Amplification of chemotactic responses of motile bacterial cells for characterizing preferential chemotaxis toward carbon sources

2011 ◽  
Author(s):  
M. Kim ◽  
S.H. Kim ◽  
S.K. Lee ◽  
T. Kim
Keyword(s):  
Carbon Sources ◽  
Bacterial Cells

Significance of External Carbon Sources on Simultaneous Removal of Nutrients from Wastewater

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1047-1055 ◽  
Author(s):  
N. F. Y. Tam ◽  
Y. S. Wong ◽  
G. Leung
Keyword(s):  
Sodium Acetate ◽  
Batch Reactor ◽  
Inorganic Nitrogen ◽  
Carbon Sources ◽  
Simultaneous Removal ◽  
Bacterial Cells ◽  
High Concentration ◽  
P Content ◽  
Carbon Substrates ◽  
Effective Source

Laboratory-scale studies were undertaken to examine the effects of easily-biodegradable organic substances upon the nutrient removal by a simulated sequencing batch reactor (SBR). The fill and react period of the SBR was 14 hours, including an instant fill, 7 hours aeration, 4 hours anoxic and 3 hours aeration period. Three kinds of commonly used carbon sources, namely methanol, glucose and sodium acetate, at the concentrations equivalent to theoretical COD values of 50, 100 and 150 mg O2 l-1 were added to each reactor prior to the anoxic stage. The results showed that the concentration of NH4+-N dropped from its initial 50 to 18 mg l-1 (64 % removal) during the first aeration period, with the NO3−-N content increased from 2 to 33 mg l−1. A 60% depletion of COD was also recorded in this period. Denitrification occurred during the anoxic period, higher amount of NO3−1-N was removed in the reactors supplemented with carbon substrates at the concentrations of 100 and 150 mg l-1. The final inorganic nitrogen content was less than 5 mg l-1 in the reactor supplemented with 150 mg l-1 sodium acetate. Simultaneous removal of phosphorus was reported in reactors supplied with high concentration of sodium acetate. In these reactors, large amount of P was released during the anoxic/anaerobic period but the released P was taken up by bacterial cells in the subsequent aeration stage, and the final P content was less than 1.5 mg l-1 (84 % removal was achieved). Among the three carbon sources used, sodium acetate was the most efficient and effective source in removing wastewater nutrients, followed by methanol, and glucose was the least reliable substrate.

Some Physiological Characteristics of Acinetobacter spp. Accumulating Large Amounts of Phosphate

1985 ◽  
Vol 17 (11-12) ◽  
pp. 119-125 ◽  
Author(s):  
Maria H. Deinema ◽  
Mark van Loosdrecht ◽  
Annie Scholten
Keyword(s):  
Dry Matter ◽  
Phosphate Uptake ◽  
Carbon Sources ◽  
Bacterial Cells ◽  
Anaerobic Conditions ◽  
Carbon And Nitrogen ◽  
P Content ◽  
Acinetobacter Strain ◽  
Acinetobacter Spp ◽  
Acetate Medium

Acinetobacter strain 210A has been grown in batch and continuous cultures in an acetate medium. The P content of the cells varied from 6–10% of the dry matter and phosphate uptake continued for months as long as carbon and nitrogen source, inorganic salts and oxygen were present. The growing ( = metabolizing) bacterial cells released phosphate under anaerobic conditions. Addition of CO2, acetate and ethanol or other reduced carbon sources stimulated the rate of the phosphate release but after 24 hours of anaerobiosis the obtained results with or without additions were similar.

3,4-Dichlorobenzoic acid biodegradation by the Edwardsiella tarda: Effect of Some Growth Conditions

2020 ◽  
Vol 6 (1) ◽  
pp. 7-14
Author(s):  
Ali Alqudah ◽  
Waleed Jaafreh
Keyword(s):  
Cell Mass ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Growth Conditions ◽  
Edwardsiella Tarda ◽  
Ring Cleavage ◽  
Bacterial Cells ◽  
Carbon And Nitrogen ◽  
Catechol 1,2 Dioxygenase ◽  
Degradation Ability

