scholarly journals New Insights into the Microbial Diversity of Cake Layer in Yttria Composite Ceramic Tubular Membrane in an Anaerobic Membrane Bioreactor (AnMBR)

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 108
Author(s):  
Rathmalgodage Thejani Nilusha ◽  
Yuansong Wei

Cake layer formation is an inevitable challenge in membrane bioreactor (MBR) operation. The investigations on the cake layer microbial community are essential to control biofouling. This work studied the bacterial and archaeal communities in the cake layer, the anaerobic sludge, and the membrane cleaning solutions of anaerobic membrane bioreactor (AnMBR) with yttria-based ceramic tubular membrane by polymerase chain reaction (PCR) amplification of 16S rRNA genes. The cake layer resistance was 69% of the total membrane resistance. Proteins and soluble microbial by-products (SMPs) were the dominant foulants in the cake layer. The pioneering archaeal and bacteria in the cake layer were mostly similar to those in the anaerobic bulk sludge. The dominant biofouling bacteria were Proteobacteria, Bacteroidetes, Firmicutes, and Chloroflexi and the dominant archaeal were Methanosaetacea and Methanobacteriacea at family level. This finding may help to develop antifouling membranes for AnMBR treating domestic wastewater.

Processes ◽  
2018 ◽  
Vol 6 (5) ◽  
pp. 50 ◽  
Author(s):  
Nsanzumukiza Martin Vincent ◽  
Juan Tong ◽  
Dawei Yu ◽  
Junya Zhang ◽  
Yuansong Wei

1999 ◽  
Vol 122 (2) ◽  
pp. 323-328 ◽  
Author(s):  
M. T. E. P. ALLSOPP ◽  
C. M. HATTINGH ◽  
S. W. VOGEL ◽  
B. A. ALLSOPP

A panel of 16S ribosomal RNA gene probes has been developed for the study of the epidemiology of heartwater; five of these detect different cowdria genotypes, one detects five distinct genotypes; one detects any Group III Ehrlichia species other than Cowdria and one detects any Group II Ehrlichia species. These probes have been used on PCR-amplified rickettsial 16S rRNA genes from over 200 Amblyomma hebraeum ticks. Control ticks were laboratory-reared and either uninfected or fed on sheep experimentally infected with different cowdria isolates, field ticks were collected from animals in heartwater-endemic areas. All tick-derived DNA samples were also examined by PCR amplification and probing for two other cowdria genes (map1 and pCS20) which have previously been used for heartwater epidemiology. This paper describes the first direct comparison of all currently available DNA probes for heartwater-associated organisms.


Archaea ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-14
Author(s):  
Wei-Yu Chen ◽  
Lucia Kraková ◽  
Jer-Horng Wu ◽  
Domenico Pangallo ◽  
Lenka Jeszeová ◽  
...  

Tetramethylammonium-degrading methanogenic consortia from a complete-mixing suspended sludge (CMSS) and an upflow anaerobic sludge blanket (UASB) reactors were studied using multiple PCR-based molecular techniques and shotgun proteomic approach. The prokaryotic 16S rRNA genes of the consortia were analyzed by quantitative PCR, high-throughput sequencing, and DGGE-cloning methods. The results showed that methanogenicarchaeawere highly predominant in both reactors but differed markedly according to community structure. Community and proteomic analysis revealed thatMethanomethylovoransandMethanosarcinawere the major players for the demethylation of methylated substrates and methane formation through the reduction pathway of methyl-S-CoM and possibly, acetyl-CoA synthase/decarbonylase-related pathways. Unlike high dominance of oneMethanomethylovoranspopulation in the CMSS reactor, diverse methylotrophicMethanosarcinaspecies inhabited in syntrophy-like association with hydrogenotrophicMethanobacteriumin the granular sludge of UASB reactor. The overall findings indicated the reactor-dependent community structures of quaternary amines degradation and provided microbial insight for the improved understanding of engineering application.


2002 ◽  
Vol 68 (10) ◽  
pp. 5064-5081 ◽  
Author(s):  
Alexander Loy ◽  
Angelika Lehner ◽  
Natuschka Lee ◽  
Justyna Adamczyk ◽  
Harald Meier ◽  
...  

ABSTRACT For cultivation-independent detection of sulfate-reducing prokaryotes (SRPs) an oligonucleotide microarray consisting of 132 16S rRNA gene-targeted oligonucleotide probes (18-mers) having hierarchical and parallel (identical) specificity for the detection of all known lineages of sulfate-reducing prokaryotes (SRP-PhyloChip) was designed and subsequently evaluated with 41 suitable pure cultures of SRPs. The applicability of SRP-PhyloChip for diversity screening of SRPs in environmental and clinical samples was tested by using samples from periodontal tooth pockets and from the chemocline of a hypersaline cyanobacterial mat from Solar Lake (Sinai, Egypt). Consistent with previous studies, SRP-PhyloChip indicated the occurrence of Desulfomicrobium spp. in the tooth pockets and the presence of Desulfonema- and Desulfomonile-like SRPs (together with other SRPs) in the chemocline of the mat. The SRP-PhyloChip results were confirmed by several DNA microarray-independent techniques, including specific PCR amplification, cloning, and sequencing of SRP 16S rRNA genes and the genes encoding the dissimilatory (bi)sulfite reductase (dsrAB).


2010 ◽  
Vol 56 (4) ◽  
pp. 352-355 ◽  
Author(s):  
Junmin Li ◽  
Zexin Jin ◽  
Binbin Yu

To explore changes in the structure and diversity of activated sludge-derived microbial communities during adaptation to gradual increases in the concentration of wastewater, RAPD–PCR and the combination of PCR amplification of 16S rRNA genes with denaturing gradient gel electrophoresis (DGGE) analysis were used. In bacterial communities exposed to 0%, 5%, 10%, 20%, or 40% wastewater, there were 27, 25, 18, 17 and 16 bands, respectively, based on DGGE data, while there were 69, 83, 97, 86, and 88 bands, respectively, based on RAPD data. The community similarity index among bacterial communities during the process of adaptation to different concentrations of wastewater was different based on DGGE and RAPD data. Based on DGGE and RAPD profiles, the Shannon–Weiner and Simpson’s diversity indices decreased sharply upon exposure to 10% wastewater, indicating that 10% wastewater might be a critical point at which the growth of bacteria could be significantly inhibited and the genotypic diversity could change. This indicated that changes in structure and diversity might have an inhibitory effect on the toxicity of organic matter and that selection and adaptation could play important roles in the changes.


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