Publications in peer reviewed journals

3 Publications found
  • Global diversity and biogeography of bacterial communities in wastewater treatment plants

    Wu L, Ning D, Zhang B, Li Y, Zhang P, Shan X, Zhang Q, Brown M, Li Z, Van Nostrand JD, Ling F, Xiao N, Zhang Y, Vierheilig J, Wells GF, Yang Y, Deng Y, Tu Q, Wang A, Global Water Microbiome Consortium, Zhang T, He Z, Keller J, Nielsen PH, Alvarez PJJ, Criddle CS, Wagner M, Tiedje JM, He Q, Curtis TP, Stahl DA, Alvarez-Cohen L, Rittmann BE, Wen X, Zhou J
    2019 - Nat Microbiol, in press
    Sources of microbes in activated sludge


    Microorganisms in wastewater treatment plants (WWTPs) are essential for water purification to protect public and environ- mental health. However, the diversity of microorganisms and the factors that control it are poorly understood. Using a systematic global-sampling effort, we analysed the 16S ribosomal RNA gene sequences from ~1,200 activated sludge samples taken from 269 WWTPs in 23 countries on 6 continents. Our analyses revealed that the global activated sludge bacterial communities contain ~1 billion bacterial phylotypes with a Poisson lognormal diversity distribution. Despite this high diversity, activated sludge has a small, global core bacterial community (n=28 operational taxonomic units) that is strongly linked to activated sludge performance. Meta-analyses with global datasets associate the activated sludge microbiomes most closely to freshwater populations. In contrast to macroorganism diversity, activated sludge bacterial communities show no latitudinal gradient. Furthermore, their spatial turnover is scale-dependent and appears to be largely driven by stochastic processes (dispersal and drift), although deterministic factors (temperature and organic input) are also important. Our findings enhance our mechanistic understanding of the global diversity and biogeography of activated sludge bacterial communities within a theoretical ecology framework and have important implications for microbial ecology and wastewater treatment processes.

  • Cometabolic biotransformation and microbial-mediated abiotic transformation of sulfonamides by three ammonia oxidizers

    Zhou L-J, Han P, Yu Y, Wang B, Men Y, Wagner M, Wu QL
    2019 - Water Res., in press


    The abilities of three phylogenetically distant ammonia oxidizers, Nitrososphaera gargensis, an ammonia-oxidizing archaeon (AOA); Nitrosomomas nitrosa Nm90, an ammonia-oxidizing bacterium (AOB); and Nitrospira inopinata, the only complete ammonia oxidizer (comammox) available as a pure culture, to biotransform seven sulfonamides (SAs) were investigated. The removals and protein-normalized biotransformation rate constants indicated that the AOA strain N. gargensis exhibited the highest SA biotransformation rates, followed by N. inopinata and N. nitrosa Nm90. The transformation products (TPs) of sulfadiazine (SDZ), sulfamethazine (SMZ) and sulfamethoxazole (SMX) and the biotransformation mechanisms were evaluated. Based on the analysis of the TP formulas and approximate structures, it was found that during biotransformation, i) the AOA strain carried out SA deamination, hydroxylation, and nitration; ii) the AOB strain mainly performed SA deamination; and iii) the comammox isolate participated only in deamination reactions. It is proposed that deamination was catalyzed by deaminases while hydroxylation and nitration were mediated by nonspecific activities of the ammonia monooxygenase (AMO). Additionally, it was demonstrated that among the three ammonia oxidizers, only AOB contributed to the formation of pterin-SA conjugates. The biotransformation of SDZ, SMZ and SMX occurred only when ammonia oxidation was active, suggesting a cometabolic transformation mechanism. Interestingly, SAs could also be transformed by hydroxylamine, an intermediate of ammonia oxidation, suggesting that in addition to enzymatic conversions, a microbially induced abiotic mechanism contributes to SA transformation during ammonia oxidation. Overall, using

    experiments with pure cultures, this study provides important insights into the roles played by ammonia oxidizers in SA biotransformation.

  • Resolving the individual contribution of key microbial populations to enhanced biological phosphorus removal with Raman-FISH.

    Fernando EY, McIlroy SJ, Nierychlo M, Herbst FA, Petriglieri F, Schmid MC, Wagner M, Nielsen JL, Nielsen PH
    2019 - ISME J, in press


    Enhanced biological phosphorus removal (EBPR) is a globally important biotechnological process and relies on the massive accumulation of phosphate within special microorganisms. Candidatus Accumulibacter conform to the classical physiology model for polyphosphate accumulating organisms and are widely believed to be the most important player for the process in full-scale EBPR systems. However, it was impossible till now to quantify the contribution of specific microbial clades to EBPR. In this study, we have developed a new tool to directly link the identity of microbial cells to the absolute quantification of intracellular poly-P and other polymers under in situ conditions, and applied it to eight full-scale EBPR plants. Besides Ca. Accumulibacter, members of the genus Tetrasphaera were found to be important microbes for P accumulation, and in six plants they were the most important. As these Tetrasphaera cells did not exhibit the classical phenotype of poly-P accumulating microbes, our entire understanding of the microbiology of the EBPR process has to be revised. Furthermore, our new single-cell approach can now also be applied to quantify storage polymer dynamics in individual populations in situ in other ecosystems and might become a valuable tool for many environmental microbiologists.

Book chapters and other publications

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