Publication: Monitoring of changes in methanogenic populations during operation of anaerobic reactors with molecular biology tools
Abstract
Bu çalışmada, üç farklı laboratuar ölçekli anaerobik reaktör, yukarı akışlı çamur yatağı (UASB), anaerobik filtre (AF) ve hibrit reaktör, yüksek amonyak ihtiva eden sızıntı suyu ile 1000 günden fazla süre beslenmiştir. Serbest amonyak konsantrasyonu inhibisyon seviyesine ulaşmadığı sürece, her üç reaktörde de benzer performanslar gözlenmiştir. Sonuçlar anaerobik filtre (AF) veya hibrit reaktör'ün yüksek amonyak konsantrasyonlarında sızıntı suyunu başarıyla arıtabildiğini göstermektedir. Yukarı akışlı çamur yatağı (UASB) serbest amonyak ve organik yük artışlarına karşı en duyarlı reaktör tipidir. Ham sızıntı suyunun pH'ı 175-860 günleri arasında serbest amonyak inhibisyonunun metanojenler üzerindeki etkisini engellemek için düşürülmüştür. DGGE ve FISH metotları aynı sızıntı suyunu arıtan üç farklı anaerobik reaktörden alınan çamur numunelerindeki mikrobiyolojik popülasyonun tanımlanmasında kullanılmıştır. Moleküler tekniklerden elde edilen bulgular, aynı sızıntı suyu ile uzun süreli beslenen reaktörlerde reaktör konfigürasyonunun mikroorganizma türlerinin dağılımı üzerinde etkisi olmadığını göstermektedir . DGGE sonuçları bakteri ve archaea topluluklarının yapısının tüm reaktörlerde aynı olduğunu göstermiştir. Bir diğer manada, aynı sızıntı suyu ile uzun süreli beslenen reaktörlerde, reaktör konfigürasyonunun mikroorganizmalar üzerinde önemli bir etkisinin olmadığını gösterilmiştir. Sonuçlar aşı çamurundaki metanojenik türlerin reaktörlerde tutunamayıp kaybolduğunu yerine büyük ihtimalle ham sızıntı suyu ile gelen türlerin dominant olduğunu göstermiştir. FISH deneyleri sonucunda reaktörlerde, archaea türlerinin bakterilere karşı daha baskın, asetoklastik metanojenler arasında ise Methanosaeta'nın Methanosarcina'ya karşı daha baskın olduğu gözlenmiştir. Reaktör yüksekliği boyunca alınan numunelerde de benzer sonuçlar gözlenmiştir.
MONITORING OF CHANGES IN METHANOGENIC POPULATIONS DURING OPERATION OF ANAEROBIC REACTORS WITH MOLECULAR BIOLOGY TOOLS In this study, three different laboratory scale anaerobic reactors namely upflow anaerobic sludge bed reactor (UASB), anaerobic upflow filter (AF) and hybrid bed reactor were operated for more than 1000 days in the treatment of high ammonia landfill leachate. All the reactors showed similar performances unless free ammonia reach to inhibitory levels. The results indicated that high ammonia leachate can be treated successfully by anaerobic filter or hybrid bed reactor. UASB is the most sensitive reactor type against free ammonia and organic shocks. Reducing the influent pH can be used to prevent the free ammonia inhibition on methanogens. Denaturing gradient gel electrophoresis (DGGE) and FISH were used complimentary to each other in the identification of microbial population in the sludge samples taken from these three different anaerobic reactors treating the same leachate. Findings of molecular techniques suggest that, reactor configuration does not have an impact on microbial diversity which were fed with the same leachate, in long-term. DGGE results indicated that bacterial and archaeal community structures were similar in all the reactors, meaning no significant effect of reactors configuration, which were fed with the same wastewater, in long-term. The microorganisms in the reactor came from not only seed sludge but also influent wastewaters. FISH experiments indicated that archaea species were dominant against bacteria species and among acetoclastic methanogens Methanosaeta was dominant against Methanosarcina in all the reactors. The results were similar through height of the reactors.
MONITORING OF CHANGES IN METHANOGENIC POPULATIONS DURING OPERATION OF ANAEROBIC REACTORS WITH MOLECULAR BIOLOGY TOOLS In this study, three different laboratory scale anaerobic reactors namely upflow anaerobic sludge bed reactor (UASB), anaerobic upflow filter (AF) and hybrid bed reactor were operated for more than 1000 days in the treatment of high ammonia landfill leachate. All the reactors showed similar performances unless free ammonia reach to inhibitory levels. The results indicated that high ammonia leachate can be treated successfully by anaerobic filter or hybrid bed reactor. UASB is the most sensitive reactor type against free ammonia and organic shocks. Reducing the influent pH can be used to prevent the free ammonia inhibition on methanogens. Denaturing gradient gel electrophoresis (DGGE) and FISH were used complimentary to each other in the identification of microbial population in the sludge samples taken from these three different anaerobic reactors treating the same leachate. Findings of molecular techniques suggest that, reactor configuration does not have an impact on microbial diversity which were fed with the same leachate, in long-term. DGGE results indicated that bacterial and archaeal community structures were similar in all the reactors, meaning no significant effect of reactors configuration, which were fed with the same wastewater, in long-term. The microorganisms in the reactor came from not only seed sludge but also influent wastewaters. FISH experiments indicated that archaea species were dominant against bacteria species and among acetoclastic methanogens Methanosaeta was dominant against Methanosarcina in all the reactors. The results were similar through height of the reactors.