The biodegradation of 3,4-DiChlorobenzoic acid was investigated by using Edwardsiella tarda and it used 3,4-DCBA as sole carbon and energy source. Several concentrations of 3,4-D CBAs (1mM, 2mM ,3mM ,4mM and 5mM) were used. The highest rate of degradation of 3,4-D CBAs was obtained at a concentration (2mM). The experiments were included substrate concentration, temperature, pH, starvation, adaptation, carbon and nitrogen sources. The degradation ability was monitored through the release of chloride disappearance of the substrate and finally the growth of bacterial cells on that substrate. The optimal temperature and pH for the bacteria were 42ºC and 7.5, respectively. Adaptation of the cells on 3,4-DCBA for 48 hours and cells starvation for 24 hours and 48 hours increasing the initial degradation rate. The carbon sources affected the 3,4 –DCBA degradation differently from that on chloride and cell mass production. Nitrogen sources supplied (yeast extract, L-proline, casein, NH4, K-Nitrate, arginine, urea and glycine). Urea and casine caused a repression in 3,4-DCBA degradation. Catechol 1,2 dioxygenase activity was found to be present in cell free extracts suggesting that 3,4-DCBA is catabolized by ortho-ring cleavage pathway.

Biodegradation of Chlorobenzoic Acid Substitutes, Particularly, 2- Chlorobenzoic Acid by Aeromonas hydrophila

2019 ◽  
Vol 5 (2) ◽  
pp. 124-135
Author(s):  
Khaled Tarawneh ◽  
Farah AL-Quraishi ◽  
Haitham Qaralleh ◽  
Amjad Al Tarawneh ◽  
Muhamad Al-limoun ◽  
...  
Keyword(s):  
Aeromonas Hydrophila ◽  
Cell Mass ◽  
Carbon Sources ◽  
Treatment Plant ◽  
Nitrogen Sources ◽  
Inoculum Size ◽  
Ring Cleavage ◽  
Enhancement Effect ◽  
Bacterial Cells ◽  
Chlorobenzoic Acid

Bacterium Aeromonas hydrophila (A. hydrophila) was isolated from the Petra Wastewater Treatment Plant effluent in southern Jordan. It was identified by using morphological and biochemical characteristics. A. hydrophila was found to be able of using chlorobenzoate compounds as carbon and energy source. These capabilities were with different biodegradation rates (4- chlorobenzoic acid 5µM/hr, 3,4-dichlorobenzoic acid 15.5µM/hr, 2- chlorobenzoic acid 41µM/hr and 3- chlorobenzoic acid 65µM/hr). The degradation ability was monitored through the release of chloride, disappearance of the substrate and finally the growth of bacterial cells on these substrates. A. hydrophila dioxygenases physiologically induced by chlorobenzoic acid compounds, were analyzed for both ortho or meta ring-cleavage of these aromatic compounds. Only 1, 2-dioxygenase activity was detected which suggest that the cleavage is through the ortho pathway. The best results of degradation of 2-CBA compound were obtained with 3mM substrate concentration, 25ºC, pH 7and 200µl inoculum size. The carbon sources affected the 2-CBA degradation differently from that on chloride and cell mass production. Nitrogen sources used reduced the degradation activity of the 2-CBA as well as in the chlorine release from 2-CBA. However, the nitrogen source L-proline had a slight enhancement effect on the biodegradation between the 40-80h.

THE UTILIZATION OF CARBON SOURCES MIXTURE (GLUCOSE, GLYCEROL AND FORMATE) AND GENERATION OF FERMENTATION END-PRODUCTS BY ESCHERICHIA COLI

2020 ◽  
Vol 54 (1 (251)) ◽  
pp. 55-62
Author(s):  
H.Kh. Gevorgyan
Keyword(s):  
Escherichia Coli ◽  
Carbon Sources ◽  
Bacterial Cells ◽  
E Coli ◽  
End Products ◽  
Glycerol Utilization ◽  
First Time ◽  
External Ph

In this study anaerobic utilization of mixed carbon sources (glucose, glycerol, formate) and generation of fermentation end-products by Escherichia coli at slightly alkaline and slightly acidic pHs was investigated at the first time. It has been shown that E. coli is able to perform co-fermentation of glucose and glycerol in the presence of external formate. The latter was utilized by bacterial cells at first. Acetate is the permanent product (25–50 mM) during both glucose and glycerol utilization. It has been revealed that composition of fermentation end-products depends not only on external pH, but also on co-utilization of substrates.

scholarly journals Degradation of the microbial stress protectants and chemical chaperones ectoine and hydroxyectoine by a bacterial hydrolase–deacetylase complex

2020 ◽  
Vol 295 (27) ◽  
pp. 9087-9104 ◽  
Author(s):  
Christopher-Nils Mais ◽  
Lucas Hermann ◽  
Florian Altegoer ◽  
Andreas Seubert ◽  
Alexandra A. Richter ◽  
...  
Keyword(s):  
Ecological Impact ◽  
Carbon Sources ◽  
Pyrimidine Ring ◽  
Bacterial Cells ◽  
Chemical Chaperones ◽  
Catabolic Genes ◽  
Halomonas Elongata ◽  
Ruegeria Pomeroyi ◽  
Covalent Intermediate ◽  
Microbial Stress

