Person: MERTOĞLU, BÜLENT
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MERTOĞLU
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BÜLENT
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Publication Metadata only Investigation of nitrogen converters in membrane bioreactor(TAYLOR & FRANCIS INC, 2011) MERTOĞLU, BÜLENT; Ozdemir, Burcu; Mertoglu, Bulent; Yapsakli, Kozet; Aliyazicioglu, Cigdem; Saatci, Ahmet; Yenigun, OrhanIn this study, the activity and diversity of nitrogen converters, ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB), ammonia-oxidizing archaea (AOA) and Anammox bacteria in a pilot-scale membrane bioreactor (MBR) were investigated and monitored using amoA and 16S rDNA-based molecular tools. The pilot-scale MBR (100 m(3)/day) was located inside the full-scale Pasakoy Advanced Wastewater Treatment Plant (WWTP), and operated for approximately 5 months without sludge purge. During 148 days of operation, volatile suspended solids (VSS) concentration increased from 2,454 mg/L to 10,855 mg/L and the average organic carbon and ammonia nitrogen removal rates were 92% and 99%, respectively. Real-time PCR results indicated that the fraction of AOB increased from 2.94% to 4.05% when VSS concentration reached to 3,750 mg/L throughout 148 days of operation. At higher VSS concentrations, the fraction of AOB declined gradually to 1.15% while the fraction of Nitrospira population was varied between 8.23 and 13.01%. However, significant change or any positive and negative correlations between VSS concentration and Nitrospira population were not observed in this period. The phylogenetic analysis revealed that MBR harbored diverse AOB community which was related to the Nitrosomonas and Nitrosospira lineage. Candidatus Nitrospira defluvii was the only detected NOB in this study.Publication Metadata only Effects of insufficient air injection on methanogenic Archaea in landfill bioreactor(ELSEVIER, 2007) ÇALLI, BARIŞ; Mertoglu, Bulent; Calli, Baris; Guler, Nuray; Inanc, Bulent; Inoue, YuzoIn this study, methanogenic Archaea diversity in an aerated landfill bioreactor filled with co-disposed incineration bottom ashes and shredded incombustible wastes was monitored and analyzed as a function of time using molecular techniques. Besides, the effects of insufficient air injection on the bioreactor performance and methanogenic diversity were evaluated thoroughly. Results indicated that rapid bio-stabilization of solid waste are possible with aerated landfill bioreactor at various oxygen and oxidation reduction potential levels. Slot-blot hybridization results of leachate samples collected from aerated landfill bioreactor showed that archaeal and bacterial activities increased as stabilization accelerated and bacterial populations constituted almost 95% of all microorganisms. The results of slot-blot hybridization and phylogenetic analysis based on 16S rRNA gene revealed that Methanobacteriales and Methanomicrobiales were dominant species at the beginning while substituted by Methanosarcina-related methanogens close to the end of the operation of bioreactor. (c) 2006 Elsevier B.V. All rights reserved.Publication Metadata only Evaluation of in situ ammonia removal in an aerated landfill bioreactor(ELSEVIER SCI LTD, 2006) ÇALLI, BARIŞ; Mertoglu, Bulent; Calli, Baris; Inanc, Bulent; Ozturk, IzzetThe composition of nitrifying bacteria in an aerated landfill bioreactor filled with municipal solid waste incineration bottom ashes and shredded incombustible wastes was monitored and analyzed as a function of time during 1 year operation using molecular techniques. Besides, the effects of differing operational conditions on the bioreactor performance and diversity of nitrifiers were evaluated thoroughly. The results confirmed the viability of rapid aerobic bio-stabilization in an aerated landfill bioreactor operated at various ORP levels (-400 to 150 mV). BOD5 decreased faster than TOC and dropped below 10 mg/l after day 120. Subsequently, it remained quite constant until the end of the operational period. This rapid BOD5 degradation in the aerated landfill bioreactor increased the possibility of nitrification by promoting nitrifying bacteria having high oxygen affinities. The nitrification activity in the bioreactor was approved by identification of intensive amounts of Nitrosomonas-like ammonia oxidizers and Nitrospira related nitrite oxidizers with 16S rDNA and amoA based molecular microbiology techniques. (c) 2006 Elsevier Ltd. All rights reserved.Publication