MICROBIAL CELLULOSE AS SUPPORT MATERIAL FOR THE IMMOBILIZATION OF DENITRIFYING BACTERIA

2008 ◽  
Vol 7 (5) ◽  
pp. 589-594 ◽  
Author(s):  
Abbas Rezaee ◽  
Hatam Godini ◽  
Hossein Bakhtou
Keyword(s):  
Denitrifying Bacteria ◽  
Support Material ◽  
Microbial Cellulose

scholarly journals Biological Removal of Nitrates from Groundwater Resources in Saudi Arabia

2020 ◽  
Vol 14 (3) ◽  
pp. 2203-2213
Author(s):  
Essam J. Alyamani ◽  
Rayan Y. Booq ◽  
Ali H. Bahkali ◽  
Sulaiman A. Alharbi
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Saudi Arabia ◽  
Removal Rate ◽  
Groundwater Resources ◽  
Nitrate Removal ◽  
Reduction Rate ◽  
Denitrifying Bacteria ◽  
Molecular Techniques ◽  
Microbial Cellulose ◽  
Denitrification Process

Groundwater is the main water source for many areas in Saudi Arabia and the only source of water in some areas. Many local studies have reported that high nitrate concentrations in some wells of groundwater. To provide safe drinking water, the excess amounts of nitrate have to be removed by bio-denitrification process. This study aims to develop a denitrifying biological filter using denitrifying bacteria immobilized on microbial cellulose for the removal of nitrates from water contaminated with nitrate. Denitrifying bacteria that can form biofilter on microbial cellulose were isolated from different regions in Saudi Arabia and were characterized by molecular techniques. They were evaluated for their ability to analyze nitrates and to develop biofilter to remove nitrates from contaminated water. In the results of this project, an optimal microbial cellulose production was achieved by Gluconacetobacter xylinus ATCC 23768 in the lab, which had facilitated the use of biofilter with the immobilized nitrate-reducing bacteria Pseudomonas aeruginosa. The reduction rate of nitrate was reached 1.9mg/L from the starting concentration of 100 mg/L after 18h. Promising results of nitrate removal rate on MC immobilized with Pseudomonas aeruginosa on biofilter at optimized lab conditions of pH, and proper carbon source were achieved. The results suggest that water contaminated with nitrate can be removed by the bio-denitrification process effectively.

The Reducing Action of Denitrifying Bacteria

1900 ◽  
Vol 50 (1303supp) ◽  
pp. 20889-20890
Author(s):  
G. Ampola ◽  
C. Ulpiani
Keyword(s):  
Denitrifying Bacteria

Employing Exfoliated Graphite as Novel Support Material for Heterogeneous Model Catalysts

2019 ◽  
Author(s):  
Moritz Wolf ◽  
Nico Fischer ◽  
Michael Claeys
Keyword(s):  
Surface Area ◽  
Graphite Powder ◽  
Model Catalysts ◽  
Model Systems ◽  
Exfoliated Graphite ◽  
Support Material ◽  
Heterogeneous Model ◽  
Support Materials ◽  
Metal Support Interaction ◽  
Catalyst Systems

<p>The inert nature of graphitic samples allows for characterisation of rather isolated supported nanoparticles in model catalysts, as long as sufficiently large inter-particle distances are obtained. However, the low surface area of graphite and the little interaction with nanoparticles result in a challenging application of conventional preparation routes in practice. In the present study, a set of graphitic carbon materials was characterised in order to identify potential support materials for the preparation of model catalyst systems. Various sizes of well-defined Co<sub>3</sub>O<sub>4</sub> nanoparticles were synthesised separately and supported onto exfoliated graphite powder, that is graphite after solvent-assisted exfoliation <i>via</i> ultrasonication resulting in thinner flakes with increased specific surface area. The developed model catalysts are ideally suited for sintering studies of isolated nano-sized cobaltous particles as the graphitic support material does not provide distinct metal-support interaction. Furthermore, the differently sized cobaltous particles in the various model systems render possible studies on structural dependencies of activity, selectivity, and deactivation in cobalt oxide or cobalt catalysed reactions.</p>

PEMBENIHAN DAN AKLIMATISASI PADA SISTEM ANAEROBIK

2018 ◽  
Vol 6 (2) ◽  
Author(s):  
Indriyati Indriyati
Keyword(s):  
Growth Rate ◽  
Total Population ◽  
Fixed Bed ◽  
Support Material ◽  
Anaerobic Process ◽  
Anaerobic Reactor

Seeding in Fixed Bed anaerobic reactor are infl uenced by several condition such as the growth rate total population of microbial, bacterial adaption to infl uent and the retention of biomass in reactor. The aim of this observation is to fi nd out the seeding and acclimation process in anaerobic process by using plastic as support material. Seeding and acclimatization process run smoothly can be seen from the increasing of infl uent or substrate and following by the increasing degradation of soluble COD, beside that the decreasing of VSS concentration indicates that microorganism are all ready fi x in support material, therefore reactor can be operated continuously and the acclimatization process can be stopped.Keywords : anaerobic seeding, acclimation anaerobic process

Influence of Seeding Conditions on Initial Biofilm Development during the Startup of Anaerobic Fluidized Bed Reactors

1989 ◽  
Vol 21 (4-5) ◽  
pp. 157-165 ◽  
Author(s):  
F. Ehlinger ◽  
J. M. Audic ◽  
G. M. Faup
Keyword(s):  
Fluidized Bed ◽  
Future Development ◽  
Protein Concentration ◽  
Specific Activity ◽  
Fluidized Bed Reactor ◽  
Fluidized Bed Reactors ◽  
Support Material ◽  
Biofilm Development ◽  
Initial Biofilm

