The microbial community analysis of a 5-stage BNR process with step feed system

2003 ◽  
Vol 48 (8) ◽  
pp. 135-141 ◽  
Author(s):  
H.W. Lee ◽  
S.Y. Lee ◽  
J.O. Lee ◽  
H.G. Kim ◽  
J.B. Park ◽  
...  
Keyword(s):  
16S Rdna ◽  
Community Analysis ◽  
Cell Number ◽  
Total Cell ◽  
Microbial Community Analysis ◽  
Feed System ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Cell Counts

The microbial communities of 5-stage BNR activated sludge samples were analyzed using fluorescence in-situ hybridization (FISH) and 16S rDNA characterization. The total cell numbers of each reactor were from 2.36 × 109 cells/ml to 2.83 × 109 cells/ml. From 56.5% to 62.0% of total DAPI cell counts were hybridized to the most bacterial specific probe EUB 338. Among them, b-proteobacteria were most dominant in each tank. The number of phosphate accumulating organisms (PAOs) was almost 50% of the total cell number in anoxic-1 tank, and these results indicate that this process has a high content of denitrifying phosphorus accumulating organisms (dPAOs). In contrast with FISH, 16S rDNA analysis showed that dominant groups were the Cytophaga-Flavobacterium group and high G+C% gram-positive bacteria, which were determined as PAOs in anoxic-1 tank. The beta subclass Proteobacteria did not accumulate a large amount of polyphosphate. The overall results indicate that high G+C% gram-positive bacteria and the Cytophaga-Flavobacterium group might play a key role as dPAOs in this process.

Microbial community analysis of a full-scale membrane bioreactor treating industrial wastewater

2008 ◽  
Vol 58 (8) ◽  
pp. 1589-1594 ◽  
Author(s):  
D. Naidoo ◽  
N. Ramdhani ◽  
F. Bux
Keyword(s):  
In Situ Hybridization ◽  
Microbial Community ◽  
Manufacturing Industry ◽  
Community Analysis ◽  
Microbial Community Analysis ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Positive Hybridization ◽  
Gram Negative Organisms

A Kubota™ submerged membrane bio-reactor was applied to treat wastewater from a sugar manufacturing industry. To achieve optimal results, fundamental and extended understanding of the microbiology is important. Fluorescence in situ hybridization was used to evaluate the microbial community present. The majority of cells visualized in the sludge flocs by staining with the DNA fluorochrome DAPI, hybridized strongly with a bacterial probe. Probes specific for the alpha-, beta-, and gamma-subclasses of proteobacteria and high G + C Gram positive bacteria were used to characterize the community structures by in situ hybridization. Sampling was carried out over 12 weeks and samples were fixed with 4% paraformaldehyde for gram positive organisms and ice cold ethanol for gram negative organisms. The activated sludge population usually constitutes about 80 to 90% of proteobacteria. However, in this study it was found that a relatively small amount of proteobacteria was present within the system. No positive hybridization signal was observed with any of the applied eubacterial family- level probes.

Lysozyme Treatment Makes 16S rRNA Amplicon Sequencing Results Less Biased

2021 ◽  
Author(s):  
Yuting Jiao ◽  
Zijie Gao ◽  
Shiyu Gui ◽  
Lu Ren ◽  
Yongyue Lu ◽  
...  
Keyword(s):  
Structure Analysis ◽  
Community Analysis ◽  
Amplicon Sequencing ◽  
Microbial Community Analysis ◽  
Effective Agent ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
16S Rrna Amplicon Sequencing ◽  
Structure Result ◽  
Total Bacteria

Abstract Background Amplicon sequencing is widely applied in gut bacteria structure analysis. However, the proportion of Gram-positive bacteria may greatly affect the results of microbial community analysis. Lysozyme is an effective agent to extract DNA of Gram-positive bacteria. In this study, we assessed the influence of lysozyme treatment on results of Bactrocere dorsalis rectal bacteria structure. Result The results indicated that the total bacteria content can be significantly increased in lysozyme treated samples. Moreover, rectal bacteria diversity was significantly higher in lysozyme treated samples. A detail analysis revealed that abundance of Gram-positive bacteria significantly increased in samples treated with lysozyme. Conclusion This study indicates that lysozyme treatment before DNA extraction is an effective way to reduce bias in bacteria structure analysis, especially for samples with high proportion of Gram-positive bacteria.

scholarly journals Community Analysis of Biofilters Using Fluorescence In Situ Hybridization Including a New Probe for theXanthomonas Branch of the ClassProteobacteria

1999 ◽  
Vol 65 (8) ◽  
pp. 3547-3554 ◽  
Author(s):  
Udo Friedrich ◽  
Michèle M. Naismith ◽  
Karlheinz Altendorf ◽  
André Lipski
Keyword(s):  
In Situ Hybridization ◽  
Community Analysis ◽  
Specific Probe ◽  
Efficient Tool ◽  
Gram Positive ◽  
Detection Rates ◽  
Gram Positive Bacteria ◽  
Practical Tool ◽  
Direct Counts

