Browsing by Author "Denecke, Martin"

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Assessment of molecular detection of anaerobic ammonium-oxidizing (anammox) bacteria in different environmental samples using PCR primers based on 16S rRNA and functional genes
(2017-10-01)
Han, Ping
;
Kluemper, Uli
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Wong, Alex
;
Li, Meng
;
Lin, Jih-Gaw
Eleven published PCR primer sets for detecting genes encoding 16S ribosomal RNA (rRNA), hydrazine oxidoreductase (HZO), cytochrome cd(1)-containing nitrite reductase (NirS), and hydrazine synthase subunit A (HzsA) of anaerobic ammonium-oxidizing (anammox) bacteria were assessed for the diversity and abundance of anammox bacteria in samples of three environments: wastewater treatment plant (WWTP), wetland of Mai Po Nature Reserve (MP), and the South China Sea (SCS). Consistent phylogenetic results of three biomarkers (16S rRNA, hzo, and hzsA) of anammox bacteria were obtained from all samples. WWTP had the lowest diversity with Candidatus Kuenenia dominating while the SCS was dominated by Candidatus Scalindua. MP showed the highest diversity of anammox bacteria including C. Scalindua, C. Kuenenia, and Candidatus Brocadia. Comparing different primer sets, no significant differences in specificity for 16S rRNA gene could be distinguished. Primer set CL1 showed relatively high efficiency in detecting the anammox bacterium hzo gene from all samples, while CL2 showed greater selectivity for WWTP samples. The recently reported primer sets of the hzsA gene resulted in high efficiencies in detecting anammox bacteria while nirS primer sets were more selective for specific samples. Results collectively indicate that the distribution of anammox bacteria is niche-specific within different ecosystems and primer specificity may cause biases on the diversity detected.
Insights into the roles of anammox bacteria in post-treatment of anaerobically-treated sewage
(2018-01-01)
Wang, Qian
;
Tan, Giin-Yu Amy
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Azari, Mohammad
;
Huang, Xiaowu
;
Denecke, Martin
Complete anaerobic treatment of sewage has the potential to achieve net energy production via capturing the energy of organics in sewage, but not nitrogen, which remains a concern. Anaerobic ammonium oxidation (anammox) is potential for energy-efficient nitrogen removal from anaerobically-treated sewage. Given the sensitivity of anammox bacteria and the challenge of the low ammonium-bearing influent with reduced compounds such as volatile fatty acids, methane, and sulfide, this article critically reviewed and analyzed, using thermodynamic computation as a tool, the potential interactions of anammox bacteria with other microbes induced by the reduced compounds in anaerobically-treated sewage. The dynamics of anammox bacteria to cooperate with these microbes that metabolize non-ammonium pollutants and to outcompete for the common substrate, i.e., nitrite, are extensively discussed. The versatile metabolism of anammox bacteria on volatile fatty acids and iron, which would help facilitate the treatment efficiency, was also reviewed. The information offered in this review will be beneficial to researchers and engineers in controlling process stability, enhancing total nitrogen removal, and achieving better effluent quality in post-treatment of anaerobically-treated sewage by anammox-based processes.
Occurrence of anammox bacteria in a traditional full-scale wastewater treatment plant and successful inoculation for new establishment
(2017-05-01)
Meng, Han
;
Yang, Yu-Chun
;
Lin, Jih-Gaw
;
Denecke, Martin
;
Gu, Ji-Dong
A new biochemical pathway for reactive nitrogen removal from wastewater has been recognized as anaerobic ammonium oxidation (anammox) since its first discovery in the 1990's. Over the past decades, many studies have been focused on laboratory scale reactors for enrichment of the anammox bacteria for potential applications on an industrial scale. The research reported here investigated the occurrence, community diversity and abundance of anammox bacteria observed for the first time in a full-scale wastewater treatment plant (Plant N) in Taiwan and then successful inoculation of the initially enriched anammox bacteria granules into another full-scale wastewater treatment plant (Plant S). The community composition was similar in both plants, showing similarity in the existence of Ca. Brocadia as the dominating genus of anammox bacteria. Inoculation of the existing sludge containing active anammox bacteria into other plant resulted in an effective establishment of anammox bacteria in as little as 6 months in a full-scale wastewater treatment plant. The abundance of anammox bacteria was significantly different between these two plants with the newly inoculated one containing 2 to 100 times higher gene copies of the anammox bacteria than Plant N serving as an inoculum. In addition, differences were also observed between the sludge and immobilizing carrier materials, which supported the colonization of anammox bacteria and retained them to reach to a much high density in the wastewater treatment system. Based on qPCR results and TEM observation, anammox bacteria in those treatment plants were active and contributed to inorganic N removal. The inoculation study showed that anammox process can be activated without re-design of the system and inoculation was successful to activate anammox process effectively to achieve the inorganic N removal in conventional wastewater treatment plants. (C) 2017 Elsevier Ltd. All rights reserved.
Specific and effective detection of anammox bacteria using PCR primers targeting the 16S rRNA gene and functional genes
(2020-09-10)
Yang, Yuchun
;
Li, Meng
;
Li, Hui
;
Li, Xiao-Yan
;
Lin, Jih-Gaw