The characterization of the biofilm of an anaerobic fluidized-bed reactor was completed under standard conditions. The distribution of the fixed protein concentration depended on the level in the reactor. The protein concentration reached 1520 µg.g−1 of support at the top of the reactor and only 1200 µg.g−1 at the bottom after 504 hours of operation but the specific activity of the biofilm was 33×10−4 µM acetate.h−1.mg−1 proteins at the bottom and only 26×10−4 µM.h−1.mg−1 at the top. The efficiency of a fluidized bed reactor and the composition of the biofilm changed with an increase of the pH from 7 to 8.5 during the seeding of the support material. Future development of the biofilm and the specific activity of the support were affected.

scholarly journals Effects of Supplement of Marichromatium gracile YL28 on Water Quality and Microbial Structures in Shrimp Mariculture Ecosystems

Genes ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 40
Author(s):  
Liang Cui ◽  
Bitong Zhu ◽  
Xiaobo Zhang ◽  
Zhuhua Chan ◽  
Chungui Zhao ◽  
...  
Keyword(s):  
Water Quality ◽  
16S Rrna ◽  
Relative Abundance ◽  
Animal Health ◽  
Denitrifying Bacteria ◽  
Nitrite Reduction ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Sequencing Analysis ◽  
Shrimp Culture

The elevated NH3-N and NO2-N pollution problems in mariculture have raised concerns because they pose threats to animal health and coastal and offshore environments. Supplement of Marichromatium gracile YL28 (YL28) into polluted shrimp rearing water and sediment significantly decreased ammonia and nitrite concentrations, showing that YL28 functioned as a novel safe marine probiotic in the shrimp culture industry. The diversity of aquatic bacteria in the shrimp mariculture ecosystems was studied by sequencing the V4 region of 16S rRNA genes, with respect to additions of YL28 at the low and high concentrations. It was revealed by 16S rRNA sequencing analysis that Proteobacteria, Planctomycete and Bacteroidetes dominated the community (>80% of operational taxonomic units (OTUs)). Up to 41.6% of the predominant bacterial members were placed in the classes Gammaproteobacteria (14%), Deltaproteobacteria (14%), Planctomycetacia (8%) and Alphaproteobacteria (5.6%) while 40% of OTUs belonged to unclassified ones or others, indicating that the considerable bacterial populations were novel in our shrimp mariculture. Bacterial communities were similar between YL28 supplements and control groups (without addition of YL28) revealed by the β-diversity using PCoA, demonstrating that the additions of YL28 did not disturb the microbiota in shrimp mariculture ecosystems. Instead, the addition of YL28 increased the relative abundance of ammonia-oxidizing and denitrifying bacteria. The quantitative PCR analysis further showed that key genes including nifH and amoA involved in nitrification and nitrate or nitrite reduction significantly increased with YL28 supplementation (p < 0.05). The supplement of YL28 decreased the relative abundance of potential pathogen Vibrio. Together, our studies showed that supplement of YL28 improved the water quality by increasing the relative abundance of ammonia-oxidizing and denitrifying bacteria while the microbial community structure persisted in shrimp mariculture ecosystems.

scholarly journals An Exploration of Seaweed Polysaccharides Stimulating Denitrifying Bacteria for Safer Nitrate Removal

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3390
Author(s):  
Hui Zhang ◽  
Lin Song ◽  
Xiaolin Chen ◽  
Pengcheng Li
Keyword(s):  
Growth Rate ◽  
Bacillus Subtilis ◽  
Nitrate Removal ◽  
Denitrifying Bacteria ◽  
Soil Salinization ◽  
Nitrate Content ◽  
Weak Efficiency ◽  
N Accumulation ◽  
N Removal ◽  
Intensively Managed

Excessive use of nitrogen fertilizer in intensively managed agriculture has resulted in abundant accumulation of nitrate in soil, which limits agriculture sustainability. How to reduce nitrate content is the key to alleviate secondary soil salinization. However, the microorganisms used in soil remediation cause some problems such as weak efficiency and short survival time. In this study, seaweed polysaccharides were used as stimulant to promote the rapid growth and safer nitrate removal of denitrifying bacteria. Firstly, the growth rate and NO3−-N removal capacity of three kinds of denitrifying bacteria, Bacillus subtilis (BS), Pseudomonas stutzeri (PS) and Pseudomonas putida (PP), were compared. The results showed that Bacillus subtilis (BS) had a faster growth rate and stronger nitrate removal ability. We then studied the effects of Enteromorpha linza polysaccharides (EP), carrageenan (CA), and sodium alginate (AL) on growth and denitrification performance of Bacillus subtilis (BS). The results showed that seaweed polysaccharides obviously promoted the growth of Bacillus subtilis (BS), and accelerated the reduction of NO3−-N. More importantly, the increased NH4+-N content could avoid excessive loss of nitrogen, and less NO2−-N accumulation could avoid toxic effects on plants. This new strategy of using denitrifying bacteria for safely remediating secondary soil salinization has a great significance.

Microbial population selection in integrated fixed-film sequencing batch reactors operated with different lengths of oxic and anoxic conditions

2021 ◽  
Author(s):  
Hussain Aqeel ◽  
Mahendran Basuvaraj ◽  
Steven N. Liss
Keyword(s):  
Microbial Population ◽  
Denitrifying Bacteria ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Anoxic Conditions ◽  
Population Selection ◽  
Fixed Film

BNR granules rich in amyloid adhesins and denitrifying bacteria were formed in the SBRs that were operated with extended anoxic conditions.

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