Metadata only Long-term assessment of nitrification in a full-scale wastewater treatment plant(TAYLOR & FRANCIS INC, 2008) MERTOĞLU, BÜLENT; Mertoglu, BulentIn this study, long term nitrification performances and microbial composition in a full-scale oxidation ditch type wastewater treatment plant (WWTP) were monitored and evaluated using different molecular methods; fluorescent in situ hybridization (FISH), slot-blot hybridization and quantitative real-time polymerase chain reaction (PCR) method. In situ and membrane hybridization results indicated that Nitrosomonas species were identified as the dominant ammonia oxidizing bacteria and Nitrospira related species were detected as the prevailing nitrite oxidizing bacteria in a full-scale wastewater treatment plant throughout 2 years of operation. Real-time PCR using the LightCyclerinstrument has been developed for the quantification of ammonia monooxygenase (amoA) and 16S rRNA genes. Results suggest that real-time PCR analysis, amoA/16S rRNA ratio, is an alternative method to understand nitrifying bacterial population and activity in wastewater treatment plant compared with the FISH and slot-blot hybridization assays. The autotrophic/heterotrophic bacterial ratio and their influence on reactor performances were investigated using real-time PCR amoA/16S rRNA gene copy ratios and the results showed that this ratio varied from 3.6% to 8.3% during operational period.Publication Metadata only Identification and quantitative evaluation of nitrogen-converting organisms in a full-scale leachate treatment plant(ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2011) MERTOĞLU, BÜLENT; Yapsakli, Kozet; Aliyazicioglu, Cigdem; Mertoglu, BulentThe presence of ammonia nitrogen in landfill leachates poses a significant problem for treatment plant operators. The nitrification-denitrification process mostly carries out the nitrogen conversion in biological treatment systems. However, recent research shows that other processes by anaerobic ammonia-oxidizing bacteria (Anammox) and ammonia-oxidizing archaea (AOA) were also responsible for the removal of nitrogen in biological systems. In this study, the nitrogen-converting microorganisms in the Bursa Hamitler Leachate Treatment Plant were identified and monitored by using molecular tools. Fluorescent in situ hybridization (FISH) and slot-blot hybridization results showed that the Nitrosomonas and Nitrospira species were the dominant ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB), respectively. Quantitative real-time PCR results indicated that AOB, NOB, AOA and Anammox bacteria exist in the leachate treatment plant. However, the removal of ammonia can be ascribed mainly to nitrification because AOB (1.5%) and NOB (11.3%) were predominant among all nitrogen-converting bacteria. The results of the phylogenetic analysis based on amoA and 16S rDNA gene revealed that the uncultured bacterium clone 4-24, Kuenenia stuttgartiensis genome fragment KUST_E and the uncultured Crenarchaeota clone NJYPZT-C1 belong to AOB, Anammox and AOA populations, respectively, and were the dominant species in their cluster. (C) 2010 Elsevier Ltd. All rights reserved.Publication Metadata only Identification of prevalent microbial communities in a municipal solid waste landfill(I W A PUBLISHING, 2006) ÇALLI, BARIŞ; Calli, B; Durmaz, S; Mertoglu, BTo identify the microbial communities in Istanbul, Odayeri Municipal Solid Waste Landfill, leachate samples were collected from different sections at different stabilization phases. In identification of microbial communities in leachate samples, molecular techniques such as FISH, DGGE and cloning based on 16S rRNA and mcrA genes were used. As the chemical and microbiological compositions of the samples were compared, obvious correlations were found between the stability of the landfill section and abundance of active methanogens. On the other hand, there were considerable differences between acidogenic and mature leachate samples in DGGE profiles of archaeal and bacterial 16S rRNA genes. Moreover, in acidogenic leachate samples having BOD5/COD ratio of about 0.5 acetate utilizing Methanosarcina and Methanosaeta species were intensively detected in FISH. Although only very few H-2-utilizing methanogens were identified with FISH analysis, most of the clones isolated from mature leachate samples clustered within H-2-utilizing Methanobacteriales and Methanomicrobiales according to phylogenetic analysis of 16S rRNA and mcrA clones, respectively.