ABSTRACT Domain-, class-, and subclass-specific rRNA-targeted probes were applied to investigate the microbial communities of three industrial and three laboratory-scale biofilters. The set of probes also included a new probe (named XAN818) specific for the Xanthomonasbranch of the class Proteobacteria; this probe is described in this study. The members of the Xanthomonas branch do not hybridize with previously developed rRNA-targeted oligonucleotide probes for the α-, β-, and γ-Proteobacteria. Bacteria of the Xanthomonas branch accounted for up to 4.5% of total direct counts obtained with 4′,6-diamidino-2-phenylindole. In biofilter samples, the relative abundance of these bacteria was similar to that of the γ-Proteobacteria. Actinobacteria(gram-positive bacteria with a high G+C DNA content) and α-Proteobacteria were the most dominant groups. Detection rates obtained with probe EUB338 varied between about 40 and 70%. For samples with high contents of gram-positive bacteria, these percentages were substantially improved when the calculations were corrected for the reduced permeability of gram-positive bacteria when formaldehyde was used as a fixative. The set of applied bacterial class- and subclass-specific probes yielded, on average, 58.5% (± a standard deviation of 23.0%) of the corrected eubacterial detection rates, thus indicating the necessity of additional probes for studies of biofilter communities. The Xanthomonas-specific probe presented here may serve as an efficient tool for identifying potential phytopathogens. In situ hybridization proved to be a practical tool for microbiological studies of biofiltration systems.

Microbial Community Analysis inside a Biooxidation Heap for Gold Recovery in Equador

2017 ◽  
Vol 262 ◽  
pp. 135-138 ◽  
Author(s):  
Carlos L. Aspiazu ◽  
Paulina Aguirre ◽  
Sabrina Hedrich ◽  
Axel Schippers
Keyword(s):  
Microbial Community ◽  
Fine Fraction ◽  
Community Analysis ◽  
Gold Recovery ◽  
Microbial Community Analysis ◽  
Most Probable Number ◽  
Rrna Gene ◽  
Probable Number ◽  
Cell Numbers ◽  
Cell Counts

In a mine owned by the company Orenas S.A. (Equador), a biooxidation process for gold recovery has been developed. Refractory gold ore was crushed, milled and 500 ton of flotation concentrate was agglomerated by coating a support rock. This was piled up on a liner and the biooxidation process in the heap of 35x25x6 m3 was run for approximately 150 days. The oxidized material was subsequently removed for further processing. An outcrop allowed for depth dependent sampling of altogether 36 samples at three sites over the complete depth of 6 m. The fine fraction was removed from the host rock and sent to the laboratory for analysis of the microbial community. The pH ranged between 2.2 and 2.9. Total cell counts determined via counting under a fluorescence microscope after SYBR Green staining indicated a high microbial colonialization of the heap in all depths between 106 to 109 cells per g concentrate, however the highest cell numbers were mainly found in the upper 50 cm. Most-probable-number determination of living, acidophilic iron (II)-oxidizers for one site also revealed a decrease of cell numbers with depth (between 104 to 108 cells per g concentrate). Further molecular analyses of the community composition based on extracted DNA and 16S rRNA gene analyses by TRFLP and qPCR revealed a complex archaeal and bacterial community within the heap. It can be stated that an active community of acidophiles runs the biooxidation process in all sampled parts of the heap.

scholarly journals Peptide-Based Formulation from Lactic Acid Bacteria Impairs the Pathogen Growth in Ananas Comosus (Pineapple)

Coatings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 457 ◽  
Author(s):  
Gabriela N. Tenea ◽  
Daniela Olmedo ◽  
Clara Ortega
Keyword(s):  
Significant Proportion ◽  
High Capacity ◽  
Total Cell ◽  
Ananas Comosus ◽  
Street Vending ◽  
E Coli ◽  
Cell Counts ◽  
Total Cell Density

Worldwide, street vending commerce has grown exponentially, representing in some countries, including Ecuador, a significant proportion of food consumed by the urban population. Pineapple is one of the common fruits sold as ready-to-eat slices by ambulant vendors in the street or on public transport at risk of contamination by various microorganisms. Previously, we selected Lactobacillus plantarum UTNCys5-4 and Lactococcus lactis subsp. lactis Gt28 strains producing peptides with high capacity to inhibit pathogen growth in vitro. In this study, the effect of different edited formulations containing a mixture of Cys5-4/Gt28 peptides was evaluated in vitro and ex vitro against a pathogenic cocktail containing E. coli (2), Salmonella (2) and Shigella (1). The growth of bacterial cocktail co-inoculated with cell-free supernatant containing peptides (formulation T1) and precipitated peptides (formulation T6), in a ratio of Cys5-4/Gt28:1:1 (v/v), results in a decrease of total cell viability with 1.85 and 1.2 log CFU/mL orders of magnitude at 6 h of incubation. About the same decrease (1.9 log CFU/g) was observed when pineapple slices artificially inoculated with the pathogenic cocktail were coated with T1 formulation, indicating the capacity to diminish simultaneous pathogens in situ, thus demonstrating its great biological control and protection. However, the E. coli cell counts reduced by 2.08 log CFU/g while Salmonella and Shigella cell counts reduced by 1.43 and 1.91 log CFU/g, respectively, at 5 days of refrigeration. In the untreated pineapple slices, the total cell density was maintained during storage, suggesting the adaptation of the pathogens to the fruit matrix. The peptide-based formulation exerted a bacteriolytic mode of action inducing pathogenic cell death. The results indicate that coating pineapple slices with peptide-based formulation is a promising approach to protect them from further contamination by microbial spoilage as well as an alternative to increase the food safety.

