The study of microbial hydrocarbons removal is of great importance for the development of future bioremediation strategies.In this study,we evaluated the removal of a gaseous mixture containing toluene,m-xylene,ethylb...The study of microbial hydrocarbons removal is of great importance for the development of future bioremediation strategies.In this study,we evaluated the removal of a gaseous mixture containing toluene,m-xylene,ethylbenzene,cyclohexane,butane,pentane,hexane and heptane in aerated stirred bioreactors inoculated with Rhodococcus erythropolis and operated under non-sterile conditions.For the real-time measurement of hydrocarbons,a novel systematic approachwas implemented using Selected-Ion Flow TubeMass Spectrometry(SIFTMS).The effect of the carbon source(~9.5 ppmv)on(i)the bioreactors’performance(BR1:dosed with only cyclohexane as a single hydrocarbon versus BR2:dosed with a mixture of the 8 hydrocarbons)and(ii)the evolution of microbial communities over time were investigated.The results showed that cyclohexane reached a maximum removal efficiency(RE)of 53%±4%in BR1.In BR2,almost complete removal of toluene,m-xylene and ethylbenzene,being the most water-soluble and easy-to-degrade carbon sources,was observed.REs below 32%were obtained for the remaining compounds.By exposing the microbial consortium to only the five most recalcitrant hydrocarbons,REs between 45%±5%and 98%±1%were reached.In addition,we observed that airborne microorganisms populated the bioreactors and that the type of carbon source influenced the microbial communities developed.The abundance of species belonging to the genus Rhodococcus was below 10%in all bioreactors at the end of the experiments.This work provides fundamental insights to understand the complex behavior of gaseous hydrocarbon mixtures in bioreactors,along with a systematic approach for the development of SIFT-MS methods.展开更多
基金supported by Ghent University through a special research grant(No.BOFSTG2019005701)The assistance provided by Ann Dirckx in the microbiology lab was greatly appreciated.Allan A.Alvarado-Alvarado thanks the European Commission under the Erasmus+EMJMD Program for funding his research at Ghent University(No.2017-1957/001-001-EMJMD).
文摘The study of microbial hydrocarbons removal is of great importance for the development of future bioremediation strategies.In this study,we evaluated the removal of a gaseous mixture containing toluene,m-xylene,ethylbenzene,cyclohexane,butane,pentane,hexane and heptane in aerated stirred bioreactors inoculated with Rhodococcus erythropolis and operated under non-sterile conditions.For the real-time measurement of hydrocarbons,a novel systematic approachwas implemented using Selected-Ion Flow TubeMass Spectrometry(SIFTMS).The effect of the carbon source(~9.5 ppmv)on(i)the bioreactors’performance(BR1:dosed with only cyclohexane as a single hydrocarbon versus BR2:dosed with a mixture of the 8 hydrocarbons)and(ii)the evolution of microbial communities over time were investigated.The results showed that cyclohexane reached a maximum removal efficiency(RE)of 53%±4%in BR1.In BR2,almost complete removal of toluene,m-xylene and ethylbenzene,being the most water-soluble and easy-to-degrade carbon sources,was observed.REs below 32%were obtained for the remaining compounds.By exposing the microbial consortium to only the five most recalcitrant hydrocarbons,REs between 45%±5%and 98%±1%were reached.In addition,we observed that airborne microorganisms populated the bioreactors and that the type of carbon source influenced the microbial communities developed.The abundance of species belonging to the genus Rhodococcus was below 10%in all bioreactors at the end of the experiments.This work provides fundamental insights to understand the complex behavior of gaseous hydrocarbon mixtures in bioreactors,along with a systematic approach for the development of SIFT-MS methods.
