Denitration of 2,4,6-trinitrotoluene byPseudomonas savastanoi

1997 ◽  
Vol 43 (5) ◽  
pp. 447-455 ◽  
Author(s):  
J. L. Martin ◽  
S. D. Comfort ◽  
P. J. Shea ◽  
R. A. Drijber ◽  
T. A. Kokjohn
Keyword(s):  
Cell Density ◽  
Growth Medium ◽  
Contaminated Soil ◽  
Pure Culture ◽  
Minimal Medium ◽  
Microbial Population ◽  
Glucose Addition ◽  
Pseudomonas Spp ◽  
N Source ◽  
Ordnance Plant

Past disposal of wastewaters containing 2,4,6-trinitrotoluene (TNT) at the former Nebraska Ordnance Plant has resulted in numerous acres of TNT-contaminated soil. Examining the microbial population of these soils revealed several TNT-tolerant Pseudomonas spp. We selected one species, P. savastanoi, to determine its ability to transform TNT. Pure culture experiments were performed in pseudomonas minimal medium containing 0.31 mM TNT (70 mg TNT∙L−1) under varied nutrient and cell density regimes. Experiments with TNT as a sole C or N source showed that P. savastanoi has the ability to denitrate TNT, as evidenced by production of 2,4-dinitrotoluene (2,4-DNT) and NO2−with time. TNT denitration and formation of 2,4-DNT were enhanced by removing NH4+and adding NO2−to the growth medium. In all experiments, 2-amino-4,6-dinitrotoluene (2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT) appeared as incidental reduction products. Glucose addition to the medium enhanced 2-ADNT and 4-ADNT production and decreased denitration of TNT. Mid-log phase cells rapidly transformed [ring-14C(U)]TNT but were unable to mineralize significant quantities of TNT, as evidenced by conversion of less than 1% of the label to14CO2. These results indicate that P. savastanoi is a TNT-tolerant pseudomonad that can promote TNT degradation through reductive denitration and nitro moiety reduction.Key words: TNT, biodegradation, transformation, reduction, nitrite.

scholarly journals Plasmid Localization and Organization of Melamine Degradation Genes in Rhodococcus sp. Strain Mel

2011 ◽  
Vol 78 (5) ◽  
pp. 1397-1403 ◽  
Author(s):  
Anthony G. Dodge ◽  
Lawrence P. Wackett ◽  
Michael J. Sadowsky
Keyword(s):  
454 Pyrosequencing ◽  
Minimal Medium ◽  
Doubling Time ◽  
Cyanuric Acid ◽  
Acid Hydrolase ◽  
Content Type ◽  
N Source ◽  
Genes Encoding ◽  
Rhodococcus Sp ◽  
Roche 454

ABSTRACTRhodococcussp. strain Mel was isolated from soil by enrichment and grew in minimal medium with melamine as the sole N source with a doubling time of 3.5 h. Stoichiometry studies showed that all six nitrogen atoms of melamine were assimilated. The genome was sequenced by Roche 454 pyrosequencing to 13× coverage, and a 22.3-kb DNA region was found to contain a homolog to the melamine deaminase genetrzA. Mutagenesis studies showed that the cyanuric acid hydrolase and biuret hydrolase genes were clustered together on a different 17.9-kb contig. Curing and gene transfer studies indicated that 4 of 6 genes required for the complete degradation of melamine were located on an ∼265-kb self-transmissible linear plasmid (pMel2), but this plasmid was not required for ammeline deamination. TheRhodococcussp. strain Mel melamine metabolic pathway genes were located in at least three noncontiguous regions of the genome, and the plasmid-borne genes encoding enzymes for melamine metabolism were likely recently acquired.

Treatment of PAHs in contaminated soil by extraction with aqueous DNA followed by biodegradation with a pure culture of Sphingomonas sp.

