Patent EP-2597461-A2 (EP)
Inventor: PAUTREMAT NATHALIE
IPC: C02F3/30
Filed: 2012-11-21
Abstract: The method comprises preparing an organic sample, incubating the organic sample for 12-24 hours in a microplate with a fluorescent and/or colorimetric bioreagent and an inoculum of micro-organisms for degrading the sample, where the microorganisms are optionally prepared from lyophilized strains or from a culture of bacterial strains analysis of the absorbance-fluorescence emitted by a mixture over time, and calculating an industrial parameter from a calculated organic matter concentration. The method comprises preparing an organic sample, incubating the organic sample for 12-24 hours in a microplate with a fluorescent and/or colorimetric bioreagent and an inoculum of micro-organisms for degrading the sample, where the microorganisms are optionally prepared from lyophilized strains or from a culture of bacterial strains analysis of the absorbance-fluorescence emitted by a mixture over time, and calculating an industrial parameter from a calculated organic matter concentration. The analysis of absorbance-fluorescence comprises: measurement of an intensity of absorbance-fluorescence emitted following degradation of the sample by the inoculum of micro-organisms, where the obtained fluorescence intensity profile allows determination of the minimum measurement time by analysis of a coefficient of determination of a calibration curve associating the intensity of the fluorescence with a concentration of organic matter obtained by carrying out measurements of absorbance-fluorescence on samples of known increasing concentrations constituting a standard range and/or by comparison of the results obtained on samples of known concentrations by a usual standardized method, or deducing instantaneous rate of biodegradation profiles; and calculating a reference organic matter concentration using the intensity of absorbance-fluorescence measurement and using a correlation with a standard range or with a mathematical model. The step of measuring the absorbance-fluorescence intensity is carried out through an underside of the plate. The sample to be analyzed is collected at a treatment site, and the inoculum of microorganisms originates from a bacterial system present on the same site having a composition that is stable over time. The inoculum is optionally passed through 1.2 mu m mesh polyethersulfone filters. The measurement is carried out, at most every 15 minutes under aerobic conditions, by leaving the microplate open or covering the plate with a film allowing oxygen exchange without evaporation. The incubation is carried out for 12-24 hours. The measured fluorescence is converted into mg0 2.L -> 1>according to standard biological request oxygenates over 5 days by comparison with a standard range and by use of a mathematical model connecting the fluorescence intensity to the concentration. The mathematical equation is adjusted as a function of the fluorescence intensities measured on control solutions having known concentrations placed under the same conditions as the samples to be analyzed. The measurement is carried out under anaerobic conditions by covering each well of the microplate with paraffin and then closing the microplate using a cover. The plate is optionally turned over so that the fluorescence measurement takes place from above. The measurement time is chosen automatically such that the coefficient of determination of the calibration curve is closest to 1 over a total incubation period. The fluorescence emitted is converted to LCH 4.kg -> 1>raw matter according to a methane potential (BMP) standard according to a calculation comprising: converting the profiles of absorbance-fluorescence intensities or the profiles of instantaneous rates to gC-Acetate.Kg -> 1>using the mathematical equation originating from the linear regression of the calibration curve; or referring to a database constituted by the samples with known gC-Acetate.Kg -> 1>and BMP LCH 4.Kg -> 1>raw matter values in order to predict the methane potential in terms of LCH 4.kg -> 1>raw matter. The methane potential of unknown samples is directly estimated from the calibration curve in terms of LCH 4.kg -> 1>raw matter. Independent claims are included for: (1) a kit for direct measurement of biodegradability of organic samples; and (2) an analysis system.