Toward the bioremediation of dioxin-polluted soil: structural and functional analyses of in situ microbial populations by quinone profiling and culture-dependent methods

2001 ◽  
Vol 57 (1-2) ◽  
pp. 248-256 ◽  
Author(s):  
Hiraishi A. ◽  
Miyakoda H. ◽  
Lim B.-R. ◽  
Hu H.-Y. ◽  
Fujie K. ◽  
...  
Keyword(s):  
Polluted Soil ◽  
Microbial Populations ◽  
Functional Analyses ◽  
Culture Dependent

Bio-P and non-bio-P bacteria identification by a novel microbial approach

1999 ◽  
Vol 39 (6) ◽  
pp. 13-20 ◽  
Author(s):  
Philip L. Bond ◽  
Jürg Keller ◽  
Linda L. Blackall
Keyword(s):  
In Situ Hybridisation ◽  
Microbial Populations ◽  
Biological Phosphorus Removal ◽  
Gram Positive Bacteria ◽  
P Content ◽  
Identification Of Bacteria ◽  
Widespread Belief ◽  
Biological Phosphorus ◽  
P Removal

Culturing bacteria from activated sludge with enhanced biological phosphorus removal (EBPR) has strongly implicated Acinetobacter with the process. However, using fluorescent in-situ hybridisation (FISH) probing to analyse microbial populations, we have shown evidence opposing this widespread belief. We describe the phosphorus (P) removing performance and microbial population analyses of sludges obtained in a laboratory scale EBPR reactor. Two sludges with extremely high P removing capabilities were examined, the P content of these sludges was 8.6% (P sludge) and 12.3% (S sludge) of the MLSS. Identification of bacteria using FISH probing indicated both sludges were dominated by microbes from the beta proteobacteria and high mol% G+C Gram positive bacteria. Acinetobacter could make up only a small proportion of the cells in these sludges. Sludge with extremely poor P removal (P content of 1.5%, referred to as T sludge) was then generated by reducing the P in the influent. Bacteria resembling the G-bacteria became abundant in this sludge and these were identified using FISH probing. The anaerobic transformations of the T and P sludges correlated well with that of the non-EBPR and EBPR biological models respectively, indicating that bacteria in the T sludge have the potential to inhibit P removal in EBPR systems.

scholarly journals Molecular biology approaches in bioadhesion research

2014 ◽  
Vol 5 ◽  
pp. 983-993 ◽  
Author(s):  
Marcelo Rodrigues ◽  
Birgit Lengerer ◽  
Thomas Ostermann ◽  
Peter Ladurner
Keyword(s):  
Molecular Biology ◽  
Biological Function ◽  
Molecular Approach ◽  
Research Groups ◽  
Blast Search ◽  
Search Facility ◽  
New Research ◽  
And Function ◽  
Functional Analyses

The use of molecular biology tools in the field of bioadhesion is still in its infancy. For new research groups who are considering taking a molecular approach, the techniques presented here are essential to unravelling the sequence of a gene, its expression and its biological function. Here we provide an outline for addressing adhesion-related genes in diverse organisms. We show how to gradually narrow down the number of candidate transcripts that are involved in adhesion by (1) generating a transcriptome and a differentially expressed cDNA list enriched for adhesion-related transcripts, (2) setting up a BLAST search facility, (3) perform an in situ hybridization screen, and (4) functional analyses of selected genes by using RNA interference knock-down. Furthermore, latest developments in genome-editing are presented as new tools to study gene function. By using this iterative multi-technologies approach, the identification, isolation, expression and function of adhesion-related genes can be studied in most organisms. These tools will improve our understanding of the diversity of molecules used for adhesion in different organisms and these findings will help to develop innovative bio-inspired adhesives.

scholarly journals A microscopic approach to investigate bacteria under in situ conditions in sea-ice samples

2001 ◽  
Vol 33 ◽  
pp. 304-310 ◽  
Author(s):  
Karen Junge ◽  
Christopher Krembs ◽  
Jody Deming ◽  
Aaron Stierle ◽  
Hajo Eicken
Keyword(s):  
Sea Ice ◽  
Pore Space ◽  
Three Dimensional ◽  
Epifluorescence Microscopy ◽  
Microbial Populations ◽  
Microbial Life ◽  
Dimensional Network ◽  
In Situ Conditions ◽  
Fluorescent Stain

AbstractMicrobial populations and activity within sea ice have been well described based on bulk measurements from melted sea-ice samples. However, melting destroys the micro-environments within the ice matrix and does not allow for examination of microbial populations at a spatial scale relevant to the organism. Here, we describe the development of a new method allowing for microscopic observations of bacteria localized within the three-dimensional network of brine inclusions in sea ice under in situ conditions. Conventional bacterial staining procedures, using the DNA-specific fluorescent stain DAPI, epifluorescence microscopy and image analysis, were adapted to examine bacteria and their associations with various surfaces within microtomed sections of sea ice at temperatures from −2° to −15°C. The utility and sensitivity of the method were demonstrated by analyzing artificial sea-ice preparations of decimal dilutions of a known bacterial culture. When applied to natural, particle-rich sea ice, the method allowed distinction between bacteria and particles at high magnification. At lower magnifications, observations of bacteria could be combined with those of other organisms and with morphology and particle content of the pore space. The method described here may ultimately aid in discerning constraints on microbial life at extremely low temperatures.