Chemosphere ◽  
2008 ◽  
Vol 73 (9) ◽  
pp. 1414-1419 ◽  
Author(s):  
Ronald R. Navarro ◽  
Yosuke Iimura ◽  
Hiroyasu Ichikawa ◽  
Kenji Tatsumi
Keyword(s):  
Contaminated Soil ◽  
Pure Culture

Inactivation of chloramphenicol by Gram-negative microorganisms

1968 ◽  
Vol 14 (8) ◽  
pp. 891-899 ◽  
Author(s):  
David Sompolinsky ◽  
Ruth Ziegler-Schlomowitz ◽  
Dora Herczog
Keyword(s):  
Escherichia Coli ◽  
Growth Medium ◽  
Minimal Medium ◽  
Resistance Factor ◽  
The Other ◽  
Gram Negative ◽  
Resistant Strains ◽  
Gram Negative Organisms ◽  
High Level ◽  
Level Resistance

Two derivative strains of Escherichia coli with high-level resistance to chloramphenicol, one carrying an episomal resistance factor and the other a chromosomal mutant, were both shown to be potent inactivators of the drug. When 1 mM chloramphenicol was added to an exponential culture in minimal medium, growth was halted until 85–90% of the drug was inactivated by acylation. At this state the drug was essentially monoacylated. During and after growth, esterification of the second alcoholic group occurred, though at a slower rate. Arylamines, in amounts up to 10% of chloramphenicol equivalents, were demonstrated in the growth medium after 1–3 days' incubation.With an acetateless mutant of Escherichia coli K12, carrying a resistance factor, it was shown that 5–6 moles of acetate was consumed for every mole of chloramphenicol acylated.Inactivation of chloramphenicol by Gram-negative organisms from infections in hospitalized patients was also examined. Among 103 strains susceptible to chloramphenicol, none produced considerable amounts of chloramphenicol esters. The same was the case with 14 resistant strains of Pseudomonas. Of 134 other resistant organisms examined, including strains of Escherichia, Proteus, Klebsiella, Salmonella, and Shigella, 133 were producers of chloramphenicol esters, and in most cases the drug was partly or entirely diacylated.

scholarly journals The effect of inoculum and glucose addition on polyhydroxyalkanoate production by Brevibacterium sp. B45

2021 ◽  
Vol 89 (1) ◽  
Author(s):  
Diah - RATNANINGRUM ◽  
Een Sri ENDAH ◽  
Akbar Hanif Dawam ABDULLAH ◽  
Vienna SARASWATY ◽  
Puspita - LISDIYANTI ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Energy Storage ◽  
Minimal Medium ◽  
Differential Scanning Calorimetric ◽  
Alternative Source ◽  
Glucose Addition ◽  
Erlenmeyer Flask ◽  
Plastic Materials ◽  
Scanning Electron

Petroleum-based plastics are the major cause of environmental pollution because the plastics need years to be degraded. The difficulties in handling waste of petroleum-based plastic have motivated researchers to produce environmentally friendly plastic materials that are biologically degradable; one of them is polyhydroxyalkanoate (PHA). Polyhydroxyalkanoate is natural biodegradable biopolymers produced by bacteria as an intracellular carbon  and  energy storage. This polymer is an alternative source of plastics  with similar physical properties to petroleum-based plastic.It can be easily biodegraded aerobically and anaerobically. This study examined the potential of one superior isolate as PHA producers, i.e.,Brevibacterium sp. B45. Brevibacterium sp. B45 was cultivated in Ramsay’s minimal medium with inoculum concentrations were 1, 2, and 3% (v/v)and glucose concentrations were 1, 3, and 5% (w/v). The cultivation of  Brevibacterium sp. B45 was carried out in a 500 mL Erlenmeyer flask on a shaker incubator with 150 rpm and 30 oC for 72 hours. PHA recovery was carried out by chloroform extraction and characterized by scanning electron microscopy (SEM), Fourier transformed infrared (FTIR), and differential scanning calorimetric (DSC) methods. The highest yield of dried biomass (2.92%) was obtained using 3% inoculum and 3% glucose. The melting temperature (Tm), enthalpy (ΔHf), and crystallinity (Xc) of the PHA product were 172.1 °C, 61.04 J g-1, and 41.08%, respectively. Data of SEM show that a porous surface characterized morphological of purified PHA grains. The functional units of purified PHA grains were C=O, CH3, C-O, C-O-C, C-C, C-H, and -OH. The purified PHA grains show a similar spectrum to the standard Poly-3-hydroxybutyrate (PHB). Therefore, it could be assumed that PHA produced by Brevibacterium sp. B45 was most likely PHB.

scholarly journals Production of poultry feather hydrolysate using HCl and NaOH as a growth medium substrate for indigenous strains