When faced with increased osmolarity in the environment, many bacterial cells accumulate the compatible solute ectoine and its derivative 5-hydroxyectoine. Both compounds are not only potent osmostress protectants, but also serve as effective chemical chaperones stabilizing protein functionality. Ectoines are energy-rich nitrogen and carbon sources that have an ecological impact that shapes microbial communities. Although the biochemistry of ectoine and 5-hydroxyectoine biosynthesis is well understood, our understanding of their catabolism is only rudimentary. Here, we combined biochemical and structural approaches to unravel the core of ectoine and 5-hydroxy-ectoine catabolisms. We show that a conserved enzyme bimodule consisting of the EutD ectoine/5-hydroxyectoine hydrolase and the EutE deacetylase degrades both ectoines. We determined the high-resolution crystal structures of both enzymes, derived from the salt-tolerant bacteria Ruegeria pomeroyi and Halomonas elongata. These structures, either in their apo-forms or in forms capturing substrates or intermediates, provided detailed insights into the catalytic cores of the EutD and EutE enzymes. The combined biochemical and structural results indicate that the EutD homodimer opens the pyrimidine ring of ectoine through an unusual covalent intermediate, N-α-2 acetyl-l-2,4-diaminobutyrate (α-ADABA). We found that α-ADABA is then deacetylated by the zinc-dependent EutE monomer into diaminobutyric acid (DABA), which is further catabolized to l-aspartate. We observed that the EutD–EutE bimodule synthesizes exclusively the α-, but not the γ-isomers of ADABA or hydroxy–ADABA. Of note, α-ADABA is known to induce the MocR/GabR-type repressor EnuR, which controls the expression of many ectoine catabolic genes clusters. We conclude that hydroxy–α-ADABA might serve a similar function.

scholarly journals Chaperonin overproduction and metabolic erosion caused by mutation accumulation in Escherichia coli

2019 ◽  
Vol 366 (10) ◽  
Author(s):  
José Aguilar-Rodríguez ◽  
Mario A Fares ◽  
Andreas Wagner
Keyword(s):  
Escherichia Coli ◽  
Metabolic Activity ◽  
Carbon Sources ◽  
Mutation Accumulation ◽  
Bacterial Cells ◽  
Rich Medium ◽  
Chaperonin Groel ◽  
Genome Decay ◽  
Phenotype Microarrays ◽  
Bacterial Endosymbionts

AbstractBacterial cells adapting to a constant environment tend to accumulate mutations in portions of their genome that are not maintained by selection. This process has been observed in bacteria evolving under strong genetic drift, and especially in bacterial endosymbionts of insects. Here, we study this process in hypermutable Escherichia coli populations evolved through 250 single-cell bottlenecks on solid rich medium in a mutation accumulation experiment that emulates the evolution of bacterial endosymbionts. Using phenotype microarrays monitoring metabolic activity in 95 environments distinguished by their carbon sources, we observe how mutation accumulation has decreased the ability of cells to metabolize most carbon sources. We study if the chaperonin GroEL, which is naturally overproduced in bacterial endosymbionts, can ameliorate the process of metabolic erosion, because of its known ability to buffer destabilizing mutations in metabolic enzymes. Our results indicate that GroEL can slow down the negative phenotypic consequences of genome decay in some environments.

Microfluidic device for analyzing preferential chemotaxis and chemoreceptor sensitivity of bacterial cells toward carbon sources

The Analyst ◽  
2011 ◽  
Vol 136 (16) ◽  
pp. 3238 ◽  
Author(s):  
Minseok Kim ◽  
Su Hyun Kim ◽  
Sung Kuk Lee ◽  
Taesung Kim
Keyword(s):  
Microfluidic Device ◽  
Carbon Sources ◽  
Bacterial Cells

scholarly journals Use of a Bacterial Luciferase Monitoring System To Estimate Real-Time Dynamics of Intracellular Metabolism in Escherichia coli

2016 ◽  
Vol 82 (19) ◽  
pp. 5960-5968 ◽  
Author(s):  
Tomohiro Shimada ◽  
Kan Tanaka
Keyword(s):  
Escherichia Coli ◽  
Real Time ◽  
Monitoring System ◽  
Carbon Sources ◽  
Tca Cycle ◽  
Bacterial Cells ◽  
Bacterial Luciferase ◽  
Content Type ◽  
Time Dynamics ◽  
The Tca Cycle

