Ivana Radojević , Violeta Jakovljević , Sandra Grujić , Aleksandar Ostojić , Katarina Ćirković
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引用次数: 0
Abstract
Wastewater often contains an increased amount of mercury and, at the same time, resistant microorganisms. During wastewater treatment, a biofilm of indigenous microorganisms is often unavoidable. Therefore, the objective of this research is to isolate and identify microorganisms from wastewater and investigate their ability to form biofilms for possible application in mercury removal processes.
The resistance of planktonic cells and their biofilms to the effects of mercury was investigated using Minimum Biofilm Eradication Concentration-High Throughput Plates. The formation of biofilms and the degree of resistance to mercury were confirmed in polystyrene microtiter plates with 96 wells. Biofilm on AMB Media carriers (Assisting Moving Bad Media) was quantified using the Bradford protein assay. The removal of mercury ions by biofilms formed on AMB Media carriers of selected isolates and their consortia was determined by a removal test in Erlenmeyer flasks simulating MBBR.
All isolates in planktonic form showed some degree of resistance to mercury. The most resistant microorganisms (Enterobacter cloacae, Klebsiella oxytoca, Serratia odorifera, and Saccharomyces cerevisiae) were tested for their ability to form biofilms in the presence and absence of mercury, both in polystyrene plates and on ABM carriers. The results showed that among planktonic forms, K. oxytoca was the most resistant. A biofilm of the same microorganisms was more than 10-fold resistant. Most consortia biofilms had MBEC values > 100,000 μg/mL. Among individual biofilms, E. cloacae showed the highest mercury removal efficiency (97.81% for 10 days). Biofilm consortia composed of three species showed the best ability to remove mercury (96.64%–99.03% for 10 days).
This study points to the importance of consortia of different types of wastewater microorganisms in the form of biofilms and suggests that they can be used to remove mercury in wastewater treatment bioreactors.
期刊介绍:
Research in Microbiology is the direct descendant of the original Pasteur periodical entitled Annales de l''Institut Pasteur, created in 1887 by Emile Duclaux under the patronage of Louis Pasteur. The Editorial Committee included Chamberland, Grancher, Nocard, Roux and Straus, and the first issue began with Louis Pasteur''s "Lettre sur la Rage" which clearly defines the spirit of the journal:"You have informed me, my dear Duclaux, that you intend to start a monthly collection of articles entitled "Annales de l''Institut Pasteur". You will be rendering a service that will be appreciated by the ever increasing number of young scientists who are attracted to microbiological studies. In your Annales, our laboratory research will of course occupy a central position, but the work from outside groups that you intend to publish will be a source of competitive stimulation for all of us."That first volume included 53 articles as well as critical reviews and book reviews. From that time on, the Annales appeared regularly every month, without interruption, even during the two world wars. Although the journal has undergone many changes over the past 100 years (in the title, the format, the language) reflecting the evolution in scientific publishing, it has consistently maintained the Pasteur tradition by publishing original reports on all aspects of microbiology.