2022 ◽  
Vol 951 (1) ◽  
pp. 012064
Author(s):  
N A Fitriyanto ◽  
Y Ramadhanti ◽  
Rismiyati ◽  
I Rusyadi ◽  
A Pertiwiningrum ◽  
...  
Keyword(s):  
Growth Medium ◽  
Colour Change ◽  
Local Breed ◽  
Chicken Feathers ◽  
N Source ◽  
Layer Chicken ◽  
Poultry Feathers ◽  
Poultry Feather ◽  
Substrate Medium ◽  
Very High

Abstract The poultry feathers have a very high protein content due to it consists of 90% of crude protein, and it is an ideal material to obtain keratin protein. Due to Keratin’s difficulties and time-consuming decomposition, further processing is needed to degrade Keratin into simpler proteins that can be used as an alternative N-source. This study was aimed to evaluate the keratin hydrolysate from poultry feathers prepared by acidic (HCl) and alkaline (NaOH) compound utilization and its potency as the substrate medium for growth keratinolytic bacteria at a laboratory scale. Poultry feathers, including kampung (local breed) chicken feathers, layer chicken feathers, and local goose treat with HCL 12% and NaOH 20%. The results of the hydrolysate of poultry feathers using 12% HCl showed no significant changes. Visually, the feathers of birds that have been treated with 12% HCl show a colour change to brownish-yellow. The results of hydrolysis using NaOH showed better results than HCl for producing feather meals. The highest yield has occurred at local goose feathers at 95.7%, followed by Kampung and Layer chicken feathers at 93.17% and 78,75%. Based on the viability test, three indigenous strains (Bacillus cereus TD5B, B. cereus LS2B and Pseudomonas sp. PK4) grew in a medium with a substrate of kampung chicken feathers, layer chickens, and local goose feathers. It can be concluded that the hydrolysed poultry feathers made by NaOH 20% preparation had a potency as N-source in the bacterial growth medium.

scholarly journals Applying Statistical Design of Experiments To Understanding the Effect of Growth Medium Components on Cupriavidus necator H16 Growth

2020 ◽  
Vol 86 (17) ◽  
Author(s):  
Christopher C. Azubuike ◽  
Martin G. Edwards ◽  
Angharad M. R. Gatehouse ◽  
Thomas P. Howard
Keyword(s):  
Amino Acids ◽  
Design Of Experiments ◽  
Cell Density ◽  
Growth Medium ◽  
Statistical Design ◽  
Statistical Design Of Experiments ◽  
Content Type ◽  
Medium Components ◽  
Defined Media ◽  
The Impact

ABSTRACT Cupriavidus necator H16 is gaining significant attention as a microbial chassis for range of biotechnological applications. While the bacterium is a major producer of bioplastics, its lithoautotrophic and versatile metabolic capabilities make the bacterium a promising microbial chassis for biofuels and chemicals using renewable resources. It remains necessary to develop appropriate experimental resources to permit controlled bioengineering and system optimization of this microbe. In this study, we employed statistical design of experiments to gain understanding of the impact of components of defined media on C. necator growth and built a model that can predict the bacterium’s cell density based on medium components. This highlighted medium components, and interaction between components, having the most effect on growth: fructose, amino acids, trace elements, CaCl2, and Na2HPO4 contributed significantly to growth (t values of <−1.65 or >1.65); copper and histidine were found to interact and must be balanced for robust growth. Our model was experimentally validated and found to correlate well (r2 = 0.85). Model validation at large culture scales showed correlations between our model-predicted growth ranks and experimentally determined ranks at 100 ml in shake flasks (ρ = 0.87) and 1 liter in a bioreactor (ρ = 0.90). Our approach provides valuable and quantifiable insights on the impact of medium components on cell growth and can be applied to model other C. necator responses that are crucial for its deployment as a microbial chassis. This approach can be extended to other nonmodel microbes of medical and industrial biotechnological importance. IMPORTANCE Chemically defined media (CDM) for cultivation of C. necator vary in components and compositions. This lack of consensus makes it difficult to optimize new processes for the bacterium. This study employed statistical design of experiments (DOE) to understand how basic components of defined media affect C. necator growth. Our growth model predicts that C. necator can be cultivated to high cell density with components held at low concentrations, arguing that CDM for large-scale cultivation of the bacterium for industrial purposes will be economically competitive. Although existing CDM for the bacterium are without amino acids, addition of a few amino acids to growth medium shortened lag phase of growth. The interactions highlighted by our growth model show how factors can interact with each other during a process to positively or negatively affect process output. This approach is efficient, relying on few well-structured experimental runs to gain maximum information on a biological process, growth.

