8), respectively. Satisfactory results were obtained when this method was used to simultaneously study the biodegradation processes of mixtures of dissolved Ace, Ph and Py in an MSM aqueous solution.