scholarly journals Relationships between Microbial Community Structure and Hydrochemistry in a Landfill Leachate-Polluted Aquifer

2001 ◽  
Vol 67 (10) ◽  
pp. 4619-4629 ◽  
Author(s):  
Wilfred F. M. Röling ◽  
Boris M. van Breukelen ◽  
Martin Braster ◽  
Bin Lin ◽  
Henk W. van Verseveld
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Communities ◽  
16S Rdna ◽  
Microbial Community Structure ◽  
Landfill Leachate ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Numerical Comparison ◽  
Gram Positive ◽  
Gram Positive Bacteria

ABSTRACT Knowledge about the relationship between microbial community structure and hydrogeochemistry (e.g., pollution, redox and degradation processes) in landfill leachate-polluted aquifers is required to develop tools for predicting and monitoring natural attenuation. In this study analyses of pollutant and redox chemistry were conducted in parallel with culture-independent profiling of microbial communities present in a well-defined aquifer (Banisveld, The Netherlands). Degradation of organic contaminants occurred under iron-reducing conditions in the plume of pollution, while upstream of the landfill and above the plume denitrification was the dominant redox process. Beneath the plume iron reduction occurred. Numerical comparison of 16S ribosomal DNA (rDNA)-based denaturing gradient gel electrophoresis (DGGE) profiles of Bacteria andArchaea in 29 groundwater samples revealed a clear difference between the microbial community structures inside and outside the contaminant plume. A similar relationship was not evident in sediment samples. DGGE data were supported by sequencing cloned 16S rDNA. Upstream of the landfill members of the β subclass of the class Proteobacteria(β-proteobacteria) dominated. This group was not encountered beneath the landfill, where gram-positive bacteria dominated. Further downstream the contribution of gram-positive bacteria to the clone library decreased, while the contribution of δ-proteobacteria strongly increased and β-proteobacteria reappeared. The β-proteobacteria (Acidovorax,Rhodoferax) differed considerably from those found upstream (Gallionella, Azoarcus). Direct comparisons of cloned 16S rDNA with bands in DGGE profiles revealed that the data from each analysis were comparable. A relationship was observed between the dominant redox processes and the bacteria identified. In the iron-reducing plume members of the familyGeobacteraceae made a strong contribution to the microbial communities. Because the only known aromatic hydrocarbon-degrading, iron-reducing bacteria areGeobacter spp., their occurrence in landfill leachate-contaminated aquifers deserves more detailed consideration.

scholarly journals Antibacterial Properties of Some Cyclic Organobismuth(III) Compounds

2005 ◽  
Vol 49 (7) ◽  
pp. 2729-2734 ◽  
Author(s):  
Toshiaki Kotani ◽  
Daisuke Nagai ◽  
Kensuke Asahi ◽  
Hitomi Suzuki ◽  
Fumiaki Yamao ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Properties ◽  
Cell Number ◽  
Viable Cell Number ◽  
Electron Microscopic ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Ring Compounds ◽  
Medical Disorders

ABSTRACT Bismuth compounds are known for their low levels of toxicity in mammals, and various types of bismuth salts have been used to treat medical disorders. As part of our program to probe this aspect of bismuth chemistry, cyclic organobismuth compounds 1 to 8 bearing a nitrogen or sulfur atom as an additional ring member have been synthesized, and their antimicrobial activities against five standard strains of gram-negative and gram-positive bacteria were assessed. The eight-membered-ring compounds, compounds 1 to 3, exhibited MICs of less than 0.5 μg/ml against Staphylococcus aureus and were more active than the six-membered ones, compounds 5 to 8 (MICs, 4.0 to 16 μg/ml). The gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis, and Enterococcus faecalis) were more susceptible to both types of ring compounds than the gram-negative ones (Escherichia coli and Pseudomonas aeruginosa). Treatment with polymyxin B nonapeptide increased the susceptibility of E. coli to cyclic organobismuth compounds, indicating the low permeability of the outer membrane of gram-negative bacteria to the compounds. Compound 1 also had activity against methicillin-resistant S. aureus, which had an MIC for 90% of the hospital stock strains of 1.25 μg/ml. The killing curves for S. aureus treated with compound 1 or 3 revealed a static effect at a low dose (2× the MIC). However, when S. aureus was treated with 10× the MIC of compound 1 or 3, there was an approximately 3-log reduction in the viable cell number after 48 h of treatment. Electron microscopic inspection demonstrated a considerable increase in the size of S. aureus and the proportion of cells undergoing cell division after treatment with compound 1 at 0.5× the MIC.

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