scholarly journals Dehalorespiration with Polychlorinated Biphenyls by an Anaerobic Ultramicrobacterium

2008 ◽  
Vol 74 (7) ◽  
pp. 2089-2094 ◽  
Author(s):  
Harold D. May ◽  
Greg S. Miller ◽  
Birthe V. Kjellerup ◽  
Kevin R. Sowers
Keyword(s):  
Polychlorinated Biphenyls ◽  
Organic Pollutants ◽  
Persistent Organic Pollutants ◽  
Contaminated Soil ◽  
Pure Culture ◽  
Treatment Strategies ◽  
Cell Extract ◽  
Contaminated Sediments ◽  
Pcb Dechlorination

ABSTRACT Anaerobic microbial dechlorination is an important step in the detoxification and elimination of polychlorinated biphenyls (PCBs), but a microorganism capable of coupling its growth to PCB dechlorination has not been isolated. Here we describe the isolation from sediment of an ultramicrobacterium, strain DF-1, which is capable of dechlorinating PCBs containing double-flanked chlorines added as single congeners or as Aroclor 1260 in contaminated soil. The isolate requires Desulfovibrio spp. in coculture or cell extract for growth on hydrogen and PCB in mineral medium. This is the first microorganism in pure culture demonstrated to grow by dehalorespiration with PCBs and the first isolate shown to dechlorinate weathered commercial mixtures of PCBs in historically contaminated sediments. The ability of this isolate to grow on PCBs in contaminated sediments represents a significant breakthrough for the development of in situ treatment strategies for this class of persistent organic pollutants.

scholarly journals Modification of the Technical Properties of Lactobacillus johnsonii NCC 533 by Supplementing the Growth Medium with Unsaturated Fatty Acids

2011 ◽  
Vol 77 (19) ◽  
pp. 6889-6898 ◽  
Author(s):  
J. A. Muller ◽  
R. P. Ross ◽  
W. F. H. Sybesma ◽  
G. F. Fitzgerald ◽  
C. Stanton
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Growth Medium ◽  
Minimal Medium ◽  
Unsaturated Fatty Acids ◽  
Cell Integrity ◽  
Lactobacillus Johnsonii ◽  
Content Type ◽  
Serovar Typhimurium ◽  
Technical Properties

ABSTRACTThe aim of this study was to investigate the influence of supplementing growth medium with unsaturated fatty acids on the technical properties of the probiotic strainLactobacillus johnsoniiNCC 533, such as heat and acid tolerance, and inhibition ofSalmonella entericaserovar Typhimurium infection. Our results showed that the membrane composition and morphology ofL. johnsoniiNCC 533 were significantly changed by supplementing a minimalLactobacillusmedium with oleic, linoleic, and linolenic acids. The ratio of saturated to unsaturated plus cyclic fatty acids in the bacterial membrane decreased by almost 2-fold when minimal medium was supplemented with unsaturated fatty acids (10 μg/ml). The subsequent acid and heat tolerance ofL. johnsoniidecreased by 6- and 20-fold when the strain was grown in the presence of linoleic and linolenic acids, respectively, compared with growth in oleic acid (all at 10 μg/ml). Following acid exposure, significantly higher (P< 0.05) oleic acid content was detected in the membrane when growth medium was supplemented with linoleic or linolenic acid, indicating that saturation of the membrane fatty acids occurred during acid stress. Cell integrity was determined in real time during stressed conditions using a fluorescent viability kit in combination with flow cytometric analysis. Following heat shock (at 62.5°C for 5 min),L. johnsoniiwas unable to form colonies; however, 60% of the bacteria showed no cell integrity loss, which could indicate that the elevated heat inactivated vital processes within the cell, rendering it incapable of replication. Furthermore,L. johnsoniigrown in fatty acid-enriched minimal medium had different adhesion properties and caused a 2-fold decrease inS. entericaserovar Typhimurium UK1-lux invasion of HT-29 epithelial cells compared with bacteria grown in minimal medium alone. This could be related to changes in the hydrophobicity and fluidity of the membrane. Our study shows that technical properties underlying probiotic survivability can be affected by nutrient composition of the growth medium.

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