Impact of sludge retention time on sludge characteristics and microbial community in MBR

2011 ◽  
Vol 63 (10) ◽  
pp. 2250-2254 ◽  
Author(s):  
Yuchun Su ◽  
Jill Ruhsing Pan ◽  
Chihpin Huang ◽  
Chialing Chang
Keyword(s):  
Microbial Community ◽  
Retention Time ◽  
Membrane Fouling ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Membrane Surface ◽  
Sludge Characteristics ◽  
Sludge Retention Time ◽  
Gradient Gel Electrophoresis ◽  
Microbial Products ◽  
The Impact

In this study, the impact of sludge retention time (SRT) on sludge characteristics and microbial community and the effect on membrane fouling in membrane bioreactor (MBR) was investigated. The results show that MBR with longer SRT has less fouling propensity, in agreement with other studies, despite the fact that the MBR with longer SRT contained higher MLSS and smaller particle size. However, much more soluble microbial products (SMPs) were released in MBR with shorter SRT. More slime on the membrane surface was observed in MBR with shorter SRT while sludge cakes formed on the membrane surface in MBR with longer SRT. The results show that SMP contributes to the severe fouling observed in MBR with shorter SRT, which is in agreement with other studies showing that SMPs were the major foulants in MBR. Under different SRTs of operation, the bacterial community structures of the sludge obtained by use of polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) were almost identical, but those on the membrane surface differed substantially. It suggests that, although SRT has impact on sludge characteristics, it doesn't affect the microbial community in the suspension.

Characteristics of different fractions of microbial flocs and their role in membrane fouling

2011 ◽  
Vol 63 (2) ◽  
pp. 262-269 ◽  
Author(s):  
H. J. Lin ◽  
W. J. Gao ◽  
K. T. Leung ◽  
B. Q. Liao
Keyword(s):  
Microbial Community ◽  
Membrane Fouling ◽  
Extracellular Polymeric Substances ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Sludge Flocs ◽  
Microbial Flocs ◽  
Thermomechanical Pulping ◽  
Gradient Gel Electrophoresis ◽  
Sludge Cake ◽  
The Difference

Characteristics of different fractions (small flocs vs. large flocs) of sludge flocs from a submerged anaerobic membrane bioreactor treating thermomechanical pulping (TMP) whitewater were determined using various analytic techniques, including extraction and chemical analysis of extracellular polymeric substances (EPS), particle size analyzer, and polymer chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE). The results showed that the fraction of smaller flocs contained a higher level of bound EPS and had a higher fractal dimension as compared to the fraction of larger flocs. PCR-DGGE analysis indicated that there were significant differences in microbial community between the fraction of smaller flocs and large flocs. The microbial community of the smaller flocs was similar to that of the sludge cake layers, indicating the pioneering role of the microbial community in smaller flocs in membrane fouling. These findings provide a new insight in the difference of membrane fouling potential between smaller flocs and larger flocs fraction.

scholarly journals Impact of Intensive Land-Based Fish Culture in Qingdao, China, on the Bacterial Communities in Surrounding Marine Waters and Sediments

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Qiufen Li ◽  
Yan Zhang ◽  
David Juck ◽  
Nathalie Fortin ◽  
Charles W. Greer
Keyword(s):  
Bacterial Communities ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Fish Culture ◽  
Fish Ponds ◽  
Marine Area ◽  
Gradient Gel Electrophoresis ◽  
Reducing Bacteria ◽  
The Impact ◽  
Nitrate Reducing Bacteria

The impact of intensive land-based fish culture in Qingdao, China, on the bacterial communities in surrounding marine environment was analyzed. Culture-based studies showed that the highest counts of heterotrophic, ammonium-oxidizing, nitrifying, and nitrate-reducing bacteria were found in fish ponds and the effluent channel, with lower counts in the adjacent marine area and the lowest counts in the samples taken from 500 m off the effluent channel. Denaturing gradient gel electrophoresis (DGGE) analysis was used to assess total bacterial diversity. Fewer bands were observed from the samples taken from near the effluent channel compared with more distant sediment samples, suggesting that excess nutrients from the aquaculture facility may be reducing the diversity of bacterial communities in nearby sediments. Phylogenetic analysis of the sequenced DGGE bands indicated that the bacteria community of fish-culture-associated environments was mainly composed of Flavobacteriaceae, gamma- and deltaproteobacteria, including generaGelidibacter, Psychroserpen, Lacinutrix,andCroceimarina.

Study of microbial community of brewery-treating granular sludge by denaturing gradient gel electrophoresis of 16S rRNA gene

2001 ◽  
Vol 43 (1) ◽  
pp. 77-82 ◽  
Author(s):  
O.-C. Chan ◽  
W.-T. Liu ◽  
H. H. Fang
Keyword(s):  
Microbial Community ◽  
16S Rrna ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Rrna Gene ◽  
Related Sequence ◽  
Gradient Gel Electrophoresis

The microbial community structure of granular sludge from an upflow anaerobic sludge blanket (UASB) reactor treating brewery effluent was studied by denaturing gradient gel electrophoresis (DGGE). Twelve major bands were observed in the DGGE fingerprint for the Bacteria domain and four bands for the Archaea domain. Of the bacterial bands observed, six were successfully purified and sequenced. Among them, three were related to the gram-positive low G+C group, one to the Delta subclass of the Proteobacteria, one to the Gamma subclass, and one to the Cytophaga group with no close related sequence. The 16S rRNA sequences of the four archaeal bands were closely associated with Methanosaeta concilii and Methanobacterium formicum.

Individual responses of mother sows to a probiotic Enterococcus faecium strain lead to different microbiota composition in their offspring

2013 ◽  
Vol 4 (4) ◽  
pp. 345-356 ◽  
Author(s):  
I.C. Starke ◽  
R. Pieper ◽  
K. Neumann ◽  
J. Zentek ◽  
W. Vahjen
Keyword(s):  
Enterococcus Faecium ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Probiotic Strain ◽  
Quantitative Composition ◽  
Pronounced Increase ◽  
Gradient Gel Electrophoresis ◽  
Suckling Piglets ◽  
Weaning Piglets ◽  
The Impact ◽  
Faecium Strain

Pregnant gilts were fed the probiotic Enterococcus faecium NCIMB10415 (SF68) one month before birth of piglets. DNA extracts of sow faeces taken in weekly intervals as well as extracts from the intestine of their offspring during the suckling period at 12 and 26 days of life were analysed by denaturing gradient gel electrophoresis (DGGE) and quantitative PCR. DGGE profiles of faecal bacterial communities from three out of six probiotic-fed sows were distinctly different from the control and other probiotic-fed sows at all time points after probiotic supplementation. The probiotic-fed sows and their offspring were therefore divided into non-responder (n=3) and responder (n=3) groups. The probiotic strain significantly increased faecal lactobacilli cell numbers in mother sows, which could be assigned to a significant increase of Lactobacillus amylovorus and Lactobacillus acidophilus. Responding sows showed a more pronounced increase than non-responding sows. Similarly, suckling piglets from non-responding and responding sows showed numeric and significant differences for different bacterial groups and species. DGGE profiles of suckling piglets from responding sows also grouped more closely than profiles from control animals. Non-metric multiscaling of suckling piglets showed the same tendency for suckling piglets, but not for post-weaning piglets. This study showed that the probiotic E. faecium strain modified the faecal microbiota of sows. This modification is carried over to their offspring, but leads to changes that do not mirror the quantitative composition in the mother sow. Individual variations in the bacterial composition of mother sows before probiotic feed intake may influence the impact of a probiotic in sows and their offspring.

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