ABSTRACTRegulation of central carbon metabolism has long been an important research subject in every organism. While the dynamics of metabolic flows during changes in available carbon sources have been estimated based on changes in metabolism-related gene expression, as well as on changes in the metabolome, the flux change itself has scarcely been measured because of technical difficulty, which has made conclusions elusive in many cases. Here, we used a monitoring system employingVibrio fischeriluciferase to probe the intracellular metabolic condition inEscherichia coli. Using a batch culture provided with a limited amount of glucose, we performed a time course analysis, where the predominant carbon source shifts from glucose to acetate, and identified a series of sequential peaks in the luciferase activity (peaks 1 to 4). Two major peaks, peaks 1 and 3, were considered to correspond to the glucose and acetate consuming phases, respectively, based on the glucose, acetate, and dissolved oxygen concentrations in the medium. The pattern of these peaks was changed by the addition of a different carbon source or by an increasing concentration of glucose, which was consistent with the present model. Genetically, mutations involved in glycolysis or the tricarboxylic acid (TCA) cycle/gluconeogenesis specifically affected peak 1 or peak 3, respectively, as expected from the corresponding metabolic phase. Intriguingly, mutants for the acetate excretion pathway showed a phenotype of extended peak 2 and delayed transition to the TCA cycle/gluconeogenesis phase, which suggests that peak 2 represents the metabolic transition phase. These results indicate that the bacterial luciferase monitoring system is useful to understand the real-time dynamics of metabolism in living bacterial cells.IMPORTANCEIntracellular metabolic flows dynamically change during shifts in available carbon sources. However, because of technical difficulty, the flux change has scarcely been measured in living cells. Here, we used aVibrio fischeriluciferase monitoring system to probe the intracellular metabolic condition inEscherichia coli. Using a limited amount of glucose batch culture, a series of sequential peaks (peaks 1 to 4) in the luciferase activity was observed. Changes in the pattern of these peaks by the addition of extra carbon sources and in mutant strains involved in glycolysis or the TCA cycle/gluconeogenesis gene assigned the metabolic phase corresponding to peak 1 as the glycolysis phase and peak 3 as the TCA cycle/gluconeogenesis phase. Intriguingly, the acetate excretion pathway engaged in peak 2 represents the metabolic transition phase. These results indicate that the bacterial luciferase monitoring system is useful to understand the real-time dynamics of metabolism in living bacterial cells.

scholarly journals Mutants with Enhanced Nitrogenase Activity in Hydroponic Azospirillum brasilense-Wheat Associations

2000 ◽  
Vol 66 (5) ◽  
pp. 2175-2184 ◽  
Author(s):  
Lily Pereg Gerk ◽  
Kate Gilchrist ◽  
Ivan R. Kennedy
Keyword(s):  
Azospirillum Brasilense ◽  
Nitrogenase Activity ◽  
Carbon Sources ◽  
Spontaneous Mutant ◽  
Bacterial Cells ◽  
Wild Type ◽  
Colonization Pattern ◽  
Vegetative Form ◽  
Lateral Flagellum ◽  
Spontaneous Mutants

ABSTRACT The effect of a mutation affecting flocculation, differentiation into cyst-like forms, and root colonization on nitrogenase expression by Azospirillum brasilense is described. The geneflcA of strain Sp7 restored these phenotypes in spontaneous mutants of both strains Sp7 and Sp245. Employing both constitutive pLA-lacZ and nifH-lacZ reporter fusions expressed in situ, the colony morphology, colonization pattern, and potential for nitrogenase activity of spontaneous mutants andflcA Tn5-induced mutants were established. The results of this study show that the ability of Sp7 and Sp245 mutant strains to remain in a vegetative form improved their ability to express nitrogenase activity in association with wheat in a hydroponic system. Restoring the cyst formation and colonization pattern to the spontaneous mutant Sp7-S reduced nitrogenase activity rates in association with plants to that of the wild-type Sp7. Although Tn5-induced flcA mutants showed higher potentials for nitrogenase expression than Sp7, their potentials were lower than that of Sp7-S, indicating that other factors in this strain contribute to its exceptional nitrogenase activity rates on plants. The lack of lateral flagella is not one of these factors, as Sp7-PM23, a spontaneous mutant impaired in swarming and lateral-flagellum production but not in flocculation, showed wild-type nitrogenase activity and expression. The results also suggest factors of importance in evolving an effective symbiosis between Azospirillum and wheat, such as increasing the availability of microaerobic niches along the root, increased supply of carbon sources by the plant, and the retention of the bacterial cells in vegetative form for faster metabolism.

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