scholarly journals Composition of estuarine bacterial communities assessed by denaturing gradient gel electrophoresis and fluorescence in situ hybridization

2004 ◽  
Vol 2 (9) ◽  
pp. 303-314 ◽  
Author(s):  
Dawn Castle ◽  
David L. Kirchman
2000 ◽  
Vol 41 (10-11) ◽  
pp. 259-268 ◽  
Author(s):  
B.S. Luxmy ◽  
F. Nakajima ◽  
Kazuo Yamamoto

The bacterial communities of membrane-separation bioreactors (MBR) fed with raw sewage were analyzed by a pilot scale study. The community was analyzed by both Fluorescent in Situ Hybridization (FISH) and PCR-DGGE (polymerase chain reaction-denaturing gradient gel electrophoresis) techniques. Five rRNA targeted group specific oligonucleotide probes showed that the alpha- and beta- subclasses of proteobacteria were the most dominant groups among them. The identification of ammonia-oxidizing bacteria in MBR was confirmed by three probes: NEU, Nsv 443 and Nso 190. Mostly the ammonia-oxidizers were found in groups and present in the form of clusters or aggregates. The ratio of NEU/EUB was estimated by double hybridization and image analysis techniques as 6%. The Nitrobacter sp. was also identified inside the MBR with the help of a NIT3 probe and they were also found to be present in the form of a cluster. Usually the clusters formed by the Nitrobacter sp. were smaller than those of ammonia-oxidizing groups. After numerical analysis on the band pattern of DGGE, it was found that the MBR bacterial communities were different from that of conventional activated sludge (CAS) communities with dissimilarity indexes more than 0.6. The diversity of the microbial community was estimated by the Shannon-Weaver index of general diversity. It was found that the value of the diversity index for the CAS process was 1.61 while those for two MBR processes were 1.68 and 1.59.


2012 ◽  
Vol 610-613 ◽  
pp. 331-336
Author(s):  
Yuan Hua Xie ◽  
Tong Zhu ◽  
Xiao Jiang Liu ◽  
Hui Liu ◽  
Jin Han

An anoxic-oxic activated sludge process (AOASP) was carried out to degrade nonylphenol polyethoxylates (NPEOs). The carbon source in influent was replaced stepwise by a mixture of nonylphenol decaethoxylate (M-NP10EO). The 2nd-derivative UV-spectrometry was applied to determine the total amount of M-NP10EO in water samples. Chemical oxygen demand (COD) removal efficiency achieves about 85% under the highest M-NP10EO loading rate, and M-NP10EO removal efficiency is about 80%. Denaturing gradient gel electrophoresis (DGGE) results of activated sludges show that the microbe species decrease but gradually stabilize with the increase of M-NP10EO concentration in influent. Fluorescence in situ hybridization (FISH) results of activated sludges showe that the dominant microflora under the highest M-NP10EO loading rate is β-Proteobacteria (35%), followed by α-Proteobacteria (15%), γ-Proteobacteria (5%) and Actinobateria (4%).


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Qiufen Li ◽  
Yan Zhang ◽  
David Juck ◽  
Nathalie Fortin ◽  
Charles W. Greer

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.


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