Microbial ecology of sulfate-reducing bacteria in wastewater biofilms analyzed by microelectrodes and fish (fluorescent in situ hybridization) technique

1999 ◽  
Vol 39 (7) ◽  
pp. 41-47 ◽  
Author(s):  
Satoshi Okabe ◽  
Hisashi Satoh ◽  
Tsukasa Itoh ◽  
Yoshimasa Watanabe
Keyword(s):  
In Situ Hybridization ◽  
Sulfate Reduction ◽  
Sulfate Reducing Bacteria ◽  
Hybridization Technique ◽  
Concentration Profiles ◽  
Reduction Zone ◽  
Sulfate Reducing ◽  
Reducing Bacteria ◽  
Culture Dependent

The vertical distribution of sulfate-reducing bacteria (SRB) in microaerophilic wastewater biofilms grown on fully submerged rotating disk reactors (RDR) was determined by the conventional culture-dependent MPN method and in situ hybridization of fluorescently-labelled 16S rRNA-targeted oligonucleotide probes for SRB in parallel. Chemical concentration profiles within the biofilm were also measured using microelectrodes for O2, S2-, NO3- and pH. In situ hybridization revealed that the SRB probe-stained cells were distributed throughout the biofilm even in the oxic surface zone in all states from single scattered cells to clustered cells. The higher fluorescence intensity and abundance of SRB probe-stained cells were found in the middle part of the biofilm. This result corresponded well with O2 and H2S concentration profiles measured by microelectrodes, showing sulfate reduction was restricted to a narrow anaerobic zone located about 500 μm below the biofilm surface. Results of the MPN and potential sulfate reducing activity (culture-dependent approaches) indicated a similar distribution of cultivable SRB in the biofilm. The majority of the general SRB probe-stained cells were hybridized with SRB 660 probe, suggesting that one important member of the SRB in the wastewater biofilm could be the genus Desulfobulbus. An addition of nitrate forced the sulfate reduction zone deeper in the biofilm and reduced the specific sulfate reduction rate as well. The sulfate reduction zone was consequently separated from O2 and NO3- respiration zones. Anaerobic H2S oxidation with NO3- was also induced by addition of nitrate to the medium.

In-situ, Ex-situ, and nano-remediation strategies to treat polluted soil, water, and air – A review

Chemosphere ◽  
2021 ◽  
pp. 133252
Author(s):  
Asim Hussain ◽  
Fazeelat Rehman ◽  
Hamza Rafeeq ◽  
Muhammad Waqas ◽  
Asma Asghar ◽  
...  
Keyword(s):  
Soil Water ◽  
Polluted Soil ◽  
Ex Situ ◽  
Remediation Strategies

Methanotrophs for Clean-Up of Polluted Aquifers

1991 ◽  
Vol 24 (11) ◽  
pp. 9-17 ◽  
Author(s):  
K. Halden ◽  
H. A. Chase
Keyword(s):  
Drinking Water ◽  
Microbial Populations ◽  
Distilled Water ◽  
Rich Medium ◽  
Methylosinus Trichosporium Ob3b ◽  
Methylosinus Trichosporium ◽  
Pump And Treat ◽  
Neutral Ph ◽  
Chlorinated Pollutants

Aquifers are vital reserves of drinking water which are under threat from pollution. Particular problems are posed by chlorinated compounds such as pesticides and solvents which native microbial populations are unable to degrade. Pump and treat regimes have proved unsuccessful since pollutants remain adsorbed to sediments but a possible solution is the use of introduced microorganisms to degrade pollutants in-situ. It is suggested that methanotrophs may be suitable candidates. Methanotrophs have an extraordinary range of degradative powers due to the non-specificity of their methane mono-oxygenase enzyme. We have shown that Methylosinus trichosporium OB3b is capable of degrading many common chlorinated pollutants co-metabolically when it is grown in a copper-depleted, oxygen-rich medium at neutral pH. In the subsurface however, such conditions do not exist and cultures grown in a medium made with untreated Cambridge aquifer water have a reduced range of degradative powers compared to similar cells grown in a medium made with distilled water. This means that to use methanotrophs for aquifer clean-up, the cells may need to be cultured above ground in ideal conditions and then introduced by some method of injection or infiltration. This may be possible because the degradative reactions are not coupled to growth and Methylosinus trichosporium OB3b cells maintain pollutant degrading ability up to 19 days after they have stopped growing. A suspension of these cells may thus be treated as a biocatalyst.

scholarly journals Energy-Saving Strategies and their Energy Analysis and Exergy Analysis for In Situ Thermal Remediation System of Polluted-Soil

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 4018 ◽  
Author(s):  
Tian-Tian Li ◽  
Yun-Ze Li ◽  
Zhuang-Zhuang Zhai ◽  
En-Hui Li ◽  
Tong Li
Keyword(s):  
Energy Saving ◽  
Exergy Analysis ◽  
Energy Analysis ◽  
Waste Heat ◽  
Polluted Soil ◽  
Severe Problem ◽  
Industrial Soil ◽  
Thermal Remediation ◽  
Variable Condition

The environmental safety of soil has become a severe problem in China with the boost of industrialization. Polluted-soil thermal remediation is a kind of suitable remediation technology for large-scale heavily contaminated industrial soil, with the advantages of being usable in off-grid areas and with a high fuel to energy conversion rate. Research on energy-saving strategies is beneficial for resource utilization. Focused on energy saving and efficiency promotion of polluted-soil in situ thermal remediation system, this paper presents three energy-saving strategies: Variable-condition mode (VCM), heat-returning mode (HRM) and air-preheating mode (APM). The energy analysis based on the first law of thermodynamics and exergy analysis based on the second law of thermodynamics are completed. By comparing the results, the most effective part of the energy-saving strategy for variable-condition mode is that high savings in the amount of natural gas (NG) used can be achieved, from 0.1124 to 0.0299 kg·s−1 in the first stage. Energy-saving strategies for heat-returning mode and air-preheating mode have higher utilization ratios than the basic method (BM) for the reason they make full use of waste heat. As a whole, a combination of energy-saving strategies can improve the fuel savings and energy efficiency at the same time.

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